Using a double indexing head milling small lead spiral groove on the X5032 vertical milling machine

When the milling head is used to connect the milling groove to the milling machine, the calculation formula of the hanging wheel is:

i=z1/z2×z3/z4=40P/L=40P/Dπcotβ

Where i is the gear ratio between the indexing head spindle and the table longitudinal feed screw;

Z1, z3 - the number of active hanging gears;

Z2, z4 - the number of teeth of the passive hanging wheel;

40 - the number of divisions;

P——Workpiece screw pitch, P=6mm;

L——the workpiece lead;

D——the outer diameter of the workpiece;

β——The spiral angle of the workpiece spiral groove.

If a small lead spiral groove is milled on the X5032 vertical milling machine, the lead L=9mm, and the formula is:

i=z1/z2×z3/4=40P/L=(40×6)/9=26.6667

In practice, there is no hanging wheel set with a hanging wheel ratio of 26.6667. It can be seen from the hanging wheel table that the maximum speed ratio and the minimum speed ratio of the hanging wheel are 14.4000 and 0.06944, respectively, that is, 0.06944 ≤ i ≤ 14.4000, that is, the range of the lead change is 16.67 mm ≤ L ≤ 3456.00 mm, then the lead L = 9mm has exceeded the range of the processed lead.

In order to solve the above problem, a double indexing head can be used. Install an indexing head II between the indexing head I and the longitudinal feed screw of the vertical milling machine table, and connect the hanging wheel shaft of the indexing head I with the hanging wheel of the indexing head II with a Z to Zb gear. The hanging wheel is installed between the main shaft of the indexing head II and the table screw. Thus, the indexing head II is the required speed increasing device, the speed increasing ratio is 40, and the dividing head I is for clamping the workpiece and indexing. At work, it should be noted that the indexing handle of the indexing head I must be rotated to make the milling table work longitudinally. It is forbidden to use the table for motorized feeding, otherwise the worm gear pair of the indexing head II will be damaged.

After such a change, the calculation formula of the hanging wheel ratio is:

Ii=Z1/Z2×Z3/Z4=P/L×Za/Zb=P/Dπcotβ×Za/Zb

Usually when processing, Za:Zb=1:1

I=Z1/Z2×Z3/Z4=6/L=6/ Dπcotβ

When processing small leads, Za:Zb=1:2

Ii= Z1/Z2×Z3/Z4=3/L=3/ Dπcotβ

The calculated hanging wheel ratio can also be used to find the hanging wheel matching group.

Now calculate the hanging wheel of the small lead workpiece in front.

Solution: The formula shows that the hanging wheel ratio is:

i= Z1/Z2×Z3/Z4=6/L=6/9=0.6667

Check the hanging wheel table: Z1/Z2×Z3/Z4=100/90×60/100