JP2545906B2 - Throw-away tip outer peripheral grinding method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for grinding an outer circumference of a throwaway chip using a numerically controlled grinding machine.

[Prior Art] Generally, when processing a throwaway chip, dimensional control is performed so that an inscribed circle of the throwaway chip is kept within an allowable tolerance. However, even if the inscribed circle of the throwaway chip falls within the allowable tolerance, the tolerance causes the corner position to vary with reference to the outer periphery of the throwaway chip. There was a problem when installing it on the.

Therefore, the present applicant has previously provided a method for grinding the outer periphery of a throwaway chip using a numerically controlled grinding machine suitable for eliminating the variation in the corner position when the outer periphery is used as a reference (Japanese Patent Application No. 2000-242242). 62-138646).

In this method, the outer circumference of the throwaway chip is ground, the inscribed circle of the throwaway chip is measured, and the difference between this measured value and the reference value is substituted into a preset correction formula. By correcting the distance from the outside of the chip reference to the corner and grinding the corner based on this correction, the variation in the corner position when the outside periphery is taken as a reference is eliminated.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional outer peripheral grinding method, since the corner radius is not corrected, when the machining is performed with a constant radius, due to the difference in the diameter of the inscribed circle, As shown in, a discontinuity may occur between the adjacent outer periphery and the round corner.

That is, as shown in FIG. 9, the reference inscribed circle C ₀ is the reference inscribed circle of the throwaway chip S ₀ , and its reference diameter is φ ₀ , and the inscribed circle C of the processed throwaway chip S ₁ is C 0. ₁
Let φ _{1 be} the diameter of φ ₁ (φ ₁ > φ ₀ ), each throwaway tip S ₀ with respect to the outer perimeters l and m,
The dimensional difference 2ε between the corners K ₀ and K _{1 of} S ₁ is 2ε = (φ ₁ / cos θ) − (φ ₀ / cos θ) = (φ ₁ −φ ₀ ) / cos θ (1) (where θ Is a half of the internal angle shown in FIG. 9).

In addition, as shown in Fig. 10, each throwaway chip
Assuming that the corner radii of the round corners M ₀ and M ₁ of S ₀ and S ₁ are R ₀ and R ₁ , the dimension δ from the corner K ₀ to the round corner M ₀ or M ₁ is δ = (R ₀ / cos θ) −R ₀ = R ₀ (1-cos θ) / cos θ (2) Also, 2ε + δ = (R ₁ / cos θ) −R ₁ = R ₁ (1-cos θ) / cos θ (3) Substituting (1) and (2) into the equation (3), (φ ₁ −φ ₀ ) / cos θ + R ₀ (1-cos θ) / cos θ = R ₁ (1-cos θ) / cos θ Therefore, R ₁ −R ₀ = (Φ ₁ −φ ₀ ) / (1-cos θ) (4) Further, since φ ₁ > φ ₀ , R ₁ −R ₀ > 0.

Therefore, if the corner radius is set to a constant R ₀ , as shown in Fig. 11, the adjacent outer periphery and the round corner are
There is a problem that discontinuities 2 and 2 are generated between M ₀ .
If φ ₁ <φ ₀ , R ₁ −R ₀ <0, and the 12th
As shown in the figure, there is a problem that discontinuous edge-shaped corners project at the boundary between the adjacent outer periphery and the round corner M ₀ .

An object of the present invention is to solve the above problems.

[Means for Solving the Problems] In the present invention, first, after grinding the entire outer periphery of the throwaway chip, the diameter of the inscribed circle of the throwaway chip is measured, and the diameter of the inscribed circle and the reference throw. Based on the difference from the reference diameter of the reference inscribed circle of the outer tip, the position of the round corner of the slow outer tip is corrected by the outer peripheral reference, and the round corner is continuously formed in the adjacent outer periphery. The corner radius is corrected so that the round corner is ground.

[Operation] In this outer peripheral grinding method, after grinding the outer periphery of the throwaway chip, the diameter of the inscribed circle of the throwaway chip is measured,
Substituting the difference between this diameter and the reference diameter of the reference inscribed circle of the reference throwaway chip into a preset correction formula, and correcting the position of the round corner with the outer periphery as the reference,
The corner radius is corrected so that the round corners are continuously formed on the adjacent outer periphery, and the round corners are ground.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 7. Elements common to those shown in FIGS. 9 to 11 are designated by the same reference numerals to simplify the description.

1 to 3 show an example of a numerically controlled grinding machine for carrying out the method of the present invention, and FIG. 1 is a schematic configuration diagram,
FIG. 2 is an explanatory diagram showing the relationship between the grindstone and the work clamp device, and FIG. 3 is a diagram showing an example of the measuring device. In these figures, the numerically controlled grinding machine includes a machine body 10, a measuring device 20, and a control board 30.

The above machine body 10, the slow Au H. Tsu and workpiece clamping device 12 for clamping the upper and lower surfaces S ₁ 1 clamp body 11 from the left and right-flop S _1, slow Au H. class tap between a pair of the left and right clamp bodies 11 of the workpiece clamping device 12 A supply device 13 for supplying S ₁ , a grindstone base 15 having a grindstone 14 in a state facing the work clamp device 12 mounted on a grindstone shaft, and a conveyor for carrying out the throwaway tip S ₁ after completion of grinding.
16 and a collection desk 17 for accommodating the throw-away chip S ₁ carried out by the conveyor 16.

The supply device 13 supplies the throw-away chip S ₁ so that the throw-away chip S ₁ can be held between both clamp bodies 11 of the work clamp device 12. Further, the work clamp device 12 has the clamp body 11
By rotating the clamp body 11 around the axis of, the throwaway tip S _{1 held} by the clamp body 11 is rotated with reference to the center of the throwaway tip S ₁ . As shown in FIG. 2, it is configured so that it can be horizontally swiveled with respect to the centers of both clamp bodies 11 and the upper surface of the throwaway tip S _{1 in} principle. Further, the grinding wheel 14 is rotated about the wheel axis and, as shown in FIG. 2, the wheel head 15 is moved along the XY slide so as to be movable in the front-rear and left-right directions in a horizontal plane. It is configured to have a grindstone shaft mounted on the mechanism.

In the measuring device 20, as shown in FIG. 3, the measuring probe 21 is arranged so as to be able to move up and down above the throwaway chip S _{1 held} by the clamp body 11 of the work clamp device 12. The value at the time when the probe 23 at the tip of the contacting the outer periphery of the throwaway tip S ₁ is displayed on the digital indicator 22 and is simultaneously output to the control panel 30. The value displayed and output at this time is the difference (φ ₁ −φ ₀ ) / 2 from the value when the probe 23 contacts the outer periphery of the reference throwaway tip S ₀ . Further, the control board 30 is configured to control the machine body 10 based on a program stored in advance to perform the outer peripheral grinding of the throwaway tip S ₁ .

Next, a case where the outer peripheral grinding method for the throwaway tip S ₁ of the present invention is carried out using the numerically controlled grinding machine configured as described above will be described with reference to the flowchart shown in FIG.

First, as shown in step SP1 of FIG. 4, the outer periphery to be the cutting edge is processed. That is, the above-mentioned supply device 13 supplies the throw-away chip S ₁ between the pair of left and right clamp bodies 11 of the work clamp device 12, and holds the throw-away chip S ₁ between both clamp bodies 11. Next, as shown in FIG. 5, with one outer periphery S ₁₂ of the throwaway tip S ₁ facing the grinding wheel 14, the grinding wheel 14
After approaching to _one outer periphery S ₁ 2 of the throwaway chip S ₁ by fast-forwarding (a), cutting feed (b) is performed. That is, the grinding wheel 14 is reciprocally moved in the depth direction and the front direction while being fed left and right toward the paper surface in FIG. 5 (reciprocally moved in the left and right directions while being fed downward in FIG. 2). , Grinding _one outer periphery S ₁ 2 of the throwaway chip S ₁ (grinding of the cutting edge) is completed. continue,
As shown in FIG. 5, the grinding wheel 14 is retracted from the throwaway tip S _{1 by} quick return (c).

Then, both clamp bodies 11 are rotated by 90 ° about their axes, the outer periphery S ₁₃ next to the throwaway tip S ₁ is made to face the grinding wheel 14, and the same operation as described above is repeated, Grind the outer periphery S ₁ 3 of the throwaway tip S ₁ . In this way, when the grinding of all four outer peripheries of the throwaway tip S ₁ is completed, the measuring probe 21 is lowered as shown in FIG. 3 with the outer peripheries S ₁₂ facing upward. , The diameter 23 (φ ₁ −φ ₀ ) / 2 of the reference inward circle C ₀ of the throwaway tip S ₀ is measured by bringing the probe 23 into contact with the outer periphery S ₁₂ and the difference is measured. (Φ ₁ −φ
₀ ) / 2 is output to the control panel 30 (see step SP2 in FIG. 4).

Then, as shown in step SP3 of FIG.
At 0, the difference (φ ₁ −
φ ₀ ) / 2 is compared with the reference tolerance that is input in advance. Until the difference (φ ₁ -φ ₀₎ / 2 is within tolerance, the step SP1 repeats the processing of SP3, a difference (φ ₁ -φ ₀₎ / If 2 is within tolerance, the step SP4 Proceed to. At step SP4, the difference (φ ₁ −φ ₀ ) / 2
In addition to correcting the distance from the center of the inscribed circle C ₁ of the throwaway tip S _{1 to} the round corner M ₁ , the adjacent outer circumference becomes the tangent of the round corner M ₁ and the outer circumference and the round corner M ₁ The round corner M ₁ is processed while correcting the corner radius R ₁ so that and are continuously formed.

The calculation of the correction amount is as shown in the equations (1) and (4) shown in "Problems to be solved by the invention".

That is, the correction of the distance from the center of the inscribed circle C ₁ of the throwaway tip S _{1 to} the round corner M ₁ uses 2ε = (φ ₁ −φ ₀ ) cos θ (1). However, since the above formula (1) is a correction formula based on the outer perimeters l and m, it is transformed into a correction formula based on the center of the inscribed circle, and ε = (φ ₁ − Input φ ₀ ) 2cosθ (5) into the control panel 30 and use it.

The correction formula for the corner radius R ₁ is obtained by inputting R ₁ = (φ ₁ −φ ₀ ) (1-cos θ) + R ₀ (6) into the control panel 30 by modifying the equation (4).

Then, if θ which is different depending on the type of the throwaway chip S ₁ is input to the control panel 30, the difference (φ ₁ −φ ₀ ) / 2
Correction amount is calculated immediately based on, on the basis of the correction amount, the round corner M ₁ Slow Au H. class tap S ₁ is being ground (see step SP5 of FIG. 4).

That is, as shown in FIG. 7, the work clamp device
After the throwaway tip S _{1 held} by 12 is rotated by a predetermined angle, the grinding wheel 14 is moved by rapid feed (a) and then cut feed (b), while the throwaway tip S ₁ is moved.
Is rotated to grind one round corner M ₁ . Then, quickly return the grinding wheel 14 (C) to throw away
Is retracted from the S _1, further slow Au H. class tap S ₁ 90
Grinding the remaining rounded corners is performed in the same manner as described above while rotating each by °.

When the outer periphery of the throwaway tip S ₁ is ground in this manner, the round corner M _{1 based on the} outer perimeters l and m is used as a reference.
Position can be processed with high precision, and there is no discontinuous step between the round corner M ₁ and the outer periphery, and the center of the throwaway tip S ₁ can be clamped for grinding. . Incidentally, the step SP shown in FIG.
In the comparison process of 3, when the tolerance is negative, the process proceeds to step SP6 and the throwaway tip S ₁
Is discharged.

Although the square throwaway chips have been described in the above embodiments, the throwaway chips may have a diamond shape, an equilateral triangle, or the like. However, in the case of a regular triangle, the correction is performed as follows. That is, as shown in FIG. 8, the dimension H from the non-reference periphery n to the round corner M ₁
From the condition that a constant, because it is _{(φ 0/2) × 3} -R 0 = (φ 1/2) × 3-R 1 = H, R 1 -R 0 = (3/2) (φ _1- φ ₀ ) (7) Therefore, in the case of an equilateral triangle throwaway chip, the equation (7) can be a correction expression to make the dimension H from the non-reference periphery n to the round corner M ₁ constant, and the round corners M ₁ are adjacent to each other. It can be continuously connected to the outside.

Further, when the throwaway chip to be ground is a negative tape type, the work clamp device 12 does not need to rotate in a horizontal plane, but in the case of a positive type, a turning operation is performed to incline the throwaway chip by a predetermined angle. There is a need. In this case, the rake face of the positive tip is the reference together with the processing reference and the measurement point, and therefore the round corner correction numerical control described above is not affected by the variation in the processing thickness of the chip.
It is also possible to work on the basis of the bottom surface.

[Effects of the Invention] As described above, according to the present invention, it is possible to suppress the variation in the position of the round corner when the outer periphery is used as a reference and perform the grinding process with high accuracy. It can be processed so as to be continuously connected to the adjacent outer periphery.

[Brief description of drawings]

1 to 7 are views showing an embodiment of the present invention. FIG. 1 is a schematic configuration diagram, FIG. 2 is a plan view of a work clamp device and a grinding wheel, and FIG. 3 is a measurement device. Explanatory drawing, 4th
FIG. 5 is a flow chart for explaining the processing method, FIGS. 5 to 6 are explanatory views showing a method for grinding the outer periphery of the throwaway chip, FIG. 7 is an explanatory view showing a method for grinding a round corner, and FIG. Is an explanatory view for explaining a correction formula for a round corner of an equilateral triangular throwaway chip, and FIG. 9 is an explanatory view for explaining a correction formula for a round corner of a square throwaway chip.
FIG. 10 is an enlarged view of a main part of FIG. 9, and FIGS. 11 and 12 are explanatory views showing conventional problems. C ₀ …… Standard inscribed circle, C ₁ …… Inscribed circle, M ₁ …… Round corner, R ₁ …… Corner radius, S ₀ …… Standard throwaway tip, S ₁ …… Slowaway tip, φ ₀ …… Reference diameter, φ ₁ …… Diameter, (φ ₁ −φ ₀ ) / 2 …… Difference.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shuji Hayano 1528 Nakanishida, Yokoi, Kobe, Anpachi-gun, Gifu Prefecture Mitsubishi Metals Co., Ltd. Gifu Works (56) Reference JP-A-63-306863 (JP, A) )

Claims (1)

(57) [Claims] 1. An outer peripheral grinding method in which a throwaway chip having a round corner is held by a numerically controlled grinder to hold the upper and lower surfaces of the throwaway chip, and the outer periphery of the throwaway chip is first ground. After that, the diameter of the inscribed circle of the throw-away chip is measured, and based on the difference between the diameter of the inscribed circle and the reference diameter of the reference inscribed circle of the reference throw-away chip, the circular corner of the throw-away chip. The position of the throwaway chip is corrected by correcting the position on the basis of the outer circumference, and by correcting the corner radius so that the round corner is continuously formed on the adjacent outer circumference. Peripheral grinding method.