1. Introduction
The rotary cutting machine is used to process wood sections of a certain length and diameter into continuous veneer strips for the production of plywood, blockboard and other wood-based panel veneers. The main technical parameters of the rotary cutter are the maximum length and diameter of wood segments that can be processed. The emergence of CNC rotary cutting machine not only improves the quality and precision of veneer production, but also greatly improves the production efficiency and the degree of automation of the whole machine. Rotary cutting machine is one of the main equipment for producing plywood. The rotary cutting machine is divided into card rotary cutting machine and non-card rotary cutting machine. The card rotary cutter is suitable for large diameter wood, and the cardless rotary cutter is suitable for small diameter wood.
2. Basic principle
Rotary cutters are used to cut wood segments into veneers. The general method of rotary cutting is: the left and right chuck shafts clamp the two ends of the wood section and drive it to rotate. The rotating blade installed on the knife bed is parallel to the axis of the chuck shaft, and moves along the vertical direction and along the direction of the annual rings of the wood section. Equal thickness rotary cut veneer. Whether it is constant speed rotary cutting or constant linear speed rotary cutting, in order to obtain a veneer with a certain thickness, the feed rate of the cutter bed should be kept constant when the chuck shaft rotates each time, and the feed rate is equal to veneer. Nominal thickness. By changing the feed rate, veneers of different thicknesses can be obtained.
Figure 1: Schematic diagram of rotary cutting
During the rotary cutting process, the trajectory of the rotary cutting blade on the section of the wood profile is called the rotary cutting curve (as shown in Figure 1: a schematic diagram of rotary cutting), and its motion equation is：
r2= a2θ2 +h2
In the formula:
r—the instantaneous radius of the wood section;
a——the segment circle radius of Archimedes spiral or involute base circle, a=S/2π;
θ——polar angle, calculated from the o x direction;
h—knife installation height, that is, the distance between the rotary knife blade and the horizontal plane of the card shaft axis.
(1) The use and principle of rotary cutting machine
Purpose: The rotary cutting machine is used to process a certain length and a certain diameter of wood sections into continuous veneer strips.
Principle: Cut the thick round wood into uniform thin wood chips by sending the knife.
(2) Rotary cutting machine classification
●Hydraulic single card shaft rotary cutting machine
●Hydraulic double card shaft uranium rotary cutting machine
●Mechanical single card shaft rotary cutting machine
●CNC hydraulic double card shaft rotary cutting machine
●Mechanical single-card eight-foot rotary cutting machine
●Mechanical single card shaft rotary cutting machine
●CNC non-card shaft rotary cutting machine
●Computer Numerical Control Four-leg Card Opening Shaft Family Cutting Machine
(3) The process of making the splint
1. Cut and grind large raw materials to ensure quality.
2. Then, through woodworking splicing and other processes, the raw materials are spliced into wooden plywood of the required size.
3. Put the wood plywood in a steam wood baking oven and use steam to bake to improve the performance and appearance of the wood plywood.
4. Wrap the wood plywood with paint or other materials to get different colors of the wood plywood.
5. Put the wooden plywood in the oil-baked wood box and bake it with oil to make the surface of the wooden plywood smoother.
6. Finally, cut the oil-baked wood plywood into the specified size to complete the production of the wood plywood.
3. Technical requirements of rotary cutting machine
Process requirements
●Rotary cutting thickness: 0.4-2.6mm
●Rotary cutting diameter: 30-280mm
●Rotary cutting speed: <29m/min
Raw materials and mechanical requirements
●The thickness of the veneer after rotary cutting is uniform without large area changes.
●The diameter range of logs that can be rotary cut is wide, and there is no instability due to diameter changes.
●Electrical system is stable and reliable, with low failure rate.
4. Features and advantages of rotary cutting machine
(1) Features of rotary cutting machine
①Roller speed detection encoder: real-time detection of roller speed, providing accurate data for rotary cutting machine calculation.
②Feed detection encoder: accurately detect the feed displacement and calculate the current position.
③Displacement sensor (grating ruler): detects the current position of the feed, and has the same function as the feed detection encoder.
(2) Advantages of rotary cutting machine
①Servo motor is used to drive precision lead screw to feed.
②To change the board thickness, only need to input the board thickness number, no need to replace the gear, and the rotary cutting precision is high.
③Different wood types can also be peeled together without affecting the thickness of the board.
④The surface finish of the board is good, and it is not sensitive to the reaction of the yin and yang sides of the wood.
⑤Energy saving, simple operation and convenient maintenance.
5. Fracon Solutions
Use FR500 series inverter + PLC + HMI to control the rotary cutting machine.
(1) Operation process of rotary cutting machine
●After the start switch is toggled, the frequency converter starts to work, and the pressure roller motor starts first by default (the pressure motor contactor is controlled by the frequency converter output relay).
●After the press motor starts, press the start switch again, and the screw motor will start. If the fast-forward switch is pressed, the knife will be fed at the fast-forward speed, otherwise the speed will be calculated according to the actual diameter of the log (through the screw motor encoder Input the displacement of the tool table, calculate the actual diameter of the log, and then obtain the feed speed of the screw motor according to the mathematical model).
●When the screw motor feeds the knife, if the fast-reverse switch is pressed, the knife will be withdrawn immediately; when the knife is withdrawn or the knife is fed according to the diameter of the log, if the fast-forward switch is pressed, the knife will be forwarded immediately.
(2) Refer to the wiring diagram
6. Field Application Photos
