JPH05245739A - Determinating method of machining condition - Google Patents

Abstract

PURPOSE:To shorten a span of machining time as well as to secure good surface accuracy by selecting an optimal combination of rotational speed and feed rate of a spindle preset according to a cutting tool avaialble and its metal removal, at each cutting work. CONSTITUTION:When several times of cutting work are applied to a work and thereby a desired machining form is obtained, an infeed rate to be cut in the work is divided into plural steps of metal removal values, and according to thisremoval value, rotational speed and feed rate of a spindle of metal cutting machine are determined (S2). At this time, an optimal combination of the rotational speed and feed rate of the spindle preset according to a cutting tool available and its metal removal value is selected at each cutting work (S6). With this constitution, a span of machining time is reducible and, what is more, good surface accuracy is securable in this way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to NC for cutting machines and the like.
The present invention relates to a method for creating command data for operating a machine tool, and more particularly to a method for determining cutting processing conditions that can cope with ever-changing cutting amounts.

[0002]

2. Description of the Related Art In conventional cutting, an operator determines the rotational speed and feed rate of a spindle of a cutting machine using basic data of a tool and a material of a material to be cut. Then, the once determined numerical value such as the rotational speed of the spindle is constant from the start to the end of cutting.

[0003]

However, when the operator determines the rotational speed of the spindle in this way, the rotational speed of the spindle and the feed rate of the tool tend to be slow in order to take safety into consideration. The processing time becomes long. Moreover, since the load applied to the material to be cut is also small, it is difficult to obtain sufficient surface accuracy.

The present invention was devised in view of the above circumstances, and an object thereof is to provide a method for determining a cutting processing condition which can shorten the processing time and can obtain good surface accuracy. There is.

[0005]

A method for determining cutting conditions according to the present invention is a cut to be made in a material to be cut when the material to be cut is subjected to a plurality of cutting operations to obtain a desired shape. The cutting amount is divided into a plurality of cutting amounts, and in the method of determining cutting conditions that determines the rotation speed and feed rate of the spindle of the cutting machine according to this cutting amount, depending on the cutting tool and cutting amount used The optimum combination of the rotational speed of the main spindle and the feed rate that is determined in advance is selected for each cutting operation.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a flowchart of a method for determining cutting conditions according to an embodiment of the present invention, FIG. 2 is a schematic block diagram for realizing this method for determining cutting conditions, and FIG. FIG. 4 is an explanatory diagram showing various data of the cutting tool, FIG. 5 is an explanatory diagram showing a cutting amount, FIG. 6 is an explanatory diagram showing a tool path, and FIG. 7 is a cutting diagram. FIG. 8 is an explanatory view showing a method of calculating the amount, FIG. 8 is an explanatory view showing a cutting width and a cutting height, and FIG. 9 is data when determining the rotation speed and the feed speed of the spindle from the cutting width and the cutting height. FIG.

In the following description, a rectangular parallelepiped workpiece 100 as shown in FIG.
It is assumed that two flat plates having different sizes are stacked as shown in FIG.

First, it is defined by inputting various data regarding the cutting tool 100 used for cutting (FIG. 1).
See S ₁ ). For example, in the case of a tool as shown in FIG. 4, various data such as unique tool number, tool diameter, tool angle radius, tool attachment length, tool blade length, tool inclination angle, tool blade number, chuck holder type, etc. Enter each. Various data regarding this cutting tool 200 are stored in the tool / cut amount storage device 20.
Remembered in 2.

Next, using CAD, a shape or the like to be obtained by cutting is designed. From this design data, the cutting amount and the machining shape are derived. As shown in FIG. 5, the cutting depth is the same as the side direction of the workpiece 100 (see FIG.
It is defined by inputting each uncut amount in the Z-axis direction (see FIG. 1B) (see S _{2 in} FIG. 1). The depth of cut is stored in the tool / depth storage device 202.

The cutting amount obtained by one cutting operation can be arbitrarily designated by the operator,
It is also possible for the device side to set automatically.

A machining shape is defined from the design data obtained by the CAD (see S _{3 in} FIG. 1). This processing shape is
It is stored in the machining shape storage device 204.

Next, the tool path calculation unit 205 calculates the tool path (see S _{4 in} FIG. 1). This tool path is
It serves as a movement path of the cutting tool 200 during cutting work, and is represented as a line through which the center of the cutting edge of the cutting tool 200 passes. Here, assuming that the desired cutting amount is obtained by repeating the cutting work four times, four movement paths L _{1 to} L ₄ are obtained as shown in FIG. 6.

Next, the cutting amount calculating unit 206 calculates the cutting amount from the tool path (see S _{5 in} FIG. 1). To calculate the cutting amount, as shown in FIGS. 7A and 7B, a method of calculating from the components of the cutting width and cutting height
Calculation method based on the area where the cutting tool 100 and the workpiece 100 are in contact with each other (see (C) in the figure), and calculation method from the volume removed by the cutting tool 200 by one movement command to the cutting tool 200 ((D) in the figure) See) etc. Here, the calculation is performed from the components of the cut width and the cut height. For example, assume that the cutting width = 8.0 (mm) and the cutting height = 10.0 (mm) are calculated.

Next, based on the calculated cutting width (8.0 mm) and cutting height (10.0 mm), the machining condition search unit 207 determines the rotational speed and feed rate of the main shaft of the cutting machine. Here, the rotation speed and the feed speed of the spindle are stored in advance in the rotation speed / feed speed storage device 208. That is, in the format shown in FIG. 9, the optimum rotational speed and the like are searched using the cutting tool 200 to be used and the cutting amount (represented by the cutting width and the cutting height) as keys (FIG. 1). see S _6). In this case, spindle speed = 1400 (RPM), spindle feed rate = 80 (m
m / min). It should be noted that the combination of the rotational speed and the feed rate of the spindle is empirically obtained according to the cutting tool 200 used and the cutting amount as shown in FIG. Has been done.

Next, the command data generator 209 creates command data by combining the rotational speed and feed rate of the spindle and the tool path (see S _{7 in} FIG. 1). Since this command data must be created in all tool paths, there are four types of combinations of the spindle speed and feed rate. That is, the command data is generated as a combination of every four tool path by repeating the steps up to S ₄ to S ₇ of FIG. 1, four tool paths, the number of revolutions of the spindle for these toolpath ..

That is, the cutting width in the tool path L ₂ is
Since the cutting depth is 0.8 mm and the cutting height is 10.0 mm, the rotational speed of the spindle is
1500 (RPM), the feed rate is 100 (mm / min), the cutting width in tool path L ₃ is 0.1mm, and the cutting height is 10.0mm, so the spindle speed is 1600 (RPM), feed The speed is 120 (mm / m
in).

With the command data generated in this way, the cutting work is performed for each cutting work under the optimum machining conditions, that is, the rotation speed and feed rate of the spindle.

[0018]

The method for determining cutting conditions according to the present invention has a plurality of cutting depths to be cut into a material to be cut when the material to be cut is subjected to a plurality of cutting operations to obtain a desired shape. In the method for determining the cutting conditions for dividing the cutting amount into the following, and determining the rotation speed and the feed rate of the spindle of the cutting machine according to this cutting amount, it is predetermined according to the cutting tool to be used and the cutting amount. The optimum combination of the spindle speed and the feed rate is selected for each cutting operation. Therefore, it is possible to automatically determine the optimum machining conditions, that is, the number of rotations and the feed rate of the spindle, so that the machining time can be shortened as compared with the case where the operator has conventionally decided. Good surface accuracy can be obtained.

[Brief description of drawings]

FIG. 1 is a flowchart of a method for determining cutting conditions according to an embodiment of the present invention.

FIG. 2 is a schematic block diagram for realizing the method for determining cutting conditions.

FIG. 3 is a perspective view showing a material to be cut and a shape to be formed from this.

FIG. 4 is an explanatory diagram showing various data of a cutting tool.

FIG. 5 is an explanatory diagram showing a cut amount.

FIG. 6 is an explanatory diagram showing a tool path.

FIG. 7 is an explanatory diagram showing a method of calculating a cutting amount.

FIG. 8 is an explanatory diagram showing a cutting width and a cutting height.

FIG. 9 is an explanatory diagram showing data when determining the rotation speed and feed rate of the spindle from the cutting width and the cutting height.

[Explanation of symbols]

 100 Work material 200 Cutting tool

Claims (2)

[Claims] 1. When the material to be cut is subjected to a plurality of cutting operations to obtain a desired machining shape, the cutting amount to be cut into the material to be cut is divided into a plurality of cutting amounts, and the cutting amount is changed according to the cutting amount. In the method of determining the cutting conditions for determining the rotation speed and feed rate of the spindle of the cutting machine, the optimum combination of the rotation rate and the feed rate of the spindle determined in advance according to the cutting tool to be used and the cutting amount. A method for deciding cutting conditions, characterized in that a simple one is selected for each cutting operation. 2. The method for determining cutting conditions according to claim 1, wherein the rotational speed and feed rate of the spindle of the cutting machine are determined by the cutting tool used and the cutting amount.