Control apparatus for cutting machine and method of indication

• US 20020117021A1
• Filed: 01/22/2002
• Published: 08/29/2002
• Est. Priority Date: 12/21/2000
• Status: Active Grant

• Current Assignee: Hiroki Nakahira, Katsuaki Ono
• Original Assignee: MORI Seiki Company Limited
• Inventors: Ono, Katsuaki, Nakahira, Hiroki
• Granted Patent: US 6,819,973 B2
• Time in Patent Office: Days
• US Class Current: 74/813R
• CPC Class Codes: G05B 19/404 characterised by control arrangements for compensation, e.g. for backlash, overshoot, tool offset, tool wear, temperature, machine construction errors, load, inertia G05B19/19, G05B19/41 take precedence
• CPC Class Codes: G05B 2219/37016 Calibrate dc offset, measure offset and maintain fixed level
• CPC Class Codes: G05B 2219/50278 Send offset values from tool changer before machining
• CPC Class Codes: G05B 2219/50289 Tool offset general
• CPC Class Codes: Y10T 74/14 Rotary member or shaft indexing, e.g., tool or work turret
• CPC Class Codes: Y10T 74/1418 Preselected indexed position

Abstract

The present invention is directed to provide a control apparatus for a cutting machine in which offset values on coordinates relative to the cutting machine are indicated, regardless of the position of the turret, and an operator need not calculate the offset values in the cutting process. This invention is characterized in that an X-axis offset value (ΔX) and a Z-axis offset value (ΔZ) of a cutting edge of the cutting tool when the turret 1 has been turned to an arbitrary angle are converted to values on coordinates relative to the cutting machine, and indicated.

Claims

1. A control apparatus for numerical control adapted for a cutting machine having a turret which can be turned to an arbitrary position, wherein

an X-axis offset value (Δ

X) and a Z-axis offset value (Δ

Z) of a cutting edge of a cutting tool on coordinates with respect to said cutting machine are calculated in accordance with a turning angle of said turret, and

said X-axis offset value and said Z-axis offset value are indicated on a display.

2. A control apparatus according to claim 1, wherein an X-axis wear compensation value (Δ

Xt) and a Z-axis wear compensation value (Δ

Zt) are indicated in relation to said X-axis offset value (Δ

X) and said Z-axis offset value (Δ

Z).

3. A control apparatus according to claim 1, wherein when said turret is turned to a turning angle (α

), an X-axis value of the tool (L2), a Z-axis value of the tool (L1), an X-axis value of the turret (L4) and a Z-axis value of the turret (L3) are converted according to the following equations to calculate said X-axis offset value (Δ

X) and said Z-axis offset value (Δ

Z).

Δ

X=(Δ

Az·

cos α

−

Δ

Ax·

sin α

)×

2 

 

(Equation

     1) Δ

Ax=L2+L4 Δ

Az=L1+L3 Δ

Z=−

Δ

Az·

sin α

−

Δ

Ax·

cos α

 

 

(Equation

     2)

4. A control apparatus according to claim 2, wherein when said turret is turned to a turning angle (α

), an X-axis value of the tool (L2), a Z-axis value of the tool (L1), an X-axis value of the turret (L4) and a Z-axis value of the turret (L3) are converted according to the following equations to calculate said X-axis offset value (Δ

X) and said Z-axis offset value (Δ

Z).

Δ

X=(Δ

Az·

cos α

−

Δ

Ax·

sin α

)×

2 

 

(Equation

     1) Δ

Ax=L2+L4 Δ

Az=L1+L3 Δ

Z=−

Δ

Az·

sin α

−

Δ

Ax·

cos α

 

 

(Equation

     2)

5. A control apparatus according to any one of claims 1 through 4, wherein said cutting tool can be rotated around the tool axis to an arbitrary position,

an X-axis value (L2r) of said cutting edge of said cutting tool after a rotation of said cutting tool with a rotation angle (β

) is calculated according to the equation of L2r=L2·

cos β

,

said X-axis offset value and said Z-axis offset value when said turret is turned to a turning angle (α

) are calculated according to the following equations 3 and 4, and

said X-axis offset value (Δ

Xr) after the rotation of said cutting tool and said Z-axis offset value (Δ

Zr) after the rotation of said cutting tool are indicated on said display.

Δ

Xr=(Δ

Az·

cos α

−

Δ

Axr·

sin α

)×

2 

 

(Equation

     3) Δ

Axr=L2+L4 α

Az=L1+L3 Δ

Zr=−

Δ

Az·

sin α

−

Δ

Axr·

cos α

 

 

(Equation

     4)

6. A method of indicating an X-axis offset value (Δ

X) and a Z-axis offset value (Δ

Z) of a cutting edge of a cutting tool, in a control apparatus for a cutting machine having a turret which can be turned to an arbitrary position, said method comprising the steps of;

reading an X-axis value of the tool (L2) and a Z-axis value of the tool (L1) of the selected cutting tool;

reading an X-axis value of the turret (L4);

storing a Z-axis value of the turret (L3) in memory;

reading a turning angle (α

) of said turret;

calculating said X-axis offset value (Δ

X) and said Z-axis offset value (Δ

Z) according to the following equations 1 and 2, employing said X-axis value of the tool (L2), said Z-axis value of the tool (L1), said X-axis value of the turret (L4) and said Z-axis value of the turret (L3); and

indicating said X-axis offset value (Δ

X) and said Z-axis offset value (Δ

Z)

Δ

x(Δ

Az·

cos α

−

Δ

Ax·

sin α

)×

2 

 

(Equation

     1) Δ

Ax=L2+L4 Δ

Az=L1+L3 Δ

Z=−

Δ

Az·

sin α

−

Δ

Ax·

cos α

 

 

(Equation

     2)

7. A control apparatus for numerical control adapted for a cutting machine in which a cutting tool is rotated around the tool axis thereof to an arbitrary position, wherein an X-axis value (L2r) of a cutting edge of said cutting tool on a coordinate with respect to said cutting machine is calculated in accordance with a rotation angle of said cutting tool,

an X-axis offset value (Δ

Xr) after the rotation is obtained from the following equations employing said X-axis value of the tool (L2r) and an X-axis value of the turret (L4), and

said X-axis offset value (Δ

Xr) after the rotation is indicated on a display.

Δ

Xr=Δ

Axr×

2 Δ

Axr=L2r+L4

9. A control apparatus according to claim 7 or 8, wherein a Y-axis offset value (Δ

Y) of said cutting edge of said cutting tool on coordinates with respective to said cutting machine is calculated in accordance with the rotation angle of said cutting tool, and

an X-axis wear compensation value (Δ

Xt) and a Y-axis wear compensation value (Δ

Yt) are indicated in relation to said X-axis offset value (Δ

Xr) after the rotation and said Y-axis offset value (Δ

Y).

8. A control apparatus for numerical control adapted for a cutting machine in which a cutting tool is rotated around the tool axis to an arbitrary position, wherein a Y-axis offset value (Δ

Y) of a cutting edge of said cutting tool on a coordinate with respective to said cutting machine is calculated in accordance with a rotation angle of said cutting tool, and said Y-axis offset value is indicated on a display.