Automatic primer screwing equipment and accurate screwing depth control method

Abstract

The invention discloses automatic primer screwing equipment and a precise screwing depth control method, which are suitable for cartridge case screwing-in type primer automatic precise screwing assembly, based on the screwing equipment, a cartridge case bottom surface reference is converted to a bottom surface sensor simulation plane, a primer outer circle reference is converted to the top end of a screwing-in tool bit, and the cartridge case screwing-in type primer automatic precise screwing assembly is completed. The screwing datum points can be converted to the screwing device, and therefore the primer screwing depth can be directly controlled. A displacement sensor and a torque sensor are matched to control equipment to be screwed in place, the calculation of the screwing depth is controlled by arranging double displacement sensors, the relative displacement A between a virtual bottom surface reference surface and a fixed baffle and the relative screwing-in amount B of a screwing bit are measured respectively, and the compression amount difference value B-A of the two sensors is detected in real time in the screwing process; and a torque sensor is arranged to detect the screwing-in torque in real time, and after the screwing-in torque reaches a set range, screwing-in is stopped, and the primer is screwed in place.

Description

Technical Field

[0001] This invention relates to the field of primer assembly technology, specifically to an automated primer tightening device and a method for precise control of tightening depth, which is particularly suitable for automated and high-precision assembly of screw-in primers. Background Technology

[0002] In the field of cartridge assembly, primers are classified into press-fit primers and screw-fit primers according to their insertion method. The assembly process of screw-fit primers presents significant technical challenges: firstly, it carries high safety risks, as the screw-in depth and torque are difficult to control precisely; excessive screwing can trigger a primer hazard, while insufficient screwing can affect sealing and cause propellant failure; secondly, the assembly pass rate is low, requiring manual disassembly of primers coated with asphalt varnish, readjustment of gaskets, and manual tightening. This process is highly susceptible to damage to the primer, posing significant safety hazards, and is time-consuming and labor-intensive, severely hindering production efficiency. There is an urgent need to develop an automated tightening device to solve the safety and efficiency problems of manual assembly and improve assembly accuracy and pass rate.

[0003] The existing tightening equipment works as follows: the depth of the plateau inside the primer hole is measured by a probe of the primer hole depth measuring device, which indicates the required number of shims. The required shims are then added manually, and the automatic tightening device tightens the primer using a set torque. The torque indirectly controls the primer's screw-in depth, thus completing the assembly of the cartridge primer. However, due to poor consistency of the cartridge primer hole workpieces and indistinct plateaus in some cases, the primer hole depth measurement is inaccurate. Furthermore, the measurement reference is the outer circle of the primer hole, while manual measurement of the primer's screw-in depth is based on the entire bottom surface of the cartridge. Therefore, the given number of shims is of little reference value. Additionally, issues such as poor consistency between the cartridge bottom, copper shims, and primer thread workpieces lead to poor reliability in indirectly controlling the primer screw-in depth via torque, resulting in a low product assembly pass rate and significant safety risks. Moreover, defective products require manual disassembly of the primer coated with asphalt varnish, readjustment of the shims, and manual tightening with a special wrench. The disassembly and reassembly processes are highly susceptible to damage to the primer, posing a significant safety hazard. Summary of the Invention

[0004] To meet the above technical requirements, the purpose of this invention is to provide an automated primer tightening device that replaces manual operation, realizes automated control of the primer tightening process, and solves the technical problems of insufficient precision in controlling the tightening depth and torque, high safety risks, and low production efficiency.

[0005] Another objective of this invention is to provide a method for precise control of tightening depth based on the aforementioned automated primer tightening equipment. The tightening equipment has both depth measurement and tightening functions, unifying the device's depth measurement reference with the manual depth measurement reference. When tightening the primer, the depth of the primer is directly controlled by a displacement sensor, thereby solving the problem of poor reliability in indirect torque control of tightening depth caused by poor consistency among the cartridge, primer, and gasket workpieces. At the same time, a torque sensor is used to control the tightening torque to ensure the primer exit torque requirement of the product, thereby ensuring the tightening qualification rate and improving the inherent safety of production.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a tightening device for automatic assembly of primers for cartridge cases, comprising a base plate, a power drive module, a tightening execution module and a positioning detection module, wherein each module works together to achieve automatic positioning, precise tightening and parameter monitoring of the primer;

[0007] The power drive module includes a push cylinder, a base plate guide rail, and a stop mechanism, all mounted on the surface of the base plate. The push cylinder is connected to the mechanism support plate via a floating joint. The mechanism support plate is placed on the guide rail. The push cylinder drives the mechanism support plate to move forward on the base plate guide rail. The stop mechanism is used to limit the forward movement of the mechanism support plate. The surface of the mechanism support plate is provided with a support plate guide rail and an elastic compression mechanism. The support plate guide rail is provided with a mechanism mounting plate connected to one end of the elastic compression mechanism.

[0008] The tightening actuator includes a reducer mounting plate, a torque sensor, and a bearing mounting plate, all mounted on the surface of the mechanism mounting plate. A servo motor is connected to the reducer, which is fixed to the reducer mounting plate. A thrust bearing is fixed to the bearing mounting plate. The output end of the reducer is connected to one end of the torque sensor, and the other end of the torque sensor is connected to one end of the thrust bearing via a connecting force transmission shaft. A tightening bit is also connected to the front end of the thrust bearing on the force transmission shaft. The tightening bit is adapted to the primer groove and is used to drive the primer into the cartridge.

[0009] The positioning and detection module includes a bottom surface sensor mounting plate fixed to one end of the mechanism support plate. Three bottom surface sensors are mounted on the bottom surface sensor mounting plate. By contacting the bottom surface of the cartridge and compressing and deforming it, the sensors simulate a spatial plane to determine the reference position of the bottom of the cartridge. The bit sensor is fixed to one side of the mechanism support plate through the bit sensor mounting plate. The bit sensor is connected to a bit sensor measuring block located on one side of the mechanism mounting plate. The relative displacement between the mechanism mounting plate and the mechanism support plate is detected by the compression amount of the bit sensor. By combining the data from the bottom surface sensor and the bit sensor, precise control of the primer insertion depth is achieved.

[0010] Furthermore, the stopping mechanism includes a stop baffle on the mechanism support plate and a buffer mounting plate on the surface of the base plate. The buffer is fixed on the buffer mounting plate, and the stop baffle and the buffer are in a front-to-back corresponding state. When the mechanism support plate moves forward, the stop baffle gradually touches the buffer, causing the mechanism support plate to stop.

[0011] The elastic compression mechanism includes a linear bearing mounted on the surface of the mechanism support plate and a retaining ring for fixing the linear bearing. The guide rod passes through the retaining ring and the linear bearing in sequence and is connected to a transmission spring. The other end of the transmission spring is connected to one end of the mechanism mounting plate.

[0012] The reducer is connected to the torque sensor via the first coupling, and the torque sensor is connected to the force transmission shaft via the second coupling. A limit ring is also provided on the outer wall of the force transmission shaft between the second coupling and the bearing mounting plate.

[0013] The three bottom sensors form an equilateral triangle through the contact points of the compressed and deformed bottom surface of the cartridge, and the screwdriver bit is located at the centroid of this equilateral triangle.

[0014] The tightening device provided by this invention operates as follows: A cylinder is activated, pushing the mounting plate and support plate closer to the bottom of the cartridge via the base plate guide rail; a stop block gradually contacts the buffer, restricting the support plate from moving forward; a compressed transmission spring provides power, pushing the mounting plate to move the tightening execution module forward via the support plate guide rail; a bit sensor detects the relative displacement between the mounting plate and support plate; a servo motor is activated, driving the bit sensor to slowly rotate forward via a reducer, first coupling, second coupling, and force transmission shaft, contacting the outer edge of the primer and completing the engagement; the tightening bit continuously drives the primer into the cartridge; a bottom sensor compresses and presses against the bottom of the cartridge, simulating a spatial plane to determine the reference position of the cartridge bottom; during tightening, the displacement between the bottom sensor and the tightening bit is monitored in real time, and combined with the detection data from the torque sensor, it is determined whether the tightening meets the standard; when both the displacement and torque values ​​reach the preset standard, the tightening operation is completed, and the mechanism resets.

[0015] Based on the aforementioned method for precise control of the tightening depth of the automated primer tightening equipment, this method relies on an automated primer tightening equipment that integrates depth measurement and tightening functions. The equipment's depth measurement reference and the manual depth measurement reference are unified to the entire bottom surface of the cartridge case. The primer insertion depth is directly controlled by the displacement value of a displacement sensor, combined with torque sensor-assisted control. Specifically, the method includes the following steps:

[0016] 1) Standardized Calibration: Unify the depth measurement datum of the tightening device with the manual depth measurement datum, using the entire bottom surface of the cartridge case as the detection datum; the tightening device is equipped with three bottom surface sensors and one tightening bit. The three bottom surface sensors are distributed in an equilateral triangle, and the tightening bit is located at the centroid of this equilateral triangle; a planar compression method is used to deform all three bottom surface sensors and the bit sensor, and the displacement values ​​of the four sensors at this time are recorded as a1, a2, a3, and b, respectively. Calculate the calibration value C based on the properties of the centroid of the triangle.

[0017] (1)

[0018] This completes the spatial plane calibration of the three bottom surface sensors and the bit sensor, placing them in the same spatial plane as the zero-point reference for tightening depth detection;

[0019] 2) Real-time calculation of tightening depth: After the three bottom surface sensors are compressed, the projection of the triangle formed by the contact points in space is still an equilateral triangle, and the center of gravity is on the same straight line as the calibration center of gravity; during the tightening measurement, the values ​​e1, e2, and e3 of the three bottom surface sensors and the value f of the bit sensor are collected in real time. Based on the properties of the triangle's center of gravity, combined with the calibration value C, the actual tightening depth D is calculated. (2)

[0020] Real-time quantitative detection of primer insertion depth;

[0021] 3) Multi-sensor collaborative control: The tightening device is controlled to tighten to the required position by three bottom surface sensors, a bit sensor, and a torque sensor. The three bottom surface sensors measure the relative displacement A between the virtual bottom surface reference plane and the bottom surface sensor mounting plate, and the bit sensor measures the relative screw-in amount B between the virtual bottom surface reference plane and the tightening bit. During the tightening process, the compression difference BA between the two displacement sensors is detected in real time, which is used as the core basis to directly control the screw-in depth of the primer. At the same time, the torque sensor detects the screw-in torque in real time, realizing the coordinated control of tightening depth and torque.

[0022] Furthermore, the coordinated control rule for tightening depth and torque in step 3) is as follows: the tightening torque is detected in real time by a torque sensor. When the torque reaches the set range, the equipment stops tightening and completes the primer assembly. If the tightening depth is close to the critical value and the torque has not reached the set range, the equipment stops tightening first. Tightening depth is the primary control indicator to avoid assembly defects caused by excessive tightening.

[0023] The aforementioned method for precise control of the tightening depth in the automated bottom-tightening equipment also includes a spatial error compensation step: The compression amounts of the three bottom surface sensors are ordered as large, medium, and small as m, l, and n, respectively, and the distance between two sensors is s; the three-dimensional coordinates of the contact points of the three bottom surface sensors are determined, assuming the coordinates of the three points are (m, ..., n). ,0), (l,0, ), (n, Based on the coordinates of the three points mentioned above, the normal vector of the plane at the contact point is determined as follows:

[0024] = (3)

[0025] The normal vector of the bottom surface of the cartridge case, i.e., the xoy plane, is: =(0, 0, 1), the normal vectors of the imaginary reference planes of the three bottom sensors are: = (1,0,0); Calculate the angles between the contact plane and the bottom surface of the cartridge case and the imaginary reference plane, respectively. , ;

[0026] (4)

[0027] (5)

[0028] From equations (4) and (5), we get:

[0029] (6)

[0030] (7)

[0031] Let the error compensation value be q, and the bit radius be r; calculate the error compensation value based on the two angles. ,because This indicates whether the angle between the plane and the base is acute or obtuse; therefore, the ± sign of q is determined by... It was decided to incorporate the compensation value q into the calculation of the tightening depth D to correct the calculation error caused by the spatial plane deviation.

[0032] Considering that the screwdriver bit is cylindrical, approximating it as the center of gravity will cause calculation errors, and the unevenness at the bottom of the cartridge will cause deviations in the plane determined by the sensor. Therefore, a three-dimensional coordinate system is established through a spatial error compensation step to compensate for the error.

[0033] The above-mentioned method for precise control of the tightening depth of the automated primer tightening equipment transforms the bottom surface reference of the cartridge case to the simulated plane of the bottom sensor during operation, and transforms the outer circle reference of the primer to the top of the tightening bit, so that all tightening reference points are transformed to the tightening equipment itself.

[0034] The tightening device provided in this invention has the following advantages: it significantly improves safety by replacing manual operation with automated equipment, avoiding damage to the primer during manual disassembly and tightening, eliminating safety hazards caused by misoperation, and improving the inherent safety of the production line.

[0035] Assembly accuracy and pass rate are improved. By using a bottom surface sensor to simulate the reference plane at the bottom of the cartridge case and a displacement sensor to directly control the screwing depth, the problem of unreliable indirect depth control due to poor workpiece consistency is solved. At the same time, the torque sensor monitors the tightening torque in real time to ensure that the primer exit torque meets the requirements. Dual control enables high-precision assembly and significantly reduces the defect rate.

[0036] Increased production efficiency and automated operations eliminate the need for manual intervention in disassembly and reassembly processes, shortening the assembly cycle and adapting to the needs of mass production.

[0037] The structure is stable and reliable. The guide buffer module and the power transmission module work together to ensure smooth operation of the mechanism, reduce the impact of vibration and impact on assembly accuracy, and extend the service life of the equipment.

[0038] The beneficial effects of the precise control method for tightening depth provided in this invention are as follows: it realizes direct control of tightening depth, unifies the depth measurement benchmark with the manual benchmark, and directly calculates and controls the primer screwing depth through a displacement sensor, which completely solves the problem of poor reliability of torque-indirect control of tightening depth in the prior art, and effectively avoids assembly deviations caused by poor consistency of cartridge, primer, and gasket workpieces.

[0039] To improve the assembly qualification rate, a multi-sensor collaborative control strategy is adopted, with tightening depth as the primary control indicator and torque as the auxiliary indicator. This achieves dual control of tightening depth and torque, avoiding the defects of single indicator control, significantly improving the primer assembly qualification rate and reducing the product rework rate.

[0040] The equipment integration is improved by integrating depth measurement and tightening functions into the tightening equipment. There is no need for manual addition of shims, which reduces manual operation, reduces human error, and improves the automation level and production efficiency of the production line.

[0041] By reducing safety risks and minimizing the manual disassembly and reassembly of defective products, safety hazards caused by bumping the primer are avoided. At the same time, precise control of the tightening depth prevents safety problems caused by improper primer assembly, thus achieving inherent safety on the production site.

[0042] It has error compensation capability, establishes a spatial error compensation model in a three-dimensional coordinate system, corrects the calculation error caused by the cylindrical structure of the bit and the unevenness of the bottom of the cartridge, and further improves the control accuracy of the tightening depth. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the structure of the present invention.

[0044] Figure 2 for Figure 1 A schematic diagram of the three-dimensional structure.

[0045] Figure 3 for Figure 1 A schematic diagram of the three-dimensional structure on the back.

[0046] Appendix Figure 1-3 In this structure, the components are: 1. Drive cylinder; 2. Servo motor; 3. Reducer; 4. Reducer mounting plate; 5. First coupling; 6. Torque sensor; 7. Second coupling; 8. Force transmission shaft; 9. Limit ring; 10. Bearing mounting plate; 11. Thrust bearing; 12. Bottom surface sensor mounting plate; 13. Bottom surface sensor; 14. Tightening bit; 15. Floating joint; 16. Guide rod; 17. Fixed ring; 18. Linear bearing; 19. Transmission spring; 20. Bit sensor; 21. Bit sensor mounting plate; 22. Bit sensor measuring block; 23. Stop block; 24. Buffer; 25. Buffer mounting plate; 26. Base plate; 27. Base plate guide rail; 28. Mechanism support plate; 29. ​​Support plate guide rail; 30. Mechanism mounting plate. Detailed Implementation

[0047] 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.

[0048] Appendix Figure 1-3 This is an embodiment of the present invention, disclosing a tightening device for automatic assembly of primers for cartridge cases, including a base plate 26, a power drive module, a tightening execution module, and a positioning detection module. These modules work together to achieve automatic positioning, precise tightening, and parameter monitoring of the primer. The power drive module includes a push cylinder 1, a base plate guide rail 26, and a stop mechanism, all disposed on the surface of the base plate 26. The push cylinder 1 is connected to a mechanism support plate 28 via a floating joint 15, providing thrust for the mechanism support plate 28 to move forward. The mechanism support plate 28 is placed on the base plate guide rail 26, and the push cylinder 1 drives the mechanism support plate 28 to move forward on the base plate guide rail 26. The surface of the mechanism support plate 28 is provided with supports... The support plate guide rail 29 and the elastic compression mechanism are provided. The support plate guide rail 29 is provided with a mechanism mounting plate 30 connected to one end of the elastic compression mechanism. The elastic compression mechanism includes a linear bearing 18 provided on the surface of the mechanism support plate 28 and a fixing ring 17 for fixing the linear bearing 18. The guide rod 16 passes through the fixing ring 17 and the linear bearing 18 in sequence and is supported by a transmission spring 19. The other end of the transmission spring 19 is connected to one end of the mechanism mounting plate 30. The guide rod 16 carries the transmission spring 19 and can limit its longitudinal displacement. The fixing ring 17 is provided to limit the spring compression and the disengagement of the guide rod 16. The linear bearing 18 is fixed to the surface of the mechanism support plate 28 to realize the smooth guidance of the guide rod 16.

[0049] The stopping mechanism is used to limit the forward movement of the mechanism support plate 28. The stopping mechanism includes a stopping baffle on the mechanism support plate 28 and a buffer 24 mounting plate on the surface of the base plate 26. The buffer 24 is fixed on the buffer 24 mounting plate. The stopping baffle and the buffer 24 are in a front-to-back corresponding state. When the mechanism support plate 28 moves forward, the stopping baffle gradually touches the buffer 24, causing the mechanism support plate 28 to stop. The buffer 24 is used to buffer the impact force when the mechanism support plate 28 moves forward. The stopping block 23 is used to limit the maximum stroke of the mechanism support plate 28.

[0050] The tightening execution module includes a reducer mounting plate 4, a torque sensor 6, and a bearing mounting plate 10, all mounted on the surface of the mechanism mounting plate. The servo motor 2 is connected to the reducer 3, which is fixed on the reducer mounting plate 4, providing controllable power, torque output, and speed adjustment for primer tightening. The thrust bearing 11 is fixed on the bearing mounting plate 10. The output end of the reducer 3 is connected to one end of the torque sensor 6, and the other end of the torque sensor 6 is connected to one end of the thrust bearing 11 via a connecting force transmission shaft 8, realizing power transmission and correcting the misalignment between the two shafts. The force transmission shaft 8 is also connected to a tightening bit 14 at the front end of the thrust bearing 11, which is used to detect the dynamic and static torque during the tightening process in real time. The tightening bit 14 is adapted to the primer groove and is used to drive the primer into the cartridge.

[0051] The positioning detection module includes a bottom surface sensor mounting plate 12 fixed to one end of the mechanism support plate 28. Multiple bottom surface sensors 13 are mounted on the bottom surface sensor mounting plate 12. By contacting the bottom surface of the cartridge and compressing and deforming it, the sensors simulate a spatial plane to determine the reference position of the bottom of the cartridge. The bit sensor 20 is fixed to one side of the mechanism support plate 28 through the bit sensor mounting plate 20. The bit sensor 20 is connected to the bit sensor measuring block 22 located on one side of the mechanism mounting plate 20. The relative displacement between the mechanism mounting plate 30 and the mechanism support plate 28 is detected by the compression amount of the bit sensor 20. By combining the data from the bottom surface sensors 13 and the bit sensor 20, precise control of the primer insertion depth is achieved.

[0052] The reducer 3 is connected to the torque sensor 6 via the first coupling 5. The torque sensor 6 is connected to the force transmission shaft 8 via the second coupling 7. The outer wall of the force transmission shaft 8 is also provided with a limiting ring 9 between the second coupling 7 and the bearing mounting plate 10.

[0053] In the specific assembly of the embodiments of the present invention, the push cylinder 1 is fixed to the base plate 26; the output end of the push cylinder 1 is connected to the floating joint 15, the floating joint 15 is connected to the mechanism support plate 28, and the mechanism support plate 28 can slide along the base plate guide rail 27; the buffer mounting plate 25 is fixed to the base plate 26, and the buffer 24 is mounted on the buffer mounting plate 25, corresponding to the stop block 23, for limiting the stroke of the mechanism support plate 28 and buffering the impact force.

[0054] A linear bearing 18 and a bit sensor mounting plate 21 are installed on the mechanism support plate 28. A guide rod 16 passes through the linear bearing 18 and the transmission spring 19. One end of the transmission spring 19 is connected to the mechanism mounting plate 30, and the rear end is limited by a fixing ring 17. The bit sensor 20 is fixed to the bit sensor mounting plate 21, and the bit sensor measuring block 22 is fixed to one side of the mechanism mounting plate 30. The two work together to realize relative displacement detection.

[0055] The mechanism mounting plate 30 is fixed with a reducer mounting plate 4, a torque sensor 6, and a bearing mounting plate 10; the servo motor 2 is fixed to the reducer mounting plate 4 after being connected to the reducer 3; the output shaft of the reducer 3 is connected to the input end of the torque sensor 6 through a coupling 5, and the output end of the torque sensor 6 is connected to the force transmission shaft 8 through a coupling 7; the force transmission shaft 8 passes through the limit ring 9, the bearing mounting plate 10, and the thrust bearing 11 in sequence, and its front end is connected to the bit sensor 14; the bottom sensor mounting plate 12 is fixed to the mechanism support plate 28, and the bottom sensor 13 is installed on the bottom sensor mounting plate 12 and is set corresponding to the bottom of the cartridge.

[0056] The working process of this embodiment of the invention is as follows: After the device receives the start signal, it pushes the cylinder 1 to move, and pushes the mechanism support plate 28 to move along the bottom plate guide rail 27 towards the cartridge via the floating joint 15 until the stop block 23 contacts the buffer 24, and the mechanism support plate 28 stops moving; the push cylinder 1 continues to output thrust, which compresses the transmission spring 19, and then pushes the mechanism mounting plate 30 forward along the support plate guide rail 29. The bit sensor 20 detects the amount of movement of the mechanism mounting plate 30 by the relative displacement with the bit sensor measuring block 22.

[0057] Meanwhile, the bottom surface sensor 13 moves close to the bottom of the cartridge along with the mechanism support plate 28 and is compressed. The compression of the three bottom surface sensors 13 simulates the spatial plane at the bottom of the cartridge and determines the reference position. The servo motor 2 starts and outputs a stable torque after being reduced by the reducer 3. The torque is transmitted to the torque sensor 6 through the coupling 5. The torque sensor 6 detects the torque value in real time and provides feedback. The torque sensor 6 drives the tightening bit 14 to rotate through the coupling 7 and the force transmission shaft 8. After the tightening bit 14 approaches the outer edge of the primer and completes the engagement, the primer is slowly screwed into the cartridge.

[0058] During the tightening process, the bottom surface sensor 13 and the bit sensor 20 work together to detect the relative displacement between the tightening bit 14 and the bottom of the cartridge, and precisely control the depth of the primer insertion. When the torque value reaches the preset threshold and the displacement meets the requirements, the servo motor 2 stops working, pushes the cylinder 1 to reset, and completes one primer assembly operation.

[0059] The tightening depth is precisely controlled using the aforementioned tightening equipment, and the steps are as follows:

[0060] 1) Standardized Calibration: Fix the tightening equipment to the production frame. Use a standard flat block to compress the three bottom surface sensors 13 and the tightening bit 14 in a plane, so that all sensors produce uniform deformation. Record the displacement values ​​a1, a2, a3, and b of the four sensors at this time. Calculate the calibration value C based on the properties of the centroid of a triangle. Complete the spatial plane calibration of the sensor and the tightening bit 14, and determine the zero point for tightening depth detection.

[0061] 2) Cartridge positioning: The cartridge to be assembled is transported to the tightening station and accurately positioned. The cylinder 111 is pushed to provide thrust, which drives the mechanism support plate 28 to move forward along the bottom plate guide rail 27 until the stop block 23 contacts the buffer 24, and the mechanism support plate 28 completes the limit stop.

[0062] 3) Depth Measurement and Tightening Depth Calculation: The cylinder 1 continues to apply force, compressing the transmission spring 19 and pushing the mechanism mounting plate 30 forward along the guide rail until the three bottom surface sensors 13 are in close contact with the bottom surface of the cartridge and undergo compression deformation. The values ​​e1, e2, and e3 of the bottom surface sensors 13 and the value f of the bit sensor 20 are collected in real time. The actual tightening depth D is calculated based on the properties of the triangle's centroid. The error compensation value q is calculated using a three-dimensional coordinate system error compensation model, and the final tightening depth value is obtained by correction.

[0063] The above error compensation value is calculated as follows: The compression amounts of the three bottom surface sensors are ordered as large, medium, and small as m, l, and n, respectively; the distance between two sensors is s; the three-dimensional coordinates of the contact points of the three bottom surface sensors are determined, assuming the coordinates of the three points are (m, ..., n). ,0), (l,0, ), (n, Based on the coordinates of the three points mentioned above, the normal vector of the plane at the contact point is determined as follows:

[0064] = (3)

[0065] The normal vector of the bottom surface of the cartridge case, i.e., the xoy plane, is: =(0, 0, 1), the normal vectors of the imaginary reference planes of the three bottom sensors are: = (1,0,0); Calculate the angles between the contact plane and the bottom surface of the cartridge case and the imaginary reference plane, respectively. , ;

[0066] (4)

[0067] (5)

[0068] From equations (4) and (5), we get:

[0069] (6)

[0070] (7)

[0071] Let the error compensation value be q, and the bit radius be r; calculate the error compensation value based on the two angles. ,because This indicates whether the angle between the plane and the base is acute or obtuse; therefore, the ± sign of q is determined by... It was decided to incorporate the compensation value q into the calculation of the tightening depth D to correct the calculation error caused by the spatial plane deviation.

[0072] 4) Multi-sensor coordinated tightening: The tightening bit 14 starts and drives the primer to screw into the cartridge. The tightening device is controlled to tighten to the required position by three bottom surface sensors, a bit sensor, and a torque sensor. The three bottom surface sensors measure the relative displacement A between the virtual bottom reference surface and the bottom surface sensor mounting plate, and the bit sensor measures the relative screwing amount B between the virtual bottom reference surface and the tightening bit. During the tightening process, the compression difference BA between the two displacement sensors is detected in real time, and the primer screwing depth is tracked. The torque sensor 6 synchronously collects the screwing torque. When (BA) reaches the preset tightening depth and the torque enters the set range, the device immediately stops tightening. If the tightening depth is close to the critical value and the torque is still not up to standard, the device will stop tightening first, which is judged as abnormal torque and an alarm will be triggered.

[0073] 5) Assembly completion and reset: After the primer is tightened and assembled, push the cylinder 1 to reset, which will drive the mechanism mounting plate 30 and mechanism support plate 28 to retract. The bottom sensor 13 and the tightening bit 14 will be separated from the cartridge, completing one assembly process. Repeat the above steps after the next cartridge is delivered to the work station.

[0074] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An automated primer tightening device, characterized in that: It includes a base plate, a power drive module, a tightening execution module, and a positioning detection module. These modules work together to achieve automatic positioning, precise tightening, and parameter monitoring of the primer. The power drive module includes a push cylinder, a base plate guide rail, and a stop mechanism, all mounted on the surface of the base plate. The push cylinder is connected to the mechanism support plate via a floating joint. The mechanism support plate is placed on the guide rail. The push cylinder drives the mechanism support plate to move forward on the base plate guide rail. The stop mechanism is used to limit the forward movement of the mechanism support plate. The surface of the mechanism support plate is provided with a support plate guide rail and an elastic compression mechanism. The support plate guide rail is provided with a mechanism mounting plate connected to one end of the elastic compression mechanism. The tightening actuator includes a reducer mounting plate, a torque sensor, and a bearing mounting plate, all mounted on the surface of the mechanism mounting plate. A servo motor is connected to the reducer, which is fixed to the reducer mounting plate. A thrust bearing is fixed to the bearing mounting plate. The output end of the reducer is connected to one end of the torque sensor, and the other end of the torque sensor is connected to one end of the thrust bearing via a connecting force transmission shaft. A tightening bit is also connected to the front end of the thrust bearing on the force transmission shaft. The tightening bit is adapted to the primer groove and is used to drive the primer into the cartridge. The positioning and detection module includes a bottom surface sensor mounting plate fixed to one end of the mechanism support plate. Three bottom surface sensors are mounted on the bottom surface sensor mounting plate. By contacting the bottom surface of the cartridge and compressing and deforming it, the sensors simulate a spatial plane to determine the reference position of the bottom of the cartridge. The bit sensor is fixed to one side of the mechanism support plate through the bit sensor mounting plate. The bit sensor is connected to a bit sensor measuring block located on one side of the mechanism mounting plate. The relative displacement between the mechanism mounting plate and the mechanism support plate is detected by the compression amount of the bit sensor. By combining the data from the bottom surface sensor and the bit sensor, precise control of the primer insertion depth is achieved.

2. The automated primer tightening device according to claim 1, characterized in that: The stopping mechanism includes a stop block on the mechanism support plate and a buffer mounting plate on the surface of the base plate. The buffer is fixed on the buffer mounting plate, and the stop block and the buffer are in a front-to-back correspondence. When the mechanism support plate moves forward, the stop block gradually touches the buffer, causing the mechanism support plate to stop.

3. The automated primer tightening device according to claim 1, characterized in that: The elastic compression mechanism includes a linear bearing mounted on the surface of the mechanism support plate and a retaining ring for fixing the linear bearing. The guide rod passes through the retaining ring and the linear bearing in sequence and is connected to a transmission spring. The other end of the transmission spring is connected to one end of the mechanism mounting plate.

4. The automated primer tightening device according to claim 1, characterized in that: The reducer is connected to the torque sensor via the first coupling, and the torque sensor is connected to the force transmission shaft via the second coupling. A limit ring is also provided on the outer wall of the force transmission shaft between the second coupling and the bearing mounting plate.

5. The automated primer tightening device according to claim 1, characterized in that: The three bottom sensors form an equilateral triangle through the contact points of the compressed and deformed bottom surface of the cartridge, and the screwdriver bit is located at the centroid of this equilateral triangle.

6. The method for precise control of the tightening depth of the above-mentioned automated primer tightening equipment is achieved by relying on an automated primer tightening equipment that integrates depth measurement and tightening functions, characterized in that: The depth measurement reference of the equipment and the manual depth measurement reference are unified to the entire bottom surface of the cartridge case. The depth of the primer insertion is directly controlled by the displacement value of the displacement sensor, combined with the auxiliary control of the torque sensor. The specific steps include: 1) Standardized Calibration: Unify the depth measurement datum of the tightening device with the manual depth measurement datum, using the entire bottom surface of the cartridge case as the detection datum; the tightening device is equipped with three bottom surface sensors and one tightening bit. The three bottom surface sensors are distributed in an equilateral triangle, and the tightening bit is located at the centroid of this equilateral triangle; a planar compression method is used to deform all three bottom surface sensors and the bit sensor, and the displacement values ​​of the four sensors at this time are recorded as a1, a2, a3, and b, respectively. Calculate the calibration value C based on the properties of the centroid of the triangle. （1） This completes the spatial plane calibration of the three bottom surface sensors and the bit sensor, placing them in the same spatial plane as the zero-point reference for tightening depth detection; 2) Real-time calculation of tightening depth: After the three bottom surface sensors are compressed, the projection of the triangle formed by the contact points in space is still an equilateral triangle, and the center of gravity is on the same straight line as the calibration center of gravity; during the tightening measurement, the values ​​e1, e2, and e3 of the three bottom surface sensors and the value f of the bit sensor are collected in real time. Based on the properties of the triangle's center of gravity, combined with the calibration value C, the actual tightening depth D is calculated. (2) Real-time quantitative detection of primer insertion depth; 3) Multi-sensor collaborative control: The tightening device is controlled to tighten to the required position by three bottom surface sensors, a bit sensor, and a torque sensor. The three bottom surface sensors measure the relative displacement A between the virtual bottom surface reference plane and the bottom surface sensor mounting plate, and the bit sensor measures the relative screw-in amount B between the virtual bottom surface reference plane and the tightening bit. During the tightening process, the compression difference BA between the two displacement sensors is detected in real time, which is used as the core basis to directly control the screw-in depth of the primer. At the same time, the torque sensor detects the screw-in torque in real time, realizing the coordinated control of tightening depth and torque.

7. The method for precisely controlling the tightening depth of the automated primer tightening device according to claim 6, characterized in that: The coordinated control rule for tightening depth and torque in step 3) is as follows: the tightening torque is detected in real time by a torque sensor. When the torque reaches the set range, the equipment stops tightening and the primer assembly is completed. If the tightening depth is close to the critical value and the torque has not reached the set range, the equipment stops tightening first. Tightening depth is the primary control indicator to avoid assembly defects caused by excessive tightening.

8. The method for precisely controlling the tightening depth of the automated primer tightening device according to claim 6, characterized in that... It also includes a spatial error compensation step: The compression amounts of the three bottom surface sensors are sorted in order of large, medium, and small as m, l, and n, respectively; the distance between two sensors is s; the three-dimensional coordinates of the contact points of the three bottom surface sensors are determined, assuming the coordinates of the three points are (m, ..., n). ,0), (l,0, ), (n, Based on the coordinates of the three points mentioned above, the normal vector of the plane at the contact point is determined as follows: = （3） The normal vector of the bottom surface of the cartridge case, i.e., the xoy plane, is: =(0, 0, 1), the normal vectors of the imaginary reference planes of the three bottom sensors are: = (1,0,0); Calculate the angles between the contact plane and the bottom surface of the cartridge case and the imaginary reference plane, respectively. , ; （4） （5） From equations (4) and (5), we get: （6） （7） Let the error compensation value be q, and the bit radius be r; calculate the error compensation value based on the two angles. ,because This indicates whether the angle between the plane and the base is acute or obtuse; therefore, the ± sign of q is determined by... It was decided to incorporate the compensation value q into the calculation of the tightening depth D to correct the calculation error caused by the spatial plane deviation.

9. The method for precisely controlling the tightening depth of the automated primer tightening device according to claim 6, characterized in that: The above-mentioned method for precise control of the tightening depth of the automated primer tightening equipment transforms the bottom surface reference of the cartridge case to the simulated plane of the bottom sensor during operation, and transforms the outer circle reference of the primer to the top of the tightening bit, so that all tightening reference points are transformed to the tightening equipment itself.

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