Instrument assembly automatic riveting device and control method thereof

Abstract

This invention relates to an automatic riveting device and its control method for instrument assembly, belonging to the technical field of instrument assembly equipment. It includes a riveting structure, a conveying and transfer structure with a placement seat, a follow-up positioning structure, and a pre-assembly structure. The conveying and transfer structure is provided with a loading station, a pre-assembly station, and a riveting station. The riveting structure is located at the riveting station, and the pre-assembly structure is located at the pre-assembly station. The pre-assembly structure is used to pre-install rivets into the mounting holes. The follow-up positioning structure includes a positioning rod passing through the placement seat and a sliding track for constraining the lifting and lowering stroke of the positioning rod. The sliding track has a high section and a low section. When the positioning rod moves with the placement seat to the loading station, the high section pushes the positioning rod out to limit and fix the assembly. When the positioning rod moves with the placement seat to the pre-assembly station, the low section allows the positioning rod to retract, providing clearance space for rivet insertion. This invention has the advantages of accurate mounting hole alignment and high riveting precision.

Description

Technical Field

[0001] This invention relates to the field of instrument assembly equipment technology, and in particular to an automatic riveting device for instrument assembly and its control method. Background Technology

[0002] A Bourdon tube pressure gauge is a commonly used pressure measuring instrument. It contains a Bourdon tube and a movement, which are fixed together by rivets inserted into mounting holes that are positioned opposite each other.

[0003] In the automated riveting process of the Bourdon tube pressure gauge, the components to be assembled are continuously moved along with the conveyor. The placement position is restricted by locking the outer contour of the component. Then, the rivets are inserted into the corresponding mounting holes of the Bourdon tube and the movement and pressed tightly to make the Bourdon tube and the movement firmly connected, thus completing the riveting assembly operation between the two.

[0004] However, relying on the outer ring contour for positioning is prone to center offset and is subject to interference from shape tolerances, making it difficult to stably align with the mounting holes and ensuring the riveting accuracy of mass production. Summary of the Invention

[0005] To address the problems of inaccurate mounting hole alignment and low riveting precision, this invention provides an automatic riveting device for instrument assembly and its control method.

[0006] In a first aspect, the present invention provides an automatic riveting device for instrument assembly, which adopts the following technical solution: An automatic riveting device for instrument assembly includes a riveting structure for riveting rivets in mounting holes, and a conveying and transfer structure with a placement seat, a follow-up positioning structure, and a pre-assembly structure. The conveying and transfer structure is provided with a feeding station, a pre-assembly station, and a riveting station. The placement seat moves with the conveying and transfer structure and passes through the feeding station, the pre-assembly station, and the riveting station in sequence. The riveting structure is located at the riveting station, and the pre-assembly structure is located at the pre-assembly station. The pre-assembly structure is used to pre-assemble the rivets into the mounting holes. The follow-up positioning structure includes a positioning rod passing through the placement seat and a sliding rail for constraining the lifting stroke of the positioning rod. The positioning rod is used to pass through the mounting hole of the assembly to achieve centering and limiting. The sliding track has a high section and a low section. When the positioning rod moves with the placement seat to the loading station, the high section pushes out the positioning rod to limit and fix the assembly. When the positioning rod moves with the placement seat to the pre-assembly station, the low section provides clearance space for the positioning rod to retract into the rivet insertion.

[0007] By adopting the above technical solution, the high and low sections of the sliding track are used to control the lifting and lowering of the positioning rod. The assembly parts are centered and limited at the loading station, and the rivets are retracted and avoided at the pre-assembly station. The holes are coaxially positioned from the inside of the mounting holes, thereby improving the alignment accuracy and riveting accuracy of the mounting holes.

[0008] Optionally, the follow-up positioning structure further includes a guide rod passing through the placement seat and a pulley connected to the positioning rod and the guide rod; The guide rod is arranged parallel to the positioning rod to provide guidance and limit for the reciprocating sliding of the positioning rod, and the pulley is in rolling contact with the sliding track.

[0009] By adopting the above technical solution, the positioning rod is constrained to slide vertically by parallel guide rods, and the rolling contact between the pulley and the sliding track is used to reduce motion friction and reduce the probability of jamming when the positioning rod is raised or lowered.

[0010] Optionally, a rivet supply structure is provided on one side of the pre-assembly station, and a rivet supply station is provided on the rivet supply structure. The pre-assembly structure transfers the rivets on the rivet supply station to the assembly at the pre-assembly station. The rivet supply structure includes a rivet arrangement assembly, a feeding turntable, and a detection assembly. The feeding turntable has several hook slots for the rivets fed by the rivet arrangement assembly to be placed into. The hook slots rotate with the feeding turntable and pass through the rivet supply station in sequence. The detection assembly is set on the side of the rivet supply station to detect the positioning status of the rivets and ensure that there are always rivets to be picked up at the rivet supply station.

[0011] By adopting the above technical solution, the rivets are cyclically carried by the mounting groove on the surface of the feeding turntable, while the positioning status of the rivets is detected in real time by the detection component on the side, ensuring a stable supply of rivets and preventing pre-assembly failure due to missing rivets at the rivet supply station.

[0012] Optionally, the conveying and transfer structure is further provided with a pressing structure, which corresponds one-to-one with the placement seat and is located on one side of the placement seat; The clamping structure includes a clamping block and a tension spring. The clamping structure has a loosened state and a pressed state. When the tension spring is in the pressed state, it has a pulling force that drives the clamping block to abut against the assembly.

[0013] By adopting the above technical solution, the tension provided by the tension spring drives the clamping block to press and fix the assembly, so that the assembly is not easy to shift or deviate during the transportation of the placement seat. The structure is compact and can move synchronously with the placement seat.

[0014] Optionally, the conveying and transfer structure is further provided with a material unloading station, and the material unloading station is provided with a material unloading structure; The unloading structure includes an unlocking push block and a clamping assembly. The unlocking push block slides along the direction close to the clamping block to drive the clamping block to overcome the tension of the tension spring, thereby releasing the clamping block from pressing the assembly. The clamping assembly is used to automatically unload the assembly at the unloading station.

[0015] By adopting the above technical solution, the unlocking pusher pushes the clamping block laterally to overcome the tension of the tension spring and completes the unlocking. Then, the clamping assembly completes the picking and unloading of the assembly, automatically releasing the clamping limit of the assembly, realizing the automated unloading of the finished assembly without manual operation.

[0016] Secondly, this application provides a control method for an automatic riveting device for instrument assembly, which adopts the following technical solution: A control method for an automatic riveting device for instrument assembly, applied to an automatic riveting device for instrument assembly as described in the first aspect, comprising: S10: In response to a pre-installed signal, measure the obstruction distance above the positioning rod using a distance measuring structure pre-installed on the upper end of the positioning rod; S11: Obtain the standard distance between the upper end of the positioning rod and the rivet to be installed when the positioning rod is in the low position. S12: Determine the current installation status of the component based on the relationship between the obstruction distance and the standard distance. The installation status includes whether the mounting hole is not offset or the mounting hole is offset. S13: Based on the fact that the mounting hole is not offset, control the pre-assembled structure to execute a preset feeding command to insert the rivet into the mounting hole; S14: Based on the offset of the mounting hole, control the correction structure preset on the placement seat to push the assembly to correct its position; S15: After correction, control the pre-assembled structure to restart the execution of S11.

[0017] By adopting the above technical solution, the distance measuring structure at the upper end of the positioning rod is used to detect the obstruction distance between the upper end of the positioning rod and the obstacle. The size of the obstruction distance and the standard distance are used to determine whether the mounting holes of the two components of the assembly are coaxial. When the hole position is offset, the drive correction structure is used to finely adjust the position of the workpiece, thus ensuring the coaxiality of the mounting hole alignment.

[0018] Optionally, after obtaining the occlusion distance, the following can be included: S20: Obtain the thickness of the spring tube; S21: Determine the spring tube blocking distance and the movement blocking distance by combining the spring tube thickness and the preset retraction position of the positioning rod; S22: When the blocking distance is the same as the blocking distance of the spring tube, it is determined to be an overall offset; S23: Issue a skip signal to control subsequent structures to skip the processing of the current assembly, and at the same time issue an audible and visual alarm to remind manual adjustment; S24: When the obstruction distance is the same as the movement blocking distance, it is determined to be movement offset; S25: Based on the movement's blocking distance, control the positioning lever to rise and begin executing S14.

[0019] By adopting the above technical solution, the overall offset and the single offset of the movement can be distinguished by the blocking distance of the Bourdon tube and the blocking distance of the movement. Skip alarm or position correction can be performed for different situations to achieve classified processing of different situations.

[0020] Optionally, after obtaining the occlusion distance and standard distance, the following can be included: S30: Read the no-load distance for removing rivets from the standard distance; S31: When the obstruction distance is the same as the unloaded distance, read the sliding distance of the pre-installed structure; S32: If the sliding distance is consistent with the preset reference distance, it is determined that the rivet has fallen off; S33: Control the conveying and transfer structure to suspend operation, and then control the pre-assembled structure to grab it again.

[0021] By adopting the above technical solution, the missing status of rivets above the pre-assembly station can be initially identified by the no-load distance. The sliding distance can be further compared with the reference distance to determine whether the pre-assembly structure has slid into place, and then the rivet grabbing status can be determined. Depending on the situation, the conveying and transfer structure can be paused in time and the rivets can be picked up again.

[0022] Optionally, after reading the sliding distance of the pre-assembled structure, the following may also be included: S40: If the sliding distance is inconsistent with the reference distance, collect the adsorption pressure used to grab the rivets in the pre-assembled structure. S41: When the adsorption pressure is consistent with the preset negative pressure threshold, it is determined that the sliding is not in place; S42: Control the pre-assembled structure to reset and slide again, and re-execute S30; S43: When the adsorption pressure is inconsistent with the negative pressure threshold, it is determined that the rivet has fallen off, and the process jumps to execute S33.

[0023] By adopting the above technical solution, the adsorption pressure of the floating vacuum nozzle is used to distinguish between two types of faults: misalignment and rivet detachment. Then, the pre-assembled structure is reset and repositioned or re-fed, which improves the accuracy of equipment fault identification.

[0024] Optionally, after the assembly is moved to perform positional correction, the following may also be included: S50: In response to the correction completion signal, the movement thickness is obtained and the assembly thickness is calculated by combining the Bourdon tube thickness; S51: Control the rise of the positioning rod based on the thickness of the assembly; S52: Simultaneously send a trigger signal to control the pre-installed structure to restart the execution of S11; S53: Collect the interval distance above the positioning rod; S54: When the interval distance is consistent with the preset bonding distance, determine and execute the synchronous command to control the positioning rod to descend according to the feeding command.

[0025] By adopting the above technical solution, the overall thickness of the assembly is calculated using the thickness of the spring tube and the movement, thereby limiting the upward stroke of the positioning rod. After the distance is measured to reach the fitting distance, the positioning rod is retracted synchronously to avoid the rivet pressing channel and prevent the rod from hitting the rivet. At the same time, the state of the assembly is restricted throughout the entire rivet insertion process, further reducing the probability of misalignment of the mounting hole.

[0026] In summary, the present invention has at least one of the following beneficial technical effects: By using the high and low sections of the sliding track to control the lifting and lowering of the positioning rod, the assembly parts are centered and limited at the loading station, and the rivets are retracted and avoided at the pre-assembly station. Coaxial positioning of the holes is achieved from the inside of the mounting holes, thereby improving the alignment accuracy and riveting accuracy of the mounting holes. The distance measuring structure at the upper end of the positioning rod is used to detect the obstruction distance between the upper end of the positioning rod and the obstacle. The difference between the obstruction distance and the standard distance is used to determine whether the mounting holes of the two components of the assembly are coaxial. When the hole position is offset, the drive correction structure is used to finely adjust the position of the workpiece to ensure the coaxiality of the mounting hole alignment. The overall thickness of the assembly is calculated using the thickness of the spring tube and the movement, thereby limiting the upward stroke of the positioning rod. After the distance is measured to reach the fitting distance, the positioning rod is retracted synchronously to avoid the rivet pressing channel and prevent the rod from hitting the rivet. At the same time, the state of the assembly is restricted throughout the entire rivet insertion process, further reducing the probability of misalignment of the mounting hole. Attached Figure Description

[0027] Figure 1 This is a structural schematic diagram of an automatic riveting device for instrument assembly according to this application; Figure 2 This is a partial disassembly diagram of an automatic riveting device for instrument assembly according to this application; Figure 3 This is a schematic diagram of the placement seat and clamping structure of an automatic riveting device for instrument assembly according to this application; Figure 4 This is a partial schematic diagram of an automatic riveting device for instrument assembly according to this application. Figure 1 ; Figure 5 yes Figure 4 Enlarged view of point A in the middle; Figure 6This is a partial schematic diagram of an automatic riveting device for instrument assembly according to this application. Figure 2 .

[0028] The parts referred to by the numbers in the above attached diagrams are as follows: 1. Conveying and transferring structure; 11. Rotary table; 12. Placement seat; 13. Loading station; 14. Inspection station; 15. Pre-assembly station; 16. Riveting station; 17. Unloading station; 2. Clamping structure; 21. Mounting seat; 22. Clamping block; 23. Tension spring; 24. Connecting rod; 3. Follow-up positioning structure; 31. Positioning rod; 32. Sliding track; 321. High section; 322. Low section; 33. Guide rod; 34. Pulley; 4. Infrared detection structure; 5. Rivet supply structure; 51. Rivet arrangement assembly; 52. Feeding turntable; 521. Hanging groove; 53. Detection assembly; 54. Rivet supply station; 6. Pre-assembly structure; 7. Riveting structure; 8. Unloading structure; 81. Unlocking assembly; 811. Unlocking push block; 812. Drive cylinder; 82. Clamping assembly. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0030] This invention discloses an automatic riveting device for instrument assembly.

[0031] Reference Figure 1 An automatic riveting device for instrument assembly includes a conveying and transfer structure 1, a pressing structure 2, a follow-up positioning structure 3, an infrared detection structure 4, a pre-assembly structure 6, a nail supply structure 5, a riveting structure 7, and a material unloading structure 8; the pressing structure 2 is installed on the conveying and transfer structure 1, and the infrared detection structure 4, the pre-assembly structure 6, the nail supply structure 5, the riveting structure 7, and the material unloading structure 8 are arranged sequentially next to the conveying and transfer structure 1.

[0032] Reference Figure 2 and Figure 3 The conveying and transfer structure 1 includes a rotary table 11 and a placement seat 12. There are six placement seats 12, which are evenly arranged around the circumference of the rotary table 11. The placement seats 12 are fixedly installed on the upper surface of the rotary table 11 by bolts and are used to place the assembly parts. Starting from the stopping position of the foremost placement seat 12, the loading station 13, the inspection station 14, the pre-assembly station 15, the riveting station 16, and the unloading station 17 are arranged in a clockwise direction. There are two consecutive pre-assembly stations 15.

[0033] The follow-up positioning structure 3 includes a positioning rod 31, a sliding rail 32, a guide rod 33, and a pulley 34. Six sets of positioning rods 31, guide rods 33, and pulleys 34 are arranged in a one-to-one correspondence with the placement seat 12. Each set of positioning rods 31, guide rods 33, and pulleys 34 has two mounting holes corresponding to the mounting parts. The pulley 34 is rotatably connected to the lower ends of the positioning rods 31 and guide rods 33 in the same set. The positioning rods 31 and guide rods 33 are vertically inserted through the rotary table 11 and the placement seat 12. The sliding rail 32 is arranged in a ring below the rotary table 11. There are two coaxial inner and outer sections, and the two pulleys 34 in the same group are respectively in rolling contact with the two sliding rails 32. The sliding rails 32 are provided with a high section 321 and a low section 322. The low section 322 of the outer sliding rail 32 extends from the pre-assembly station 15 in front to the unloading station 17, and the rest of the position is the high section 321. The low section 322 of the inner sliding rail 32 extends from the pre-assembly station 15 in rear to the unloading station 17, and the rest of the position is the high section 321. The tail end of the low section 322 is smoothly connected to the head end of the high section 321.

[0034] Six clamping structures 2 are provided in a one-to-one correspondence with the placement base 12. The clamping structure 2 is located on the side of the placement base 12 near the center of the rotary table 11. The clamping structure 2 includes a mounting base 21, a clamping block 22, a tension spring 23, and a connecting rod 24. The mounting base 21 is L-shaped, and the clamping block 22 is V-shaped and rotatably mounted on the inner side wall of the mounting base 21. One end of the clamping block 22 abuts against the corresponding fitting on the placement base 12, and the other end of the clamping block 22 is fixedly connected to the connecting rod 24. The connecting rod 24 is horizontally arranged, and one end of the connecting rod 24 is hooked to one end of the tension spring 23. The other end of the connecting rod 24 is provided with a hand-held end, and the other end of the tension spring 23 is hooked to the outer side wall of the mounting base 21.

[0035] Reference Figure 4 and Figure 5 The infrared detection structure 4 is fixedly installed on the outside of the detection station 14. The infrared detection structure 4 adopts a diffuse reflection infrared photoelectric sensor, which is the existing technology. The detection position of the infrared photoelectric sensor is on the placement seat 12 of the detection station 14, and is used to determine whether there are assemblies to be riveted on the placement seat 12 of the loading station 13.

[0036] Two rivet supply structures 5 are provided corresponding to two pre-installed structures 6. The two rivet supply structures 5 are respectively installed on the outside of the rotary table 11. The rivet supply structure 5 includes a rivet arrangement assembly 51, a feeding turntable 52, and a detection assembly 53. The rivet arrangement assembly 51 adopts a rivet arrangement machine, which is existing technology. The feeding turntable 52 is rotatably installed between the rivet arrangement assembly 51 and the rotary table 11. Four hanging slots 521 are evenly opened along the circumference of the feeding turntable 52. The rivet arrangement assembly 51 feeds the rivets into the hanging slots 521 away from the rotary table 11. The feeding turntable 52 rotates clockwise to transfer the rivets to a position close to the rotary table 11. This position is the rivet supply station 54. The detection assembly 53 adopts a through-beam infrared photoelectric sensor. The transmitting unit and receiving unit of the through-beam infrared photoelectric sensor are located on both sides of the rivet supply station 54, respectively, to determine whether there are rivets to be taken in the hanging slots 521 corresponding to the rivet supply station 54.

[0037] There are two pre-installed structures 6 corresponding to the two rivet supply structures 5. The two pre-installed structures 6 are located above the two rivet supply structures 5 respectively. The pre-installed structure 6 consists of a lifting cylinder, a linear module, and a floating vacuum nozzle with a buffer compression spring, all of which are existing technologies. The lifting cylinder is fixedly installed at the output end of the linear module. The floating vacuum nozzle is connected to the output end of the lifting cylinder through the buffer compression spring and is connected by sliding rail. The linear module drives the lifting cylinder to slide back and forth above the rivet supply station 54 and the pre-installation station 15. The lifting cylinder drives the floating vacuum nozzle to slide up and down. The floating vacuum nozzle grabs the rivet by relying on negative pressure. When the floating vacuum nozzle moves down to absorb the rivet, the compression spring is compressed and contracts to buffer the rigid impact generated by the downward pressure of the lifting cylinder. The lifting cylinder, the linear module, and the floating vacuum nozzle work together to transport the rivets on the rivet supply station 54 to the mounting holes of the fittings on the pre-installation station 15 in sequence. The two pre-installed structures 6 are respectively used to install the rivets in the two mounting holes.

[0038] Reference Figure 6 The riveting structure 7 is installed at the riveting station 16. The riveting structure 7 consists of a pressing cylinder and a riveting punch, both of which are existing technologies. The riveting punch is fixedly installed at the output end of the pressing cylinder. The pressing cylinder drives the riveting punch to slide back and forth vertically. When the riveting punch moves down and fits against the two rivets in the fitting at the riveting station 16, it continues to apply pressure to squeeze the rivet ends to produce cold plastic upsetting deformation, forming a limiting rivet head locking fitting.

[0039] The unloading structure 8 includes an unlocking component 81 and a clamping component 82, both of which are installed at the unloading station 17. The unlocking component 81 is located in front of the clamping component 82 and avoids each other. The unlocking component 81 includes an unlocking push block 811 and a drive cylinder 812. The unlocking push block 811 is fixedly installed at the output end of the drive cylinder 812. The unlocking push block 811 is driven by the drive cylinder 812 to slide and drive the connecting rod 24 and the clamping block 22 to unlock in the opposite direction. The clamping component 82 clamps... The cylinder, lifting cylinder, and linear module are all existing technologies. The lifting cylinder is fixedly installed at the output end of the linear module, and the clamping cylinder is fixedly installed at the output end of the lifting cylinder. The linear module drives the lifting cylinder to slide back and forth above the unloading station 17 and the preset collection box. The lifting cylinder drives the clamping cylinder to move up and down. The clamping cylinder is used to clamp the riveted assembly. The lifting cylinder, linear module, and clamping cylinder work together to transport the assembly on the unloading station 17 to the collection box in sequence.

[0040] The movement and spring tube are respectively fitted onto the positioning rod 31 of the loading station 13 through the mounting holes. The movement and spring tube are located on the placement seat 12. The connecting rod 24 is manually pulled forward. The connecting rod 24 overcomes the tension of the tension spring 23 and drives the clamping block 22 to rotate. One end of the clamping block 22 abuts against the upper end face of the movement and spring tube. At this time, the tension spring 23 has the force to pull the connecting rod 24 and the clamping block 22 to continuously press the assembly, thereby locking and fixing the assembly. At this time, the clamping structure 2 is in the pressing state. The rotary table 11 is started. The rotary table 11 drives the placement seat 12 of the loading station 13 to move clockwise to the detection station 14 and stop. The infrared detection structure 4 at the detection station 14 detects... The system checks whether there are any assemblies on the corresponding placement seat 12. If there are assemblies, an execution signal is sent to the subsequent pre-assembly structure 6; if there are no assemblies, a pause signal is sent to the subsequent pre-assembly structure 6. The placement seat 12 with the assemblies continues to move to the first pre-assembly station 15. During the movement, the pulley 34 connected to the outer sliding rail 32 moves from the high section 321 to the low section 322. The pulley 34 moves downward and simultaneously drives the positioning rod 31 and the guide rod 33 to slide downward. The corresponding positioning rod 31 no longer passes through the mounting hole, leaving space for the subsequent insertion of rivets. The detection component 53 continuously detects whether there are rivets on the rivet supply station 54. If there are no rivets, the feeding turntable... 52. Rotate until the rivet-containing mounting slot 521 moves to the rivet supply station 54, while the rivet arrangement assembly 51 continuously supplies rivets to the mounting slot 521; activate the pre-assembly structure 6 to transfer the rivets on the rivet supply station 54 to one of the mounting holes of the assembly for insertion; the placement seat 12 continues to move to the second pre-assembly station 15, the pulley 34 connected to the inner sliding rail 32 moves from the high section 321 to the low section 322, the positioning rod 31 in the other mounting hole moves down to reserve space for subsequent rivet insertion, the rivet supply structure 5 and the pre-assembly structure 6 at the second pre-assembly station 15 are the same as the above steps, so that rivets are placed in both mounting holes of the assembly; the placement block continues The assembly continues to move to the riveting station 16. The riveting structure 7 squeezes the rivets in the two mounting holes to produce cold plastic upsetting deformation, forming a limiting rivet head locking assembly. The riveted assembly moves with the placement seat 12 to the unloading station 17. The drive cylinder 812 drives the unlocking push block 811 to fit against the connecting rod 24 and continuously apply a pushing force. The connecting rod 24 overcomes the tension of the tension spring 23 and drives the clamping block 22 to rotate backward, so that the tension of the tension spring 23 no longer drives the clamping block 22 to press down, thereby unlocking the assembly. At this time, the clamping structure 2 is in the loosened state. The control clamping assembly 82 clamps the assembly and transfers it to the collection box, completing the complete automated riveting process.

[0041] Based on the same inventive concept, embodiments of the present invention provide a control method for an automatic riveting device for instrument assembly.

[0042] A control method for an automatic riveting device for instrument assembly includes the following steps: S10: In response to the pre-installed signal, the obstruction distance above the positioning rod 31 is measured by the distance measuring structure preset on the upper end of the positioning rod 31.

[0043] The pre-installation signal refers to the signal emitted when the pre-installation structure 6 grabs the rivet and moves it directly above the assembly. The displacement of the linear module is determined by the displacement encoder pre-installed on the linear module of the pre-installation structure 6. When the sliding position is determined, the pre-installation signal is automatically emitted.

[0044] The ranging structure refers to the distance sensor fixedly mounted on the upper end of the positioning rod 31, with its detection surface facing vertically upward, used to locate the vertical distance of the obstruction above the positioning rod 31.

[0045] The obstruction distance refers to the distance between the upper end face of the positioning rod 31 and the obstruction above it; the obstruction distance is obtained in real time through the ranging structure.

[0046] S11: Obtain the standard distance between the upper end of the positioning rod 31 and the rivet to be installed when the positioning rod 31 is in the low position 322.

[0047] The standard distance refers to the distance between the upper end face of the positioning rod 31 and the lower end face of the rivet when the positioning rod 31 is in the low position section 322 and the rivet is moved by the pre-installed structure 6 to stay directly above the positioning rod 31. The standard distance is obtained by the operator in advance by actually measuring the distance under standard working conditions based on the position of the positioning rod 31 in the low position section 322, the length of the rivet, and the height at which the pre-installed structure 6 adsorbs the rivet.

[0048] S12: Determine the current installation status of the component based on the relationship between the obstruction distance and the standard distance. The installation status includes whether the mounting hole is not offset or the mounting hole is offset.

[0049] The placement state refers to the coaxial alignment of the stacked Bourdon tubes with the movement, including two types: no offset mounting holes and offset mounting holes. The standard distance range is determined based on the standard distance and the preset redundancy distance. When the obstruction distance falls within the standard distance range, it is determined that the obstruction distance is consistent with the standard distance, that is, the placement state at this time is no offset mounting holes. When the obstruction distance does not fall within the standard distance range, it is determined that the obstruction distance is inconsistent with the standard distance, that is, the placement state at this time is offset mounting holes.

[0050] When the assembly moves from the inspection station 14 to the first pre-assembly station 15, one of the positioning rods 31 retracts. At this time, the Bourdon tube and the movement can rotate around the other positioning rod 31 as the axis. When the assembly moves from the first pre-assembly station 15 to the second pre-assembly station 15, both positioning rods 31 retract. A rivet is inserted in one of the positioning rods 31. At this time, the Bourdon tube and the movement can rotate around the rivet as the axis. There is a possibility of misalignment of the mounting hole.

[0051] S13: Based on the fact that the mounting hole is not offset, control the pre-assembled structure 6 to execute the preset feeding command to insert the rivet into the mounting hole.

[0052] The material release command refers to the control command that controls the lifting cylinder of the pre-assembled structure 6 to drive the floating vacuum nozzle down to the fitting part and close the negative pressure of the floating vacuum nozzle, releasing the rivet so that the rivet passes through the mounting hole. The material release command is obtained by the operator in advance according to the position settings of the pre-assembled structure 6 and the placement seat 12, and is entered into the system. It can be directly read when in use.

[0053] S14: Based on the offset of the mounting hole, control the correction structure preset on the placement seat 12 to push the assembly to perform position correction.

[0054] The correction structure refers to the combined structure consisting of a correction rod and a micro stepper motor set on the placement base 12. The micro stepper motor controls the rotation of the correction rod. The correction rod and the movement are located on the same horizontal plane. The micro stepper motor controls the rotation angle of the correction rod to push the movement for correction. The pre-stored correction angle is directly retrieved based on the model of the movement. The correction rod executes from both sides according to the correction angle to ensure that the movement is in the standard position, thereby achieving correction.

[0055] S15: After correction, control the pre-installed structure 6 to restart the execution of S11.

[0056] After obtaining the occlusion distance, the following steps are included: S20: Obtain the thickness of the spring tube.

[0057] The thickness of the spring tube refers to the vertical thickness of the spring tube along the lifting direction of the positioning rod 31. The thickness of the spring tube is obtained by the operator in advance by actually measuring the thickness of the standard spring tube and entering it into the system. It can be retrieved directly when in use.

[0058] S21: Determine the blocking distance of the spring tube and the blocking distance of the movement by combining the thickness of the spring tube and the preset retraction position of the positioning rod 31.

[0059] The retracted position refers to the position where the positioning rod 31 is after it retracts by following the pulley 34 and moving downward along the sliding track 32. The height of the retracted position is determined in advance by the operator based on the height of the positioning rod 31 and the vertical height of the lower section 322 of the sliding track 32, using the mounting bottom surface of the sliding track 32 as the reference surface.

[0060] At the same time, fixed parameters such as the height of the upper end face of the placement seat 12 and the height of the lower end face of the floating vacuum nozzle can be measured based on the same reference plane, providing a basis for subsequent calculations.

[0061] The spring tube blocking distance refers to the distance between the upper end face of the positioning rod 31 and the spring tube when the spring tube is offset, causing the mounting hole of the spring tube to be misaligned. At this time, the upper obstruction of the positioning rod 31 is the spring tube, and the spring tube is placed on the placement seat 12. Therefore, the spring tube blocking distance is the distance between the retracted position of the positioning rod 31 and the upper end face of the placement seat 12. The spring tube blocking distance is calculated by combining the height of the upper end face and the height value in the retracted position.

[0062] The movement blocking distance refers to the distance between the upper end face of the positioning rod 31 and the movement when the Bourdon tube is not offset but the movement is offset. At this time, the object blocking the positioning rod 31 is the movement, and the movement is placed close to the Bourdon tube. Therefore, the movement blocking distance can be calculated by summing the Bourdon tube blocking distance and the thickness of the Bourdon tube.

[0063] S22: When the blocking distance is the same as the blocking distance of the spring tube, it is determined to be an overall offset.

[0064] The obstruction distance is the same as the blocking distance of the Bourdon tube, which means that the obstruction above the positioning rod 31 is the Bourdon tube. It is determined that at least the Bourdon tube has shifted at this time. Since the movement is placed on top of the Bourdon tube, it can be directly determined that the entire movement has shifted.

[0065] Overall misalignment means that the Bourdon tube and the upper movement have both shifted. Since the misalignment between the two components is unclear at this time, it cannot be corrected by pushing laterally alone and requires manual intervention.

[0066] S23: Issue a skip signal to control subsequent structures to skip processing of the current assembly, and simultaneously issue an audible and visual alarm to remind manual adjustment.

[0067] The skip signal refers to a signal that the control conveyor structure 1 will not process the assembly when it passes through the subsequent pre-assembly station 15, riveting station 16 and unloading station 17. The operator needs to wait for the assembly to be corrected or replaced at the loading station 13. When the assembly is determined to be in an overall offset state, the system will automatically generate and issue a skip signal.

[0068] Audible and visual alarms refer to the simultaneous activation of a buzzer and a warning light to remind operators to manually correct misaligned parts; when the system generates a skip signal, it automatically sends a signal to the preset warning light and buzzer, causing the warning light to flash and the buzzer to emit a prompt sound, which is an audible and visual alarm.

[0069] S24: When the obstruction distance is the same as the movement blocking distance, it is determined to be movement offset.

[0070] If the obstruction distance is the same as the movement blocking distance, it means that the obstruction above the positioning rod 31 is the movement. It is determined that the spring tube has not shifted, but the movement has shifted. Therefore, the movement is determined to be shifted. The movement blocking distance range is set according to the redundancy distance and the movement blocking distance. When the obstruction distance falls into the movement blocking distance range, it is determined that the obstruction distance is the same as the movement blocking distance.

[0071] Movement misalignment refers to a situation where the mounting holes of the Bourdon tube are in the correct position, but the mounting holes of the movement itself are misaligned. This can be corrected using a correction structure.

[0072] S25: Based on the movement blocking distance, control the positioning rod 31 to rise and begin executing S14.

[0073] The lifting structure, pre-set below the pre-assembly station 15, pushes the positioning rod 31 upward, causing the positioning rod 31 to move upward by the mechanism blocking distance. The execution distance is obtained by summing the fixed distance between the output end of the lifting structure and the lower end of the positioning rod 31 with the mechanism blocking distance. Based on this execution distance, the lifting structure is controlled to execute, thus controlling the positioning rod 31 to rise by the mechanism blocking distance. After rising, the positioning rod 31 just passes through the spring tube and contacts the lower end face of the mechanism. At this time, the corrective structure is controlled to push the mechanism without affecting the position of the spring tube itself.

[0074] The lifting structure refers to a combined structure consisting of a lifting block and a lifting cylinder, which is set below the pre-assembly station 15. The lifting cylinder drives the lifting block to move in the vertical direction. When the lifting block rises, it abuts against the positioning rod to control the lifting and lowering of the positioning rod.

[0075] After obtaining the occlusion distance and standard distance, the following steps are included: S30: Read the no-load distance for removing rivets from the standard distance.

[0076] The no-load distance refers to the standard distance between the upper end of the positioning rod 31 in the lower section 322 and the floating vacuum nozzle when the floating vacuum nozzle does not hold any rivets. The distance under standard working conditions is actually measured by the operator in advance based on the position of the positioning rod 31 in the lower section 322 and the height of the floating vacuum nozzle.

[0077] S31: When the obstruction distance is the same as the unloaded distance, read the sliding distance of the pre-installed structure 6.

[0078] If the obstruction distance is the same as the no-load distance, it means that the floating vacuum nozzle located above the assembly has not caught the rivet. However, there is also the possibility that the floating vacuum nozzle has not moved completely above the positioning rod 31. Further judgment is needed. The no-load distance range is set according to the redundancy distance and the no-load distance. When the obstruction distance falls into the no-load distance range, it is determined that the obstruction distance is the same as the no-load distance.

[0079] The sliding distance refers to the displacement value by which the linear module of the pre-installed structure 6 drives the floating vacuum nozzle to move from the nail supply station 54 to the pre-installation station 15; the number of pulses is recorded in real time by the encoder pre-set in the linear module and converted into the actual moving distance, i.e., the sliding distance.

[0080] S32: If the sliding distance is consistent with the preset reference distance, it is determined that the rivet has fallen off.

[0081] The reference distance refers to the standard distance that the floating vacuum nozzle is driven by the linear module of the pre-installed structure 6 to move from above the nail supply station 54 to above the pre-installation station 15. The reference distance is measured in advance by the operator according to the set positions of the nail supply station 54 and the pre-installation station 15 and then entered into the system.

[0082] If the sliding distance is consistent with the reference distance, it means that the linear module has driven the floating vacuum nozzle to move from above the nail supply station 54 to above the pre-assembly station 15. There is no possibility of the sliding not being in place, so it is determined that the rivet has fallen. The reference distance range is set according to the redundancy distance and the reference distance. When the sliding distance falls into the reference distance range, it is determined that the sliding distance is consistent with the reference distance.

[0083] "Rivet falling off" means that the floating vacuum nozzle is in an unloaded state and has not captured the rivet.

[0084] S33: Control the conveying and transfer structure 1 to suspend operation, and then control the pre-installed structure 6 to grab again.

[0085] After reading the sliding distance of the pre-installed structure 6, the following steps are also included: S40: If the sliding distance is inconsistent with the reference distance, collect the adsorption pressure used to grab the rivets in the pre-installed structure 6.

[0086] The inconsistency between the sliding distance and the reference distance indicates that the linear module of the pre-installed structure 6 did not drive the floating vacuum nozzle to its position, resulting in the distance collected by the positioning rod 31 not being the actual distance. This does not prove that the rivet has fallen off and requires further verification.

[0087] Adsorption pressure refers to the negative pressure value collected in real time by the negative pressure air path inside the floating vacuum nozzle; the adsorption pressure is obtained in real time by a negative pressure sensor that is pre-set in the floating vacuum nozzle.

[0088] S41: When the adsorption pressure is consistent with the preset negative pressure threshold, it is determined that the sliding is not in place.

[0089] The negative pressure threshold refers to the lowest negative pressure value reached in the negative pressure pipeline when the rivet is stably adsorbed by the floating vacuum nozzle. The critical negative pressure value at which the rivet falls off is obtained by the operator through multiple measurements based on calibration tests and is used as the negative pressure threshold.

[0090] If the adsorption pressure is consistent with the negative pressure threshold, it means that the negative pressure in the tubing inside the floating vacuum nozzle meets the standard and the rivet is in a normal adsorption state, indicating that there is only a situation where the slippage is not in place. The negative pressure threshold range is obtained by combining the preset redundant pressure with the negative pressure threshold. When the adsorption pressure falls into the negative pressure threshold range, it is determined that the adsorption pressure is consistent with the negative pressure threshold.

[0091] Insufficient sliding means that the linear module of the pre-installed structure 6 has insufficient sliding distance, and the floating vacuum nozzle has not moved above the positioning rod 31.

[0092] S42: Control the pre-installed structure 6 to reset and slide again, and re-execute S30.

[0093] S43: When the adsorption pressure is inconsistent with the negative pressure threshold, it is determined that the rivet has fallen off, and the process jumps to execute S33.

[0094] If the adsorption pressure is inconsistent with the negative pressure threshold, it means that the negative pressure in the tubing inside the floating vacuum nozzle is not up to standard, and the rivet has fallen off the floating vacuum nozzle, which is judged as the rivet falling off.

[0095] After the assembly is moved to correct its position, the following steps are also included: S50: In response to the correction completion signal, the movement thickness is obtained and the assembly thickness is calculated by combining it with the Bourdon tube thickness.

[0096] The correction completion signal refers to the completion signal automatically issued after the correction structure has completed the correction; the miniature stepper motor that drives the correction rod has a magnetic switch, and automatically issues a correction completion signal after the miniature stepper motor has completed a single correction process.

[0097] The movement thickness refers to the vertical thickness dimension of the movement along the lifting direction of the positioning rod 31; the movement thickness is obtained by the operator in advance by actually measuring the thickness of the standard movement and entering it into the system, and can be directly retrieved when in use.

[0098] The thickness of the assembly refers to the total vertical thickness of the stacked Bourdon tubes and the entire movement; the thickness of the assembly is calculated by summing the thickness of the movement and the thickness of the Bourdon tubes.

[0099] S51: Positioning rod 31 rises based on assembly thickness control.

[0100] The positioning rod 31 is moved upward by the lifting structure to the distance corresponding to the thickness of the assembly, so that the positioning rod 31 just passes through the movement and the spring tube. The upper end face of the positioning rod 31 is flush with the upper end face of the movement. If the positioning rod 31 is already in the position of passing through the spring tube, the remaining execution distance is adjusted accordingly to ensure that the final position of the positioning rod 31 remains unchanged.

[0101] S52: Simultaneously send a trigger signal to control the pre-installed structure 6 to restart the execution of S13.

[0102] The trigger signal is the signal that controls the pre-installed structure 6 to move downwards with the rivet through the installation hole after the positioning rod 31 rises to the position; the system automatically generates and sends the trigger signal after the lifting structure drives the positioning rod 31 to the designated position.

[0103] S53: The interval distance above the positioning rod 31 is collected.

[0104] The interval distance refers to the distance between the upper end face of the raised positioning rod 31 and the upper obstruction; the interval distance is obtained in real time through the ranging structure.

[0105] S54: When the interval distance is consistent with the preset bonding distance, determine and execute the synchronous command to control the positioning rod 31 to descend according to the feeding command.

[0106] The contact distance refers to the distance data collected by the distance measuring structure when the upper end of the positioning rod 31 is in contact with the lower end face of the rivet; it is preset by the operator and entered into the system, and is set to 0 in this embodiment.

[0107] The interval distance is consistent with the bonding distance, which means that the rivet follows the pre-installed structure 6 and is pressed down to the position of the bonding positioning rod 31; the bonding distance range is set according to the redundancy distance, and when the bonding distance falls into the bonding distance range, it is determined that the interval distance is consistent with the bonding distance.

[0108] The synchronization command refers to the linkage control command that controls the positioning rod 31 to retract downwards; based on the downward movement speed in the feeding command, it is set to the descent speed of the lifting structure, i.e., the synchronization command.

[0109] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. An automatic riveting device for instrument assembly, comprising a riveting structure (7) for press-fitting rivets in mounting holes, characterized in that, It also includes a conveying and transfer structure (1) with a placement seat (12), a follow-up positioning structure (3) and a pre-assembly structure (6). The conveying and transfer structure (1) is provided with a loading station (13), a pre-assembly station (15) and a riveting station (16). The placement seat (12) moves with the conveying and transfer structure (1) and passes through the loading station (13), the pre-assembly station (15) and the riveting station (16) in sequence. The riveting structure (7) is located at the riveting station (16) and the pre-assembly structure (6) is located at the pre-assembly station (15). The pre-assembly structure (6) is used to pre-assemble rivets into the mounting holes. The follow-up positioning structure (3) includes a positioning rod (31) passing through the placement seat (12) and a sliding rail (32) for constraining the lifting stroke of the positioning rod (31). The positioning rod (31) is used to insert into the mounting hole of the assembly to achieve centering and limiting. The sliding track (32) has a high section (321) and a low section (322). When the positioning rod (31) moves with the placement seat (12) to the loading station (13), the high section (321) pushes out the positioning rod (31) to limit and fix the assembly. When the positioning rod (31) moves with the placement seat (12) to the pre-assembly station (15), the low section (322) provides clearance space for the positioning rod (31) to retract into a rivet for insertion.

2. The automatic riveting equipment for instrument assembly according to claim 1, characterized in that, The follow-up positioning structure (3) also includes a guide rod (33) passing through the placement seat (12) and a pulley (34) connected to the positioning rod (31) and the guide rod (33). The guide rod (33) is arranged parallel to the positioning rod (31) to provide guidance and limit for the reciprocating sliding of the positioning rod (31), and the pulley (34) rolls and abuts against the sliding track (32).

3. The automatic riveting equipment for instrument assembly according to claim 1, characterized in that, A rivet supply structure (5) is provided on one side of the pre-assembly station (15), and a rivet supply station (54) is provided on the rivet supply structure (5). The pre-assembly structure (6) transfers the rivets on the rivet supply station (54) to the assembly at the pre-assembly station (15). The rivet supply structure (5) includes a rivet arrangement assembly (51), a feeding turntable (52), and a detection assembly (53). The feeding turntable (52) has several hook slots (521) for the rivets fed by the rivet arrangement assembly (51) to be placed. The hook slots (521) rotate with the feeding turntable (52) and pass through the rivet supply station (54) in sequence. The detection assembly (53) is set on the side of the rivet supply station (54) to detect the positioning status of the rivets and ensure that there are always rivets to be taken at the rivet supply station (54).

4. The automatic riveting equipment for instrument assembly according to claim 1, characterized in that, The conveying and transfer structure (1) is also provided with a pressing structure (2), which corresponds one-to-one with the placement seat (12), and the pressing structure (2) is located on one side of the placement seat (12); The clamping structure (2) includes a clamping block (22) and a tension spring (23). The clamping structure (2) has an open state and a pressed state. The tension spring (23) in the pressed state has a tension that drives the clamping block (22) to abut against the assembly.

5. An automatic riveting device for instrument assembly according to claim 4, characterized in that, The conveying and transfer structure (1) is also provided with a material unloading station (17), and a material unloading structure (8) is provided at the material unloading station (17). The unloading structure (8) includes an unlocking push block (811) and a clamping assembly (82). The unlocking push block (811) slides along the direction close to the clamping block (22) to drive the clamping block (22) to overcome the tension of the tension spring (23), thereby releasing the clamping block (22) from pressing the assembly. The clamping assembly (82) is used to automatically unload the assembly at the unloading station (17).

6. A control method for an automatic riveting device for instrument assembly, applied to an automatic riveting device for instrument assembly as described in any one of claims 1 to 5, characterized in that, include: S10: In response to the pre-installed signal, the obstruction distance above the positioning rod (31) is measured by the distance measuring structure preset on the upper end of the positioning rod (31); S11: Obtain the standard distance between the upper end of the positioning rod (31) and the rivet to be installed when the positioning rod (31) is in the low position (322); S12: Determine the current installation status of the component based on the relationship between the obstruction distance and the standard distance. The installation status includes whether the mounting hole is not offset or the mounting hole is offset. S13: Based on the fact that the mounting hole is not offset, control the pre-assembled structure (6) to execute the preset feeding command to insert the rivet into the mounting hole; S14: Based on the offset of the mounting hole, control the correction structure preset on the placement seat (12) to push the assembly to perform position correction; S15: After correction, control the pre-assembled structure (6) to restart S11.

7. The control method for an automatic riveting device for instrument assembly according to claim 6, characterized in that, After obtaining the occlusion distance, the following is included: S20: Obtain the thickness of the spring tube; S21: Determine the spring tube blocking distance and the movement blocking distance by combining the spring tube thickness and the preset retraction position of the positioning rod (31); S22: When the blocking distance is the same as the blocking distance of the spring tube, it is determined to be an overall offset; S23: Issue a skip signal to control subsequent structures to skip the processing of the current assembly, and at the same time issue an audible and visual alarm to remind manual adjustment; S24: When the obstruction distance is the same as the movement blocking distance, it is determined to be movement offset; S25: Based on the movement blocking distance, the positioning rod (31) is raised and S14 is executed.

8. The control method for an automatic riveting device for instrument assembly according to claim 7, characterized in that, After obtaining the occlusion distance and standard distance, the following are included: S30: Read the no-load distance for removing rivets from the standard distance; S31: When the obstruction distance is the same as the unloaded distance, read the sliding distance of the pre-installed structure (6); S32: If the sliding distance is consistent with the preset reference distance, it is determined that the rivet has fallen off; S33: Control the conveying and transfer structure (1) to pause operation, and then control the pre-installed structure (6) to grab again.

9. The control method for an automatic riveting device for instrument assembly according to claim 8, characterized in that, After reading the sliding distance of the pre-assembled structure (6), the following is also included: S40: If the sliding distance is inconsistent with the reference distance, collect the adsorption pressure used to grab the rivets in the pre-assembled structure (6); S41: When the adsorption pressure is consistent with the preset negative pressure threshold, it is determined that the sliding is not in place; S42: Control the pre-installed structure (6) to reset and slide again, and re-execute S30; S43: When the adsorption pressure is inconsistent with the negative pressure threshold, it is determined that the rivet has fallen off, and the process jumps to execute S33.

10. The control method for an automatic riveting device for instrument assembly according to claim 7, characterized in that, After the assembly is moved to correct its position, the following steps are also included: S50: In response to the correction completion signal, the movement thickness is obtained and the assembly thickness is calculated by combining the Bourdon tube thickness; S51: The positioning rod (31) rises based on the thickness of the assembly; S52: Simultaneously send a trigger signal to control the pre-installed structure (6) to restart the execution of S11; S53: Collect the interval distance above the positioning rod (31); S54: When the interval distance is consistent with the preset fitting distance, determine and execute the synchronous command for the control positioning rod (31) to descend according to the feeding command.

Images