Carbon electrode grinding apparatus

1. A carbon electrode grinding apparatus for shaping a front end of an arc discharge carbon electrode, comprising:

front end grinding blades configured to grind a front end surface of the carbon electrode;

lateral surface grinding blades configured to grind a lateral periphery surface from the front end surface to a base end of the carbon electrode; and

a rotator configured to rotate and drive the front end grinding blades and the lateral surface grinding blades around a rotation axis line coincident with an axis line of the carbon electrode, wherein the rotator has four guide sections at positions divided in quarters with respect to the rotation axis line, the guide sections include two front end blade-guide sections to which the front end grinding blades are attached and two lateral periphery blade-guide sections to which the lateral surface grinding blades are attached, a first attachment section is formed in the front end blade-guide section to attach each of the front end grinding blades, and a second attachment section is formed in the lateral periphery blade-guide section to attach each of the lateral surface grinding blades.

2. The carbon electrode grinding apparatus as claimed in claim 1 , wherein the front end grinding blades and the lateral surface grinding blades are attached to have a symmetrical position relationship using the rotation axis line as a symmetrical point.

3. The carbon electrode grinding apparatus as claimed in claim 1 , wherein the lateral surface grinding blades are provided so as to extend in a direction along the rotation axis line, and are provided to become more distant from the rotation axis line from one end of the lateral surface grinding blades located at the front end grinding blade side toward the other end thereof.

4. The carbon electrode grinding apparatus as claimed in claim 1 , wherein the front end grinding blades are provided so as to extend in a direction perpendicular to the rotation axis line.

5. The carbon electrode grinding apparatus as claimed in claim 1 , wherein the front end grinding blades are attached to two sections of the guide sections which are not adjacent to each other around the rotation axis line, and the lateral surface grinding blades are attached to the other two sections of the guide sections which are not adjacent to each other around the rotation axis line.

6. The carbon electrode grinding apparatus as claimed in claim 5 , wherein the front end blade-guide sections to which the front end grinding blades are attached and the lateral periphery blade-guide sections to which the lateral surface grinding blades are attached are arranged so as to be adjacent to each other around the rotation axis line.

7. The carbon electrode grinding apparatus as claimed in claim 1 , wherein a dummy blade is formed in at least one of the guide sections, to which the front end grinding blades and the lateral surface grinding blades are not attached.

8. The carbon electrode grinding apparatus as claimed in claim 1 , wherein the two front end grinding blades are attached to two of the guide sections which are not adjacent to each other, and the two lateral surface grinding blades are attached to the other two of the guide sections which are not adjacent to each other.

9. The carbon electrode grinding apparatus as claimed in claim 1 , wherein the front end blade-guide sections to which the front end grinding blades are attached do not perform grinding by the lateral surface grinding blades, and the lateral periphery blade-guide sections to which the lateral surface grinding blades are attached do not perform grinding by the front end grinding blades.