Security Operation Guidelines
Safety Precautions
- Non-employees are prohibited from entering the water shutoff operation room.
- It is strictly prohibited to extend any part of the body into the high pressure water spray area.
- During work, operators must wear protective glasses and work clothes.
- It is strictly prohibited to disassemble the hydraulic clamping system under pressure or connect the threaded connection of the high-pressure pipeline under pressure.
- During operation, avoid collisions between the body and the high-pressure water pipe.
- When the machine is running, no one can stand on either side of the ultra-high pressure generator.
- In case of a leak in the piping, first turn off the power supply and then treat the leaking part to avoid electric shock.
I. Startup Preparation
Check whether the oil tank is low on oil, add oil to the upper limit of the oil level gauge in the oil tank, and tighten the oil tank cap. Loosen the oil pipe on the plunger pump return port and pour oil into the plunger pump until it is full, then tighten the return oil pipe.
Turn on the air pump and turn on the air gun switch when the pressure at the air pump outlet is ≥0.4 MPa. Air spraying indicates that the gas supply is normal.
Start the water supply pressurization pump power supply, observe the water pressure indicator ≥0.2 MPa, and water flows into the joint of the cutter head and connecting rod, indicating that the cutting water supply is normal.
II. Hydraulic System Debugging
Turn on the main electrical switch on the side of the high pressure generator, the power switch on the industrial computer, and after the industrial computer enters the WINDOWS boot interface, click the waterjet cutting software to enter the boot interface. software control.
Momentarily press the “Oil Pump Switch” button to verify that the engine rotates in the same direction as the arrow on the oil pump body.
Start the oil pump motor and adjust the relief valve control pressure to a low value.
Open the one-way double butterfly valve at both ends of the electro-hydraulic reversing valve, adjust the magnetic switch to the appropriate position, and the booster will be in the idling state. Run for 5 to 10 minutes, observe whether there is no abnormality in the oil temperature and pump head temperature, and turn off the oil pump by pressing the “Oil Pump Switch” button to complete the debugging of the hydraulic system.
III. Debugging the high pressure generator system
Install the power converter (gem), press the “Oil Pump Switch” button to turn on the oil pump, press the “Air Valve Switch” to turn on the cutting head high pressure water switch, and press the “High Pressure Switch” button to start the high pressure generator. The cutting head will spray water at high pressure.
Note: When operating in manual interface mode, first turn on the air valve switch and then turn on the high pressure switch, otherwise it may cause a dangerous build-up of pressure in the system. When disconnecting, turn off the high pressure switch first and then the air valve switch.
Adjust the relief valve knob to gradually increase pressure in the sections. Keep it at 1-2 minutes for every 1MPa increase. During adjustment, pay attention to check whether there is oil or high-pressure water leakage, abnormal vibration and noise. Stop adjusting when the pressure gauge pointer is at 15 MPa and the oscillation range is ≤3 MPa.
Adjusting the electro-hydraulic reversing valve: Check whether there is any impact sound in the hydraulic cylinder. If so, determine which side it is on and adjust the one-way double choke valve on that side clockwise until the impact sound disappears.
Repeat turning the high pressure water switch on and off. If the high pressure water switch is sensitive, the debugging of the high pressure generator system will be completed.
III. Cutting operation
Raise the steel plate onto the cutting deck and adjust the bottom and sides of the steel plate to be parallel to the deck's X and Y axes, respectively.
Load the cutting sand into the sand bucket and connect the sand pipe.
Copy the DXF graphic file to your computer.
Load the graphic file to be cut into the cutting interface.
Move the cutting head to the origin of the graphic file setting, adjust the distance between the cutting head and the height of the steel plate, set the current coordinates to “0,0,0” in the “Manual” interface, and set the “Cut Speed” and “Relay Delay” options in the “Parameter Settings” interface.
In the “Auto” interface, press the “Start from beginning” button to start cutting.
4. Precautions and treatment for abnormal situations during the cutting process
Pay close attention to the distance between the cutting head and the plate during the cutting process. The best cutting height of the workpiece cutting head is 3mm to 5mm. It is strictly prohibited to operate without supervision, which may cause the sand tube to break, serious damage to the cutting head and traveling mechanism of the machine.
If the sand breaks during the cutting process, immediately press the “ESC” key to stop the machine and handle the sand valve and sand distribution pipe. Cut out any uncut portion. The method consists of pressing “Begin Any Section” on the “Auto” interface, entering the program section number and pressing “OK” to start cutting a previous section of the program.
Before replacing the workpiece after cutting a workpiece, move the cutting head to the opposite end to prevent the cutting head from being damaged during loading.
The oil temperature during cutting must be controlled below 65°C. Immediate cooling measures must be taken if the oil temperature exceeds this value.
If one of the following situations occurs, stop the machine immediately for maintenance:
- The high pressure is working normally, but there is no high pressure water coming out of the cutting head.
- High-pressure water intermittently comes out of the cutting head and the pressure gauge fluctuates between 0-15 MPa.
- Cracks, twists, deformations and medium leaks occur in high-pressure parts and pipelines.
V. Termination
After completing all work, exit the system, turn off the computer using the WINDOWS interface, then turn off the main electrical switch on the side of the high pressure generator and, finally, turn off the power supply to the cutting water pressurization pump and the air pump power supply.
Process Parameters of Waterjet Cutting Machine
1. Relationship between cutting plate thickness and cutting speed
| Material | Thickness (mm) |
Cutting speed (mm/min) |
Cutting pressure (MPa) |
| Steel sheet
stainless steel plate |
two 5 10 20 40 80 100 |
850~1100 400~550 160~240 60~90 25~40 10~15 3~5 |
300
(The pointer shakes, according to the central value) |
| Note: The slower the cutting speed, the better the cutting quality. | |||
| Material | Thickness (mm) |
Cutting speed (mm/min) |
Cutting pressure (MPa) |
| aluminum plate | two 5 10 20 40 80 |
1100~1500 650~950 240~360 120~180 50~80 20~30 |
300
(The pointer shakes, according to the center value) |
| Note: The slower the cutting speed, the better the cutting quality. | |||
The following image shows a cutting cross section, which guarantees a normal cutting effect of roughness 3 and cannot be lower than this.
2. Inspection points and normal values when the machine is operating normally.
Oil temperature: ≦ 65℃
Secondary pressurized pump outlet water pressure: 6~8 kgf/cm 2
2. Normal service life of machine consumables
Jewelry lifespan: 50~80 hours
Sand tube life: 200 hours
Common faults and maintenance of high pressure CNC water jet cutting machine
| Serial number | Failure phenomenon | Cause of occurrence | Elimination methods |
| 1 | Oil pump noise | 1) Blocked suction oil filter | Clean or replace the oil filter core with a new one |
| 2) The viscosity of the oil is too high | Use lubricating oil with specified grades according to the seasons | ||
| 3) The fuel tank is not breathable | Clean the oil tank air filter element | ||
| 4) Low fuel tank level | Fill to the upper limit of the liquid level gauge | ||
| two | There is foam in the oil | 1) Leak in the oil suction tube | Eliminate air leak or replace with new tube |
| 2) Oil pump shaft seal leak | Replace the sealing ring | ||
| 3 | Excessive heating of the oil pump | 1) Worn or damaged oil pump | Repair or update |
| 2) Oil viscosity is too low, too high or deteriorated | Replace with new oil | ||
| 4 | Overflow valve whistling | Damaged valve spring or core or blocked damping hole | Replace damaged parts or clean them |
| 5 | Oil temperature too high | Overflow Valve Excessive Overflow Rate | Reduce overflow to match high pressure |
| 6 | Pressureless hydraulic system | 1) There is air in the oil pump head and the oil has not come out | Remove the oil return tube for inspection and fill the pump head with oil |
| 2) Solenoid valve core is stuck or has no signal | Clean overflow valve or restore electrical signal | ||
| 7 | No high pressure water spraying from the blade | 1) The hydraulic system has no pressure outlet | Reference hydraulic system without pressure treatment |
| 2) Cutting water not supplied | Check the water supply pump and booster pump | ||
| 3) Clogged high pressure filter | Clean the filter screen | ||
| 4) Blade gemstone blocked or water switch not turned on | Check the above components | ||
| 8 | Booster does not change direction | 1) Blade gemstone blocked or water switch not turned on | Check the above components |
| 2) The core of the electro-hydraulic directional valve is stuck | Clean the valve core | ||
| 3) Electrohydraulic directional valve not receiving signal | Eliminate faults and ensure that the electro-hydraulic directional valve receives a signal | ||
| 9 | When reversing, the pressure gauge needle oscillates excessively | If one side returns to zero | |
| 1) Check for leakage (overheating) of the one-way valve | Replace the high pressure valve core and spring | ||
| 2) Check the plug assembly | Check whether the low pressure valve core is loose | ||
| 3) Damaged high pressure sealing rubber ring | Replace the high pressure seal ring | ||
| 4) Damaged hydraulic cylinder piston seal ring | To replace | ||
| If both sides return to zero | |||
| 1) There is no power converter installed (gem) | Install | ||
| 2) Check the high pressure piping for leaks | Eliminate leaks | ||
| 3) Insufficient or leaking hydraulic pressure | Problems solution | ||
| 10 | There is a knocking sound coming from the left and right turbochargers at different reverse speeds | The one-way double butterfly valve is not adjusted correctly | Adjusting the one-way double butterfly valve |
| 11 | The pressure gauge indicates that the pressure cannot be relieved | 1) Blocked power converter | to replace |
| 2) High pressure water switch not turned on | Turn on the high pressure water switch | ||
| 3) Relief valve solenoid has no signal or is stuck | Check signal circuit and overflow valve | ||
| 12 | Water leakage at the interface between the high pressure cylinder end cap and the high pressure cylinder | High pressure cylinder end cap or damaged high pressure cylinder | Replace the high pressure cylinders at both ends, |
| 13 | Water leaking from cylinder end cover observation hole | Damage to the high pressure ring | To replace |
| 14 | Water and oil leaking from the small hole in the cylinder end cap | Damaged piston rod | Replace piston rod Y-shaped sealing ring and D3 |
| 15 | Water leaking from the observation hole in the water switch valve body | Damaged sealing ring or pressure ring | Replace the sealing ring or snap ring |
Note: Droplet water or oil leakage can be temporarily ignored, but continuous water or oil leakage in a line must be stopped for maintenance.
