Stator core weld strength checking device and method

Abstract

The application discloses a stator core weld seam strength checking device and method, and relates to the technical field of motor stator manufacturing and detection. The device comprises a base and a cover plate which are arranged in parallel; a lower positioning plate which is detachably connected with the positioning structure of the base; an upper positioning plate which is detachably connected with the positioning structure of the cover plate; a plurality of tension and compression rods which are arranged between the base and the cover plate, and the two ends of each tension and compression rod are fastened by fasteners to pressurize the stator core after stacking; a plurality of universal adjustable connectors which are arranged on the opposite end faces of the base and the cover plate in pairs, and each pair of universal adjustable connectors is arranged oppositely; and a plurality of force gauges, the two ends of each force gauge are connected with a pair of universal adjustable connectors, and the force gauges are used to directly measure the resilience of the stator core after the fasteners are loosened. The device can directly measure the resilience of the stator core, provide real resilience for weld seam strength checking, and improve the real reliability of the weld seam strength checking conclusion.

Description

Technical Field

[0001] This invention relates to the field of motor stator manufacturing and testing technology, and more specifically, to a stator core weld strength verification device and method. Background Technology

[0002] In the manufacturing of stators for housing-type motors, stator laminations are typically stacked and fixed by welding with evenly spaced slots on the outer circumference. After welding, when the stacking and fastening device is loosened, the weld will bear a certain springback force from the stator core laminations. If the weld strength is insufficient, the stator core lamination weld may crack. Therefore, it is essential to perform strength checks on the stator core welds before production to ensure reliable product quality and reduce trial production costs.

[0003] Currently, the strength verification of stator core welds mainly relies on the following two methods: 1. Welding Procedure Qualification: Metallographic examination ensures that the weld penetration and width meet the process specifications, thus solidifying the welding parameters. While this guarantees weld quality, it does not reveal the actual springback force the weld needs to withstand; in other words, the weld load-bearing capacity cannot be determined.

[0004] 2. Theoretical Calculation Verification: Estimate the rebound force using theoretical formulas, and then perform a strength verification. The theoretical formula for calculating the rebound force is: ; Where K is the lamination correction factor, E is the material elastic modulus, and A is the lamination area. For rebound amount, This refers to the height before stacking. However, in actual production, the K value is affected by factors such as stamping burrs, stacking gaps, and surface roughness, making it difficult to give an accurate value. Measurements are also prone to errors, resulting in a large deviation between the calculated rebound force and the actual value.

[0005] Therefore, how to solve the problem that the current stator core weld strength verification cannot accurately obtain the true springback force of the stator core, and is difficult to directly compare with the weld bearing capacity to obtain the weld bearing coefficient, resulting in unreliable weld strength verification conclusions, is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a stator core weld strength verification device, which can directly measure the springback force of the stator core to provide a true springback force for weld strength verification, thereby improving the authenticity and reliability of the weld strength verification conclusion.

[0007] Another objective of this invention is to provide a verification method for a stator core weld strength verification device.

[0008] To achieve the above objectives, the present invention provides the following technical solution: A method for verifying the strength of stator core welds, employing a stator core weld strength verification device, the device comprising: The base and cover are arranged in parallel opposite directions, and both of their opposite end faces are provided with positioning structures; The lower positioning plate is detachably connected to the positioning structure of the base and is used to position the lower end component of the sub-core to be measured. The upper positioning plate is detachably connected to the positioning structure of the cover plate and is used to position the upper part of the sub-core to be tested. Multiple tension rods are inserted between the base and the cover plate and are evenly distributed along the outer periphery of the stator core. Both ends of each tension rod are fastened with fasteners to maintain pressure on the stator core after stacking. Multiple universal adjustable connectors are arranged in pairs on the opposite end faces of the base and the cover plate, and are evenly distributed along the outer periphery of the stator core. Each pair of universal adjustable connectors is arranged vertically opposite each other. Multiple force gauges, each of which is connected to a pair of universal adjustable connectors at both ends, are used to directly measure the springback force of the stator core after the fasteners are loosened. The method includes the following steps: The lower end component, stator lamination assembly, and upper end component of the stator core to be measured are sequentially positioned between the lower positioning plate and the upper positioning plate. The pressurizing equipment applies pressure to the cover plate, compressing the stator core to the target height. Then, the fasteners at both ends of all the tension rods are tightened to lock the stator core. After that, the pressure from the pressurizing equipment is released. The first measurement of the stator core height involved measuring at four evenly spaced points and recording the measurements. The measurement locations were also marked. This yielded the average height of the stator core in its locked and compressed state. ; Loosen and remove all fasteners in sections and symmetrically to allow the stator core to fully spring back; Screw the universal adjustable connectors into the corresponding threaded holes on the base and cover plate, connect the force gauge between the upper and lower universal adjustable connectors, and adjust the screwing depth of the universal adjustable connectors symmetrically in segments to compress the stator core. The second measurement of the stator core height involved measuring and recording four points evenly distributed at the previously marked locations, thus obtaining the average height of the stator core under compressive stress. ; when Record the reading of each force gauge at that time. Where i = 1, 2, ..., n; The formula for determining the springback force of the stator core is based on the recorded final readings. The true springback force of the stator core is determined by the following formula: ; in, For the true springback force of the stator core, Let i be the force reading of the i-th force gauge. Let n be the weight of the cover plate and the upper positioning plate, n be the number of force gauges, and g be the gravitational acceleration, taken as 9.8 N / kg. The safety factor is determined based on the actual springback force of the stator core using the weld strength verification formula, which is as follows: ; in, The yield strength of the weld material. For safety reasons, This refers to the total bearing area of ​​the weld seam on the outer circle of the stator core.

[0009] Preferably, the positioning structure has a stop step, and both the lower positioning plate and the upper positioning plate have notches that engage with the stop step.

[0010] Preferably, both the lower positioning plate and the upper positioning plate have positioning steps on their end faces facing the stator core for mounting the lower and upper components.

[0011] Preferably, it further includes at least one guide rod, and both the lower positioning plate and the upper positioning plate are provided with keyways that engage with the end of the guide rod.

[0012] Preferably, the tension rod is a double-ended screw, the fastener is a nut that is threaded with the double-ended screw, and the nuts at both ends of the double-ended screw are respectively pressed with anti-loosening washers between the base and the cover plate.

[0013] Preferably, the universal adjustable connector includes an adjusting screw and a universal joint at the end of the adjusting screw. The opposite end faces of the base and the cover plate are provided with threaded holes that cooperate with the adjusting screw. After the adjusting screw is inserted into the threaded hole, it is locked to the base or cover plate by a locking nut.

[0014] Preferably, the universal adjustable connector is provided with a hook, and both ends of the force gauge are provided with connecting parts that can be detachably connected to the hook.

[0015] Preferably, the force gauge is a wireless force gauge; the device further includes a data receiving and processing terminal for wirelessly receiving, displaying, and calculating data from each of the force gauges.

[0016] Preferably, the method of positioning the lower end component, stator lamination assembly, and upper end component of the stator core to be measured sequentially between the lower positioning plate and the upper positioning plate includes: Engage the notch in the lower positioning plate with the stop step on the base; Place the lower pressure ring of the lower end component on the lower positioning plate, and position the outer circle of the lower pressure ring in conjunction with the first step of the lower positioning plate; The lower tooth pressure plate of the lower end component is stacked on the lower pressure ring, and the outer circle of the lower tooth pressure plate is positioned and engaged with the second step of the lower positioning plate. Insert at least one guide bar into the keyway of the lower positioning plate; Multiple stator laminations are stacked sequentially, and the grooves of the inner ring of each stator lamination are passed through guide bars for auxiliary positioning until they are stacked to the preset height. The upper tooth pressure plate is stacked on the topmost stator lamination; Place the upper pressure ring of the upper component onto the upper tooth pressure plate; Place the upper positioning plate of the upper component on the upper pressure ring, and make the outer circle of the upper pressure ring and the first step of the upper positioning plate position and engage, and make the outer circle of the upper tooth pressure plate and the second step of the upper positioning plate position and engage. The stop step on the cover plate is engaged with the notch in the upper positioning plate.

[0017] In use, the stator core weld strength verification device provided by this invention involves positioning the lower stator core component, stator lamination assembly, and upper stator core component sequentially between the lower and upper positioning plates. An external pressurizing device applies pressure to the cover plate, compressing the stator core to the target height. Then, all fasteners at both ends of the tension rods are tightened to lock the stator core in place. The pressure from the pressurizing device is then released, leaving the stator core firmly in place within the device. Next, all fasteners on the tension rods are symmetrically and slowly loosened and removed. At this point, the stator core rebounds due to the elasticity of the internal laminations. A universal adjustable connector and a force gauge are then installed, and axial pressure is applied to the stator core again, compressing it until it returns to the same target height as when it was first tightened. The force gauge directly displays the rebound force at this point. By summing the readings of all the force gauges and calculating (considering the weight of the cover plate and upper positioning plate), the true rebound force of the stator core can be obtained. Therefore, this device restores the elastic deformation state of the stator core through a controllable secondary compression process, and indirectly and accurately measures its internal springback force using the static equilibrium equation. This avoids the problem of unreliable estimation of springback force based on theoretical formulas, and provides a reliable and true springback force for weld strength verification.

[0018] In a further embodiment provided in this application, the total load-bearing area of ​​the weld on the outer circumference of the stator core is obtained through welding procedure qualification. and the yield strength of the weld material According to the formula for verifying weld strength: By performing a strength check, the safety factor can be obtained. The above method combines the measured rebound force with the weld bearing area determined by the process evaluation into the weld strength verification formula, and then compares it with the yield strength value of the weld material to obtain a reliable safety factor, thereby achieving a quantitative and accurate assessment of the weld bearing capacity. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of a base provided by the present invention; Figure 2 This is an assembly diagram of the base and lower positioning plate provided by the present invention; Figure 3 This is a schematic diagram of the assembly of the lower positioning plate and the lower pressure ring provided by the present invention; Figure 4 This is a schematic diagram of the assembly of the lower pressure ring and the lower tooth pressure plate provided by the present invention; Figure 5 This is a schematic diagram of the assembly of the guide rod and the lower positioning plate provided by the present invention; Figure 6 This is a schematic diagram of the assembly of multiple stator laminations stacked together according to the present invention. Figure 7 This is a schematic diagram of the assembly of the upper toothed pressure plate and the uppermost stator lamination provided by the present invention; Figure 8 This is a schematic diagram of the assembly of the upper pressure ring and the upper toothed pressure plate provided by the present invention; Figure 9 This is a schematic diagram of the assembly of the upper positioning plate and the upper pressure ring provided by the present invention; Figure 10 This is a schematic diagram of the assembly of the cover plate and the upper positioning plate provided by the present invention; Figure 11 This is a schematic diagram of the tension / compression rod and fasteners used to lock the stator core according to the present invention; Figure 12 for Figure 11 A schematic diagram showing the structure with the stator core removed; Figure 13 for Figure 11 The diagram shows a structural schematic of a stator core weld strength verification device formed after the installation of a force gauge and a universal adjustable connector.

[0021] Figure label: 1-Base; 2-Lower positioning plate; 3-Upper positioning plate; 4-Cover plate; 5-Guide rod; 6-Pull-compression rod; 7-Anti-loosening washer; 8-Fastener; 9-Stator core; 10-Slotted weld; 11-Force gauge; 12-Universal adjustable connector; 13-Lower pressure ring; 14-Lower tooth pressure plate; 15-Upper tooth pressure plate; 16-Upper pressure ring; 17-Stop step; 18-Notch; 19-Keyway; 20-First-level step; 21-Second-level step; 22-Stator lamination. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] The core of this invention is to provide a stator core weld strength verification device. This device can directly measure the springback force of the stator core to provide a true springback force for weld strength verification, thereby improving the authenticity and reliability of the weld strength verification conclusion.

[0024] Another core aspect of this invention is to provide a verification method for a stator core weld strength verification device.

[0025] It should be noted that in this embodiment, the orientation or positional relationship indicated by "up", "down", "front", "back", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing this application and simplifying the description, and is not intended to 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, it should not be construed as a limitation on this application.

[0026] Please refer to Figure 11 , Figure 12 and Figure 13 The present invention provides a specific embodiment of a stator core 9 weld strength verification device, including a base 1, a cover plate 4, a lower positioning plate 2, an upper positioning plate 3, multiple tension and compression rods 6 and multiple universal adjustable connectors 12.

[0027] The base 1 and the cover plate 4 are arranged in parallel opposite directions, and both of their opposite end faces are provided with positioning structures; The positioning structure of the lower positioning plate 2 and the base 1 is detachably connected and used to position the lower end component of the sub-core 9 to be tested (lower pressure ring 13, lower tooth pressure plate 14); the positioning structure of the upper positioning plate 3 and the cover plate 4 is detachably connected and used to position the upper end component of the sub-core 9 to be tested (upper pressure ring 16, upper tooth pressure plate 15).

[0028] The lower positioning plate 2 and the upper positioning plate 3 provide a stable reference surface for the stacking of stator laminations 22. During lamination stacking, the operator places the lower end component of the core to be tested on the lower positioning plate 2, then stacks the laminations in sequence, and finally places the upper end component and positions it with the upper positioning plate 3, thereby forming the stator core 9 to be tested between the upper positioning plate 3 and the lower positioning plate 2.

[0029] Multiple tension rods 6 are inserted between the base 1 and the cover plate 4 and are evenly distributed along the outer periphery of the stator core 9. Both ends of each tension rod 6 are fastened by fasteners 8 to maintain pressure on the stator core 9 after stacking.

[0030] Multiple tension / compression rods 6 are evenly distributed along the outer periphery of the stator core 9, which can achieve overall and uniform pressure holding of the stator core 9 and accurately measure the overall springback force. In one specific embodiment, there are four tension / compression rods 6, which are evenly distributed at 90 degrees.

[0031] When the external pressurizing equipment applies pressure to the stator core 9 through the cover plate 4 and compresses it to the required height, the operator immediately tightens all fasteners 8 symmetrically. At this time, the external pressure is removed, and the clamping force on the stator core 9 is maintained by the pressure-holding base 1 and the cover plate 4 of the tension rods 6, keeping the stator core 9 in a pressure-holding state, simulating the working condition when welding is completed. That is, in the actual manufacturing of the housing-type motor stator, the stator laminations are simulated to be stacked and welded together by uniformly distributed slotted welds 10 on the outer circle.

[0032] Multiple universal adjustable connectors 12 are arranged in pairs on the opposite end faces of the base 1 and the cover plate 4, and are evenly distributed along the outer periphery of the stator core 9. Each pair of universal adjustable connectors 12 is arranged vertically opposite each other. That is to say, the two connectors in each pair are in the same radial position on the base 1 and the cover plate 4, and are arranged vertically opposite each other.

[0033] It should be noted that the universal adjustable connector 12 is a mechanical connection component that combines multi-angle universal rotation and length position adjustment functions. It can transmit force (tension, compression, shear) and flexibly adapt to installation errors and compensate for relative displacement.

[0034] Each force gauge 11 is connected to a pair of universal adjustable connectors 12 at both ends, which are used to directly measure the springback force of the stator core 9 after the fastener 8 is loosened.

[0035] Since each universal adjustable connector 12 can independently adjust its extension length, during installation, by adjusting the length of each universal adjustable connector 12, the pressure on the stator core 9 can be adjusted so that the stator core can be compressed back to the target height locked by the tension rod 6 and the fastener 8.

[0036] It should be noted that multiple universal adjustable connectors 12 are evenly distributed in pairs along the outer periphery of the stator core 9, so that multiple force gauges 11 placed between multiple pairs of universal adjustable connectors 12 are also evenly distributed along the outer periphery of the stator core 9, eliminating the influence of load eccentricity, accurately capturing the true force distribution of the core, and accurately measuring the overall rebound force.

[0037] In this embodiment, the stator core 9 weld strength verification device is used such that the lower part of the stator core 9, the stator laminations 22 sets, and the upper part are sequentially positioned between the lower positioning plate 2 and the upper positioning plate 3. With the aid of an external pressurizing device, pressure is applied to the cover plate 4. After the stator core 9 is compressed to the target height, the fasteners 8 at both ends of all the tension rods 6 are tightened to lock the stator core 9 in a pressure-holding state. Then, the pressure from the pressurizing device is released, at which point the stator core 9 is pressed tightly within the device. Next, all the fasteners 8 on the tension rods 6 are symmetrically and slowly loosened and removed. At this point, the stator core 9 springs back due to the elasticity of the internal laminations. Then, the universal adjustable connector 12 and the force gauge 11 are installed, and axial pressure is applied to the stator core 9 again, causing the stator core 9 to compress until it returns to the same target height as when it was first locked. At this time, the force gauge 11 can directly display the rebound force. By summing the readings of all the force gauges 11 and calculating (considering the weight of the cover plate 4 and the upper positioning plate 3), the true rebound force of the stator core 9 can be obtained. Therefore, this device restores the elastic deformation state of the stator core through a controllable secondary compression process, and indirectly and accurately measures its internal rebound force using the static equilibrium equation. This avoids the problem of unreliable estimation of rebound force based on theoretical formulas, and provides a reliable and true rebound force for weld strength verification.

[0038] Furthermore, the total load-bearing area of ​​the weld seam on the outer circumference of stator core 9 was obtained through welding process evaluation. and the yield strength of the weld material According to the formula for verifying weld strength: By performing a strength check, the safety factor can be obtained. .

[0039] As described above, the core effect of the verification device in this embodiment is that by arranging universal adjustable connectors 12 and force gauges 11 around the stator core 9 under pressure, the true springback force of the stator core 9 can be directly captured after the stator core 9 is locked. This avoids the problem of unreliable estimation of springback force based on theoretical formulas, providing a reliable and true springback force for weld strength verification. Furthermore, by determining the weld bearing area through welding process evaluation, and combining the weld fusion yield strength value, a true and reliable safety factor can be obtained using the weld strength verification formula, thereby achieving a quantitative and accurate assessment of the weld bearing capacity.

[0040] Furthermore, the verification device in this embodiment employs a base 1 and a cover plate 4 that are detachably connected to their respective positioning plates. For different models of stator cores 9, only the corresponding upper and lower positioning plates need to be replaced for quick adaptation, thereby improving the versatility and economy of the device. Moreover, the verification device is a non-destructive test, and the entire verification process does not damage any components of the stator core 9, such as laminations or pressure rings. The stator core 9 being tested can be completely disassembled and continued to be used in subsequent production processes.

[0041] Based on the above embodiments, as a further preferred option, please refer to... Figure 1 and Figure 2 The positioning structure has a stop step 17, and both the lower positioning plate 2 and the upper positioning plate 3 have notches 18 that engage with the stop step 17.

[0042] In this embodiment, a first stop step 17 protrudes from the end face of the base 1 facing the cover plate 4, and a second stop step 17 protrudes from the end face of the cover plate 4 facing the base 1. The first stop step 17 and the second stop step 17 have the same structure and size and are arranged opposite to each other. The lower positioning plate 2 has a first notch 18 that matches the first stop step 17. During assembly, the first notch 18 engages with the first stop step 17, so that the lower positioning plate 2 is stably fixed on the base 1. Similarly, the upper positioning plate 3 has a second notch 18 that matches the second stop step 17. During assembly, the second notch 18 engages with the second stop step 17, so that the upper positioning plate 3 is stably fixed on the cover plate 4.

[0043] Thus, through the snap-fit ​​engagement of the stop step 17 and the notch 18, a quick and stable connection can be achieved between the positioning plate and the base 1 and the cover plate 4. When it is necessary to test different models of stator cores 9, simply remove the original upper and lower positioning plates from the stop step 17, replace them with new positioning plates that match the shape of the end components of the new stator core 9, align the notch 18 of the new positioning plate and snap it into the stop step 17, and the core can be quickly changed.

[0044] In one specific embodiment, since the stator core 9 is mostly a circular columnar structure, the stop step 17 is an annular step, and the notches 18 of the lower positioning plate 2 and the upper positioning plate 3 are both circular, it can better adapt to the positioning and installation of the stator core 9.

[0045] Based on the above embodiments, as a further preferred option, please refer to... Figure 2 Both the lower positioning plate 2 and the upper positioning plate 3 have positioning steps on their end faces facing the stator core 9 for mounting the lower and upper components.

[0046] In this embodiment, the lower positioning plate 2 has a positioning step on its end face (i.e., upper end face) facing the stator core 9. The positioning step consists of two concentric annular steps. For example, the first step 20 is fitted with the outer edge of the lower pressure ring 13 of the stator core 9, and the second positioning step is located above the first step 20, fitted with the outer edge of the lower tooth pressure plate 14. In this way, the lower pressure ring 13 and the lower tooth pressure plate 14 can be stacked and positioned on the lower positioning plate 2 in sequence, ensuring that they are concentric with the positioning plate. Figure 2 , Figure 3 and Figure 4 As shown.

[0047] Similarly, the lower positioning plate 2 also has a positioning step on its end face (i.e., lower end face) facing the stator core 9. This positioning step has the same shape and size as the positioning step on the lower positioning plate 2, and is used to install and position the upper tooth pressure plate 15 and the upper pressure ring 16 of the stator core 9 from bottom to top. Figure 7 , Figure 8 and Figure 9 As shown.

[0048] Thus, when assembling the stator core 9, the operator only needs to place the lower pressure ring 13 and the lower tooth pressure plate 14 into the corresponding steps of the lower positioning plate 2 in sequence, and place the upper tooth pressure plate 15 and the upper pressure ring 16 into the corresponding steps of the upper positioning plate 3. This will automatically center these components (i.e., the center lines coincide), avoiding the eccentricity problem that is easy to cause by manual placement. This ensures that the stator core 9 is placed vertically in the device, so that the pressure applied subsequently and the measured spring force act along the axis, thereby improving the accuracy of the spring force measurement.

[0049] Based on the above embodiments, as a further preferred option, please refer to... Figure 2 and Figure 5 The present invention also includes at least one guide rod 5, and both the lower positioning plate 2 and the upper positioning plate 3 are provided with keyways 19 that engage with the end of the guide rod 5.

[0050] In this embodiment, at least one first keyway 19 is provided on the end face edge of the lower positioning plate 2. The shape of the first keyway 19 matches the end cross-section of the guide rod 5, so that the lower end of the guide rod 5 is inserted into the first keyway 19 to achieve radial and circumferential constraints.

[0051] Correspondingly, the upper positioning plate 3 has a second keyway 19 opposite to at least one first keyway 19. When the lower end of the guide rod 5 is engaged in the first keyway 19 of the lower positioning plate 2, the upper part of the guide rod 5 can pass through the groove of the inner ring of the stacked stator laminations 22 and be engaged in the second keyway 19 of the upper positioning plate 3.

[0052] During the assembly of the stator core 9, the operator first inserts the lower end of the guide rod 5 into the lower positioning plate 2. Then, when stacking each stator lamination 22, the slots of the inner rings of the laminations are aligned and pass through the guide rod 5. Figure 6 As shown. After all the laminations are stacked, when placing the positioning plate 3, ensure that its second keyway 19 is aligned with the top of the guide rod 5 and engaged. In this way, the guide rod 5 plays a guiding and anti-rotation role throughout the lamination stacking process, avoiding distortion in the springback force measurement caused by lamination misalignment or torsion.

[0053] In one specific embodiment, there are two guide rods 5. The two guide rods 5 are arranged symmetrically with the center line of the upper positioning plate 3 and the lower positioning plate 2 coinciding. The cooperation of these two symmetrical guide rods 5 can more effectively prevent the stamping from being misaligned or twisted.

[0054] Based on the above embodiments, as a further preferred option, please refer to... Figure 11 and Figure 12 The tension rod 6 is a double-ended screw, and the fastener 8 is a nut that is threaded with the double-ended screw. The nuts at both ends of the double-ended screw are respectively pressed between the base 1 and the cover plate 4 with anti-loosening washers 7.

[0055] In this embodiment, the tension rod 6 is a double-ended screw. The two ends of the double-ended screw pass through the through holes at corresponding positions on the base 1 and the cover plate 4, respectively, so that the threaded portions at both ends extend below the base 1 and above the cover plate 4. The protruding portions at both ends of the double-ended screw are threadedly connected to bolts, and each nut is pressed between the lower surface of the base 1 or the upper surface of the cover plate 4 with an anti-loosening washer 7 (usually a spring washer or other elastic washer).

[0056] During the pressure holding operation, the operator uses tools such as a torque wrench to simultaneously or symmetrically tighten the nuts at both ends of the double-ended screw. The nuts compress the anti-loosening washer 7, thereby pulling the base 1 and the cover plate 4 together, thus locking the stator core 9 in a compressed state. Throughout the entire pressure holding, transportation, and subsequent installation of the force gauge 11, the anti-loosening washer 7, after being compressed, generates elastic force that continuously squeezes the nut, offsetting the gap in the threaded pair and preventing the nut from reversing, thereby ensuring the stability of the pressure holding state throughout the entire test cycle.

[0057] Based on the above embodiments, as a further preferred embodiment, the universal adjustable connector 12 includes an adjusting screw and a universal joint provided at the end of the adjusting screw. The opposite end faces of the base 1 and the cover plate 4 are provided with threaded holes that cooperate with the adjusting screw. After the adjusting screw is inserted into the threaded hole, it is locked onto the base 1 or the cover plate 4 by a locking nut.

[0058] In this embodiment, one end of the adjusting screw has an external thread, and the other end is fixedly connected to or integrally formed with a universal joint. The universal joint is usually a hinged structure, such as a spherical bearing composed of a pin and a connecting ring, which allows the force gauge 11 connected to it to swing freely within a certain angle range.

[0059] Threaded holes are provided on the end face (i.e., upper surface) of the base 1 facing the cover plate 4 and the end face (i.e., lower surface) of the cover plate 4 facing the base 1 at the positions corresponding to the preset measurement points.

[0060] During installation, the operator screws the threaded end of the adjusting screw into the corresponding threaded hole. By rotating the adjusting screw, the length of its protruding end face can be precisely controlled, thereby adjusting the position of the universal joint in the vertical direction. This allows for adjustment of the initial value displayed by the force gauge 11 and adaptability to stator cores 9 of different heights.

[0061] To ensure the adjusted position remains stable during testing, each adjusting screw is equipped with a locking nut. After the adjusting screw is screwed in to the required depth, the locking nut is unscrewed along the adjusting screw and pressed against the end face of the base 1 or cover plate 4, thereby locking the adjusting screw and preventing it from rotating or axially moving when subjected to the pulling force of the force gauge 11, thus improving the accuracy of the rebound force measurement.

[0062] Based on the above embodiments, as a further preferred embodiment, the universal adjustable connector 12 is provided with a hook, and both ends of the force gauge 11 are provided with connecting parts that can be detachably connected to the hook.

[0063] In this embodiment, the end of the universal adjustable connector 12 furthest from the adjusting screw is provided with a hook. The hook is typically a U-shaped hook or a connecting ring with a safety locking tongue. Its opening direction is used to hook the connecting part of the force gauge 11. The connecting part is a lifting ring, an open ring, or an opening inherent at both ends of the force gauge 11's own tension sensor that is fixed to the housing of the force gauge 11. When assembling the force gauge 11, the operator only needs to hook the connecting part of one end of the force gauge 11 into the hook of the lower universal adjustable connector 12, and then hook the connecting part of the other end into the corresponding hook of the upper universal adjustable connector 12, thereby achieving quick assembly without the need for additional tools, which is simple and convenient.

[0064] In one specific embodiment, the number of pairs of universal adjustable connectors 12 and force gauges 11 is at least three, and they are evenly distributed along the circumference, which can ensure the accuracy of rebound force measurement.

[0065] Based on the above embodiments, as a further preferred embodiment, the force gauge 11 is a wireless force gauge 11; the device also includes a data receiving and processing terminal for wirelessly receiving, displaying and calculating the data of each force gauge 11.

[0066] In this embodiment, the force gauge 11 is a wireless force gauge 11, which integrates a high-precision tension sensor, signal processing circuit, wireless communication module (such as Bluetooth or Wi-Fi), and independent power supply (such as a rechargeable battery). The data receiving and processing terminal (such as a computer) is externally connected to a wireless receiving module that communicates with the wireless communication module built into the wireless force gauge 11.

[0067] Thus, during the release of the spring force of the stator core 9, each wireless force gauge 11 transmits the measured force data to the terminal in real time via wireless signal, recording the force-time curve of the entire release process, so that the terminal can further obtain the total spring force of the stator core 9 through a preset algorithm.

[0068] Based on the above embodiments, as a further preferred embodiment, this device includes a non-contact displacement sensor (such as a laser displacement sensor). The non-contact displacement sensor is disposed on the end face (i.e., upper end face) of the base 1 facing the cover plate 4, and the end face (i.e., lower end face) of the cover plate 4 facing the base 1 is provided with a measurement mark that cooperates with the non-contact displacement sensor. In this way, the non-contact displacement sensor can measure the height of the cover plate 4 relative to the base 1 in real time, indirectly providing feedback on the real-time height of the stator core, and can transmit the data to a data receiving and processing terminal via wired or wireless signals. This effectively achieves real-time, accurate, and automated monitoring of core height changes, thereby improving the reliability and efficiency of the entire verification method.

[0069] The terminal has a built-in algorithm that automatically calculates and accumulates the data from each force gauge 11 in real time when the real-time height of the stator core is equal to the preset target height. This calculation is based on the preset formula for determining the spring force of the stator core 9 and directly outputs the total spring force of the stator core 9, which is then displayed on the screen for the operator to read the values ​​more intuitively and promptly.

[0070] Furthermore, the terminal's built-in algorithm can combine the weld bearing area and weld material yield strength values ​​input by the operator in the process evaluation, automatically derive the safety factor according to the weld strength verification formula, and output it to the screen. The operator can automatically and intelligently obtain the verification results of the stator core 9 weld.

[0071] The present invention also provides a method for verifying the strength of stator core welds, applied to the stator core weld strength verification device disclosed in the above embodiments, the method comprising the following steps: Step 1: Position the lower end component of the stator core 9 to be measured, the stator laminations 22 sets, and the upper end component sequentially between the lower positioning plate 2 and the upper positioning plate 3; Step 2: The pressurizing equipment applies pressure to the cover plate 4, compressing the stator core 9 to the target height. Then, tighten the fasteners 8 at both ends of all the tension rods 6 to lock the stator core 9 in the pressure-holding state. After that, the pressure of the pressurizing equipment is released. Step 3: Measure the height of stator core 9 for the first time. Distribute the measurement at four points evenly and record the measurements. Mark the measurement positions to obtain the average height of the stator core in its locked and compressed state. ; Step 4: Loosen and remove all fasteners 8 in sections and symmetrically to allow the stator core 9 to fully spring back; Step 5: Screw the universal adjustable connector 12 into the corresponding threaded holes on the base 1 and the cover plate 4, connect the force gauge 11 between the upper and lower universal adjustable connectors 12, and adjust the screwing depth of the universal adjustable connector 12 symmetrically in segments to compress the stator core 9. Step 6: Measure the stator core height a second time. Distribute the measurements evenly at four points marked in the previous step and record the values. Obtain the average height of the stator core under compressive stress. ; Step 7: When Record the reading of each force gauge at that time. Where i = 1, 2, ..., n; Step 8: Determine the formula based on the stator core springback force according to the recorded final readings. The true springback force of the stator core is determined by the following formula: ; in, For the true springback force of the stator core, Let i be the force reading of the i-th force gauge. Let n be the weight of the cover plate and the upper positioning plate, n be the number of force gauges, and g be the gravitational acceleration, taken as 9.8 N / kg. Step 9: Determine the safety factor based on the actual springback force of the stator core using the weld strength verification formula. The weld strength verification formula is as follows: ; in, The yield strength of the weld material. For safety reasons, This refers to the total bearing area of ​​the weld seam on the outer circle of the stator core.

[0072] The above verification method restores the elastic deformation state of the stator core through a controllable secondary compression process, indirectly and accurately measures its internal rebound force using the static equilibrium equation, and further quantitatively compares the measured force value with the structural strength of the weld.

[0073] This eliminates the problem of springback force estimation based on theoretical formulas being affected by burrs, gaps, surface roughness, and other factors existing between laminates. The influence of measurement error can directly capture the true springback force of the stator core 9. Furthermore, by placing the measured true springback force and the weld bearing area determined by the process evaluation into the weld strength verification formula, and then comparing it with the yield strength value of the weld material, a true and reliable safety factor can be obtained, thereby achieving a quantitative and accurate assessment of the weld bearing capacity.

[0074] Based on the above embodiments, as a further preferred embodiment, step 1 specifically includes the following steps: Step 11: Engage the notch 18 in the lower positioning plate 2 with the stop step 17 on the base 1, as follows: Figure 2 As shown; Step 12: Place the lower pressure ring 13 of the lower end component onto the lower positioning plate 2, and position the outer circle of the lower pressure ring 13 in conjunction with the first step 20 of the lower positioning plate 2, as follows. Figure 3 As shown; Step 13: Stack the lower tooth pressure plate 14 on the lower pressure ring 13, and position the outer circle of the lower tooth pressure plate 14 in conjunction with the second step 21 of the lower positioning plate 2, as follows. Figure 4 As shown; Step 14: Insert at least one guide rod 5 into the keyway 19 of the lower positioning plate 2, such as... Figure 5 As shown; Step 15: Stack multiple stator laminations 22 sequentially, ensuring that the grooves on the inner ring of each stator lamination 22 pass through the guide rod 5 for auxiliary positioning, until they are stacked to the preset height, such as... Figure 6 As shown; Step 16: Place the upper toothed pressure plate 15 on the topmost stator lamination 22, as follows. Figure 7 As shown; Step 17: Place the upper pressure ring 16, which is the upper component, onto the upper toothed pressure plate 15, as follows. Figure 8 As shown; Step 18: Place the upper positioning plate 3 on the upper pressure ring 16, and position the outer circle of the upper pressure ring 16 in conjunction with the first step 20 of the upper positioning plate 3, and position the outer circle of the upper toothed pressure plate 15 in conjunction with the second step 21 of the upper positioning plate 3, as follows. Figure 9 As shown; Step 19: Engage the stop step 17 on the cover plate 4 with the notch 18 in the upper positioning plate 3, as follows: Figure 10 As shown.

[0075] By employing the above steps, the centering core can be precisely positioned between the base 1 and the cover plate 4. During installation, the positioning steps on the upper and lower positioning plates automatically align the lower components (such as the lower toothed pressure plate 14 and the lower pressure ring 13) and the upper components (such as the upper toothed pressure plate 15 and the lower pressure ring 13) of the core, ensuring the vertical placement of the stator core 9 within the device. This ensures that the subsequently applied pressure and the measured springback force act along the axis, thereby improving the accuracy of the springback force measurement. Furthermore, the guide rod 5 plays a guiding and anti-rotation role throughout the lamination process, preventing distortion in the springback force measurement caused by lamination misalignment or torsion.

[0076] It should be noted that in this specification, relational terms such as first and second are used only to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities.

[0077] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0078] The above provides a detailed description of the stator core weld strength verification device and method provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the invention. The descriptions of the above embodiments are merely for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A method for checking the strength of stator core welds, characterized in that, A stator core weld strength verification device is adopted, the device comprising: The base (1) and the cover plate (4) are arranged in parallel opposite directions and both of their opposite end faces are provided with positioning structures; The lower positioning plate (2) is detachably connected to the positioning structure of the base (1) and is used to position the lower end component of the sub-core to be measured; The upper positioning plate (3) is detachably connected to the positioning structure of the cover plate (4) and is used to position the upper part of the sub-core to be measured; Multiple tension rods (6) are inserted between the base (1) and the cover plate (4) and are evenly distributed along the outer periphery of the stator core. Both ends of each tension rod (6) are fastened by fasteners (8) to maintain pressure on the stator core after stacking. Multiple universal adjustable connectors (12) are arranged in pairs on the opposite end faces of the base (1) and the cover plate (4) and are evenly distributed along the outer periphery of the stator core. Each pair of universal adjustable connectors (12) is arranged vertically opposite each other. Multiple force gauges (11), each of which is connected to a pair of universal adjustable connectors (12) at both ends, for measuring the springback force of the stator core after the fastener (8) is loosened; The method includes the following steps: The lower end component, stator lamination assembly, and upper end component of the stator core to be measured are sequentially positioned between the lower positioning plate and the upper positioning plate. The pressurizing equipment applies pressure to the cover plate, compressing the stator core to the target height. Then, the fasteners at both ends of all the tension rods are tightened to lock the stator core. After that, the pressure from the pressurizing equipment is released. The first measurement of the stator core height involved measuring at four evenly spaced points and recording the measurements. The measurement locations were also marked. This yielded the average height of the stator core in its locked and compressed state. ; Loosen and remove all fasteners in sections and symmetrically to allow the stator core to fully spring back; Screw the universal adjustable connectors into the corresponding threaded holes on the base and cover plate, connect the force gauge between the upper and lower universal adjustable connectors, and adjust the screwing depth of the universal adjustable connectors symmetrically in segments to compress the stator core. The second measurement of the stator core height involved measuring and recording four points evenly distributed at the previously marked locations, thus obtaining the average height of the stator core under compressive stress. ; when Record the reading of each force gauge at that time. , where i = 1, 2, ..., n; The formula for determining the springback force of the stator core is based on the recorded final readings. The true springback force of the stator core is determined by the following formula: ； in, For the true springback force of the stator core, Let i be the force reading of the i-th force gauge. Let n be the weight of the cover plate and the upper positioning plate, n be the number of force gauges, and g be the gravitational acceleration, taken as 9.8 N / kg. The safety factor is determined based on the actual springback force of the stator core using the weld strength verification formula, which is as follows: ； in, The yield strength of the weld material. For safety reasons, This refers to the total bearing area of ​​the weld seam on the outer circle of the stator core.

2. The method for checking the strength of stator core welds according to claim 1, characterized in that, The positioning structure is a stop step (17), and both the lower positioning plate (2) and the upper positioning plate (3) are provided with notches (18) that engage with the stop step (17).

3. The method for checking the strength of stator core welds according to claim 1, characterized in that, The lower positioning plate (2) and the upper positioning plate (3) are both provided with positioning steps on their end faces facing the stator core for mounting the lower and upper components.

4. The method for checking the strength of stator core welds according to claim 1, characterized in that, It also includes at least one guide rod (5), and both the lower positioning plate (2) and the upper positioning plate (3) are provided with keyways (19) that engage with the end of the guide rod (5).

5. The method for checking the strength of stator core welds according to claim 1, characterized in that, The tension rod (6) is a double-ended screw, the fastener (8) is a nut that is threaded with the double-ended screw, and the nuts at both ends of the double-ended screw are respectively pressed between the base (1) and the cover plate (4) with anti-loosening washers (7).

6. The method for checking the strength of stator core welds according to claim 1, characterized in that, The universal adjustable connector (12) includes an adjusting screw and a universal joint at the end of the adjusting screw. The opposite end faces of the base (1) and the cover plate (4) are provided with threaded holes that cooperate with the adjusting screw. After the adjusting screw is inserted into the threaded hole, it is locked onto the base (1) or the cover plate (4) by a locking nut.

7. The method for checking the strength of stator core welds according to claim 1, characterized in that, The universal adjustable connector (12) is provided with a hook, and both ends of the force gauge (11) are provided with a connecting part that can be detachably connected to the hook.

8. The method for checking the strength of stator core welds according to claim 1, characterized in that, The force gauge is a wireless force gauge; the device also includes a data receiving and processing terminal for wirelessly receiving, displaying and calculating the data of each of the force gauges (11).

9. The method for checking the strength of stator core welds according to claim 1, characterized in that, The method of positioning the lower end component, stator lamination assembly, and upper end component of the stator core to be measured sequentially between the lower positioning plate and the upper positioning plate includes: Engage the notch in the lower positioning plate with the stop step on the base; Place the lower pressure ring of the lower end component on the lower positioning plate, and position the outer circle of the lower pressure ring in conjunction with the first step of the lower positioning plate; The lower tooth pressure plate of the lower end component is stacked on the lower pressure ring, and the outer circle of the lower tooth pressure plate is positioned and engaged with the second step of the lower positioning plate. Insert at least one guide bar into the keyway of the lower positioning plate; Multiple stator laminations are stacked sequentially, and the grooves of the inner ring of each stator lamination are passed through guide bars for auxiliary positioning until they are stacked to the preset height. The upper tooth pressure plate is stacked on the topmost stator lamination; Place the upper pressure ring of the upper component onto the upper tooth pressure plate; Place the upper positioning plate of the upper component on the upper pressure ring, and make the outer circle of the upper pressure ring and the first step of the upper positioning plate position and engage, and make the outer circle of the upper tooth pressure plate and the second step of the upper positioning plate position and engage. The stop step on the cover plate is engaged with the notch in the upper positioning plate.

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