A group measuring gauge for fast detection before injection molding of an iron core

Abstract

The utility model relates to the technical field of core production detection, specifically relates to a group measuring gauge for the rapid detection before the injection of core, including the gauge support, install the bearing seat part on gauge support, rotate set in bearing seat part is used for the positioning core hole positioning mandrel, set up between gauge support and positioning mandrel is used for driving positioning mandrel rotation positioning mandrel rotation drive mechanism, fix in gauge support with long strip detection gauge that parallel positioning mandrel, when detecting, a plurality of cores are simultaneously sheathed on positioning mandrel and stack in turn, thereby form core stack group, long strip detection gauge with the iron core outer circle between core stack group is provided with detection gap. The utility model has realized the efficient and rapid detection of the outer circle size before the injection of core, improved the quality and efficiency of detection.

Description

Technical Field

[0001] This utility model relates to the field of iron core production and testing technology, specifically to a group measurement gauge for rapid testing of iron cores before injection molding. Background Technology

[0002] In the manufacturing process of electromagnetic devices such as motors and transformers, the iron core is one of the core components, and its manufacturing quality directly affects the performance and reliability of the product. Modern iron core production generally adopts automated injection molding technology, which involves injection molding the stamped iron core assemblies to form a structurally stable integral component. However, if the outer diameter of the iron core is out of tolerance before injection molding, especially if the outer diameter is too large, the iron core will not be able to be smoothly installed into the injection mold, causing equipment jamming, mold damage, or even machine shutdown; while if the outer diameter is too small, it may affect the subsequent assembly accuracy or the consistency of electromagnetic performance. Therefore, the outer diameter of the iron core must be strictly inspected before entering the injection molding process to ensure that it is within the tolerance range allowed by the process.

[0003] Currently, the main methods for inspecting the outer diameter of iron cores include manual sampling using general measuring tools such as vernier calipers and micrometers, or using fixed outer diameter gauges for go / no-go gauge inspection. While these methods are adequate for small-batch production, they exhibit significant drawbacks in large-scale automated production lines: low inspection efficiency, high labor intensity, high human error, high risk of missed inspections, and difficulty in achieving 100% inspection. Furthermore, traditional gauges typically only allow static inspection of individual iron cores, failing to balance production cycle time and inspection coverage, severely restricting the overall efficiency and automation level of the production line.

[0004] In recent years, some companies have attempted to introduce automated inspection equipment, such as image measuring instruments or coordinate measuring machines (CMMs). While these can improve accuracy, they are costly, complex to operate, and slow, making them unsuitable for online rapid screening scenarios. Some solutions employ rotary single-piece inspection devices, but these still operate on a piece-by-piece inspection model, failing to overcome the efficiency bottleneck of "one-to-one" inspection. More importantly, existing technologies generally lack the ability to achieve centering consistency, dynamic interference recognition, and intelligent judgment when inspecting multiple iron cores simultaneously, making it difficult to meet the demands of high-speed, high-reliability intelligent manufacturing.

[0005] Therefore, there is an urgent need for a multi-piece synchronous, rapid, non-contact, and automated inspection device for the outer diameter of iron cores. This device should be compatible with the rhythm of existing automated production lines and effectively identify defective products that exceed the upper limit (pass end) and fall below the lower limit (stop end), thereby improving inspection efficiency and quality control. Utility Model Content

[0006] To address the aforementioned problems, this utility model proposes a group measuring gauge for rapid inspection of iron cores before injection molding, aiming to achieve efficient and rapid inspection of the outer diameter of the iron core before injection molding, thereby improving the quality and efficiency of the inspection. The specific technical solution is as follows: A group measuring gauge for rapid inspection of iron cores before injection molding includes a gauge support, a bearing housing component mounted on the gauge support, a positioning mandrel rotatably mounted on the bearing housing component for positioning the inner hole of the iron core, a positioning mandrel rotation drive mechanism disposed between the gauge support and the positioning mandrel for driving the positioning mandrel to rotate, and an elongated measuring gauge fixed on the gauge support and parallel to the positioning mandrel. During inspection, multiple iron cores are simultaneously fitted onto the positioning mandrel and stacked sequentially to form an iron core stack group. A detection gap is provided between the elongated measuring gauge and the outer circle of the iron cores in the iron core stack group.

[0007] The positioning mandrel is driven to rotate together with the iron core stack group by the positioning mandrel rotation drive mechanism. The system detects whether the iron core stack group interferes with the long strip inspection gauge during the rotation process, so as to determine whether the outer circle dimension of each iron core in the iron core stack group is too large, resulting in non-compliance.

[0008] The positioning mandrel is provided with a mandrel flange for positioning the end face of the iron core.

[0009] Preferably, the positioning spindle rotation drive mechanism is one of a gear transmission mechanism, a belt transmission mechanism, or a chain transmission mechanism.

[0010] Preferably, the gear transmission mechanism includes a driven gear mounted on the positioning mandrel, a reduction motor mounted on the gauge support, and a driving gear mounted on the motor shaft of the reduction motor and meshing with the driven gear.

[0011] Preferably, the belt drive mechanism includes a driven pulley mounted on the positioning spindle, a reduction motor mounted on the gauge support, a driving pulley mounted on the motor shaft of the reduction motor, and a transmission belt connecting the driven pulley and the driving pulley.

[0012] Preferably, the chain drive mechanism includes a driven sprocket mounted on the positioning mandrel, a reduction motor mounted on the gauge support, a driving sprocket mounted on the motor shaft of the reduction motor, and a drive chain connecting the driven sprocket and the driving sprocket.

[0013] In this invention, the bearing housing component includes a bearing housing and a rolling bearing disposed on the bearing housing, and the positioning mandrel is rotatably disposed on the bearing housing via the rolling bearing.

[0014] As a further improvement of this utility model, a ranging sensor array is provided on the elongated detection gauge. The ranging sensor array includes a number of ranging sensors that are spaced apart on the elongated detection gauge and whose detection direction is perpendicular to the direction of the positioning mandrel.

[0015] Preferably, the elongated detection gauge is provided with a sensor mounting hole, and the probe of the ranging sensor is recessed into the sensor mounting hole.

[0016] Preferably, the ranging sensor is a laser ranging sensor or an inductive ranging sensor.

[0017] Preferably, the lower end of the elongated gauge is provided with a gauge mounting plate, and the elongated gauge is fixed on the gauge support by the gauge mounting plate.

[0018] Preferably, the upper end face of the gauge support is provided with a sliding groove, and the gauge mounting plate is movably disposed in the sliding groove and fixed by fastening screws.

[0019] The measuring gauge mounting plate is provided with a waist-shaped hole for the fastening screw to pass through, so as to realize the adjustment of the position of the measuring gauge mounting plate.

[0020] In this invention, each distance sensor on the elongated detection gauge points to the outer surface of the corresponding iron core in the iron core stack group. The positioning mandrel is driven to rotate together with the iron core stack group by the positioning mandrel rotation drive mechanism, so that each distance sensor can simultaneously and accurately measure the outer circle of each iron core, so as to determine whether the outer circle size of each iron core in the iron core stack group is too small and therefore unqualified.

[0021] In this invention, each of the distance measuring sensors and the positioning spindle rotation drive mechanism is connected to a controller.

[0022] In this invention, the controller determines whether the outer circle of each iron core on the positioning mandrel is qualified based on the measurement data of each ranging sensor, and then displays the judgment result on the display screen; and issues an alarm message when the outer circle of the iron core is found to be unqualified.

[0023] As a further improvement of this utility model, an airbag-type centering clamping device is also provided on the positioning mandrel. The airbag-type centering clamping device includes a number of annular grooves spaced apart on the positioning mandrel, an annular expansion ring fixedly installed at the bottom of the annular groove, a central air inlet hole provided on the positioning mandrel along the central axis of the positioning mandrel, and an air inlet nozzle provided on the annular expansion ring and inserted into the central air inlet hole for inflating the annular expansion ring. The central air inlet hole on the positioning mandrel is connected to a compressed air source through a pneumatic rotary joint.

[0024] Preferably, the annular expansion ring is retracted into the annular groove of the positioning mandrel when the compressed air is unloaded.

[0025] The spacing between adjacent ranging sensors on the elongated inspection gauge is the same as the spacing between adjacent iron cores stacked sequentially on the positioning mandrel, and also equal to the spacing between adjacent annular expansion rings mounted on the positioning mandrel, thus forming a one-to-one correspondence. This one-to-one correspondence ensures that each iron core on the positioning mandrel is centered and clamped, while simultaneously enabling each ranging sensor on the elongated inspection gauge to detect whether the outer diameter of each iron core on the positioning mandrel is within acceptable limits.

[0026] Preferably, each of the distance measuring sensors is offset from each of the annular expansion rings along the axial direction (vertical direction). This offset arrangement allows the distance measuring sensors to perform initial calibration of the positioning mandrel when it is unloaded (without the iron core installed), to determine if there is any abnormality where the elongated detection gauge is not parallel to the positioning mandrel, thus affecting measurement accuracy. An alarm message is issued when an abnormality occurs.

[0027] Preferably, the annular expansion ring is fixedly installed at the bottom of the annular groove by adhesive bonding.

[0028] As a further improvement of this utility model, a torque sensor connected to the controller is provided on the motor shaft of the geared motor. When the controller detects that the torque is too large through the torque sensor, it determines that the iron core stack group has interfered with the long strip detection gauge and jammed during the rotation process, and thus issues an alarm message.

[0029] The method of using this utility model includes the following steps in sequence: (1) Loading: The operator loads multiple iron cores onto the outer circle of the positioning mandrel in sequence to form a stack of iron cores; (2) Positioning and clamping: The operator presses the start button on the controller, and the controller uses the airbag-type centering and clamping device to position and clamp each iron core in the iron core stack group located on the positioning mandrel; (3) Through end detection: The controller drives the positioning mandrel rotation drive mechanism to rotate the iron core stack group located on the positioning mandrel. The controller determines whether the iron core stack group forms contact interference with the long strip detection gauge when rotating based on the torque measured by the torque sensor. When the torque is not greater than the set threshold, it is determined that the outer diameter of each iron core in the iron core stack group has not exceeded the upper limit value, and the through end detection of the iron core outer diameter is qualified. When the torque is greater than the set threshold, it is determined that there is an iron core in the iron core stack group whose outer diameter exceeds the upper limit value. The controller issues an alarm message and determines which iron core's outer diameter exceeds the upper limit value based on the actual measurement value of the distance sensor. The controller then displays the specific location of the iron core whose outer diameter exceeds the upper limit value on the display screen.

[0030] (4) Stop end detection: During the rotation of the iron core stack group, each distance sensor dynamically measures the change of the outer circle size of each iron core online and obtains the measurement data of the outer circle of each iron core. The controller judges whether the outer circle size of each iron core in the iron core stack group exceeds the lower limit based on the measurement data. When the outer circle size of all iron cores does not exceed the lower limit, the stop end detection of the outer circle of the iron core is qualified. When the outer circle size of an iron core exceeds the lower limit, the controller issues an alarm message and displays the specific location of the iron core whose outer circle size exceeds the lower limit on the display screen.

[0031] The beneficial effects of this utility model are: First, this utility model provides a group measuring gauge for rapid inspection of iron cores before injection molding. By stacking multiple iron cores sequentially on the same positioning mandrel to form an "iron core stack group," and combining it with a long strip measuring gauge and a distance sensor array, it achieves simultaneous inspection of the outer diameter of multiple iron cores, breaking through the efficiency bottleneck of the traditional "one-to-one" inspection method. Compared with single-piece inspection methods, the inspection efficiency is significantly improved.

[0032] Secondly, this utility model provides a group measuring gauge for rapid inspection of iron cores before injection molding. It integrates both pass and stop end detection functions for the outer diameter of the iron core. The pass end detection, by driving the iron core group to rotate and using a torque sensor to monitor rotational resistance, determines in real time whether there is excessive outer diameter of the iron core causing physical interference with the measuring gauge, thus quickly rejecting defective products exceeding the upper limit. The stop end detection utilizes a distance sensor array to perform non-contact dynamic measurement of the outer diameter of each iron core, accurately acquiring the actual outer diameter data and determining whether it is below the lower limit of the size. The two work together to comprehensively cover the dimensional tolerance zone, ensuring complete and reliable inspection results.

[0033] Third, this utility model provides a group measuring gauge for rapid inspection of iron cores before injection molding. It features a specially designed airbag-type centering clamping device. An annular expansion ring is placed on the positioning mandrel, and after air is introduced, it expands uniformly to achieve equal-diameter centering clamping of the inner hole of each iron core, avoiding measurement errors caused by eccentric stacking of iron cores. This structure has adaptive compensation capabilities, is suitable for minor differences in the inner hole of iron cores from different batches, and significantly improves repeatability and inspection stability.

[0034] Fourth, the group measuring gauge of this utility model for rapid inspection before iron core injection molding has a distance sensor and annular expansion ring offset along the axial direction, so that the sensor can directly measure the positioning mandrel body in the unloaded state without iron core loading, which is used to check whether the detection system has installation deviation or deformation, realize the online self-test and calibration function of the device, effectively prevent systematic measurement deviation caused by mechanical installation error, and improve the reliability of long-term operation. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of a group measuring gauge for rapid inspection before iron core injection molding, according to this utility model.

[0036] In the diagram: 1. Iron core, 2. Gauge support, 3. Bearing housing component, 4. Positioning mandrel, 5. Positioning mandrel rotation drive mechanism, 6. Long strip-shaped inspection gauge, 7. Distance sensor array, 8. Distance sensor, 9. Sensor mounting hole, 10. Mandrel flange, 11. Driven gear, 12. Gear motor, 13. Drive gear, 14. Bearing housing, 15. Rolling bearing, 16. Gauge mounting plate, 17. Slide groove, 18. Fastening screw, 19. Waist-shaped hole, 20. Airbag-type centering clamping device, 21. Annular groove, 22. Annular expansion ring, 23. Central air inlet, 24. Air inlet nozzle, 25. Compressed air source, 26. Display screen, 27. Controller, 28. Pneumatic rotary joint, 29. Torque sensor. Detailed Implementation

[0037] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solution of this utility model and should not be construed as limiting the scope of protection of this utility model.

[0038] like Figure 1The illustration shows an embodiment of a group measuring gauge for rapid inspection of iron cores before injection molding, comprising a gauge support 2, a bearing seat component 3 mounted on the gauge support 2, a positioning mandrel 4 rotatably mounted on the bearing seat component 3 for positioning the inner hole of the iron core 1, a positioning mandrel rotation drive mechanism 5 disposed between the gauge support 2 and the positioning mandrel 4 for driving the positioning mandrel 4 to rotate, and a long strip-shaped inspection gauge 6 fixed on the gauge support 2 and parallel to the positioning mandrel 4. During inspection, multiple iron cores 1 are simultaneously fitted onto the positioning mandrel 4 and stacked sequentially to form an iron core stack group. A detection gap is provided between the long strip-shaped inspection gauge 6 and the outer circle of the iron core 1 in the iron core stack group.

[0039] The positioning mandrel 4 is driven to rotate together with the iron core stack group by the positioning mandrel rotation drive mechanism 5. The mechanism detects whether the iron core stack group interferes with the long strip detection gauge during the rotation process, so as to determine whether the outer circle dimension of each iron core 1 in the iron core stack group is too large and thus unqualified.

[0040] The positioning mandrel 4 is provided with a mandrel flange 10 for positioning the end face of the iron core 1.

[0041] Preferably, the positioning spindle rotation drive mechanism 5 is one of a gear transmission mechanism, a belt transmission mechanism, or a chain transmission mechanism.

[0042] Preferably, the gear transmission mechanism includes a driven gear 11 mounted on the positioning spindle 4, a reduction motor 12 mounted on the gauge support 2, and a driving gear 13 mounted on the motor shaft of the reduction motor 12 and meshing with the driven gear 11.

[0043] Preferably, the belt drive mechanism (not shown in the figure) includes a driven pulley mounted on the positioning spindle, a reduction motor mounted on the gauge support, a driving pulley mounted on the motor shaft of the reduction motor, and a transmission belt connecting the driven pulley and the driving pulley.

[0044] Preferably, the chain drive mechanism (not shown in the figure) includes a driven sprocket mounted on the positioning mandrel, a reduction motor mounted on the gauge support, a drive sprocket mounted on the motor shaft of the reduction motor, and a drive chain connecting the driven sprocket and the drive sprocket.

[0045] In this embodiment, the bearing housing component 3 includes a bearing housing 14 and a rolling bearing 15 disposed on the bearing housing 14, and the positioning spindle 4 is rotatably disposed on the bearing housing 14 via the rolling bearing 15.

[0046] As a further improvement of this embodiment, a ranging sensor array 7 is provided on the elongated detection gauge 6. The ranging sensor array 7 includes a number of ranging sensors 8 that are spaced apart on the elongated detection gauge 6 and whose detection direction is perpendicular to the direction of the positioning mandrel 4.

[0047] Preferably, the elongated detection gauge 6 is provided with a sensor mounting hole 9, and the probe of the ranging sensor 8 is recessed into the sensor mounting hole 9.

[0048] Preferably, the ranging sensor 8 is a laser ranging sensor or an inductive ranging sensor.

[0049] Preferably, the lower end of the elongated gauge 6 is provided with a gauge mounting plate 16, and the elongated gauge 6 is fixed on the gauge support 2 by the gauge mounting plate 16.

[0050] Preferably, the upper end face of the gauge support 2 is provided with a sliding groove 17, and the gauge mounting plate 16 is movably disposed in the sliding groove 17 and fixed by fastening screws 18.

[0051] The measuring gauge mounting plate 16 is provided with a waist-shaped hole for the fastening screw 18 to pass through, so as to realize the adjustment of the position of the measuring gauge mounting plate 16.

[0052] In this embodiment, each distance sensor 8 on the elongated detection gauge 6 points to the outer circular surface of the corresponding iron core 1 in the iron core stack group. The positioning mandrel 4 is driven to rotate together with the iron core stack group by the positioning mandrel rotation drive mechanism 5, so that each distance sensor 8 can simultaneously and accurately measure the outer circle of each iron core 1, so as to determine whether the outer circle size of each iron core in the iron core stack group is unqualified due to being too small.

[0053] In this embodiment, each of the ranging sensors 8 and the positioning spindle rotation drive mechanism 5 is connected to the controller 27.

[0054] In this embodiment, the controller 27 determines whether the outer circle of each iron core 1 on the positioning mandrel 4 is qualified based on the measurement data of each of the ranging sensors 8, and then displays the judgment result on the display screen 26; and issues an alarm message when the outer circle of the iron core 1 is found to be unqualified.

[0055] As a further improvement of this embodiment, an airbag-type centering clamping device 20 is also provided on the positioning mandrel 4. The airbag-type centering clamping device 20 includes a number of annular grooves 21 spaced apart on the positioning mandrel 4, an annular expansion ring 22 fixedly installed at the bottom of the annular groove 21, a central air inlet hole 23 arranged on the positioning mandrel 4 along the central axis of the positioning mandrel 4, and an air inlet nozzle 24 arranged on the annular expansion ring 22 and inserted into the central air inlet hole 23 for inflating the annular expansion ring 22. The central air inlet hole 23 on the positioning mandrel 4 is connected to a compressed air source 25 through a pneumatic rotary joint 28.

[0056] Preferably, the annular expansion ring 22 is retracted into the annular groove 21 of the positioning mandrel 4 when the compressed air is unloaded.

[0057] The spacing between adjacent ranging sensors 8 on the elongated detection gauge 6 is the same as the spacing between adjacent iron cores 1 stacked sequentially on the positioning mandrel 4, and also equal to the spacing between adjacent annular expansion rings 22 mounted on the positioning mandrel 4, thus forming a one-to-one correspondence. This one-to-one correspondence ensures that each iron core 1 on the positioning mandrel 4 is centered and clamped, while simultaneously enabling each ranging sensor 8 on the elongated detection gauge 6 to detect whether the outer diameter of each iron core 1 on the positioning mandrel 4 is within acceptable limits.

[0058] Preferably, each of the distance measuring sensors 8 is offset from each of the annular expansion rings 22 along the axial direction (vertical direction). This offset arrangement allows the distance measuring sensor 8 to perform an initial check on the positioning mandrel 4 when it is unloaded (without the iron core 1 installed), to determine if there is any abnormality where the elongated detection gauge 6 is not parallel to the positioning mandrel 4, thus affecting measurement accuracy. An alarm message is issued when an abnormality occurs.

[0059] Preferably, the annular expansion ring 22 is fixedly installed at the bottom of the annular groove 21 by adhesive bonding.

[0060] As a further improvement of this embodiment, a torque sensor 29 connected to the controller 27 is provided on the motor shaft of the geared motor 12. When the controller 27 detects that the torque is too large through the torque sensor 29, it determines that the iron core stack group has interfered with the long strip detection gauge 6 and jammed during the rotation process, and thus issues an alarm message.

[0061] The usage method of this embodiment includes the following steps in sequence: (1) Loading: The operator loads multiple iron cores 1 onto the outer circle of the positioning mandrel 4 in sequence to form a stack of iron cores; (2) Positioning and clamping: The operator presses the start button on the controller 27, and the controller 27 uses the airbag-type centering clamping device 20 to position and clamp each iron core 1 in the iron core stack group located on the positioning mandrel 4. (3) Through end detection: The controller 27 drives the positioning spindle rotation drive mechanism 5 to rotate, so that the iron core stack group located on the positioning spindle 4 rotates. The controller 27 determines whether the iron core stack group forms contact interference with the long strip detection gauge 6 when rotating based on the torque measured by the torque sensor 29. When the torque is not greater than the set threshold, it is determined that the outer circle size of each iron core 1 in the iron core stack group has not exceeded the upper limit value, and the through end detection of the outer circle of the iron core 1 is qualified. When the torque is greater than the set threshold, it is determined that there is an iron core 1 in the iron core stack group whose outer circle size exceeds the upper limit value. The controller 27 issues an alarm message and determines which iron core 1 has an outer circle size that exceeds the upper limit value based on the actual measurement value of the distance sensor 8. The controller 27 then displays the specific location of the iron core 1 whose outer circle size exceeds the upper limit value on the display screen 26.

[0062] (4) Stop end detection: During the rotation of the iron core stack group, each distance sensor 8 dynamically measures the change of the outer circle size of each iron core 1 online, and obtains the measurement data of the outer circle of each iron core 1. The controller 27 judges whether the outer circle size of each iron core 1 in the iron core stack group exceeds the lower limit based on the measurement data. When the outer circle size of all iron core 1 does not exceed the lower limit, the stop end detection of the outer circle of the iron core 1 is qualified. When the outer circle size of an iron core 1 exceeds the lower limit, the controller 27 issues an alarm message and displays the specific location of the iron core whose outer circle size exceeds the lower limit on the display screen 26.

[0063] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A group measurement gauge for rapid inspection before iron core injection molding, characterized in that, The system includes a gauge support, a bearing housing component mounted on the gauge support, a positioning mandrel rotatably mounted on the bearing housing component for positioning the inner hole of the iron core, a positioning mandrel rotation drive mechanism disposed between the gauge support and the positioning mandrel for driving the positioning mandrel to rotate, and an elongated inspection gauge fixed on the gauge support and parallel to the positioning mandrel. During inspection, multiple iron cores are simultaneously fitted onto the positioning mandrel and stacked sequentially to form an iron core stack group. A detection gap is provided between the elongated inspection gauge and the outer circle of the iron cores in the iron core stack group.

2. A group measurement gauge for rapid inspection before iron core injection molding according to claim 1, characterized in that, The positioning spindle rotation drive mechanism is one of the following: gear transmission mechanism, belt transmission mechanism, and chain transmission mechanism.

3. A group measurement gauge for rapid inspection before iron core injection molding according to claim 2, characterized in that, The elongated detection gauge is equipped with a ranging sensor array, which includes a number of ranging sensors spaced apart on the elongated detection gauge and whose detection direction is perpendicular to the direction of the positioning mandrel.

4. A group measurement gauge for rapid inspection before iron core injection molding according to claim 3, characterized in that, The ranging sensor is a laser ranging sensor or an inductive ranging sensor.

5. A group measurement gauge for rapid inspection of iron cores before injection molding, as described in claim 1, is characterized in that, The lower end of the elongated measuring gauge is provided with a measuring gauge mounting plate, and the elongated measuring gauge is fixed on the measuring gauge support by the measuring gauge mounting plate.

6. A group measurement gauge for rapid inspection of iron cores before injection molding, as described in claim 1, is characterized in that, Each distance sensor on the elongated inspection gauge points to the outer surface of the corresponding iron core in the iron core stack group. The positioning mandrel is driven to rotate together with the iron core stack group by the positioning mandrel rotation drive mechanism, so that each distance sensor can simultaneously and accurately measure the outer circle of each iron core to determine whether the outer circle size of each iron core in the iron core stack group is too small and therefore unqualified.

7. A group measurement gauge for rapid inspection before iron core injection molding according to claim 3, characterized in that, Each of the aforementioned ranging sensors and positioning spindle rotation drive mechanisms is connected to the controller.

8. A group measurement gauge for rapid inspection before iron core injection molding according to claim 7, characterized in that, The controller determines whether the outer circle of each iron core on the positioning mandrel is qualified based on the measurement data of each ranging sensor, and then displays the judgment result on the display screen; and issues an alarm message when the outer circle of the iron core is found to be unqualified.

9. A group measurement gauge for rapid inspection of iron cores before injection molding, as described in claim 1, characterized in that, An airbag-type centering clamping device is also provided on the positioning mandrel. The airbag-type centering clamping device includes a number of annular grooves spaced apart on the positioning mandrel, an annular expansion ring fixedly installed at the bottom of the annular groove, a central air inlet hole provided on the positioning mandrel along the central axis of the positioning mandrel, and an air inlet nozzle provided on the annular expansion ring and inserted into the central air inlet hole for inflating the annular expansion ring. The central air inlet hole on the positioning mandrel is connected to a compressed air source through a pneumatic rotary joint.

10. A group measurement gauge for rapid inspection of iron cores before injection molding, as described in claim 9, is characterized in that, The annular expansion ring is fixedly installed at the bottom of the annular groove by adhesive bonding.

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