JPH0455908A - Production of numerically controlling data - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a method for creating numerical control data by automatic programming.

(Prior Art) Normally, the required finished surface roughness of a workpiece differs depending on the part to be machined. Therefore, during final machining (finish machining) after rough machining, it is necessary to perform machining under cutting conditions (depth of cut, feed rate, cutting speed) that correspond to the surface roughness required for each machined part. be. In turning, if the cutting speed is appropriate, theoretically, the larger the feed rate, the faster the cutting speed will be.
The surface roughness becomes rough. For this reason, the feed amount is set to be small for the machined parts that require high finished surface roughness.

On the other hand, from the viewpoint of improving productivity, it is preferable to perform machining at the maximum allowable depth of cut when the cutting speed is constant.

From the above, when machining a part that requires high surface roughness with good productivity, the cutting conditions are set to a large depth of cut and a small feed amount.

However, when turning a material with relatively low hardness such as aluminum or mild steel for boat fishing, chips tend to get wrapped around the workpiece or tool. In particular, when machining is performed under cutting conditions in which the depth of cut is large and the feed amount is small, the cross-sectional shape of the chips becomes flat, making it easier for the chips to wrap around each other.

For this reason, as mentioned above, when machining parts that require high surface roughness with high productivity using cutting conditions such as a large depth of cut and a small feed rate, the cross-sectional shape of the chips becomes flat. Chips wrap around the workpiece or tool, reducing surface roughness or damaging the tool, making stable machining impossible.

Conventionally, when creating numerical control data using automatic programming, rough machining is performed using heavy cutting (large depth of cut and feed rate) and light cutting (small depth of cut and feed rate are both performed). The machining is performed in two stages, including finishing machining, and in the finishing machining, the depth of cut for each machined surface is set uniformly, and the feed rate is adjusted according to the finished surface roughness required for each machined part. The tool path data was created by changing the tool path.

(Problems to be Solved by the Invention) According to the above-mentioned conventional method, processing is performed under cutting conditions that make it difficult for chips to wrap around, so it is naturally effective in preventing chips from wrapping around.

However, light cutting finishing is performed even on machined parts where high surface roughness is not required, resulting in a long machining time and poor productivity.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a numerical control data creation method that can prevent chips from being entangled and reduce machining time.

[Configuration of the Invention (Means for Solving the Problem) The method for creating data for numerical control of the present invention is a method for creating data for numerical control by automatic programming, which includes the following steps:
The standard depth of cut during rough machining depends on the workpiece material and tool type.
The process of determining standard cutting conditions such as standard feed rate and standard cutting speed, and the process of determining the final depth of cut for each machined part based on the workpiece material, tool type, and surface roughness of each finished surface of the workpiece. , creating tool path data for rough machining for machining under the standard cutting conditions until a shape is offset by the corresponding sum of the standard depth of cut and the final depth of cut with respect to the finished shape of the workpiece; After machining according to the standard cutting conditions from the offset shape to a shape with the final depth of cut remaining, the final depth of cut and finished surface roughness of the machined part with the final depth of cut are adjusted. The present invention is characterized by executing a step of creating final machining tool path data for machining at a corresponding feed rate and cutting speed.

(Function) According to the above means, the machining parts other than the machining parts that require a high finished surface roughness are machined under cutting conditions with high productivity, and the machining parts that require a high finished surface roughness are processed to reduce the amount of chips. Tool path data is created so that machining is performed under cutting conditions that do not cause wrapping.

(Example) Hereinafter, one embodiment of the present invention will be described based on the drawings.

First, in FIG. 3 showing the hardware configuration, 1 is a ROM that stores loading programs, etc., 2 is a processor that performs automatic programming processing, 3 is a RAM that stores automatic programs and created tool path data, etc.;
is a keyboard, 5 is a display device, 6 is a hard disk that stores numerical control data and various files,
7 is a communication control device, and 8 is a numerically controlled machine tool.

The above automatic program is set to execute the following steps as shown in FIG.

Information input step S1 in which graphic information such as the workpiece shape and finished shape of the workpiece, attribute information such as workpiece material, tool type, and finished surface roughness of each machined part of the workpiece is received from the keyboard 4. Based on the workpiece material and tool type, the standard maximum depth of cut tsa* and the standard minimum depth of cut t+sl during rough machining are determined from the cutting condition data. , standard feed amount f1 Standard cutting degree S, etc. Standard cutting conditions (of course set to conditions that do not cause chip wrapping) etc. are determined S2゜ Work material, tool type, and finished surface roughness of each machined part Based on the cutting condition data, determine the final depth of cut Δt for each part in step S3.The standard maximum depth of cut in the radial and axial directions for the finished shape of the workpiece input in step S1. t3.8~Standard minimum depth of cut j mla
Step S4 of creating rough machining tool path data for machining under the standard cutting conditions into a shape that is offset by the corresponding sum of the required standard depth of cut t1 and the final depth of cut Δt1 within the range of S4. Machining was performed under the standard cutting conditions for a machining part where the cutting amount from the shape offset by the relative sum of the standard depth of cut t and the final depth of cut Δtl to the finished shape was equal to or greater than the standard minimum depth of cut e + mle. After that, step S of creating final machining tool path data for machining each machining part with the final depth of cut, feed amount and cutting speed according to the finished surface roughness.

Step S6 of converting the created tool path data for rough machining and tool path data for final machining into numerical control data for the numerically controlled machine tool 8 to be used; converting the converted numerical control data into numerical values by the communication control device 7 Process S7 to be transmitted to the control machine tool 8. Furthermore, the standard maximum depth of cut tl1mK and the standard minimum depth of cut j1t according to the workpiece material and tool type
-+. , standard feed ML f , standard cutting speed S, final depth of cut Δ according to workpiece material, tool type, and finished surface roughness
The feed amount and cutting speed are stored in a table in the automatic program.

The procedure for creating numerical control data using the automatic program configured as described above will be explained in detail with reference to FIG.

In addition, here, when processing a round bar-shaped workpiece 9 shown by a two-dot chain line in FIG. 1 into a stepped round bar shape shown by a solid line in the same figure, the explanation will be given by taking as an example the case in which cutting is performed in the radial direction. do.

(1) Process S+ First, while looking at the various menu screens displayed on the display device 5, the operator inputs the shape of the workpiece, the finished shape of the workpiece, the material of the workpiece, the type of tool to be used, and each part of the workpiece using the keyboard 4. Perform input operations such as finished surface roughness. Here, the shape of the workpiece and the finished shape are the first
It is assumed that the shapes shown by the two-dot chain line and the solid line are input in the figure, and the finished surface roughness of the outer circumferential surface of each machined part is shown by the finishing symbol.

(2) Step S2 Next, from among the cutting conditions stored in a table in the automatic program, the highest productivity is achieved when cutting the workpiece of the material input in step S1 with the same tool. Standard depth of cut range for rough machining that does not cause chip wrapping (standard maximum depth of cut t1.1 to standard minimum depth of cut 1m)
11. Determine standard cutting conditions such as standard feed rate f1 and standard cutting degree S.

(3) Process S.

In this process, when cutting a workpiece of the material input in process S1 with the same tool from among the cutting conditions stored in a table in the automatic program, each machining part is input in process sI. Determine the final depth of cut Δ1 when finishing the finished surface with roughness.

Here, for the sake of simplicity, the final depth of cut for the first stage 9a of the workpiece 9 is determined to be 0 because the required finished surface roughness is relatively low, and the final depth of cut for the second stage 9b is determined to be 0. Assume that the amount is determined to be Δt2 because the required finished surface roughness is relatively high.

(4) Process S4 Rough machining conditions and final depth of cut Δ1.
is determined, next the standard maximum depth of cut t amx and the final depth of cut Δ1. are determined in the radial direction for the finished shape of the workpiece. The shape is offset in the axial direction by the corresponding sum of Create tool path data for machining (indicated by a broken line in Figure 1).As a result, the tool is determined to sequentially follow the path Pa...p6.p3.p4 in Figure 1.This tool Route data is in RAM
3.

At this time, since the final depth of cut of the first stage 9a is set to 0 in the stroke S3, the radial offset amount of the first stage 9a is the standard maximum depth of cut tyo.

becomes. If rough machining is performed twice to obtain a shape offset by the standard maximum depth of cut t1.8, the first rough machining is performed by the standard maximum depth of cut t1.8. ．． , the second rough machining is performed at the standard minimum depth of cut i1 t −+. You may need to do the following.

In this case, the first depth of cut is set to be small so that the depth of cut in the second rough machining is equal to or greater than the standard minimum depth of cut ilt=+7.

In addition, here, for the purpose of simplifying the explanation, the first stage 9a
is the standard maximum depth of cut t1.1 for both the first and second cuts.
It is assumed that by performing rough machining, the shape is offset from the finished shape by the standard maximum depth of cut tffi@1.

(5) Process S5 Next, final machining tool path data is created.

In this case, the final depth of cut of the first stage 9a is O, so the first
The stage is machined under the cutting conditions of rough machining, that is, the standard maximum depth of cut t @ 811, the standard feed rate f, and the standard cutting speed S. For the second stage, the final depth of cut is Δt2, so first Cutting conditions for rough machining, i.e. standard maximum depth of cut ji
After machining with t want , standard feed amount f, and standard cutting speed S, the final depth of cut Δt2 is set to a small feed amount and cutting speed corresponding to the finished surface roughness (in the case of this example, the standard cutting speed S
) to create tool path data. This causes the tool to move to p4 in FIG. p7. p
8, . . . is determined to follow the route of PIiPO in order. This tool path data is stored in RAM3. Here, in the tool path P 13 + P 14, the feed rate corresponding to the surface roughness is set so that chips do not wrap around the final depth of cut Δt2, so stable cutting is possible. .

(6) In the step S, the rough machining tool path data and final machining tool path data stored in the RAM 3 as described above are converted into numerical control data used in the numerically controlled machine tool 8, It is stored on the hard disk 6.

(7) Step S7 The numerical control data stored in the hard disk 6 in step Sb is stored in the hard disk 6 in this step. By manual operation, the numerical control data is retrieved from the hard disk 6 and transmitted to the numerically controlled machine tool 8 via the communication control device 7.

[Effects of the Invention] As explained above, according to the present invention, machining parts other than the machining parts that require high finished surface roughness are machined under highly productive cutting conditions, and high finished surface roughness is required. The tool path data is created so that finishing machining is performed under cutting conditions that do not cause chips to wrap around the machined parts, which has the excellent effect of preventing chips from wrapping around and shortening machining time. Obtainable.

[Brief explanation of the drawing]

FIG. 1 is a tool path diagram showing one embodiment of the present invention, FIG. 2 is a flowchart showing the procedure for creating numerical control data, and FIG. 3 is a hardware configuration diagram. In the figure, 1 is RAM, 2 is processor, 3 is ROM, 4 is keyboard, 5 is display, 6 is hard disk,
8 is a numerically controlled machine tool. Applicant: Toshiba Corporation

Claims (1)

[Claims] 1. In the method of creating numerical control data through automatic programming, there is a process of determining standard cutting conditions such as standard depth of cut, standard feed rate, and standard cutting speed during rough machining based on the workpiece material and tool type, and , the process of determining the final depth of cut for each machined part based on the tool type and the surface roughness of each finished surface of the workpiece, and the process of determining the sum of the standard depth of cut and final depth of cut for the finished shape of the workpiece. A process of creating tool path data for rough machining to perform machining under the standard cutting conditions until a shape offset by the amount of cut is obtained, and a step of performing the standard cutting until a shape with the final depth of cut remaining from the offset shape is obtained. After processing according to the conditions, for the machining part with the final depth of cut, the final depth of cut,
A method for creating data for numerical control, comprising: creating final machining tool path data for machining at a feed rate and cutting speed according to finished surface roughness.