JPS61136707A - Multiple-step machining process - Google Patents

Abstract

PURPOSE:To aim at shortening of a machining period of time, by controlling the period of time for a step or for cut machining gradually shorter as the step progresses from the start of cut machining, in a feed-step process of work. CONSTITUTION:In relation to a cutting period of time T set on the basis of a cutting resistance at the final step (6) or at the step (5) immediately preceding the final, the periods of time assigned to the successively preceding steps are defined to be the values calculated form a formula, TX(1+nalpha). Here at, n is an integer which is zero for the standard step used for setting the cutting period of time T and increased by 1 for every successively preceding steps, and alpha is a constant. The cutting period of time is set long in early steps because of easier ejection of chips and the period of time is set shorter as the step progresses.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a cutting method using a drill, and particularly to an improvement of a stepwise cutting feed control method in deep hole drilling.

[Technical background of the invention and its problems] When drilling a hole with a drill, there are cases where the hole cannot be drilled to the desired depth at once due to the relationship between the drill diameter and the hole depth. In this case, a method is used in which the drill is reciprocated several times to process the hole little by little and finally complete the hole drilling to the desired depth. This is a processing method called step feed processing.

One of the control methods for the step feed machining method described above is to set a certain machining time, move the drill forward to perform machining, and when the set time is reached, move the drill back and move forward again. There is a method of repeating the process until the hole depth is reached. This method is often used as a simple method because it improves chip evacuation and cools the drill cutting edge, preventing drill breakage and prolonging the life of the drill.Moreover, it is relatively easy to control. .

However, the method of setting the machining time constant as described above has the following disadvantages: In normal drilling, the cutting load of the drill varies depending on the machining depth due to the evacuation of chips, etc. It generally increases as the depth increases. The above-mentioned constant machining time setting is determined so that the drill will not be overloaded even if the machining depth becomes deeper and the machining load increases. However, when the machining depth is shallow, chips are discharged smoothly, so when the machining depth is deep, the load on the drill is smaller, and the drill is forced to retreat while there is still room. This results in wasted processing time.

[Objective and Summary of the Invention] Therefore, the present invention aims to shorten machining time and improve production by changing the set time depending on the machining depth while taking advantage of the simplicity of control by time setting. be.

In order to achieve this objective, the present invention has a shallow cutting depth.
Control is performed so that the setting time becomes shorter as the cutting depth becomes deeper (the number of steps increases).

[Embodiments of the invention] Next, the present invention will be explained in detail with reference to examples.

FIG. 1 is a process diagram of step feed processing to which the present invention is applied. FIG. 2 is a process diagram of step feed processing which has been commonly used in the past.

Straight lines represent forward and backward movement by rapid traverse, and wavy lines represent cutting processes. The difference between Figure 1 and Figure 2 is that
! ! In I, the cutting time T for each step is constant from beginning to end, whereas in the present invention shown in Fig. 1, the cutting time gradually becomes shorter as the steps progress compared to the cutting time at the start of cutting. That's true. In the process shown in FIG. 2, the cutting time T' is set to such a degree that the drill D does not become overloaded even when the cutting resistance applied to the drill D becomes the largest. Generally, as the cutting depth increases, the cutting force applied to the drill increases.
The time rWIT' is set based on the cutting force at the final step or the step just before the final step. for that,
In the initial machining step, the cutting force is small, and even though there is still some margin, the tool will retreat for a time T''. However, in the process of the present invention shown in Fig. For the cutting time T, which is set based on the cutting resistance of α is an integer that increases by l for each step, and α is a constant.By doing this, during the initial step when it is easy to eject chips, the resistance applied to the drill is small, so the cutting time is lengthened, and the step is As the process progresses, it becomes possible to gradually shorten the cutting time, and as a result of various experiments, the load applied to the drill was not much different in the processing method of the present invention than in the conventional processing method, and it could be carried out effectively.First The table shows the experimental results of calculating and comparing the cutting load value of the present invention method and the conventional method as a value proportional to the cutting torque.The specifications of the experiment were as follows: drill diameter φ2.0 cutting depth 14 - Feed amount 0, 015sw/rev Work material 5
S41 Data Average value of machining 5 holes Figure 3 shows a comparison between the conventional machining method and the machining method of the present invention.The solid line represents the machining method of the present invention, and the broken line represents the conventional machining method. , ■, ■, ... represent the order of step machining. As is clear from the figure, it can be seen that the processing efficiency of the processing method of the present invention is extremely high.

Furthermore, the same effect can be obtained when the method for setting the cutting time described above is applied to the step time from when the drill starts moving forward until it moves backward in each process.

[Effects of the Invention] As explained in detail above, the present invention reduces the machining time in step feed machining by controlling the step time or opening during cutting to be gradually shortened as the step progresses from the start of cutting. This is an extremely useful processing method that can achieve a reduction in the length of time, and can have an extremely large effect in this field.

[Brief explanation of drawings]

Figure 1 is a process diagram of step feed machining in which the present invention is applied to cutting time, Figure 2 is a process diagram of step feed machining that has been commonly used in the past, and Figure 3 is a diagram of the conventional machining method and the book. FIG. 4 is a diagram showing a comparison of the processing methods of the invention, FIG. 4 is a process diagram of a process in which the invention is applied to step time, and FIG. 6 is a process diagram of a conventional method. Patent Applicant Sugitsu Machine Co., Ltd. Figure 1 Suna, A Collection

Claims (3)

[Claims] (1) A multi-step machining method characterized in that in step-feed machining in which the cutting depth is increased step by step, when setting the step time, the time is gradually shortened according to the number of steps. . (2) In claim 1, the step time is the time from when the tool starts moving forward until it moves backward.
Multi-step processing method. (3) In claim 1, the step time is the time from when the tool starts cutting until it retreats;
Multi-step processing method.