A control method and production line for automatic welding of 1-3.8t balanced heavy frame

Abstract

The present application belongs to the technical field of forklift production, and particularly relates to a control method for automatic welding of a 1-3.8t counterbalance frame and a production line. The production line comprises a frame assembly station, a to-be-welded frame conveying line, a first rotary table, a frame online conveying line, a handling robot movement track provided with a first RGV in a common track at a downstream end of the frame online conveying line, and a frame welding workstation arranged around the frame online conveying line and matched with the handling robot; the production line further comprises a post-welding frame offline conveying line, a sub-mother vehicle connected post-welding frame offline conveying line repair welding station, an offline conveying line matched with a correction station, the correction station connected with the conveying line, and the conveying line matched with a post-welding to-be-painted vertical warehouse through a second RGV. The technical scheme realizes automatic welding production of the counterbalance frame and improves the buffer warehouse to realize order demand sequence sending of the required frame to the painting line.

Description

Technical Field

[0001] This invention belongs to the field of forklift manufacturing technology, specifically relating to a control method and production line for automatic welding of 1-3.8t counterbalanced truck frames. Background Technology

[0002] As a key component of forklifts, the production efficiency and quality of the chassis directly restrict product improvement. To achieve production capacity planning within a given site space, it is necessary to design an automated chassis welding production line to improve chassis manufacturing quality and efficiency. Summary of the Invention

[0003] The purpose of this invention is to provide a control method and production line for automatic welding of 1-3.8t counterbalanced vehicle frames, so as to improve the manufacturing quality of the frames and increase production efficiency.

[0004] To achieve the above objectives, this application employs the following technical solution:

[0005] A control method for automatic welding of 1-3.8t counterbalance vehicle frames includes the following steps:

[0006] S1. Complete the assembly of the frame at the assembly station, affix the product information code to the fixed position of the frame, and take a picture of the assembled frame and transmit it to the control system.

[0007] S2. The assembled chassis is transferred to the chassis to be welded conveyor line. The chassis is then transferred to the turntable via the chassis to be welded conveyor line. The turntable rotates the chassis 90° and then transfers it to the chassis to be loaded onto the conveyor line.

[0008] S3. The scanning device scans the passing vehicle frame and transmits the scanning information to the control system. At the same time, the vehicle frame conveyor line transports the vehicle frame downstream.

[0009] S4. The laser line scanning station takes a picture of the passing frame and transmits it to the control system. The control system compares the picture with the picture in step S1 to determine whether to release the frame. If released, the frame on the online conveyor line drives the frame to continue moving.

[0010] S5, the frame conveyor line transports the frame to the frame welding point located upstream of the frame conveyor line, and the handling robot transports the frame to be welded to the frame welding workstation;

[0011] S6. After the frame welding is completed, the transport robot will transport the welded frame to its accompanying bracket. The RGV, which is on the same line as the transport robot, will transfer the welded frame on the accompanying bracket to the welded frame off-line conveyor line.

[0012] S7. The welded frame is transferred to the repair welding station by the mother and daughter car for repair welding of the frame;

[0013] S8. The welded frame is transferred to the off-line conveyor line via a mother car and daughter car. The frame is then transferred to the calibration station for calibration via the off-line conveyor line. The calibrated frame is then transported via the conveyor line.

[0014] S9. At the end of the conveyor line, the RGV will transfer the qualified chassis that has been welded and corrected to the vertical warehouse for painting after welding.

[0015] Furthermore, step S4 also includes transferring the unreleased frames to the assembly station via a re-inspection conveyor line for re-inspection or sending an alarm signal.

[0016] Furthermore, the assembly station transferred by the re-inspection conveyor is not the same assembly station as the one in step S1.

[0017] Furthermore, in step S5, the working method of the handling robot includes the following steps:

[0018] S51. After the transport robot lifts the frame to be welded at the frame welding line point, it determines whether the frame to be welded is directly sent to the idle welding station if there is only one idle welding station in the frame welding workstation. If there are two or more idle welding stations in the frame welding workstation at the same time, it proceeds to step S52.

[0019] S52. The transport robot determines the remaining completion time of each welding station currently in operation and sorts the remaining completion times. Then, the transport robot inserts the time required to transport the frame to be welded to each idle welding station into the sorted list and determines the difference between the inserted time and the time before and after it. If the difference between the inserted time and the time before and after it is greater than half of the difference between the remaining completion times of adjacent welding stations, proceed to step S53. If the difference is less than half, proceed to step S54.

[0020] S53. The transport robot moves the frame to be welded to an empty welding station at a distance.

[0021] S54. The transport robot moves the frame to be welded to the nearest available welding station.

[0022] Furthermore, in step S5, the robot's operation also includes the following steps:

[0023] S051. Before the handling robot moves, it determines the remaining completion time of each welding station that is currently working and sorts the remaining completion times.

[0024] S052. The handling robot determines the time required to move the frame to be welded from the frame welding line point to any idle welding station, and inserts this time into the sorting in step S051. Then, it determines: if the difference between any time and the time before and after is within the set range, then proceed to step S053; if there is a time whose difference with the time before or after is less than the minimum value of the set range, then it determines whether the time for the handling robot to move the frame to be welded from the frame welding line point to the nearest idle welding station is less than the remaining time of any welding station in operation. If it is greater than the remaining time, then proceed to step S054; otherwise, proceed to step S055.

[0025] S053. The transport robot transports the frame to be welded and moves it to the furthest available welding station.

[0026] S054. The transport robot transports the frame to be welded and moves it to the nearest available welding station.

[0027] S055. The handling robot does not transport the frame to be welded, but moves to the welding station where welding has been completed and transports the frame that has been welded. Then it transports the frame to be welded and makes judgments according to steps S51 to S54.

[0028] A production line for automatic welding of 1-3.8t counterbalanced vehicle frames includes a frame assembly station, which is connected to a frame conveyor line to be welded via a hoisting device. The downstream end of the frame conveyor line is connected to a first turntable, which is also connected to the upstream end of the frame loading conveyor line. A frame welding loading point is provided at the downstream end of the frame loading conveyor line.

[0029] A first RGV with a common track is set on the movement track of the handling robot at the downstream end of the frame conveyor line. The handling robot cooperates with the frame welding line point and the frame welding workstation set around the frame conveyor line.

[0030] The first RGV works in conjunction with the handling robot and the post-weld frame off-line conveyor. The mother and daughter vehicles, which move on the mother and daughter vehicle running track, are connected to the welding station of the post-weld frame off-line conveyor. At the same time, the mother and daughter vehicles work in conjunction with the welding station and the off-line conveyor. The off-line conveyor works in conjunction with the calibration station. The calibration station is connected to the conveyor. The conveyor is connected to the post-weld painting vertical warehouse through the second RGV.

[0031] Furthermore, on both sides of the frame loading conveyor line, there are frame loading conveyor lines to be welded, and both are connected to the frame loading conveyor line via the first turntable.

[0032] Furthermore, a barcode scanner is installed at the upstream end of the vehicle frame conveyor line, and the barcode scanner is connected to the control system via electrical signals. A laser line scanning station is installed at the middle position of the vehicle frame conveyor line, and the laser line scanning station is connected to the control system via electrical signals.

[0033] Furthermore, the upper surface of the first turntable is an inclined surface, and the plane located inside the first turntable is lower than the plane outside the first turntable.

[0034] Furthermore, the upper surface of the conveyor line for the frame to be welded is higher than the highest surface of the first turntable.

[0035] The beneficial effects of this invention are:

[0036] This technical solution can realize the automated welding production of 1-3.8t counterbalanced vehicle frames and improve the buffer warehouse to deliver the required vehicle frames to the painting line in the order of order demand. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the production line process for the automatic welding of the counterweight frame of the present invention.

[0038] Explanation of reference numerals in the attached figures:

[0039] 1. Assembly station; 2. Frame conveyor line to be welded; 3. Frame loading conveyor line; 4. Frame welding loading point; 5. Moving track of the handling robot; 6. Frame welding workstation; 7. Frame unloading conveyor line after welding; 8. Mother and daughter vehicles; 9. Repair welding station; 10. Unloading conveyor line; 11. Calibration station; 12. Conveyor line; 13. First RGV; 14. Second RGV; 15. Post-weld painting warehouse. Detailed Implementation

[0040] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings. The following embodiments are merely exemplary and can only be used to explain and illustrate the technical solution of the present invention, and should not be construed as limiting the technical solution of the present invention.

[0041] like Figure 1 As shown, this application provides an automated welding production method for 1-3.8t counterbalanced vehicle frames and improves the buffer library to deliver the required vehicle frames to the painting line in the order of order demand.

[0042] The production line of this application is a 1-3.8t counterbalance frame production line, including an assembly area. In this embodiment, the assembly area is described as having six assembly stations 1. The counterbalance frame is manually assembled at the six assembly stations and labeled. Specifically, product information codes are affixed to fixed positions on the counterbalance frame, and after taking a photo, the product information code information is transmitted to the control system and stored in the product feature database of the control system. Then, the assembled frame to be welded is transferred to the frame to be welded conveyor line 2 by manual use of a hoisting device.

[0043] In this application, there are two frame conveyor lines 2, located on both sides of the frame conveyor line opposite to the assembly station, thereby avoiding excessive transportation distance from the assembly station to the frame conveyor line. In production, the conveying direction of the frame conveyor lines is towards the center. A first turntable is set at the upstream end of the two frame conveyor lines and the frame conveyor line. In this application, the first turntable is a ring structure composed of conveying rollers, and it cooperates with the upstream ends of the two frame conveyor lines and the frame conveyor line respectively. The upper surface of the first turntable (i.e., the conveying rollers are inclined inward) is a slope, and the height of the outer surface is higher than the height of the inner surface. The purpose of this structure is to prevent the frame from moving outward and falling off or deviating during the conveying and turning of the frame to be welded. After the frame to be welded achieves a 90-degree rotation and change of direction on the first turntable, it moves out of the first turntable and enters the frame conveyor line.

[0044] In this application, a barcode scanner is installed at the upstream end of the frame conveyor line 3. When the frame passes by, it is scanned and the scanned data is transmitted to the control system. The control system initially confirms the product information of the frame, and then the frame is conveyed to the downstream end on the frame conveyor line.

[0045] A laser scanning station is set up in the middle of the frame conveyor line 3. When the frame passes through the laser scanning station, the frame model is scanned and photographed to identify the frame model (i.e., compared with the aforementioned feature library data to call up the frame signal). The information is then compared with the information scanned by the front-end barcode scanner for secondary error correction. Only when the barcode information and the laser scanning information are consistent can the frame be allowed to continue transmission.

[0046] A frame welding point 4 is located at the downstream end of the frame conveyor line. A first RGV13, sharing a common track with the transport robot's motion track 5 at the same downstream end of the frame conveyor line, is installed. The transport robot cooperates with the frame welding point 4 and the frame welding workstations 6 located around the frame conveyor line. In this embodiment, 12 frame welding workstations are arranged around the downstream end of the frame conveyor line. The transport robots on the transport robot's motion track can provide the 12 frame welding workstations with frames to be welded and remove the welded frames.

[0047] The working method of the handling robot in this application includes the following steps:

[0048] S51. After the transport robot lifts the frame to be welded at the frame welding line point (this judgment is made after lifting the frame to be welded first), it judges whether the frame welding workstation has only one empty welding station. If the frame welding workstation has two or more empty welding stations at the same time, it proceeds to step S52.

[0049] S52. The transport robot determines the remaining completion time of each welding station currently in operation and sorts the remaining completion times. For example, if there are 12 chassis welding workstations, with 10 working and two idle (specifically, already completed welding work awaiting new chassis to be welded), and the remaining completion times for the 10 currently working workstations are 180s, 150s, 135s, 120s, 100s, 90s, 75s, 40s, 30s, and 15s respectively, then the transport robot inserts the time required to move the chassis to be welded to each idle welding station into the time allocation. In the sorting process, if the time required for the transport robot to deliver the frame to be welded to the 11th and 12th frame welding workstations is 60s and 45s respectively, the new sorting is: 180s, 150s, 135s, 120s, 100s, 90s, 75s, 60s, 45s, 40s, 30s, 15s. The robot then checks the difference between the inserted time and the time before and after it. If the difference is greater than half the difference in remaining completion time of the adjacent welding workstations (i.e., the difference between the 60s time and the time before and after it is 15s, which is greater than or equal to half the difference between any two times), then proceed to step S53. If the difference between the 45s time and the subsequent time is 5s, which is less than half the difference between any two times, then proceed to step S54. Therefore, the transport robot moves the lifted frame to be welded to the nearest available welding workstation.

[0050] S53. The transport robot moves the frame to be welded to an empty welding station at a distance.

[0051] S54. The transport robot moves the chassis to be welded to the nearest available welding station, and then the transport robot will sequentially move the welded chassis off the production line from the 15s chassis welding workstation.

[0052] The handling robot in this application also includes a control method for not lifting the welding frame, specifically including the following steps:

[0053] S051. Before the handling robot moves, it determines the remaining completion time of each welding station that is currently working and sorts the remaining completion times.

[0054] S052. The handling robot determines the time required to move the frame to be welded from the frame welding line point to any idle welding station, and inserts this time into the sorting in step S051. Then, it determines: if the difference between any time and the time before and after is within the set range, then proceed to step S053; if there is a time whose difference with the time before or after is less than the minimum value of the set range, then it determines whether the time for the handling robot to move the frame to be welded from the frame welding line point to the nearest idle welding station is less than the remaining time of any welding station in operation. If it is greater than the remaining time, then proceed to step S054; otherwise, proceed to step S055.

[0055] S053. The transport robot transports the frame to be welded and moves it to the furthest available welding station.

[0056] S054. The transport robot transports the frame to be welded and moves it to the nearest available welding station.

[0057] S055. The handling robot does not transport the frame to be welded, but moves to the welding station where welding has been completed and transports the frame that has been welded. Then it transports the frame to be welded and makes judgments according to steps S51 to S54.

[0058] The control method described above is only one control method for handling robots. More suitable control methods can be developed in this field according to specific circumstances.

[0059] The first RGV13 is in conjunction with the handling robot and the post-weld frame off-line conveyor line 7. The mother-daughter vehicle 8, which moves on the mother-daughter vehicle running track, is connected to the post-weld frame off-line conveyor line 7 and the repair welding station 9. At the same time, the mother-daughter vehicle is in conjunction with the repair welding station and the off-line conveyor line. The off-line conveyor line 10 is in conjunction with the calibration station 11. The calibration station 11 is connected to the conveyor line 12. The conveyor line is in conjunction with the post-weld painting vertical warehouse 15 through the second RGV14.

[0060] After the frame welding is completed, the transport robot moves the welded frame to its accompanying bracket. The RGV, which is on the same line as the transport robot, transfers the welded frame on the accompanying bracket to the welded frame off-line conveyor. Through the design of the transport robot's accompanying bracket and the off-line material transfer method in cooperation with the co-line RGV, the unloading time of the transport robot and the material handling distance are reduced, which greatly improves the loading time of the transport robot. In this way, the loading and unloading cycle time of the 12 frame welding workstations can be balanced.

[0061] In this application, the post-weld frame off-line conveyor also features a second turntable structure to achieve a 90° turn in the frame conveying direction. A welding touch-up point is located at the end of the post-weld frame off-line conveyor. The mother-daughter vehicle transfers the frame at this point to five vertically arranged welding touch-up stations for welding. The welded frame is then transferred by the mother-daughter vehicle to the off-line conveyor for further transfer. The frame is then transported by conveyor to a calibration station for calibration, and finally transported by conveyor again after calibration.

[0062] A second RGV loading point is set at the end of the conveyor line. The second RGV transfers the qualified frames that have been welded and corrected to the vertical warehouse for painting after welding at this point. The vertical warehouse forms a frame buffer for one shift. When different models of frames need to be painted and assembled according to production orders, the required parts can be directly and accurately found in the vertical warehouse and taken out for painting and loading, thereby realizing the delivery of the required frames to the painting line in the order of order requirements.

[0063] This application also includes transferring non-released vehicle frames to the assembly station via a re-inspection conveyor line for re-inspection or sending alarm signals. The assembly station to which the re-inspection conveyor line transfers the frames is not the same as the initial assembly station, thus allowing different personnel to perform the re-inspection, making it easier to identify problems.

[0064] This application also includes intelligent warehouse location management: connecting upstream and downstream production planning systems to achieve a closed loop between online warehouse management planning and execution, making the execution process (abnormalities, warehouse locations, changes, etc.) knowable and controllable.

[0065] Automated warehouse operations: material identification / warehouse shelving / picking / warehouse de-shelving / inventory counting / early warning / ...

[0066] Automated warehouse safety system:

[0067] With proper maintenance, the failure rate of automated storage and retrieval systems (AS / RS) is low. AS / RS are equipped with pre-installed safety systems, including slack rope and overload switches, automatic obstruction alarms, rope breakage protection, vertical forced speed change switches with end limit switches, and horizontal forced speed change switches with end limit switches. AS / RS utilizes dual stacker cranes with only two operating modes: a 90% balance rate (same-side inbound / outbound) compound cycle operation, and a (same-side inbound / outbound) single cycle operation.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A control method for automatic welding of 1-3.8t counterbalance vehicle frames, characterized in that, Includes the following steps: S1. Complete the assembly of the frame at the assembly station, affix the product information code to the fixed position of the frame, and take a picture of the assembled frame and transmit it to the control system. S2. The assembled chassis is transferred to the chassis to be welded conveyor line. The chassis is then transferred to the turntable via the chassis to be welded conveyor line. The turntable rotates the chassis 90° and then transfers it to the chassis to be loaded onto the conveyor line. S3. The scanning device scans the passing vehicle frame and transmits the scanning information to the control system. At the same time, the vehicle frame conveyor line transports the vehicle frame downstream. S4. The laser line scanning station takes a picture of the passing frame and transmits it to the control system. The control system compares the picture with the picture in step S1 to determine whether to release the frame. If released, the frame on the online conveyor line drives the frame to continue moving. S5, the frame conveyor line transports the frame to the frame welding point located upstream of the frame conveyor line, and the handling robot transports the frame to be welded to the frame welding workstation; S6. After the frame welding is completed, the transport robot will transport the welded frame to its accompanying bracket. The RGV, which is on the same line as the transport robot, will transfer the welded frame on the accompanying bracket to the welded frame off-line conveyor line. S7. The welded frame is transferred to the repair welding station by the mother and daughter car for repair welding of the frame; S8. The welded frame is transferred to the off-line conveyor line via a mother car and daughter car. The frame is then transferred to the calibration station for calibration via the off-line conveyor line. The calibrated frame is then transported via the conveyor line. S9. At the end of the conveyor line, the RGV will transfer the qualified chassis that has been welded and corrected to the vertical warehouse for painting after welding. In step S5, the working method of the handling robot includes the following steps: S51. After the transport robot lifts the frame to be welded at the frame welding line point, it determines whether the frame to be welded is directly sent to the idle welding station if there is only one idle welding station in the frame welding workstation. If there are two or more idle welding stations in the frame welding workstation at the same time, it proceeds to step S52. S52. The transport robot determines the remaining completion time of each welding station currently in operation and sorts the remaining completion times. Then, the transport robot inserts the time required to transport the frame to be welded to each idle welding station into the sorted list and determines the difference between the inserted time and the time before and after it. If the difference between the inserted time and the time before and after it is greater than half of the difference between the remaining completion times of adjacent welding stations, proceed to step S53. If the difference is less than half, proceed to step S54. S53. The transport robot moves the frame to be welded to an empty welding station at a distance. S54. The transport robot moves the frame to be welded to the nearest available welding station.

2. The control method for automatic welding of 1-3.8t counterbalance vehicle frames according to claim 1, characterized in that, Step S4 also includes transferring the unreleased frames to the assembly station via a re-inspection conveyor line for re-inspection or sending an alarm signal.

3. The control method for automatic welding of 1-3.8t counterbalance vehicle frames according to claim 2, characterized in that, The assembly station transferred by the re-inspection conveyor line is not the same assembly station as the one in step S1.

4. The control method for automatic welding of 1-3.8t counterbalance vehicle frames according to claim 1, characterized in that, In step S5, the robot's operation also includes the following steps: S051. Before the handling robot moves, it determines the remaining completion time of each welding station that is currently working and sorts the remaining completion times. S052. The handling robot determines the time required to move the frame to be welded from the frame welding line point to any idle welding station, and inserts this time into the sorting in step S051. Then, it determines: if the difference between any time and the time before and after is within the set range, then proceed to step S053; if there is a time whose difference with the time before or after is less than the minimum value of the set range, then it determines whether the time for the handling robot to move the frame to be welded from the frame welding line point to the nearest idle welding station is less than the remaining time of any welding station in operation. If it is greater than the remaining time, then proceed to step S054; otherwise, proceed to step S055. S053. The transport robot transports the frame to be welded and moves it to the furthest available welding station. S054. The transport robot transports the frame to be welded and moves it to the nearest available welding station. S055. The handling robot does not transport the frame to be welded, but moves to the welding station where welding has been completed and transports the frame that has been welded. Then it transports the frame to be welded and makes judgments according to steps S51 to S54.

5. A production line for automatic welding of 1-3.8t counterbalance vehicle frames, characterized in that, The system includes a frame assembly station, which is connected to a frame conveyor line to be welded via a hoisting device. The downstream end of the frame conveyor line is connected to a first turntable, which is also connected to the upstream end of the frame on-line conveyor line. A frame welding on-line point is set at the downstream end of the frame on-line conveyor line. A first RGV with a common track is set on the movement track of the handling robot at the downstream end of the frame conveyor line. The handling robot cooperates with the frame welding line point and the frame welding workstation set around the frame conveyor line. The first RGV works in conjunction with the handling robot and the post-weld frame off-line conveyor. The mother and daughter vehicles, which move on the mother and daughter vehicle running track, are connected to the welding station of the post-weld frame off-line conveyor. At the same time, the mother and daughter vehicles work in conjunction with the welding station and the off-line conveyor. The off-line conveyor works in conjunction with the calibration station. The calibration station is connected to the conveyor. The conveyor is connected to the post-weld painting vertical warehouse through the second RGV.

6. The production line for automatic welding of 1-3.8t counterbalance vehicle frames according to claim 5, characterized in that, On both sides of the frame loading conveyor line, there are frame loading conveyor lines to be welded, and both are connected to the frame loading conveyor line via the first turntable.

7. The production line for automatic welding of 1-3.8t counterbalance vehicle frames according to claim 5, characterized in that, A barcode scanner is installed at the upstream end of the vehicle frame conveyor line, and the barcode scanner is connected to the control system via electrical signals. A laser line scanning station is installed in the middle of the vehicle frame conveyor line, and the laser line scanning station is connected to the control system via electrical signals.

8. The production line for automatic welding of 1-3.8t counterbalance vehicle frames according to claim 5, characterized in that, The upper surface of the first turntable is inclined, and the plane inside the first turntable is lower than the plane outside the first turntable.

9. The production line for automatic welding of 1-3.8t counterbalance vehicle frames according to claim 8, characterized in that, The upper surface of the conveyor line for the frame to be welded is higher than the highest surface of the first turntable.

Images