The servo position control module of the sawing machine system adopts the position control combined with the sampling interpolation and the foresight control (the specific control is omitted), and determines the position of the feeding cylinder to be closed, so that the feeding cylinder stops at the target position.
Due to electromagnetic mechanical hysteresis and motion inertia, it is almost impossible to control the feed slide to move 0.1 mm by “on” and “off”.
In order to ensure the minimum feeding length and feeding accuracy, the rear pliers retracts the feed slide to the LK position and then moves forward to the predicted position LT to close the feed solenoid valve.
The rear clamp is clamped when the feed cylinder stops moving.
Sawing machine classification
(1) Circular sawing machine
Circular sawing machines can be classified into fully automatic sawing machine and semi-automatic sawing machine.
The circular saw blade performs a rotating cutting motion while feeding with the saw blade.
The circular sawing machine is divided into three types according to the feeding direction of the saw blade:
- Horizontal sawing machine (horizontal feed)
- Vertical sawing machine (vertical feed)
- Pendulum sawing machine (swing feed at one point)
There are also a variety of special circular sawing machines, such as a head sawing machine for cutting large castings and a sawing and drilling machine for rail sawing and drilling.
(2) Band sawing machine
The annular saw band is tensioned on the two saw wheels and the saw wheel drives the saw band for cutting.
Band sawing machines are mainly available in vertical and horizontal.
The saw frame of the vertical band sawing machine is vertically arranged, and the workpiece is moved during cutting to cut the curved contour of the sheet and the formed part, and the saw band can be replaced with an shackle or a belt for repairing or grinding.
The horizontal band saw blade’s saw frame is horizontally or slanted and fed in a vertical direction or in a direction that oscillates around a point. The saw band is typically twisted by 40° to keep the saw teeth perpendicular to the workpiece.
The horizontal type is divided into scissors type, double column and single column type band sawing machine; it is divided into manual type (economic manual feeding manual cutting material) and automatic type according to the use condition; it can be divided into manual type ( semi-automatic manual feeding) and fully automatic type (automatic feeding automatic cutting) according to the automatic program using the controller.
(3) Bow sawing machine
The saw bow with the saw blade reciprocates and feeds the saw frame around a point.
The machine has a simple structure and a small size, but the efficiency is low.
The saw blade has two kinds of motion paths: straight line and arc.
When moves in the arc motion, the saw bow swings a small angle around a point. Each saw tooth has a large amount of cutting, easy chip removal and high efficiency. Most of the new bow sawing machines adopt this method.
The main components of the sawing machine are:
- Sitting at the bottom
- Bed, column
- Saw beam and transmission
- Guiding device
- Workpiece clamping
- Tensioning device
- Feed rack
- Hydraulic drive system
- Electrical control system
- Lubrication and cooling system
The base is a box-shaped structure welded by steel plates. The bed and the column are fixed on it.
There is a large space in the inner cavity of the base. The front left side is the electric button control box, the right side is the electric switchboard box, and the middle is made of steel plate welded hydraulic oil tank. The chamber is equipped with hydraulic pump station, hydraulic pipeline. The right side is cooling cutting fluid tank and water pump.
The frame is made of cast iron and is fixed to the base.
The column is composed of a large and small cylinder. The large round column acts as a guide rail for the saw frame to support the lifting movement of the saw beam up and down, and to ensure accurate guiding. The small cylinder plays an auxiliary role to ensure the normal cutting of the saw blade.
In the middle is a clamp vise and a manual feeding mechanism. The front of the vise is connected with a worktable for receiving the finished product. The clamping device on the left side is a clamping screw that passes through the inner hole of the hydraulic clamping cylinder rod, and rotates the hand wheel or pushes button to move the left jaw left and right.
(3) Saw beam and transmission mechanism
It is formed by cutting and welding thick steel plate and has strong rigidity.
The worm wheel box is fixed on the right rear side, and the worm wheel in the box is fixed with the driving wheel on the saw beam. The two rotate synchronously, and the left side is the passive wheel and the saw blade tensioning position.
The rotary motion of the saw blade is driven by the main motor, the pulley and the worm wheel to be transmitted to the driving wheel through two-stage shifting, and then driven by the driving wheel and the saw blade to drive the driven wheel. The saw blade has three running speed in total.
(4) Saw blade guiding device
The guiding device mounted on the saw beam support plate is composed of left and right guiding arms and guiding heads.
Both the left and right guide arms can be moved along the dovetail (or the right guide arm is fixed on the column sleeve), and the distance between the two guide arms is adjusted to be about 40 mm wider than the workpiece size.
The guiding device is used to change the mounting angle of the saw blade so that the saw blade is perpendicular to the table.
In order to ensure the cutting precision and reduce the vibration of the saw blade, a pair of guide wheels (rolling bearings) and wear-resistant guide blocks are arranged on the left and right guide arms, and the guide blocks of the wear-resistant alloy are also arranged on the back of the saw blade.
(5) Clamping mechanism
The right vise is fixed on the bed, the clamping screw passes through the inner hole of the hydraulic clamping cylinder, and the left vise is connected to the left and right along the guide rail by the screw, and is connected when the left vise is 10-30 mm away from the workpiece.
Press the control panel to clamp or loosen the clamp to clamp or loosen the workpiece.
(6) Tensioning device
The tensioning device is composed of a skateboard seat, a skateboard, a ball screw.
When the saw blade is to be tensioned, use a torque wrench to rotate in a clockwise direction to tighten the saw blade and make it in the work state.
If the sawing machine is in a long-term stop state, release the saw blade by the torque wrench rotates the saw blade in a counterclockwise direction.
The hydraulic transmission system consists of a hydraulic circuit consisting of pumps, valves, cylinders, fuel tanks, pipelines and other auxiliary components. Under the electrical control, the lifting of the saw beam and the clamping of the workpiece are completed.
Through the speed control valve, the stepless speed regulation of the feed speed can be realized to achieve the sawing needs of workpieces of different materials.
The electrical control system consists of a control circuit consisting of an electrical box, a control box, a junction box, a travel switch, an electromagnet, etc. It’s been used to control the rotation of the saw blade, the lifting of the saw beam, the clamping of the workpiece, etc., so that it can be operated according to certain working procedures to achieve a normal cutting cycle.
The lubrication system must be refueled according to the lubrication parts of the machine (wire brush shaft, worm gear box, active bearing housing, worm bearing, lifting cylinder upper and lower shaft, movable vise sliding surface clamping screw) before running.
The worm gear and the worm in the worm gear box are lubricated with a #30 oil, and are injected from the oil plug hole in the upper part of the worm gear box.
The box is equipped with an oil mark. When the saw beam is at the lowest position, the oil level should be between the upper and lower limits of the oil mark.
After one month of trial, the oil should be changed. After that, the oil should be changed once every 3-6 months. The lower part of the worm gear box is equipped with a drain plug.
The saw blade drives the motor mounted on the worm gear box through the pulley. The triangular tape drives the worm and the worm wheel in the worm gear box to drive the driving wheel to rotate, and then drives the saw blade wound around the active/passive rim to perform the cutting and turning motion.
The saw blade feed motion is a hydraulic circulation system consisting of a lift cylinder and a speed control valve to control the saw beam lowering speed to control the saw blade feed (stepless speed regulation) movement.
The saw blade rotates where the saw blade is chipped, and rotates in the direction of the saw blade, and is cooled by a cooling pump to remove the chips on the saw teeth.
The coolant is cooled in the cutting fluid tank on the right side of the base and directly driven by the water pump for the coolant.
Press the stop (stop) button, rotate clockwise, the oil pump motor works, the gear pump works, the oil enters the pipeline through the filter, and the relief valve is adjusted to make the working pressure of the system meet the requirements.
Otherwise the button is pressed inward and all motors stop working.
The workpiece is clamped according to the clamp button, the solenoid valve works, the hydraulic oil enters the left side of the clamp cylinder, the right hydraulic oil returns to the oil tank, and the left clamp clamps to the workpiece.
The saw beam descends by pressing the work button, the hydraulic oil enters the lift cylinder through the solenoid valve and has a rod cavity; the rodless chamber hydraulic oil passes through the electromagnetic valve, and the one-way speed control valve returns to the oil tank.
The saw beam is lowered by pressing the down button, the hydraulic pressure is operated by the solenoid valve, the oil enters the lift cylinder and has a rod cavity, and the rodless chamber oil is returned to the oil tank through the electromagnetic valve.
The saw beam rises and presses the up button, and the hydraulic oil enters the rodless cavity of the lift cylinder through the solenoid valve; the rod cavity oil passes through the solenoid valve and returns to the oil tank.
When the workpiece is loosened, press the clamp button, the hydraulic oil enters the right side of the clamping cylinder through the solenoid valve; the left hydraulic oil can pass the solenoid valve back to the oil tank, and the left jaw moves to the left to release the workpiece.
The analog input and output module of the system makes the monitoring of the sawing process have a wide range of significance. For example, the sawing machine can adjust the sawing speed adaptively by increasing the feedback of the saw blade deformation.
The servo valve is added to optimize the speed and position control of the sawing process.
The management functions of the system make the management of materials and workpieces more convenient.
The system’s Chinese interface and real-time graphical status display make the operation more friendly and intuitive.