Test piece measuring device

Abstract

The utility model discloses a test piece measuring device which comprises a control system, a test piece weight measuring device and a test piece size measuring device, the test piece weight measuring device and the test piece size measuring device are both connected with the control system, at least two measuring spaces are arranged in a box body, and the test piece weight measuring device and the test piece size measuring device are arranged in each measuring space; the test piece size measuring device adopts an industrial camera, has the characteristics of non-contact, high speed, high precision, strong field anti-interference capability and the like, is high in automation degree, meets the requirement of large-batch detection, and overcomes the defects of traditional manual detection. The weight and the size of the test piece can be measured simultaneously, the measurement efficiency is high, and large-batch measurement is facilitated. And errors caused by manual measurement are effectively eliminated, measurement data are accurate, no mechanical motion exists in the measurement process, equipment is free of noise, and the service life is long. Measurement data can be automatically uploaded to a control system, the data are automatically recorded, calculation and results are accurate, manual calculation errors are reduced, and the credibility of the data is improved.

Description

Technical Field

[0001] This utility model relates to a specimen measuring device, and more particularly to a measuring device for tensile specimens in material tensile testing, belonging to the technical field of testing equipment. Background Technology

[0002] Reinforcing steel refers to steel used in reinforced concrete and prestressed reinforced concrete. Its cross-section is circular, and sometimes square with rounded corners. A large amount of reinforcing steel is needed in the construction process to improve the stability of the building. Tensile strength is a very important technical indicator of reinforcing steel.

[0003] Before testing a specimen, its cross-section is typically measured manually using common measuring tools such as vernier calipers. The data is then manually entered into the corresponding computer software system. However, manual measurement is not only tedious and inefficient, but also prone to significant errors in measurement accuracy due to variations in the inspector's technique and visual biases. Different testers may record data differently. Therefore, manually measuring specimen dimensions severely impacts testing accuracy, reduces testing efficiency, and is extremely labor-intensive.

[0004] The testing methods for reinforcing bars also stipulate that the allowable deviation between the actual weight and the theoretical weight of the reinforcing bars should meet the requirements of the specifications. When measuring the quality deviation of reinforcing bars, specimens should be cut from different reinforcing bars, with a minimum of 5 specimens, and each specimen should be at least 500 mm long. Currently, it is common practice to cut 5 sections of reinforcing bars, weigh them separately, measure their lengths separately, and finally calculate whether the weight per unit length of the tested reinforcing bars meets the standard. This process requires multiple weighing and length measurement operations, which is inefficient, and the sum of multiple measurements is prone to errors.

[0005] Therefore, existing steel bar tensile strength testing devices cannot quickly weigh and measure the dimensions of steel bars simultaneously, have poor applicability, and cannot keep up with the operating pace of fully automatic testing machines, thus reducing overall testing efficiency.

[0006] With the development of machine vision technology, non-contact measurement methods have emerged. These methods measure workpiece dimensions by capturing visual images of the workpiece and then applying image processing and artificial intelligence techniques. One approach involves using an industrial camera to acquire workpiece images, first extracting the workpiece's edge contour information, then calculating the linear parameters of the edge contour, and finally combining this with camera calibration data to calculate the workpiece's physical dimensions. However, current machine vision-based measurement methods heavily rely on the extracted workpiece edge information. In actual measurements, interference from surface reflections, textures, and noise can lead to irregularities, incompleteness, or even distortion in the extracted workpiece edges, causing measurement errors. Furthermore, different lighting conditions, workpiece materials, and environmental backgrounds can all affect the detection of workpiece edges, resulting in poor adaptability for edge-based dimensional measurement methods. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a specimen measuring device to solve the problems existing in the background art.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A specimen measuring device includes a control system, a specimen weight measuring device, and a specimen size measuring device, characterized in that: it further includes a housing, the housing having at least two measuring spaces, each measuring space having a specimen weight measuring device and a specimen size measuring device; both the specimen weight measuring device and the specimen size measuring device are connected to the control system.

[0010] By adopting the above technical solution, at least two measurement spaces are set inside the chamber. Each measurement space is equipped with a specimen weight measuring device and a specimen size measuring device, which can simultaneously weigh and measure the size of multiple specimens. The measurement efficiency is high, and the measurement data can be automatically uploaded to the control system.

[0011] In the above-mentioned specimen measuring device, the box body includes a left side plate, a right side plate, an upper box plate, a middle box plate, and a lower box plate. The upper box plate and the middle box plate form an upper measuring space, and the middle box plate and the lower box plate form a lower measuring space.

[0012] In the upper measurement space, the specimen weight measuring device is set on the middle box plate, the specimen weight measuring device is provided with a specimen shelf, the specimen shelf is provided with multiple placement slots, and multiple specimens are placed parallel in the placement slots; the specimen size measuring device is set on the upper box plate, including two industrial cameras located above the ends of the specimens respectively.

[0013] In the lower measurement space, the specimen weight measuring device is set on the lower box plate, and the specimen weight measuring device is provided with a specimen shelf. The specimen shelf is provided with multiple placement slots, and multiple specimens are placed parallel in the placement slots. The specimen size measuring device is set on the middle box plate, including two industrial cameras located above the ends of the specimens respectively.

[0014] By adopting the above technical solution, the specimen size measuring device uses an industrial camera, which has the characteristics of non-contact, high speed, high precision, strong anti-interference ability on site, high degree of automation, adapts to the needs of large-scale testing, and overcomes the drawbacks of traditional manual testing.

[0015] In the above-mentioned specimen measuring device, the specimen weight measuring device is an S-type tensile and compressive load cell.

[0016] In the above-mentioned specimen measuring device, the specimen shelf includes a shelf plate connected to the specimen weight measuring device at the bottom, and a left shelf and a right shelf are provided at the top of the shelf plate. The placement slot is provided on the top surface of the left shelf and the right shelf, and the distance between the left shelf and the right shelf is less than the length of the shortest specimen.

[0017] By adopting the above technical solution, the specimen is placed in the placement groove, so that adjacent specimens are separated, which facilitates the detection of the specimen size measuring device and also makes it easier for the specimen clamp to grab the specimen from between the left and right shelves.

[0018] In the above-mentioned specimen measuring device, a light source is provided between the two industrial cameras, and both the two industrial cameras and the light source are connected to the bottom surface of the upper box plate / middle box plate.

[0019] Furthermore, the light source is an LED light panel, which emits light onto the specimen shelf and illuminates the specimens on the shelf. By adopting the above technical solution, the industrial camera can take pictures and perform visual recognition on multiple steel bar specimens at one time, and calculate the actual length of each steel bar through a visual recognition algorithm.

[0020] Furthermore, the LED light panel emits white light onto the specimen shelf.

[0021] By adopting the above technical solution, the LED light board emits white light onto the test piece shelf. The supplementary lighting operation using the LED light board can improve the clarity of the test piece images captured by the industrial camera, enhance the success rate of visual recognition, and thus improve the accuracy of length measurement. Beneficial effects

[0022] This utility model's specimen measuring device includes a specimen weight measuring device and a specimen size measuring device, capable of simultaneously measuring both the weight and size of the specimen. It boasts high measurement efficiency and is suitable for large-batch measurements. Furthermore, it effectively eliminates human measurement errors, ensuring accurate measurement data. The measurement process is noiseless, with no mechanical movement and a long service life. Measurement data is automatically uploaded to the control system for automatic data recording and calculation, resulting in accurate results, reducing manual calculation errors, and increasing data reliability. Attached Figure Description

[0023] Figure 1 , Figure 2 This is a schematic diagram of the front top view of this utility model.

[0024] Figure 3 This is a schematic diagram of the front side upward view of this utility model.

[0025] Figure 4 This is a schematic diagram of the rear top view of this utility model.

[0026] Figure 5 This is a schematic diagram of the rear-view angle of this utility model.

[0027] In the diagram: 1. Box body, 1-1. Upper box plate, 1-2. Middle box plate, 1-3. Lower box plate, 1-4. Left side plate, 1-5. Right side plate, 2. Upper measuring space, 3. Specimen weight measuring device, 4. Lower measuring space, 5. Specimen gripping mechanism, 6. Toolbox, 7. LED light board, 8. Industrial camera, 9. Specimen, 10. Shelf plate, 11. Left shelf, 12. Right shelf, 13. Placement slot. Detailed Implementation

[0028] To clearly illustrate the technical features of this solution, the present invention will be further described below through non-limiting embodiments and in conjunction with the accompanying drawings.

[0029] The front, back, left, and right directions described in this utility model are based on the front, back, left, and right directions shown in the accompanying drawings. For ease of explanation, only the parts relevant to the embodiments of this utility model are shown.

[0030] Please see Figures 1 to 5 A specimen measuring device includes a control system (not shown in the figure), a specimen weight measuring device 3, a specimen size measuring device, and a housing 1. The housing 1 has two measuring spaces, upper and lower, each equipped with a specimen weight measuring device 3 and a specimen size measuring device. To match with robots, testing machines, specimen storage racks, etc., a support or similar device is provided at the bottom of the housing 1 to place the housing 1 at an appropriate height. In this embodiment, a toolbox 6 is used to store maintenance tools, etc. The housing 1 is located on the upper part of the toolbox 6 and includes a left side plate 1-4, a right side plate 1-5, an upper box plate 1-1, a middle box plate 1-2, and a lower box plate 1-3. The upper box plate 1-1 and the middle box plate 1-2 form the upper measuring space 2, and the middle box plate 1-2 and the lower box plate 1-3 form the lower measuring space 4.

[0031] In the upper measurement space 2, the specimen weight measuring device 3 is mounted on the middle box plate 1-2. The specimen weight measuring device 3 has a specimen shelf with multiple placement slots 13, in which multiple specimens 9 are placed parallel to each other. The specimen size measuring device is mounted on the upper box plate 1-1 and includes two industrial cameras 8 located above the ends of the specimens 9. In this embodiment, the industrial cameras 8 are MGS630-H industrial cameras equipped with MVL-KF1228M-12MP lenses. An LED light board 7 is provided between the two industrial cameras 8, and both industrial cameras 8 and the LED light board 7 are connected to the lower surface of the upper box plate 1-1. Both industrial cameras 8 and the LED light board 7 are connected to the control system.

[0032] In the lower measurement space 4, the specimen weight measuring device 3 is mounted on the lower box plate 1-3. The specimen weight measuring device 3 has a specimen shelf with multiple placement slots 13, in which multiple specimens 9 are placed parallel to each other. The specimen size measuring device is mounted on the middle box plate 1-2, including two industrial cameras 8 located above the ends of the specimens 9. An LED light panel 7 is positioned between the two industrial cameras 8, and both the two industrial cameras 8 and the LED light panel 7 are connected to the lower surface of the middle box plate 1-2. Both the two industrial cameras 8 and the LED light panel 7 are connected to the control system.

[0033] In this embodiment, the specimen weight measuring device 3 uses four S-shaped tensile and compressive load cells, which are connected to the control system. The specimen shelf includes a shelf plate 10, a left shelf, and a right shelf 12. The shelf plate 10 is located above the four S-shaped tensile and compressive load cells. The shelf plate 11 and the right shelf 12 are located on the upper part of the shelf plate 10. Each of the left shelf 11 and the right shelf 12 has five V-shaped placement slots 13 on its top surface. The spacing between two adjacent placement slots 13 is equal. The distance between the left shelf 11 and the right shelf 12 is less than the length of the shortest specimen 9 specified in the standard. The specimen 9 is placed parallel to each other in the placement slots 13.

[0034] After the industrial camera 8 and LED light board 7 are installed, their angle and position must first be adjusted to ensure that the LED light board 7 emits white light onto the specimen shelf and illuminates the specimen 9 on the shelf, which can enhance the success rate of visual recognition. Then, the industrial camera 8 is calibrated using the Zhang Zhengyou calibration method or other calibration methods. After calibration, the distance between the end of the specimen and the left side plate 1-4 and right side plate 1-5 of the box 1 can be measured: ① Image acquisition: The industrial camera 8 takes pictures of the end of the specimen 9 to be measured and the side plate of the box 1 to acquire images; ② Image preprocessing: The acquired images are converted into binary images; ③ Size detection: The distance between the end of the specimen 9 and the side plate of the box 1 in the image space is detected; ④ Size calculation: Combining the camera calibration parameters and the distance between the end of the specimen 9 and the side plate of the box 1 detected in the image space, the physical distance between the end of the specimen 9 and the side plate of the box 1 is calculated. The aforementioned industrial camera 8 can take pictures and perform visual recognition on multiple steel bar specimens 9 at the same time, and calculate the actual length of each steel bar through a visual recognition algorithm, converting the pixel size of the captured image into the length size. This is an existing industrial size measurement technology, which will not be elaborated further.

[0035] Principle of specimen length measurement:

[0036] First, set the distance B0 between the inner sides of the left side panel 1-4 and the right side panel 1-5 of the housing 1, and the distance Bn between the outer sides of the left shelf 11 and the right shelf 12. According to the current standard GB / T1499.2-2018, the length of the specimen should not be less than 500mm. In this embodiment, Bn is 480mm and B0 is 820mm. When measuring the length of the specimen 9, the industrial camera 8 on the left automatically measures the distance b1 between the left end of the specimen 9 and the left side panel 1-4 of the housing 1, and the industrial camera 8 on the right automatically measures the distance b2 between the right end of the specimen 9 and the right side panel 1-5 of the housing 1. The length of the specimen 9 is obtained by subtracting the distance b1 between the left end of the specimen 9 and the left side panel 1-4 of the housing 1, and the distance b2 between the right end of the specimen 9 and the right side panel 1-5 of the housing 1 from the distance B0 between the inner sides of the left side panel 1-4 and the right side panel 1-5 of the housing 1.

[0037] In this embodiment, the control system uses a host computer software + PLC control system, which is existing technology and will not be described in detail.

[0038] The working process of this measuring device:

[0039] (1) The robot-driven sample gripping mechanism 5 picks up the first sample 9 from the sample storage rack;

[0040] (2) The robot delivers the first sample to the placement slot 13 of the measuring device in the upper measuring space 2;

[0041] (3) Repeat steps (1)-(2) to send the other specimens 9 in a set of specimens 9 one by one to the placement slot 13 of the measuring device in the upper measuring space 2;

[0042] (4) The robot drives the sample gripping mechanism 5 back to the initial position;

[0043] (5) The S-type tensile and compressive load cell uploads the measured weight signal to the control system;

[0044] (6) The industrial camera 8 on the left takes pictures and performs visual recognition of the left end of a set of test pieces 9 and the left side plate 1-4 of the box 1, and calculates the distance b1 between the left end of the test piece 9 and the left side plate 1-4 of the box 1 through the visual recognition algorithm.

[0045] The industrial camera 8 on the left takes pictures and performs visual recognition of the right end of a set of test pieces 9 and the right side plate 1-5 of the box 1, and calculates the distance b2 between the right end of the test piece 9 and the right side plate 1-5 of the box 1 through the visual recognition algorithm.

[0046] (7) The control system calculates the length dimension B1 of each sample according to the following formula:

[0047] B1 = B0 - b1 - b2;

[0048] (8) If the measured length B1 of at least one of the test specimens 9 in a group is less than the length of the shortest test specimen 9 specified in the standard, then the test specimens 9 in this group are invalid test specimens;

[0049] If the length of each specimen in a group of specimens meets the minimum specimen length specified in the standard, the control system calculates the weight deviation of specimen 9 in this group according to the following formula and further determines it:

[0050] A weight deviation of no more than 1% is considered acceptable; a weight deviation of more than 1% is considered unacceptable.

[0051] Weight deviation = (Actual total weight of sample - Theoretical total weight of sample) / Theoretical total weight of sample × 100%

[0052] The actual total weight of the sample is measured in step (5) and uploaded to the control system;

[0053] Theoretical total weight of specimen = Total length of specimen × Theoretical weight

[0054] The theoretical weight is input into the control system in advance based on the material and nominal diameter of the sample. The total length of the specimen 9 is calculated by accumulating the actual measured length of each specimen 9 in a set of specimens 9.

[0055] (9) The robot-driven specimen gripping mechanism 5 places qualified specimens on the specimen holder into the qualified material rack, and invalid specimens and unqualified specimens into the unqualified material box; according to the test cycle of the tensile testing machine, qualified specimens can also be sent into the test station of the tensile testing machine.

[0056] (10) Repeat steps (1)-(9) to measure the next set of specimens.

[0057] It should be noted that only one of the upper measurement space 2 and the lower measurement space 4 can be used; or they can be used simultaneously. The robot-driven sample gripping mechanism 5 first sends a set of specimens 9 to the placement slot 13 of the measuring device in the upper measurement space 2 to perform the operation of steps (2)-(9). Then the robot-driven sample gripping mechanism 5 sends another set of specimens 9 to the placement slot 13 of the measuring device in the lower measurement space 4, similar to the operation of steps (2)-(9). In this way, the upper measurement space 2 and the lower measurement space 4 are used alternately, which can further improve the measurement efficiency.

[0058] In the description of this utility model, it should be noted that the terms "left", "right", "front", "back", "up", "down", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. The above terms are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0059] Unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0060] Except for the technical features described in the specification, all other technologies are known to those skilled in the art.

[0061] The embodiments listed above are for understanding the present utility model only and are not intended to limit the technical solutions described in the present utility model. Those skilled in the art can make various changes or modifications based on the technical solutions described in the claims, and all equivalent changes or modifications should be covered within the scope of protection of the claims of the present utility model.

Claims

1. A specimen measuring device, comprising a control system, a specimen weight measuring device, and a specimen size measuring device, characterized in that: It also includes a housing, which contains at least two measurement spaces. Each measurement space is equipped with a specimen weight measuring device and a specimen size measuring device. Both the specimen weight measuring device and the specimen size measuring device are connected to the control system.

2. The specimen measuring device according to claim 1, characterized in that: The enclosure includes a left side panel, a right side panel, an upper box panel, a middle box panel, and a lower box panel. The upper box panel and the middle box panel form an upper measurement space, and the middle box panel and the lower box panel form a lower measurement space. In the upper measurement space, the specimen weight measuring device is set on the middle box plate, the specimen weight measuring device is provided with a specimen shelf, the specimen shelf is provided with multiple placement slots, and multiple specimens are placed parallel in the placement slots; the specimen size measuring device is set on the upper box plate, including two industrial cameras located above the ends of the specimens respectively. In the lower measurement space, the specimen weight measuring device is set on the lower box plate, and the specimen weight measuring device is provided with a specimen shelf. The specimen shelf is provided with multiple placement slots, and multiple specimens are placed parallel in the placement slots. The specimen size measuring device is set on the middle box plate, including two industrial cameras located above the ends of the specimens respectively.

3. The specimen measuring device according to claim 2, characterized in that: The specimen weight measuring device is an S-type tensile and compressive load cell.

4. The specimen measuring device according to claim 2, characterized in that: The specimen shelf includes a shelf plate at the bottom connected to the specimen weight measuring device, and a left shelf and a right shelf at the top of the shelf plate. The placement slot is set on the top surface of the left shelf and the right shelf, and the distance between the left shelf and the right shelf is less than the length of the shortest specimen.

5. The specimen measuring device according to claim 2, characterized in that: A light source is provided between the two industrial cameras, and both industrial cameras and the light source are connected to the bottom surface of the upper / middle box plate.

6. The specimen measuring device according to claim 5, characterized in that: The light source is an LED light panel, which emits light onto the specimen shelf and illuminates the specimens on the shelf. An industrial camera takes pictures and performs visual recognition on multiple steel bar specimens at the same time, and calculates the actual length of each steel bar through a visual recognition algorithm.

7. The specimen measuring device according to claim 6, characterized in that: The LED light panel emits white light onto the specimen shelf.

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