JPS60123211A - Equihelical machining method of tool - Google Patents

Abstract

PURPOSE:To perform the machining of metals speedily and surely, by conducting automatic operation with only necessary data inputted into a NC system by means of a computer-numerical control method. CONSTITUTION:A grinding wheel 4 is opposed to a taper surface 2 of a tool 1 having a taper angle theta with a helical angle phi. Then, each of numerical values (X, theta, phi, small end O.D., large end O.D., tool length and rake angle) of tha tool 1 is inputted into a computer-numerical-control system (unillustrated herein). With this, the CNC system automatically calculates an infeed stroke Z- of the wheel 4 to a divided value X- and a turning angle A- of the tool 1 or the like and thereby controls rotation in both the tool 1 and the wheel 4, making equihelical machining set forward.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a processing method for grinding or cutting an equihelical cutting edge on the outer peripheral surface of a tapered tool.

For example, in order to grind a cutting edge of one nokal onto the outer peripheral surface of a taper end mill, etc., the taper angle, outer diameter, Z-axis depth of cut, X-axis division value, etc. must be adjusted so that the helix angle of the end mill remains constant. Grinding must proceed while processing various information. Conventionally, this grinding process was done mechanically, so the end mill was moved along the helical cam by tracing the helical cam.
Cal processed. The disadvantage of this mechanical method is that a complicated mechanism for helical machining must be mounted on the tool grinder, which is disadvantageous because it occupies space, and there is no adjustment means when changing the end mill. Unable to handle this, we had to replace it with another mechanism.

In view of the above situation, the present invention uses a CNC numerical control method to
A processing method has been developed in which an equihelical cutting edge is cut or ground on the outer peripheral surface of a tapered tool, and when cutting from the tool tip to the base, the rotation angle of the tool is changed every unit length in the tool length direction. Control is based on the helical constant, division value variable, and correction value of the rake face angle, and this enables equihelical machining.

A brief explanation of the drawings will be given below. 1 shown in Fig. 1 is a tool such as an end mill, and its tip has a tapered outer peripheral surface (tapered blade surface) 2 with a taper angle θ, and a cutting edge 2 α with a helical angle φ. ing. The above cutting blade 2a...
- is a grindstone 4 attached to an index rotation shaft (not shown) and a rotation shaft 3 of a tool grinder (not shown)
Grinded by. This rotating shaft 3 can be rotated horizontally and in the direction of the water belly. That is, with respect to the tool 1, the grindstone 4 is opposed to the Taber outer peripheral surface 2 at a helix angle of φ,
The depth of cut of the grindstone relative to the tool is adjusted according to the taper angle θ and the feed amount in the tool length direction, and the rotation angle A of the tool for equihelical grinding is adjusted by adjusting the torsion per unit length in the tool length direction. Grinding is performed using a processing method that is controlled by setting variables and rake angle correction values.

Next, to explain a machining example, in tool 1 of a Taber end mill where the angle of the Taber surface is 0, the longitudinal direction of the tool (
The division value (unit length for grinding) of the X axis, which is the tool length direction), is defined as X, and this value is usually 0.05 to 300 m1m.
It is carried out within the range of The amount of cut 2 of the grindstone 4 into the tool 1 is given by "z - division value x tα rule θ".

Further, the rotation angle A of the tool 1 is given by "A-axλog (division value constant) ten-point rake angle correction value". That is, the helical constant α is [α-(180/π)×(torsion angle/
The division value variable is given by "division value/b - division value variable". In addition, the rake angle a is determined by the small diameter tip 2a of the tool 1, which is the machining starting point, as shown in FIG.
If a predetermined rake angle a is set on the I side, the rake angle decreases from α to α' as it moves toward the large diameter side 2b. Therefore, a correction value α' for the rake angle that gradually increases is added so that the rake angle α is constant over the entire length of the taper surface of the cutting edge. FIG. 3 shows a curve corresponding to the division value of the grindstone 4 that moves this correction value α1 in the tool length direction.

Accordingly, in the equihelical machining method of a tool such as a taper end mill of the present invention, first, as shown in FIG. 1, a grindstone 4 is opposed to the taper surface 2 of the tool 1 having a taper angle θ at a helix angle φ. Then, to a CNC numerical control device (not shown),
Each value of tool 1 (X.

0, φ, small end outer diameter, large end outer diameter, tool length, rake angle, etc.). Now, the CNC numerical control device calculates the division value
The cutting depth 2- of the grindstone 4 with respect to 1-1, the rotation angle A-2 of the tool 1, etc. are automatically calculated to control the rotation axes of the tool 1 and the grindstone 4, and the helical car U machining is proceeded.

That is, each time the grindstone 4 moves on the tool by the amount of movement X per unit length (divided value), "amount of cut 2 = divided value X tan θ"
and "rotation angle A - helical constant x 20g division value variable - rake angle correction value" of tool 1 are corrected, and an equihelical cutting edge 2σ is cut and ground on the Taber blade surface 2.

As described above, when using the equihelical processing method of the present invention,
When grinding from the tip of a tool such as a Taber end mill to the large-diameter base, the rotation angle A of the tool and the cutting depth Z of the grindstone are calculated as "Z - division value x tan θ" every time the unit length division value is advanced in the tool length direction. Since the correction is controlled using "A - helical constant Just by inputting the information, automatic operation has the effect of quickly and reliably performing equal helical machining.

[Brief explanation of drawings]

Fig. 1 is a side view showing cutting (grinding) of a tool by the equihelical machining method of the present invention, and Fig. 2 is a tool end view and partial view showing the relationship between rake angle correction values as the tool diameter changes. , FIG. 3 is a curve diagram showing the rake angle correction value with respect to the tool division value. 1... Tool, 2... Tapered outer peripheral surface, 2a... Cutting edge, 3... Rotating shaft, 4... Grindstone, φ... Helix angle,
θ... Taper angle, X... Division value, Z... Depth of cut, A... Tool rotation angle, α... Rake angle, α'...
・Rake angle correction value, 2a'...Small diameter side, 2h...
Large diameter side. Applicant Dashu Seisaku Co., Ltd. (σ) (b) 72M 13 Group

Claims (1)

[Claims] When advancing the grindstone from the small diameter tool tip to the large diameter side and grinding at a predetermined helix angle φ, each time the unit length division value X is advanced in the tool length direction, the cutting depth 2 of the grindstone and the rotation angle A of the tool are increased.
An equihelical machining method for a tool, characterized in that correction control is performed using "2 - division value x tctrLθ" and "A - helical constant x og division value variable - correction value of A angle".