Laser refers to a type of light that is intensified through stimulation to emit radiation. Its properties such as good directionality, high brightness and monochromatic nature make it widely applicable in various fields including laser cutting, welding, engraving, drilling and marking, among others.
Laser applications are considered one of the most promising and growing fields. Among its diverse applications, laser cutting stands out as a fundamental technical process. There are two main types of laser cutting: the pulsed laser, suitable for cutting metallic materials, and the continuous laser, ideal for non-metallic materials.
In the automotive industry, laser cutting technology has found significant application. The following is an overview of the use of sim laser cutting technology in the automotive industry.
Principles and advantages of laser cutting
Laser cutting is a process that uses a high-density laser beam to heat material to several thousand to ten thousand degrees Celsius in a short period of time. This causes the material to melt or vaporize, and a high-pressure gas blows the molten or vaporized material away from the cutting line, resulting in a clean cut.
In the production of automotive parts, laser cutting has several advantages:
(1) High accuracy: Positioning accuracy is approximately 0.05mm.
(2) Narrow cut: The laser beam is focused on a small spot, resulting in a high power density that heats the material to the point of vaporization. This forms small, continuous cracks with a very narrow width.
(3) Smooth surface: The cutting surface is smooth and burr-free.
(4) Fast speed: The cutting speed is much faster than wire cutting.
(5) Good cutting quality: No contact cutting and minimal thermal impact on the cutting edge, there is little or no thermal deformation of the workpiece, and cutting generally does not require secondary processing.
(6) No damage to the workpiece: The laser cutting head does not contact the workpiece, avoiding scratches or damage.
(7) Material versatility: Material hardness does not affect the laser cutting process, allowing you to cut steel, stainless steel, aluminum alloys, carbide and other materials.
(8) Shape Flexibility: The laser cutting process can be programmed to cut any graphic or shape, including tubes and other profiles.
(9) Reduced investment in dies: Laser cutting requires no dies, reducing investment and maintenance costs.
(10) Saving materials: With computer programming, the entire board can be used to produce products of different shapes, improving the use of material.
(11) Shorter development cycle: New products can be developed faster without the need for manufacturing matrices.
(12) Cutting non-metallic materials: The laser cutting process can also be used to cut non-metallic materials.
laser cutting equipment
There are several types of laser cutting equipment, including:
(1) Flat laser cutting machine: This type of machine is specifically designed for cutting flat parts.
(2) Three-dimensional laser cutting machine: This machine is capable of cutting parts with three-dimensional shapes.
(3) Laser cutting robot (Figure 1): This type of laser cutting equipment is capable of cutting complex three-dimensional parts.
Fig.1 Laser cutting robot workstation
With the growth of the automotive industry, the use of laser cutting robots is becoming more widespread. This type of laser cutting equipment is capable of cutting flat parts and simple 3D parts. Below we describe the components of a robotic laser cutting workstation:
(1) High-precision trajectory robot: This component provides high-precision, high-speed three-dimensional processing and at the same time reduces costs.
(2) Laser generator: There are three types of laser generators: solid state laser generator, gas laser generator and fiber laser generator. The laser generator is the device that produces the laser source.
(3) Cooler: This component is used to cool the laser generator.
(4) Fiber optic cable: This component is used to transmit the laser beam.
(5) Cutting head: This component mainly includes parts such as cavity, focusing lens holder, focusing mirror, capacitive sensor and auxiliary gas nozzle.
(6) Working table: This component is used to hold the part to be cut and can be moved precisely according to the control program, driven by a servo motor.
(7) CNC: This component controls the movements of the table's X, Y and Z axes and also controls the laser output power.
(8) Handling platform: This component controls the entire working process of the cutting unit.
(9) Gas cylinders: These components include middle working cylinders and auxiliary cylinders for the laser cutting machine.
(10) Air compressor: This component is used to supply compressed air.
(11) Air Cooling Dryers and Filters: These components are used to remove moisture and impurities from compressed air.
(12) Auxiliary equipment: Includes components such as extractor and dust collector.
The Practice of Laser Cutting Robot in Automobile Manufacturing
The illustration below demonstrates the use of laser cutting robots in the production of automotive components.
Cutting pipe parts
As illustrated in Figure 2, the part is made by laser cutting all the holes in the tube, with 4 holes on the left and 5 holes on the right.
Due to the large number of holes and different hole sizes, the use of a punching tool would require a complex tool configuration and a relatively large number of dies, leading to substantial investment and frequent maintenance that consumes a lot of time and labor. . Furthermore, it may result in low quality products, requiring special quality inspection to prevent such occurrences.
Laser cutting technology, on the other hand, can significantly reduce capital investment in dies and bring the following benefits:
- Ensures Part Quality: Parts are cut precisely and this non-contact process eliminates the risk of collapsed corners.
- Saves labor and equipment: After adjusting the program, laser cutting only requires a worker to complete a series of tasks, such as removing parts, top or bottom parts. Using dies would require at least three sets of molds, three operators, and three stamping equipment.
- Simple and economical operation: In practice, the part can be cut 400 times a day, resulting in less fatigue and greater efficiency for workers. With the dies, 400 sets can be produced per day under normal conditions, but any problems with the die would require time-consuming repairs, installations, and debugging.
- Prevents missed or incorrect cuts: If there is a missed or incorrect cut with laser cutting, the equipment will trigger an alarm, preventing the release of unqualified products. With tools, undetected leaks can result in significant losses due to unqualified products leaving.
Fig.2 Tube parts
To ensure the accuracy of part positioning, a positioning device (as shown in Figure 3) must be used. The structure of the device is made up of three parts:
- Fixed Board: It is fixed to the workstation table using screws and pins. The design of the accessory must be adapted to the size of the work table and must not be arbitrary.
- Part positioning device: The device must be selected based on the specific requirements of the part. In this case, as the position of the hole at the end is crucial, the positioning is defined at the end of the part.
- Part Holding Device: Due to the multiple cuts in various directions on the part, it needs to be held in place while the table rotates. To prevent the part from falling, four sets of clamping cylinders are required.
In conclusion, the accessory structure is simple, easy to operate and economical, which makes it a practical solution.
Fig.3 Positioning device for making pipe parts
Profile cutting
As shown in Figure 4, the part requires cutting two large holes and two ends, which would cause distortion if drilled with a die. To avoid this, laser cutting is used to guarantee the quality of the part.
Cutting the holes is relatively simple, but cutting and machining the end of the profile is a challenge. The profile has a B-shaped cross section that requires 360 degree cuts in each direction.
Therefore, it is necessary that the laser cutting head has the ability to rotate 360 degrees and has enough space to do so. If there is limited space in the normal direction, a small angled cut can be used without affecting the part.
Setting the cutting trajectory of the cutting head requires continuous trial and error to ensure part quality while reducing manufacturing costs and improving production efficiency.
Fig.4 Parts made of profiles
The laser cutting fixture for this part is shown in Figure 5. Its design is similar to the pipe fitting and consists of three components:
- Fixed Plate: This component has the same method of fixing as the tube.
- Part Positioning Device: The part has critical mounting holes that require precise positioning, which is achieved through the use of this device.
The positioning mechanism employs a cylinder-driven positioning pin that can move back and forth, facilitating easy picking and positioning of the workpiece.
- Part clamping device: This device is similar to the pipe part, but the clamping head has been changed to match the shape of the part.
Fig. 5 Positioning device fixed to the table
These two examples of laser cutting accessories are relatively simple compared to dies and are composed of three parts: a fixed plate, a positioning device, and a clamping device.
It demonstrates that the implementation of laser cutting robots can address numerous challenges in the production of automotive components and bring numerous benefits.
Conclusion
In summary, laser cutting has become a prominent advantage in the field of automotive processing due to its ability to reduce costs and improve the quality of automobiles.
The use of robotic laser processing workstations in the automotive industry is becoming more and more common, covering not only laser cutting, but also laser welding, laser marking, laser engraving and non-metallic materials processing.
