JPH07204951A - Cutting method by nc machine tool - Google Patents

Abstract

PURPOSE:To maintain an excellent dimensional accuracy and flatness by securely removing the R part at the corner of a work, and increase the productivity and reduce the production cost. CONSTITUTION:Under the conditions that a main spindle 5 holds a slot end mill 4 and is fixed by a main spindle rotating lock means 11, a spindle head 6 is moved reciprocatedly in the direction of z-axis based on the control of a control means 8, and the R part remaining at each corner of a work 2 is removed by the slot end mill 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting method using a numerically controlled machine tool, and more particularly to a cutting method for removing an R portion remaining at a corner of a workpiece.

[0002]

2. Description of the Related Art Generally, when forming a hole or groove in a work piece with high dimensional accuracy, a numerical control machine tool such as a numerical control milling machine or a machining center is used for cutting. There is. A numerically controlled machine tool rotatably supports a spindle on a movable spindle head, holds a cutting tool such as an end mill on this spindle, places a workpiece on a movable table, and then numerically controls it. A machine that performs a cutting process by moving a spindle head or a table while rotating a spindle.

[0003]

By the way, a square hole, a quadrangular pyramid hole, a quadrangular pyramid trapezoidal hole, or a square groove or an inclined square groove is formed in a workpiece machined by a numerically controlled machine tool. Sometimes. Each of these holes and grooves is a machining surface that is composed of only flat surfaces, not curved surfaces, but the workpiece is a mold, copper for making the mold, graphite electrodes, aluminum sashes, or graphite. In the case of a semiconductor jig, the hole or groove is required to have high flatness without a curved surface portion.

However, in the conventional cutting method using a numerically controlled machine tool, as shown in FIGS. 10 (A) and 10 (B), R is formed at each corner of a square hole or a square groove formed in a workpiece. The part has been left. If the size of a cutting tool such as an end mill is made smaller, the size of the R part will also become smaller. However, as long as cutting is performed by rotating the cutting tool, the R part is always formed at the tip of the cutting tool. Therefore, the R portion does not completely disappear from the corner of the workpiece. Therefore, in the present situation, the R part is completely removed by manually grinding with a file or a wire. Such a manual removal work of the R portion has problems that work efficiency is low and productivity is low.

Further, in order to remove the R portion, a method of performing electric discharge machining or using a plain cutter having a bevel gear (Japanese Patent Laid-Open No. 379213) has been proposed. However, in these cases, special equipment and unique equipment are required. Therefore, this is a factor that causes a rise in manufacturing costs, which is economically disadvantageous.

Further, when the processed surface of the work piece is an inclined surface, there is no other way but to remove the R portion from the corner of this inclined surface by manual work, resulting in low productivity. Therefore, conventionally, a cutting method for easily removing the R portion from the corner of the inclined surface has been awaited.

The present invention has been proposed in view of the above circumstances, and its main purpose is to reliably remove the R portion of the corner of the workpiece to ensure excellent dimensional accuracy and flatness. In addition, it is to provide a cutting method using a numerically controlled machine tool that improves productivity and reduces manufacturing cost.

Another object of the present invention is to provide a cutting method using a numerically controlled machine tool which can easily remove the R portion of the corner of the inclined surface even if the surface to be processed is an inclined surface. is there.

[0009]

In order to achieve the above-mentioned object, the invention of claim 1 rotates the main spindle by numerical control and causes at least one of the table for mounting the workpiece and the main spindle head to move in a predetermined direction. A method of cutting a workpiece using a numerically controlled machine tool, wherein the numerically controlled machine tool has a spindle rotation lock means for fixing the spindle so that the spindle cannot rotate with respect to the spindle head. The cutting tool includes a square blade, and first, based on the control of the control means, the spindle holding the cutting tool rotates and the spindle head moves to form an R portion at the corner of the workpiece. The primary cutting process is carried out so that the machining is completed in the remaining state, and then the spindle holds the square blade, and the spindle is locked by the spindle rotation lock means, and then the spindle is controlled based on the control of the control means. Head is moved, and performing secondary machining to eliminate the remaining R portion at a corner of a workpiece by square tool.

According to a second aspect of the present invention, when the horizontal x-axis is set on the processing surface of the workpiece, the y-axis orthogonal to the x-axis and the z-axis perpendicular to the x-axis and the y-axis are set, the secondary When performing cutting, the spindle head moves simultaneously in the x-axis, y-axis and z-axis directions under the control of the control means.

[0011]

In the invention of claim 1 having the above-mentioned structure, the spindle head is moved by numerical control and the square blade removes the R portion remaining in the corner of the workpiece, so that the corner of the workpiece is removed. It is possible to form an edge portion on the. Therefore, the flatness of the workpiece can be increased, and excellent dimensional accuracy can be ensured. Therefore, the present invention is suitable when the cut portion is a square hole or a square groove.

According to the second aspect of the invention, even if the machined surface is inclined, the spindle head can move simultaneously in three directions of the x-axis, the y-axis and the z-axis, so that it remains at the corner of the inclined surface. The R portion can be easily removed.

[0013]

【Example】

[Structure of Embodiment] An embodiment of the cutting method by the numerically controlled machine tool according to the present invention will be specifically described below with reference to FIGS.

FIG. 1 is a model diagram showing an outline of a machining center 1 adopting this embodiment. The machining center 1 is provided with a table 3 on which a work 2 as a workpiece is placed. A spindle 5 and a spindle head 6 are arranged above the table 3. The main spindle 5 is configured to hold a cutting tool including a slot end mill 4 (see FIG. 2) which is a square blade. Also the spindle 5
A spindle motor 7 or the like is connected as a drive source for supplying a rotational force thereto. This spindle motor 7
The servo lock works when the rotational force is not supplied to the main shaft 5.

The slot end mill 4 is attached to the spindle 5 by a milling chuck.
The shape is such that a quadrangular prism having a side of 12 mm extends from a base of φ20 mm, and a quadrangular pyramid diamond-coated chip having a bottom side having a side of 12.6 mm is attached to the tip thereof.
Also, the length of the square pole and diamond coated chip is 50
mm.

The spindle head 6 rotatably supports the spindle 5, and is configured to reciprocate with respect to the work 2 in the x-axis, y-axis, and z-axis directions. Where x-axis, y
The axes and z-axis are defined as follows. That is, FIG.
As shown in FIG. 6 and FIG.
The straight line is the x-axis, the straight line that is horizontal to the machining surface of the workpiece 2 and is orthogonal to the x-axis is the y-axis, and the straight line that is perpendicular to the intersection of the x-axis and the y-axis is the z-axis.

The machining center 1 is also provided with control numerical value input means 8, control means 9, automatic tool changer 10 and spindle rotation lock means 11. The control value input means 8 is composed of a numeric keypad, a display unit, a pulse handle, etc., and has data on the shape and dimensions of the work 2 and the cutting portion, the moving direction and moving amount of the spindle head 6, the feed speed and the returning speed of the spindle head 6, Further, the rotation speed of the spindle 5 and the like are input. The fast-forward speed of the spindle head 6 is usually set in advance.

The control means 9 controls the movement operation of the spindle head 6 and the rotation operation of the spindle 5 based on the numerical value input by the control numerical value input means 8 and the operation of the automatic tool changer 10 and the spindle rotation lock means 11. It is designed to control. Further, the control means 9 is installed with a program for executing a cutting procedure which will be described later so that the special software dedicated to the slot can be used to instruct one block.

The automatic tool changing device 10 has a magazine for accommodating a plurality of cutting tools, a mechanism for taking out a desired cutting tool from the magazine and conveying it to the spindle 5, and a cutting tool and a spindle 5 conveyed. And a mechanism for fixing the cutting tool to the spindle 5 by matching the formed keys.

The spindle rotation lock means 11 is a tool holder for holding the slot end mill 4 when the slot end mill 4 is replaced by an automatic tool changing device as shown in FIG.
As shown in FIG. 5, a holder 12 with a rotation stopper is provided. A shear pin 1 is provided above the slot end mill 4.
3 are provided.

The holder 12 with a detent has a tapered pin 12a for positioning on the outside. The taper pin 12a is a turning stopper piece 14 formed on the spindle head 6 side.
It is designed to fit in. Then, by matching the key formed on the spindle 5 by exchanging the cutting tool, the taper pin 12a of the holder 12 with a detent and the detent piece 14 on the side of the spindle head 6 are matched, whereby the head of the spindle 6 is prevented. The rotational movement is mechanically locked. Further, a limit switch 15 is provided on the holder 12 with a rotation stopper. The limit switch 15 is a switch that electrically interlocks with the spindle motor 7, and is activated when the taper pin 12a and the rotation stopping piece 14 coincide with each other.

[Cutting Procedure of Embodiment] Next, the cutting procedure of this embodiment will be specifically described with reference to FIGS. 4 to 8. The work 2 here is a graphite rectangular parallelepiped having a thickness of 43 mm, and the shape and dimensions of the cut portion are as follows. That is, the shape of the machined portion is a through-angled hole in which the upper part is a quadrangular pyramid and the lower part continuous to this is a regular quadrangular prism, and the dimensions of the quadrangular pyramid are 40 mm at the upper side and 20 mm at the lower side. Sa (depth) is 10
mm, the angle of the hypotenuse is 45 degrees. On the other hand, the length of one side of the plane portion of the regular square pole is 20 mm.

FIG. 4 is a block diagram showing a cutting procedure of this embodiment, and FIGS. 5 (A), 5 (B) and 5 (C) are a plan view and a side sectional view of the work 2 at the stage when the primary cutting is completed. And FIG. 6 (A), (B) and (C) are two perspective views.
A plan view, a side sectional view and a perspective view of the work 2 at the stage where the next cutting process is completed, and FIGS. 7A and 7B are a plan view and a side sectional view illustrating the working operation in the first half of the secondary cutting process. FIG. 8 is a side sectional view for explaining a working operation in the latter half of the secondary cutting process.

Preparatory Step for Machining The work 2 is placed on the table 3, the shape and size data relating to the work 2 and the cutting portion are input to the control numerical value input means 8, and the spindle head 6 is also used.
The moving direction, the feeding speed and the returning speed thereof, and the rotation speed of the spindle 5 are input. Further, in the initial state, a φ10 mm end mill (flat) is attached to the spindle 5. Further, the automatic tool changer 10 is set so that the R3 end mill (ball) and the slot end mill 4 are fed to the main spindle 5 in this order.

Primary cutting process ... See FIG. 4. After the above preparation steps, the primary cutting process is performed. First, the spindle motor 7 operates under the control of the control means 9 to rotate the spindle 5, the spindle head 6 moves in parallel with the z-axis, and the φ10 mm end mill (flat) moves to 20 mm.
A mm-square through hole is formed (step 21).

Next, the automatic tool changer 10 operates under the control of the control means 9, removes the φ10 mm end mill (flat) from the spindle 5 and replaces it with the R3 end mill (ball), and attaches this to the spindle 5 (step 22). Then, the spindle motor 7 operates to rotate the spindle 5, the spindle head 6 simultaneously moves in the x-axis, y-axis, and z-axis directions, and the R3 end mill (ball) performs 45 ° tapered surface machining (step 23). ). At the time when this primary cutting process is completed, the R portion remains at each corner of the work 2.

Rotation lock of the spindle 5 The automatic tool changer 10 operates under the control of the control means 9, removes the R3 end mill (ball) from the spindle 5, replaces it with the slot end mill 4, and attaches it to the spindle 5 (step 24). ). At this stage, the taper pin 12a and the anti-rotation piece 14 are aligned with each other, and the anti-rotation holder 12 holding the slot end mill 4 mechanically fixes the spindle 5 (step 25). Moreover, since the taper pin 12a and the rotation stopping piece 14 are aligned with each other, the limit switch 15 is actuated to electrically interlock with the spindle motor 7, and the spindle 5 and the spindle 5 do not move.

Secondary cutting process: See FIGS. 6 to 8 As described above, the slot process is performed at the slot speed F3000 as the secondary cutting process while the rotation of the spindle 5 is locked. First, the spindle head 6 is reciprocally moved in the z-axis direction by the control of the control means 9, and the slot end mill 4 is rotated by 2.
The R portion of each corner of the 0 mm square through hole is cut (step 26). At this time, the cutting amount per time is 0.05 mm,
The processing time is 1 minute and 11 seconds per location.

Then, the spindle head 6 is simultaneously moved in the x-axis, y-axis and z-axis directions under the control of the control means 9,
The R part of each corner of the taper surface of the degree (step 2
7). At this time, the depth of cut is 0.05 mm,
The processing time is 37 seconds per place. When the secondary cutting as described above is completed, the spindle rotation lock means 11 operates under the control of the control means 9 to release the lock, and the rotation fixing of the spindle 5 is released (step 28).

[Operation and Effect of the Embodiment] In the present embodiment having the above-mentioned structure, the spindle head 6 reciprocates in the z-axis direction by numerical control, and the slot end mill 4 remains at the corner of the work 2. Since the curved R portion is removed, an edge portion can be formed at each corner of the work 2. Therefore, the flatness of each processed surface of the work 2 can be increased, and excellent dimensional accuracy can be secured. Moreover, the work of removing the R portion does not require manual work such as a file, special equipment, or a unique device. Therefore, the work efficiency is increased, and the productivity and the manufacturing cost can be reduced.

Further, in this embodiment, when the R portion of each corner of the 45 ° taper surface is cut, the spindle head 6 is moved to the x-axis,
Since it moves in the y-axis and z-axis directions at the same time, the R portion could be easily removed.

[Other Embodiments] The cutting method by the numerically controlled machine tool of the present invention is not limited to the above-mentioned one embodiment, and for example, a V-shaped tool may be used as a square tool. Include. When the square hole or the square groove is cut according to the present invention, the state shown in FIG. 10 can be changed to the state shown in FIGS. 9 (A) and 9 (B). Further, the shape of the cut portion can be combined with various shapes such as a square hole and a square groove, and the time required for cutting work derived from the feed speed, the return speed and the fast feed speed of the spindle head 6 can be reduced. It can be appropriately changed according to the material and size of the workpiece. Further, not only the spindle head 6 can be moved, but the table 3 on which the work 2 is placed may be movable. In short, if the relative position between the work 2 and the spindle 5 can be changed. good.

Further, there are various kinds of workpieces such as a mold, copper for making a mold, a graphite electrode, an aluminum sash or a graphite semiconductor jig, and the materials thereof are copper, aluminum, graphite and the like. When the hardness is low, the load on the numerically controlled machine tool side is small and it can be said that the present invention is suitable for the present invention. Further, as the numerically controlled machine tool, not only a machining center but also a numerically controlled (NC) milling machine can be used, and its model can be suitably selected such as a machine capable of 5-face machining. Further, the specific configurations of the control numerical value input means 8, the control means 9, the automatic tool changer 10, the spindle rotation lock means 11 and the like can also be appropriately changed.

[0034]

As described above, according to the cutting method by the numerical control machine tool of the present invention, the numerical control means is provided with the spindle holding the rectangular tool and the spindle rotation lock means being fixed. The spindle head moves based on the control of R, and the square-shaped blade removes the R portion remaining at the corner of the workpiece, thereby ensuring excellent dimensional accuracy and flatness and improving productivity and manufacturing cost. We were able to reduce it.

[Brief description of drawings]

FIG. 1 is a model diagram showing an outline of a machining center 1 adopting an embodiment of the present invention.

FIG. 2 is a side view of the slot end mill 4.

FIG. 3 is a side view of the spindle rotation lock means 11 of the present embodiment.

FIG. 4 is a block diagram showing a cutting procedure according to the present embodiment.

5A and 5B are views showing the work 2 at the stage where the primary cutting process is completed, in which FIG. 5A is a plan view and FIG. 5B is a side sectional view.
(C) is a perspective view.

6A and 6B are views showing the work 2 at the stage where the secondary cutting process is completed, in which FIG. 6A is a plan view and FIG. 6B is a side sectional view.
(C) is a perspective view.

7A and 7B are views for explaining a machining operation before the secondary cutting, in which FIG. 7A is a plan view and FIG. 7B is a side sectional view.

FIG. 8 is a side sectional view for explaining a working operation in the latter half of the secondary cutting process.

FIG. 9 is a perspective view of a machined surface of a workpiece formed by the cutting method by the numerically controlled machine tool of the present invention,
(A) shows a square hole and (B) shows a square groove.

FIG. 10 is a perspective view of a machined surface of a workpiece formed by a cutting method using a conventional numerically controlled machine tool,
(A) shows a square hole and (B) shows a square groove.

[Explanation of symbols]

 1 Machining Center 2 Work 3 Table 4 Slot End Mill 5 Spindle 6 Spindle Head 7 Spindle Motor 8 Control Numerical Value Input Means 9 Control Means 10 Tool Automatic Change Device 11 Spindle Rotation Lock Means 12 Holder with Detent 13 Shear Pin 14 Detent Piece 15 Limit Switch

Claims (2)

[Claims] 1. A table on which a workpiece is placed,
A spindle for holding a cutting tool and a spindle head for rotatably supporting the spindle are provided, and at least one of the table and the spindle head is movable, and further, the table and the spindle head. Control numerical value input means for inputting a numerical value relating to a relative movement operation and a rotation operation of the spindle, and a relative movement operation between the table and the spindle head based on the numerical value input by this control numerical value input means and the aforesaid A numerically controlled machine tool comprising: a control means for controlling the rotational movement of the spindle, wherein the numerically controlled machine tool controls the spindle so that the spindle cannot rotate with respect to the spindle head. It has a spindle rotation lock means for fixing, the cutting tool includes a square blade, and the cutting tool is held under the control of the control means. The main spindle is rotated and the main spindle head is moved to perform a primary cutting process in which the machining is finished in a state where an R portion is left at a corner of the workpiece, and then the main spindle is the rectangular blade. And the main shaft rotation lock means fixes the main spindle, and then the main spindle head moves under the control of the control means, and the R portion left at the corner of the workpiece by the square blade. A cutting method using a numerically controlled machine tool, characterized in that secondary cutting is performed to remove the above. 2. A straight line horizontal to the machined surface of the workpiece is x-axis, a straight line horizontal to the machined surface of the workpiece and orthogonal to the x-axis is y-axis, and the x-axis and y-axis. When the z-axis is one straight line perpendicular to the intersection with the axis, the spindle head is simultaneously moved in the x-axis, y-axis and z-axis directions under the control of the control means when the secondary cutting is performed. The cutting method by the numerically controlled machine tool according to claim 1, wherein the cutting method is performed by moving.