Detection clamp for measuring metal sample based on micro resistance value

Abstract

The utility model relates to the field of measurement clamps, and particularly provides a detection clamp for measuring a metal sample based on a micro resistance value, and the detection clamp comprises a fixing assembly which is provided with a contact electrode, and the contact electrode is in contact with the surface of the metal sample; the contact tube further comprises a contact tube body, one end of the contact tube body is connected with the contact electrode, and the other end of the contact tube body is connected with a cable. A first protruding conductive part is arranged on the contact electrode, and when the contact electrode makes contact with the contact tube body, current flows to the contact tube body through the first protruding conductive part and then flows to a cable. Through the detection clamp, the micro resistance value of the metal sample can be accurately measured, and the first convex conductive part can ensure that basic data of the contact resistance between the contact electrode and the contact tube body are kept consistent during each measurement, so that the accuracy and the reliability of measurement are improved.

Description

Technical Field

[0001] This application relates to the field of measuring fixture technology, and in particular to a testing fixture for measuring metal samples based on minute resistance values. Background Technology

[0002] Measuring minute resistance values ​​using a field fingerprint constant current source can be achieved with more precise measurements by spot-welding nickel-based steel strips onto the surface. This method not only utilizes the constant current source and field fingerprint technology but also reduces the influence of contact resistance and lead resistance by spot-welding the nickel-based steel strips, thereby improving measurement accuracy.

[0003] Spot welding involves applying pressure with electrodes and heating the material with an electric current, causing the material to melt at the contact point and form a weld. When measuring minute resistance values, nickel-based steel strips are spot-welded to the two ends of the resistor under test. These spot-welded steel strips are then connected to a constant current source and a data acquisition system. A field fingerprint sensor collects electromagnetic field distribution data around the resistor, and the minute resistance value is calculated from this data.

[0004] However, during spot welding, the settings of relevant parameters such as pressure, current, and time affect the size and penetration of the weld joint, which in turn affects its resistance value. Furthermore, the length of the steel bar and the contact point of the measuring instrument fixture have a significant impact on the minute resistance, resulting in low accuracy of the measured minute resistance value. Utility Model Content

[0005] This application provides a testing fixture for measuring metal samples based on minute resistance values, in order to solve the problem of low accuracy in measuring minute resistance values.

[0006] This application provides a testing fixture for measuring metal samples based on minute resistance values, comprising:

[0007] A fixing component, wherein a contact electrode is provided on the fixing component, and the contact electrode is in contact with the surface of the metal sample;

[0008] A conductive nozzle body, one end of which is connected to a contact electrode, and the other end of which is connected to a cable;

[0009] The contact electrode is provided with a first protruding conductive part. When the contact electrode comes into contact with the conductive nozzle body, the current flows through the first protruding conductive part to the conductive nozzle body and then to the cable.

[0010] By using the testing fixture of this application, the minute resistance value of a metal sample can be accurately measured. The first protruding conductive part ensures that the basic contact resistance data between the contact electrode and the conductive nozzle body remains consistent during each measurement, thereby improving the accuracy and reliability of the measurement.

[0011] In some feasible embodiments, the fixing assembly includes: an insulating base plate, an insulating top plate, and a connector;

[0012] The insulating base plate is connected to the insulating top plate via the connector. The insulating base plate is parallel to the insulating top plate. The contact electrode passes through the insulating top plate and extends out to one end of the insulating top plate near the insulating base plate.

[0013] The metal sample is placed on the insulating base plate;

[0014] The distance between the insulating base plate and the insulating top plate is greater than the length of the contact electrode.

[0015] By setting up a fixing component, a platform can be provided for placing metal samples, and by setting up an insulating top plate and an insulating bottom plate, electrical isolation between the metal samples and the test circuit can be achieved.

[0016] In some feasible embodiments, the insulating top plate includes a base, an arm, a motor, and a gripping element;

[0017] The base is connected to the insulating base plate via a connector, which is a hinge.

[0018] The arm is mounted on the base away from the insulating base plate, the arm is connected to the gripper, the gripper is connected to the contact electrode, and the arm and the gripper are connected to the motor.

[0019] By introducing motors, arms, and grippers, automatic control and precise positioning of the contact electrodes can be achieved, thereby improving the efficiency and accuracy of testing.

[0020] In some feasible embodiments, a fixing groove is provided at one end of the insulating base plate near the contact electrode, an elastic pressure plate is provided on the fixing groove, and an adsorption element is provided near the connection between the fixing groove and the insulating base plate. The metal sample is placed on the insulating base plate through the elastic pressure plate and the adsorption element.

[0021] By combining the fixing groove, elastic pressure plate and adsorption component, the metal sample can be stably fixed and accurately positioned, thus improving the accuracy and reliability of the test.

[0022] In some feasible embodiments, the insulating top plate is provided with a fixing hole, and a conductive nozzle body is provided on the fixing hole;

[0023] The number of fixing holes is a first number, the number of contact electrodes is a second number, the number of resistance values ​​measured by the contact electrodes at one time is a first number, and the second number is twice the first number.

[0024] By measuring multiple resistance values ​​for each contact electrode, the number of measurements can be reduced, thus improving measurement efficiency.

[0025] In some feasible embodiments, the connector is a telescopic assembly, which includes a first fixing plate, a second fixing plate, and a telescopic tube;

[0026] One end of the first fixing plate is connected to the insulating base plate, and the other end of the first fixing plate is connected to the telescopic tube.

[0027] One end of the second fixing plate is connected to the insulating top plate, and the other end of the second fixing plate is connected to the telescopic tube;

[0028] The telescopic assembly also includes a locking bolt, which is disposed on the telescopic tube.

[0029] By setting up telescopic components, the distance between the insulating base plate and the insulating top plate can be adjusted, thereby adjusting the distance between the contact electrode penetrating the insulating top plate and the metal sample, which can increase the flexibility and adaptability of the test.

[0030] In some feasible embodiments, it also includes: a locking component;

[0031] The locking assembly includes a fixing rod and a locking member. The surface of the fixing rod is provided with an external thread, and the locking member is provided with an internal thread. The fixing rod is disposed on the insulating base plate and passes through the insulating top plate, and is rotatably connected to the internal thread of the locking member through the external thread.

[0032] A spring is also provided on the fixing rod.

[0033] By adjusting the locking mechanism to generate downward pressure, it can be ensured that the contact electrode has the same pressure every time it is tested, which can make the test results more accurate.

[0034] In some feasible embodiments, it further includes: a second protruding conductive portion;

[0035] The second raised conductive portion is disposed on the contact electrode, and the first raised conductive portion is spaced apart from the second raised conductive portion by a first distance. Multiple raised conductive portions can increase the number of conductive structures and improve testing efficiency.

[0036] In some feasible embodiments, the first protruding conductive portion and the second protruding conductive portion are shaped as one of hemispherical, conical, or cylindrical.

[0037] Both the first and second protruding conductive portions include a conductive portion body and a coating, wherein the coating is applied to the conductive portion body.

[0038] By adjusting the shape of the raised conductive part, the contact area of ​​the raised conductive part can be increased, as well as the accuracy of the test can be improved.

[0039] As can be seen from the above technical solution, this application provides a testing fixture for measuring the minute resistance value of a metal sample, comprising: a fixing component, on which a contact electrode is disposed, the contact electrode being in contact with the surface of the metal sample; and a conductive nozzle body, one end of which is connected to the contact electrode, and the other end of which is connected to a cable; the contact electrode is provided with a first protruding conductive portion, and when the contact electrode contacts the conductive nozzle body, current flows through the first protruding conductive portion to the conductive nozzle body, and then to the cable. Through this testing fixture, the minute resistance value of the metal sample can be accurately measured. The first protruding conductive portion ensures that the basic contact resistance data between the contact electrode and the conductive nozzle body remains consistent each time, thereby improving the accuracy and reliability of the measurement. Attached Figure Description

[0040] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a front view of the detection fixture provided in an embodiment of this application;

[0042] Figure 2 This is a schematic diagram of the conductive protrusion provided in an embodiment of this application;

[0043] Figure 3 This is a top view of the testing fixture provided in an embodiment of this application.

[0044] Illustration:

[0045] Among them, 1-insulating base plate; 2-contact electrode; 3-insulating top plate; 4-cable; 5-measuring equipment; 6-conductive nozzle body; 7-first protruding conductive part; 8-second protruding conductive part; 9-locking assembly. Detailed Implementation

[0046] The embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described below do not represent all embodiments consistent with this application. They are merely examples of systems and methods consistent with some aspects of this application as detailed in the claims.

[0047] The pressure, current, time, and related parameter settings during spot welding have a significant impact on the formation of the weld joint, and consequently, on its resistance value. Insufficient pressure leads to insufficient contact area, poor weld contact, and a tendency to produce incomplete welds or increased contact resistance. Excessive pressure may cause material deformation and weld spread, also affecting weld quality. Uneven pressure distribution results in uneven stress on the weld joint, potentially leading to localized incomplete welds or inconsistent penetration depth, thus affecting the weld joint's resistance value.

[0048] If the current is too low, the heat generated will be insufficient to fully melt the material, resulting in a weak solder joint and increased contact resistance. If the current is too high, the heat generated will be excessive, which may cause the material to overheat or even burn through. Excessive solder joint penetration may also affect the structure and resistance value of the solder joint.

[0049] If the welding time is too short, insufficient heat accumulation will prevent the material from melting completely, resulting in a weak weld and high contact resistance. If the welding time is too long, excessive heat accumulation may cause the material to overheat, leading to excessive weld penetration or even burn-through, affecting the weld's structure and resistance value.

[0050] For example, insufficient contact area at the solder joint increases contact resistance, leading to a higher measured resistance value. Overheating of the solder joint causes material burn-through and structural damage, resulting in unstable or higher measured resistance values. Excessive solder penetration, overheating, and a loose solder joint structure also lead to higher measured resistance values. Material deformation and solder joint diffusion, resulting in an excessively large contact area, may lead to lower measured resistance values.

[0051] To address the problem of inaccurate resistance measurements, embodiments of this application provide a testing fixture for measuring metal samples based on minute resistance values, such as... Figure 1 , Figure 2 As shown, the testing fixture includes: a fixing component, on which a contact electrode 2 is disposed, the contact electrode 2 being in contact with the surface of the metal sample. The fixing component is used to fix the contact electrode 2 and ensure that the contact electrode 2 can be in close contact with the surface of the metal sample. It can also be used to provide a placement space for placing the metal sample and a space for contact with the contact electrode 2.

[0052] In some embodiments, the fixing assembly includes an insulating base plate 1, an insulating top plate 3, and a connector, wherein the insulating base plate 1 and the insulating top plate 3 may be made of non-conductive materials, such as plastic or ceramic.

[0053] The structures of the insulating base plate 1 and the insulating top plate 3 may be the same or different. Taking the case where the structures of the insulating base plate 1 and the insulating top plate 3 are the same, the insulating base plate 1 and the insulating top plate 3 are arranged in parallel. The insulating base plate 1 is connected to the insulating top plate 3 through a connector. The connector can be a hinge, a fixing rod, a telescopic component, or other structure used to connect the insulating base plate 1 and the insulating top plate 3.

[0054] In some embodiments, the connector is a telescopic assembly, which includes a first fixed plate, a second fixed plate, and a telescopic tube. One end of the first fixed plate is connected to the insulating base plate 1, and the other end of the first fixed plate is connected to the telescopic tube. The first fixed plate connects the insulating base plate 1 to the telescopic tube, thereby indirectly connecting the insulating base plate 1 to the insulating top plate 3. One end of the second fixed plate is connected to the insulating top plate 3, and the other end of the second fixed plate is connected to the telescopic tube. Similarly, the second fixed plate connects the insulating top plate 3 to the telescopic tube, thereby indirectly connecting the insulating top plate 3 to the insulating base plate 1.

[0055] The telescopic tube is a pipe that can be extended or shortened. Its two ends are connected to a first fixed plate and a second fixed plate, respectively. By adjusting the length of the telescopic tube, the distance between the insulating base plate 1 and the insulating top plate 3 can be changed. The telescopic tube is equipped with locking bolts to lock its length. Once the telescopic tube is adjusted to the appropriate length, tightening the locking bolts will keep the telescopic tube at that length and prevent it from extending or shortening arbitrarily.

[0056] The contact electrode 2 penetrates the insulating top plate 3 and extends beyond one end of the insulating top plate 3 near the insulating bottom plate 1. The distance between the contact electrode 2 and the metal sample can be adjusted via a telescopic assembly. The contact electrode 2 is a conductive element that contacts the metal sample to guide current through the sample. The distance between the insulating bottom plate 1 and the insulating top plate 3 is greater than the length of the contact electrode 2, allowing the sample to be sampled via edge contact with the electrode 2.

[0057] The insulating base plate 1 is used to place the metal sample to ensure that the metal sample is on a stable platform during measurement. To improve the accuracy of the test, the metal sample can be fixed on the insulating base plate 1 by a clamping fixture. Specifically, the clamping fixture may include a clamping arm, a clamping surface and an adjustment mechanism. The clamping arm generates clamping force through the adjustment mechanism, such as a bolt, nut or knob. The clamping surface contacts and fixes the metal sample.

[0058] In some embodiments, a fixing groove is provided at one end of the insulating base plate 1 near the contact electrode 2. The fixing groove is a recessed groove in which metal specimens can be placed. However, due to the different structures of metal specimens, an elastic pressure plate is provided on the fixing groove to improve the placement stability. The elastic pressure plate is made of elastic material. The metal specimen can be fixed in the elastic pressure plate by setting fixing blocks on the fixing groove. Taking a rectangular groove as an example, the fixing blocks can be set at the four corners of the fixing groove to reduce the impact on the contact electrode 2 and thus improve stability.

[0059] Alternatively, an adsorption element can be provided near the connection between the fixed groove and the insulating base plate 1. The adsorption element can be a magnet, and the metal sample is adsorbed onto the base plate by its magnetism. Furthermore, the metal sample can be fixed on the insulating base plate 1 by the elastic pressure plate, the fixing block and the adsorption element to improve the test accuracy.

[0060] The fixture also includes a conductive nozzle body 6, one end of which is connected to the contact electrode 2, and the other end of which is connected to a cable 4. The conductive nozzle body 6 connects the contact electrode 2 and the external cable 4 to transmit current, so that the current can flow from the contact electrode 2 through the conductive nozzle body 6 and then to the cable 4, and finally reach the measuring device 5. The measuring device 5 is a device used to measure the minute resistance value of the metal specimen.

[0061] For example, a metal sample is placed on an insulating base plate 1 and fixed to ensure that the contact electrode 2 is in close contact with the surface of the metal sample. Then, the contact electrode 2 is connected to an external cable 4 through the conductive nozzle body 6 to form a closed circuit. The measuring device 5 supplies power to the circuit and measures the current and voltage passing through the metal sample, thereby calculating the minute resistance value of the metal sample.

[0062] To improve measurement accuracy, a first protruding conductive part 7 is provided on the contact electrode 2. When the contact electrode 2 contacts the conductive nozzle body 6, current flows through the first protruding conductive part 7 to the conductive nozzle body 6, and then to the cable 4. During each measurement, the basic contact resistance data between the contact electrode 2 and the conductive nozzle body 6 remains consistent. Thanks to the protruding conductive part, even after multiple uses, the contact surface between the contact electrode 2 and the conductive nozzle body 6 will not change due to wear or other factors, thus ensuring the consistency of the basic data for each measurement. Due to the presence of the protruding conductive part, the contact state between the contact electrode 2 and the conductive nozzle body 6 remains relatively stable during each measurement, helping to ensure that the basic resistance data for each measurement is the same, thereby improving the repeatability and accuracy of the measurement.

[0063] like Figure 2 As shown, in some embodiments, the contact electrode 2 is further provided with a second raised conductive portion 8, and the first raised conductive portion 7 and the second raised conductive portion 8 are spaced apart by a first distance. The second raised conductive portion 8 has the same structure as the first raised conductive portion 7. By providing two raised conductive portions on the contact electrode 2, a dual current conduction path can be achieved. That is, the current can flow from the first raised conductive portion 7 to the conductive nozzle body 6, or it can flow from the second raised conductive portion 8 to the conductive nozzle body 6. Due to the presence of the two raised conductive portions, the current can be distributed more evenly on the surface of the metal sample, reducing the risk of local overheating and extending the service life of the fixture.

[0064] To improve the efficiency of current transmission, the first protruding conductive part 7 and the second protruding conductive part 8 are one of the following shapes: hemispherical, conical, or cylindrical. By setting hemispherical, conical, or cylindrical protruding conductive parts, good contact with the contact electrode 2 can be ensured, thereby achieving stable current transmission.

[0065] In some embodiments, both the first protruding conductive portion 7 and the second protruding conductive portion 8 include a conductive portion body and a coating, with the coating applied to the conductive portion body. Applying one or more layers of coating to the surface of the conductive portion body can improve the surface properties of the protruding conductive portion; for example, applying a nano-coating can further improve the surface properties of the conductive portion body and the service life of the conductive nozzle assembly.

[0066] To facilitate contact between the contact electrode 2 and the metal specimen, in some embodiments, the insulating top plate 3 includes a base, an arm, a motor, and a gripper. In this case, the connector can be a hinge. The base is connected to the insulating bottom plate 1 through the connector and remains stationary relative to the insulating base. The arm is set on the base away from the insulating bottom plate 1 and is connected to the gripper. The gripper is connected to the contact electrode 2, and the arm and gripper are connected to the motor.

[0067] When it is necessary to measure the resistance value of a metal specimen by moving the contact electrode 2, the arm can be driven by a motor to further move the gripper. The gripper moves the contact electrode 2 to contact the metal specimen, which can measure metal specimens that cannot be moved.

[0068] like Figure 3 As shown, in some embodiments, the insulating top plate 3 is provided with fixing holes for inserting the contact electrodes 2 and the conductive nozzle body 6. The number of fixing holes is a first number, the number of contact electrodes 2 is a second number, and the number of resistance values ​​measured by the contact electrodes 2 at one time is the first number, and the second number is twice the first number. Specifically, the first number is 24, and the second number is 12. That is, through 12 fixing holes, 12 different resistance values ​​can be measured simultaneously. Each resistance value is composed of two contact electrodes 2, requiring a total of 24 contact electrodes 2.

[0069] By setting fixing holes on the insulating top plate 3, the positions of the contact electrode 2 and the conductive nozzle body 6 can be relatively stable, thus ensuring consistent measurement results each time. Simultaneously, multiple resistance values ​​can be measured at the same time, thereby improving work efficiency.

[0070] To ensure that the contact electrode 2 applies the same downward pressure during each measurement, some embodiments include a locking assembly 9. The locking assembly 9 includes a fixing rod and a locking member. The fixing rod has external threads, and the locking member has internal threads. The fixing rod is mounted on the insulating base plate 1 and passes through the insulating top plate 3, rotatably connected to the locking member via its external threads. During use, the fixing rod passes through the insulating top plate 3 and engages with the internal threads of the locking member. By rotating the locking member, the position of the fixing rod can be adjusted, thereby adjusting the distance between the insulating top plate 3 and the insulating base plate 1. Once the desired downward pressure is achieved, the fixing rod is secured by the locking member, ensuring that the contact electrode 2 applies the same pressure during each measurement, thus improving the accuracy of the measurement results.

[0071] In some embodiments, a pressure sensor may also be installed on the fixed rod to monitor and display the current pressure value in real time, so that the user can understand and adjust it at any time.

[0072] The fixing rod is also equipped with a spring. When the contact electrode 2 comes into contact with the metal specimen, the spring can absorb the impact force and prevent damage or errors caused by instantaneous impact. The spring can also keep the pressure of the contact electrode 2 on the metal specimen within a relatively constant range, and can maintain the original pressure level as much as possible even when the external conditions change slightly.

[0073] As can be seen from the above technical solution, this application provides a testing fixture for measuring the minute resistance value of a metal sample, comprising: a fixing component, on which a contact electrode 2 is disposed, the contact electrode 2 being in contact with the surface of the metal sample; and a conductive nozzle body 6, one end of which is connected to the contact electrode 2, and the other end of which is connected to a cable 4; the contact electrode 2 is provided with a first protruding conductive portion 7, and when the contact electrode 2 contacts the conductive nozzle body 6, current flows through the first protruding conductive portion 7 to the conductive nozzle body 6, and then to the cable 4. Through this testing fixture, the minute resistance value of the metal sample can be accurately measured. The first protruding conductive portion 7 ensures that the basic contact resistance data between the contact electrode 2 and the conductive nozzle body 6 remains consistent during each measurement, thereby improving the accuracy and reliability of the measurement.

[0074] Similar parts between the embodiments provided in this application can be referred to mutually. The specific implementation methods provided above are only a few examples under the overall concept of this application and do not constitute a limitation on the scope of protection of this application. For those skilled in the art, any other implementation methods extended from the solution of this application without creative effort shall fall within the scope of protection of this application.

Claims

1. A testing fixture for measuring metal samples based on minute resistance values, characterized in that, include: A fixing component, wherein a contact electrode is provided on the fixing component, and the contact electrode is in contact with the surface of the metal sample; A conductive nozzle body, one end of which is connected to a contact electrode, and the other end of which is connected to a cable; The contact electrode is provided with a first protruding conductive part. When the contact electrode comes into contact with the conductive nozzle body, the current flows through the first protruding conductive part to the conductive nozzle body and then to the cable.

2. The detection fixture for measuring metal samples based on minute resistance values ​​according to claim 1, characterized in that, The fixing assembly includes: an insulating base plate, an insulating top plate, and connectors; The insulating base plate is connected to the insulating top plate via the connector. The insulating base plate is parallel to the insulating top plate. The contact electrode passes through the insulating top plate and extends out to one end of the insulating top plate near the insulating base plate. The metal sample is placed on the insulating base plate; The distance between the insulating base plate and the insulating top plate is greater than the length of the contact electrode.

3. The detection fixture for measuring metal samples based on minute resistance values ​​according to claim 2, characterized in that, The insulating top plate includes a base, an arm, a motor, and a gripping component; The base is connected to the insulating base plate via a connector, which is a hinge. The arm is mounted on the base away from the insulating base plate, the arm is connected to the gripper, the gripper is connected to the contact electrode, and the arm and the gripper are connected to the motor.

4. The detection fixture for measuring metal samples based on minute resistance values ​​according to claim 2, characterized in that, A fixing groove is provided at one end of the insulating base plate near the contact electrode. An elastic pressure plate is provided on the fixing groove. An adsorption element is provided near the connection between the fixing groove and the insulating base plate. The metal sample is placed on the insulating base plate through the elastic pressure plate and the adsorption element.

5. The detection fixture for measuring metal samples based on minute resistance values ​​according to claim 2, characterized in that, The insulating top plate is provided with a fixing hole, and a conductive nozzle body is provided on the fixing hole; The number of fixing holes is a first number, the number of contact electrodes is a second number, the number of resistance values ​​measured by the contact electrodes at one time is a first number, and the second number is twice the first number.

6. The detection fixture for measuring metal samples based on minute resistance values ​​according to claim 2, characterized in that, The connector is a telescopic assembly, which includes a first fixed plate, a second fixed plate, and a telescopic tube. One end of the first fixing plate is connected to the insulating base plate, and the other end of the first fixing plate is connected to the telescopic tube. One end of the second fixing plate is connected to the insulating top plate, and the other end of the second fixing plate is connected to the telescopic tube; The telescopic assembly also includes a locking bolt, which is disposed on the telescopic tube.

7. The detection fixture for measuring metal samples based on minute resistance values ​​according to claim 2, characterized in that, Also includes: locking components; The locking assembly includes a fixing rod and a locking member. The surface of the fixing rod is provided with an external thread, and the locking member is provided with an internal thread. The fixing rod is disposed on the insulating base plate and passes through the insulating top plate, and is rotatably connected to the internal thread of the locking member through the external thread. A spring is also provided on the fixing rod.

8. The detection fixture for measuring metal samples based on minute resistance values ​​according to claim 1, characterized in that, Also includes: Second protruding conductive part; The second protruding conductive portion is disposed on the contact electrode, and the first protruding conductive portion and the second protruding conductive portion are spaced apart by a first distance.

9. The detection fixture for measuring metal samples based on minute resistance values ​​according to claim 1, characterized in that, The first and second protruding conductive portions are shaped like a hemisphere, a cone, or a cylinder. Both the first and second protruding conductive portions include a conductive portion body and a coating, wherein the coating is applied to the conductive portion body.

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