JP2005131731A - Method for manufacturing solid end mill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a solid end mill by which very excellent positioning accuracy in the range of ≤ 5 μm can be realized, the positioning of a grinding wheel can be further accurately executed in a short period of time, a setup time can be shortened, and the working costs can be reduced. <P>SOLUTION: The method for manufacturing a solid end mill has the following characteristics. A part to be gripped of an exciting type sensor being a detection object is clamped by the same chuck as the chuck used for an end mill blank being an object to be worked by using a one chuck NC tool grinding machine. A conductive connection member is mounted to the contact part and connected to a machine body through a power supply switch. The grinding wheel, which is an object to be detected mounted to a grinding wheel flange in a state of turning on the power supply switch, is moved toward the exciting type sensor in parallel to a rotary shaft of the grinding wheel by an NC program. When the grinding wheel comes into contact with the contact part of the exciting type sensor and dielectric breakdown occurs, a closed loop is formed and it is energized. Consequently, positional detection can be executed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing a solid end mill using a one-chuck NC tool grinder, and more particularly to a method for producing a small-diameter solid end mill having a shank diameter of 6 mm or less.

The demand for improving the processing accuracy by end milling is great, and accordingly, the demand for improving the accuracy of the end mill itself is also increasing. There is a manufacturing method using an NC tool grinder. Also, at the time of the setup, as a device for positioning the grindstone with respect to the blank of the end mill, that is, measuring the distance from the workpiece to the grindstone, the power supply device is energized between the detected object formed by the conductive member and the detected object. There is an approach detection device that can detect the approach by connecting a series circuit with the sensor, and when the object to be detected and the object to be detected approach each other, a dielectric breakdown occurs between them, and an electric current flows. For example, see Patent Document 1.)
In the energization type sensor described in Patent Document 1, although the space saving of the apparatus and the dielectric breakdown position between the detected object and the detected object can be set and the proximity detection can be accurately performed, the workpiece has a small diameter of 6 mm or less. In such a case, it is necessary to detect the accuracy itself with higher accuracy.

Japanese Patent Laid-Open No. 5-180608

  In the manufacturing method using the one-chuck NC tool grinder, the positioning accuracy of the grindstone with respect to the end mill blank greatly affects the final shape accuracy of the end mill itself. In particular, in a small-diameter end mill, since the tolerance ratio with respect to the end mill diameter is large, the positioning accuracy is still insufficient and there is a problem.

  The present invention uses a one-chuck NC tool grinder in a manufacturing method of a solid end mill, and clamps a gripped portion of a current-carrying sensor as a detected object with the same chuck as that used for an end mill blank as a workpiece. A conductive connecting member is attached to the contact part, connected to the machine body through the power switch, and the grindstone that is the object to be detected attached to the grindstone flange with the power switch turned on is rotated by the NC program. A solid end mill that moves in parallel to the energized sensor and detects the position by energizing a closed loop when the grinding wheel contacts the contact portion of the energized sensor and a dielectric breakdown occurs. Specifically, the energization sensor is made of a cemented carbide alloy to reduce bending and the like. And a parts and held part, provided the outer diameter of 該被 gripper to the shank diameter is substantially the same of the end mill blank, a manufacturing method achieved a high accuracy based also in diameter.

  By applying the present invention, the positioning accuracy is very good at a range of 5 μm or less, the grinding wheel can be positioned more accurately and in a short time, the setup time can be shortened, and the processing cost can be reduced. .

Positioning of the grindstone during the setup process of the present invention is performed in the following order.
Step 1) The gripped portion of the energization type sensor is chucked on the chuck portion of the one chuck NC tool grinder.
Step 2) By starting the NC program, the grindstone is brought closer to the contact portion of the energization sensor.
Process 3) The contact part of the energizing sensor is made of cemented carbide and is energized. When the grinding wheel and the energizing sensor come into contact with each other, a dielectric breakdown occurs between the two and the current flows, and the one-chuck NC tool grinder detects it. To position the grindstone.

In step 1, since the one-chuck NC tool grinder is used, it is necessary that the gripped portion of the energization sensor has a substantially cylindrical shape. In the present invention, the outer diameter of the gripped portion is set to the workpiece. Since the end shank blank has a shank diameter that is substantially the same, the same chuck can be used, and positioning errors caused by differences in chucks are eliminated. Next, since the energized sensor and the blank of the end mill, which is a workpiece, have the same size and shape, the calculation process can be omitted, the calculation error can be eliminated, and the setup time can be shortened.
In step 3, since a cemented carbide is used for the contact part of the energization sensor, it has conductivity, a high Young's modulus, and can suppress the bending that occurs in the energization sensor itself, further improving the positioning accuracy of the grindstone. The accuracy of the end mill itself can be improved. The cemented carbide used for the energization type sensor preferably has a Young's modulus of 550 GPa or more. In consideration of repeated use, the hardness is preferably HRA 92 or more in order to improve wear resistance. In detail, the energization type sensor 1 shown in FIG. 1 is used, and the energization type sensor 1 includes a contact portion 2 and a gripped portion 3. The same dimensions and the same shape with a total length of 50 mm and an outer diameter of 6 mm were used. The contact portion 2 is made of a cemented carbide having a Young's modulus of 580 GPa and a hardness of HRA 92.5. The gripped portion 3 is an insulating ceramic sprayed on the surface of a portion continuous from the contact portion 2. A covering layer 4 is provided. Since the insulator used for the gripped portion 3 needs to be hard to chuck the chuck portion of the NC tool grinder, and before the grindstone contacts the contact portion 2, it needs to be completely insulated. In the examples of the present invention, white alumina having high hardness and high insulation was used.
Hereinafter, it demonstrates in detail based on an Example.

The positioning method of the manufacturing method of the solid end mill of the example of the present invention will be described with reference to FIG.
1) The gripped portion 3 of the energization type sensor 1 that is a detection object is clamped by the same chuck 5 that is used for a blank of an end mill that is a workpiece.
2) A hook clip 6 is attached to the contact portion as a conductive connecting member, and connected to the machine body 8 through the power switch 7.
3) The grindstone 10 which is the object to be detected attached to the grindstone flange 9 with the power switch 7 turned on is moved toward the energized sensor 1 in parallel with the rotation axis of the grindstone 10 by the NC program.
4) When the grindstone 10 comes into contact with the contact portion of the energization sensor 1 and a dielectric breakdown occurs, a closed loop is formed and energization is performed to detect the position.

FIG. 1 shows an axial sectional view of an energization type sensor used in the present invention example. FIG. 2 shows an outline of the production method of the end mill of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Energization type sensor 2 Contact part 3 Grip part 4 Insulation coating layer 5 Chuck 6 Hook clip 7 Power switch 8 Machine body 9 Grinding wheel flange 10 Grinding wheel

Claims (3)

In the solid end mill manufacturing method, using a one-chuck NC tool grinder, the gripped part of the energized sensor that is the object to be detected is clamped with the same chuck as the chuck used for the end mill blank that is the work piece, and the contact part A conductive connecting member is attached to the machine body, connected to the machine body through the power switch, and the grindstone that is the object to be detected attached to the grindstone flange with the power switch turned on is energized in parallel with the rotation axis of the grindstone using the NC program. A method for manufacturing a solid end mill, wherein the position is detected by energizing a closed loop when a grinding wheel is moved toward a contact sensor and a dielectric breakdown occurs when the grindstone contacts a contact portion of the current sensor. 2. The method of manufacturing a solid end mill according to claim 1, wherein the energization sensor is made of cemented carbide. 3. The method of manufacturing a solid end mill according to claim 1, wherein the energization sensor has a contact portion and a gripped portion, and the outer diameter of the gripped portion is substantially the same as the shank diameter of the end mill blank. A method for producing a solid end mill.

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