Grinding characteristics and safe operation rules of centerless grinder

The centerless external grinding is carried out on a centerless grinding machine. The workpiece is placed between the guide wheel and the grinding wheel. One of the grinding wheels is used for grinding and the other is used for transmission, which is called the guide wheel. The lower part of the workpiece is supported by a pallet. The guide wheel is made of rubber bond, and its axis forms an angle θ with the grinding wheel in the vertical direction to drive the workpiece to rotate and feed.

When using centerless grinding, the grinding wheel rotates at a peripheral speed that is about 75 times greater than that of the guide wheel. Since the friction between the workpiece and the guide wheel is greater than the friction between the workpiece and the grinding wheel, the tolerance level of the workpiece after the workpiece is driven by the guide wheel and ground is IT6~IT7, and the surface roughness value is Ra0.8~0.01um .

1. When feeding the workpiece by hand, the distance from the hand to the grinding wheel should be more than 50 mm, and don’t hold it too tight.
2. When feeding with a push rod, hold the push rod firmly, and it is forbidden to use metal rods.
3. When adjusting the grinding amount, there should be no less than 3 test-grinding workpieces.
4. When correcting the grinding wheel, feed the knife slowly and give sufficient coolant to prevent damage to the diamond.
5. When the workpiece is skewed in the middle of the grinding wheel, stop urgently.
6. ​​When grinding rod materials, the center between the support frame, the grinding wheel and the guide wheel is required to be in a straight line. It is strictly forbidden to grind the material.
7. When the workpiece is not ground out of the grinding wheel, it is not allowed to take it out. When picking up the workpiece, hold the workpiece quickly and stop its rotation.
8. The workpiece on the material rack should be placed to prevent it from rolling and hurting people.
9. Wear gloves when installing the screw wheel; hold the inner hole of the screw wheel, not the outside of the screw wheel.
10. The blade of the unintentional sharpening board should be blunt to prevent cutting the hand.
11. Do not add an aniseed material that exceeds the specification. When you find an anomaly, take it out immediately to prevent accidents.
12. The replacement of the grinding wheel should comply with the general safety regulations of the miller.

Note the following when operating a centerless grinder:
(1) Check the surrounding conditions of the machine before starting the machine. No objects should be placed on the machine and the workpieces should be placed neatly. [Metal processing WeChat, the content is good, worthy of attention]
(2) Before starting the machine, check whether the berth is normal, the water level of the cooling water tank, the clearance between the grinding wheel and the guide wheel and the supporting blade is normal, and whether there is work or debris in the machine tool.
(3) Check whether the switch is reliable before starting up, and confirm whether the safety protection of the protective cover is effective.
(4) Turn on the power, start the hydraulic switch, observe whether the pressure of the hydraulic gauge of the machine tool is normal, and then check whether there is oil flowing through each port mirror and each port pipe.
(5) Before turning on the grinding wheel, the guide wheel dressing seat must be wiped clean, and the tank is filled with oil.
(6) The operators must be trained in accordance with the work instructions before starting up, so that they can understand the various work operation procedures.
(7) After the above confirmation is correct, the machine can be turned on.
(8) Turn on the main power to the ON position. 09: Turn on the hydraulic switch to the ON position.
(9) Check the parking mirror of the hydraulic system and start the grinding wheel and guide wheel only after the oil gauge is stable.
(10) After the grinding wheel and guide wheel are running normally, turn on the water pump and adjust to the proper water volume.
(11) Adjust the machine to test grind 1-3 workpieces, first check the size and appearance of the workpiece, and put the adjusted product in the adjustment box.
(12) Adjust the machine to test grind 1-3 workpieces, first check the size and appearance of the workpiece, and put the adjusted product in the adjustment box.
(13) Mass production can only be carried out after passing the test.
(14) After starting production, the operator must self-check and record the first sample in accordance with the work instruction.
(15) In the event of an abnormality during the production process, report the shutdown immediately and fill in the relevant form.
(16) When shutting down, switch the water pump motor to the OFF position to stop the water supply and take out the work that is stuck in the machine tool.
(17) The grinding wheel and guide wheel should be idling for more than 5 minutes to stop the water supply to avoid imbalance of the grinding wheel when the machine is turned on again. Turn the power switch of the grinding wheel and guide wheel to OFF position until the moisture is dried.
(18) After the grinding wheel and guide wheel are stopped, the oil pressure switch can be turned to the OFF position (the oil pressure motor must not be stopped first to avoid loss of oil and wear of the bearing bush and spindle).