Since the 21st century, in the field of sheet metal processing, CO2 laser cutting machines have been gradually replaced by fiber laser cutting machines. High quality, high precision, high efficiency, large format and low cost have become the development trend of fiber laser cutting machines. At the same time, with the increase of enterprise labor costs and the continuous highlighting of low labor efficiency, the automation of machining came into being.
This paper introduces the automatic loading and unloading equipment of the fiber laser cutting machine, which mainly includes the movable raw material (finished product) trolley, frame parts, material suction device, fork device, etc. it has the functions of automatic loading and unloading, corner turning and layering, automatic loading and unloading, and effectively reduces the dependence on people in the production process.
Design principle and parameters
For the dual worktable fiber laser cutting machine, the structure of the supporting automatic loading and unloading equipment is shown in Fig. 1 and Fig. 2. It is controlled by the control system, which can realize the whole process of manual or automatic loading and unloading, as well as the precise positioning of plates with different lengths, widths and thicknesses.
Laser loading and unloading process flow
The automatic loading and unloading equipment has an intelligent control system. The laser host works in conjunction with the loading and unloading system. It can manually realize the advance and retreat of the raw material trolley, the advance and retreat of the finished product trolley, the forking and retraction, the suction cup partition switch, the x-axis inching movement, the z-axis inching movement and other operations.
During automatic operation, the full-automatic cycle operation of a whole set of actions can be realized by pre loading of the raw material trolley - feeding of the raw material trolley, feeding of the finished product trolley - downward movement of the z-axis, suction cup suction - feeding of the suction cup - exchanging table - edge searching, cutting - exchanging table - feeding of the finished product trolley - discharging to the finished product trolley table, provided that the cutting machine sends feeding or discharging signals to cooperate with the host.
Main components and functions
Crossbeam transmission
The beam can be driven on the frame in two ways. One is to use imported high-precision linear guide as the guide and precision gear and rack as the transmission device (Fig. 3), which ensures the positioning accuracy and repeated positioning accuracy of the machine tool. The loading and unloading direction (x-axis direction) can be parallel or perpendicular to the direction of the laser cutting machine body. It is controlled by a servo motor, which can accurately ensure that the spacing of fork teeth matches the spacing of the laser table.
The other is to adopt the chain sprocket drive mode, with the roller or linear guide as the guide, and use the sprocket to drive the short pitch precision roller chain to realize the drive. The loading and unloading direction (x-axis direction) can only be perpendicular to the direction of the laser cutting machine body, which is used for the field cooperation with low transmission accuracy requirements. It can also be divided into two situations: ⑴ the chain and the cross beam are fixed, and the sprocket and the motor are placed on the frame to drive the cross beam to move along the x-axis direction, As shown in Fig. 4; ⑵ the chain is fixed to the frame, and the sprocket and motor are placed on the beam to drive the beam to move along the x-axis direction, as shown in Fig. 5.
Suction device
The structure of the material suction device is shown in Fig. 6. The plate is located on the raw material trolley, and the strong magnet on the raw material trolley layers the plate; The material suction device is driven by a motor and moves horizontally to the position directly above the raw material trolley; Driven by the motor, the z-axis moves vertically downward, the lower cavity of the balance cylinder is pressurized and vented, and the chuck frame falls onto the plate to be processed of the raw material trolley, while the fork teeth open; The suction cup is vacuumed by the vacuum generator (sucking the plate); The angle turning cylinder moves to turn over the plate for layering; When the material suction device goes up to a certain height and the fork teeth contract, it is driven by the x-axis motor and moves directly above the exchange table of the laser cutting machine; The z-axis descends, the fork teeth open, the suction is released, and the feeding is completed.
Forking device
The forking device is mainly composed of a fork extension drive mechanism, a stopper rack and a fork, as shown in Fig. 7. After the laser cutting machine finishes cutting the plate, the x-axis motor drives the forking device to move above the exchange (lifting) table, the z-axis goes down, the fork opens, and then contracts in the table pitch gap, and lifts the plate; The forking device goes up and is driven to the upper part of the finished product trolley by the x-axis motor; The z-axis descends, the fork opens, and the processed plate is placed on the finished product trolley; The fork is tightened, and the forking device goes up to complete the blanking operation.
Mobile trolley
The mobile trolley consists of a raw material trolley and a finished product trolley, as shown in Fig. 8. The raw material trolley is responsible for placing unprocessed plates, and the finished product trolley is used for placing processed plates. The two trolleys are placed in categories. When placing large-scale panel materials, considering the heavy weight of multiple plates placed on the trolley, both mobile trolleys adopt sprocket chain drive to avoid slipping due to friction drive. If the sheet size is small, such as 3000mm × 1500mm, light weight, can use the reduction motor to drive the sprocket to rotate through the chain drive, so that the mobile trolley can realize the rolling operation of the roller.
The optical fiber laser cutting machine used in this design adopts gantry structure, cast aluminum beam, Japanese high-precision linear guide, imported precision helical gear rack and screw drive, which ensures positioning accuracy and repeated positioning accuracy. The control system can be selected freely. The IPG fiber laser generator is used, and the non-contact capacitive sensor is used for the servo system. The cutting machine has the characteristics of fast response and high accuracy.
After the automatic loading and unloading equipment places the plate to be processed on the exchange table of the laser cutting machine, the CNC system receives the feeding signal and moves the table with the plate below the laser cutting head to process the plate. After the machining is completed, the drive motor and the forking device cooperate to complete the blanking operation.
Advantages and development prospects of automatic loading and unloading equipment
⑴ suction cup automatic feeding. For traditional manual feeding, for example, 3M × At least three workers are required to lift and load the 1.5m thin plate, and the electric hoist is required to assist the loading of the overweight plate. The time taken for one plate is at least three minutes, and the safety risk is great. After using the suction cup for automatic feeding, only manual key operation is required, and it takes 10 seconds to complete the feeding. Because the human-machine engineering and safety protection measures of the equipment are in place, personal injury and safety accidents are zero, which very well avoids the disadvantages of open production that are easy to cause personal injury, improves work efficiency, and reduces labor costs.
⑵ it can meet the diverse needs of users. When the production site is long and narrow, the equipment can be loaded from the rear of the machine body workbench; When the site is spacious, the material can be loaded from the side of the fuselage; According to the different needs of users, we can meet diverse production conditions, realize flexible production, and ensure compact structure and small footprint.
⑶ the overall automation of the system is high. The automatic loading and unloading equipment of the laser cutting machine can realize the cyclic operation of the whole process of plate loading, cutting and unloading through one key operation, or it can be operated manually and carried out step by step. It can be matched with a three-dimensional material warehouse to intelligently manage materials of different thicknesses in layers, which is convenient for control.
⑷ the function can be expanded at any time to realize the co production of multiple machines. One automatic feeding and unloading equipment can feed and unload multiple laser cutting machines. If the production is expanded in the later stage, multiple parallel machines can be used to increase the number of cutting machines and improve the production capacity without changing the inherent structure.
(5) the equipment has a high degree of automation, which improves the company's brand image and helps enhance the enterprise's market competitive advantage.
Concluding remarks
The automatic loading and unloading equipment of laser cutting machines plays an important role in the automatic production line. This design only provides a simple loading and unloading scheme. With this as a reference, an automatic loading and unloading scheme can be derived, which is connected in parallel with multiple laser cutting machines and equipped with a three-dimensional material warehouse. It is believed that the laser automatic loading and unloading equipment will become better and better in the development of automation.