05

 

The temperature represented by iron filings: white is less than 200 degrees

Yellow 220-240 degrees

Dark blue 290 degrees

Blue 320-350 degrees

Purple black is greater than 500 degrees

Red is greater than 800 degrees

06

 

FUNAC OI mtc general default G command:

G69: Not very clear

G21: Metric size input

G25: Spindle speed fluctuation detection disconnected

G80: Canned cycle cancellation

G54: coordinate system default

G18: ZX plane selection

G96 (G97): constant line speed control

G99: Feed per revolution

G40: Tool nose compensation cancel (G41 G42)

G22: Storage stroke detection is turned on

G67: Macro program modal call canceled

G64: Not very clear

G13.1: Polar coordinate interpolation method canceled

07

 

The external thread is generally 1.3P and the internal thread is 1.08P.

 

08

 

Thread speed S1200 / pitch * safety factor (usually 0.8).

 

09

 

Manual tool nose R compensation formula: chamfering from bottom to top: Z=R*(1-tan(a/2)) X=R(1-tan(a/2))*tan(a) From top to bottom Get off the chamfer will be reduced to add.

 

10

 

For every 0.05 increase in feed, the speed is reduced by 50-80 rpm. This is because lowering the speed means that the tool wear is reduced, and the cutting force is increased more slowly, thereby making up for the increase of the cutting force due to the increase of the feed, and the increase of the temperature. Impact.

 

11

 

The cutting speed and the influence of the cutting force on the tool are the main reasons why the cutting force is too large to cause the tool to collapse. The relationship between cutting speed and cutting force: the faster the cutting speed, the constant the cutting force, the slower the cutting force, and the faster the cutting speed, the faster the tool wears, the larger the cutting force, the more the temperature will come. The higher the cutting force and internal stress are, the more the blade can not withstand the chipping (of course, there are also reasons for the temperature and pressure drop caused by the temperature change).

 

 

12

 

When processing CNC machines, the following points should be paid special attention:

(1) For the current economic CNC lathes in China, the ordinary three-phase asynchronous motor is generally used to realize stepless speed change through the frequency converter. If there is no mechanical deceleration, the spindle output torque is often insufficient at low speed. If the cutting load is too large, it is easy to be stuffy. The car, but some gears with gears on the machine solve this problem very well.

(2) As far as possible, the tool can complete the machining of one part or one work shift. In particular, the large-piece finishing should pay attention to avoiding the middle of the tool change to ensure that the tool can be processed in one time.

(3) When using CNC machine to turn the thread, use high speed as much as possible to achieve high quality and efficient production.

(4) Use G96 whenever possible.

(5) The basic concept of high-speed machining is to make the feed exceed the heat conduction speed, so that the cutting heat is discharged along with the iron filings to isolate the cutting heat from the workpiece, ensuring that the workpiece does not heat up or heat up. Therefore, high-speed machining is very high. The cutting speed is matched with the high feed and the smaller backing knife is selected.

(6) Pay attention to the compensation of the tool nose R.

 

13

 

 

Workpiece material cutting workability classification table (small P79)

Common thread cutting times and backing knife scale (large P587)

Common geometry calculation formula (large P42)

Inch and millimeter conversion table (large P27)

 

14

 

Vibration and chipping often occur in the trough. All the root causes are the cutting force and the rigidity of the tool. The shorter the tool extension length, the smaller the back angle, the larger the blade area and the better the rigidity. With the larger cutting force, but the larger the width of the slot cutter, the cutting force can be increased correspondingly, but its cutting force will also increase. On the contrary, the slot cutter is small, and the force it can bear is small, but its The cutting force is also small.

 

15

 

Reasons for vibration during the trough:

1) The length of the tool extension is too long, and the rigidity is reduced.

2) The feed rate is too slow, causing the unit cutting force to increase and causing a large vibration. The formula is: P=F/back knife amount *f P is the unit cutting force F is the cutting force, and the rotation speed is too fast. Will vibrate the knife.

3) The rigidity of the machine tool is not enough, that is to say, the tool can bear the cutting force, but the machine can't bear it. To put it bluntly, the machine tool does not move. Generally, the new bed will not have such problems. The bed with such problems is either old or It is often encountered by machine tool killers.

 

16

 

When I was in a car, I found the size at the beginning, but after a few hours I found that the size changed and the size was unstable. It may be because the knife is new at the beginning, so the cutting force is not very Large, but after a period of time, the tool wears and the cutting force becomes larger, causing the workpiece to shift on the chuck, so the size is old and unstable.