JPH02279207A - Method for automatically changing cutting speed of saw blade - Google Patents

Abstract

PURPOSE:To apply a constant load to a blade so as to lengthen the life of the saw blade for shortening a cutting time by enabling the continuous change of a cutting speed by means of inverter control, and changing the cutting speed linking to a saw blade driving motor in response to the increase and decrease of cutting area. CONSTITUTION:In the case of cutting a work 2 with a circular saw 1, cutting depth relative to constant feeding quantity(s) is constant, but since the length of cutting (from aa' to bb', from cc' to dd') is changed at any time, a cutting area ss' is increased or decreased at any time, and if the circular saw 1 is but in cutting work at a constant speed, load per one edge is not constant to shorten the life of the blade. The increase and decrease of the cutting area of the work 2 is finely divided as a time base, and frequency is automatically changed every division by inverter control in order to properly change a cutting speed and make cutting quantity and load per one edge constant. The data of the material of the work 2 is added to be able to measure the change of the material and translation from inuring cutting to normal cutting can be automized due to time setting, etc. by a timer.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention can be used to increase or decrease the cutting cross-sectional area or to
The cutting speed of the saw J is automatically changed according to changes in the material of the workpiece (workpiece), and the amount of biting per saw blade is approximately constant, extending the life of the saw blade. This invention relates to a method for converting saw blade cutting speed t" to dynamic, which allows automatic transition to normal cutting and shortens replacement time.

(Prior art) Cutting machines such as circular saws, band saws, and high-speed cutting machines have been used mainly for the purpose of cutting various work materials (vibs, steel materials, angles, etc.). machinefff
i (4 to 5 speeds) , , lK ('I - The cutting speed that is considered to be efficient depending on the material is set in advance and the cutting work is carried out.0 For example, if it is cast iron, the cutting speed is For light alloys, the cutting speed is set at an accelerated speed, and the saw blade feed speed is also set to correspond to the various workpiece materials. Some cutting machines have a function that automatically changes the feed so that the cutting force remains constant at the beginning, end, and middle of cutting.

(Problem to be Solved by the Invention) However, in the cutting 117f, conventional cutting machines select a cutting speed suitable for one workpiece material from several set speeds.
The workpiece is only cut and cut at the cutting speed, and the beginning, middle, and end of cutting are performed at the same speed, and when cutting workpieces such as pipes, steel materials, angles, etc., the cutting area is Since the cutting speed fluctuates from time to time, the amount of penetration per blade is unstable, which places a considerable burden on the saw blade and shortens its lifespan. As mentioned above, by changing the feed rate during cutting (if cutting a cylindrical steel material, the feed rate should be slowed near the diameter where the cutting area becomes larger), the load on the saw blade can be reduced. Although measures can be taken to reduce this, additional cutting time is required and work efficiency is adversely reduced.

In addition, the cutting work to transition from break-in cutting to normal cutting on a band saw machine has traditionally been done manually, resulting in a waste of time, and therefore some manufacturers may omit break-in cutting. Problems have arisen, such as further shortening the life of the saw blade.

The present invention has been made in view of the above points, and it extends the life of the saw blade by changing the cutting speed appropriately in response to increases and decreases in the cutting cross-sectional area and changes in the material of the workpiece, and changes the life of the saw blade from smooth cutting to ordinary cutting. The purpose of the present invention is to provide a method for automatically converting the cutting speed of a saw blade, which can also automatically shift to cutting.

(Means for Solving the Problems) The gist of the present invention for achieving the above object is that in the cutting operation of cutting a workpiece with a circular saw machine, band saw machine, etc., when feeding the saw blade, The changing cutting area is temporally subdivided, and the cutting speed is made to vary steplessly by inverter control, and the cutting speed is changed slowly according to the decrease or increase in the cutting area based on the subdivided data. A method for automatically converting the cutting speed of a saw blade is characterized in that the cutting speed and load per blade are kept approximately constant by controlling the movement of the saw blade drive motor.

(Function) As described above, the method for automatically converting the saw blade cutting speed of the present invention is as follows:
In cases where the cutting area increases or decreases with a constant feed rate or amount (such as cutting cylindrical steel materials or pipes), the cutting speed can be changed steplessly by inverter control, and the saw blade drive motor (rotary motor) ) by changing the cutting speed according to the increase or decrease of the cutting area (P
A: For example, when cutting a cylindrical steel material, the cutting speed is slow at the beginning and end of the cut, and is fastest near the center and diameter positions. ), - The depth of cut and load per blade are kept approximately constant, reducing blade chatter and extending the life of the blade. In addition, the method of the present invention can significantly reduce time compared to the conventional method of varying the feed amount to equalize the cutting force and reduce the load on the blade, and is highly useful from the standpoint of work efficiency. It is possible. Also, when the material of the workpiece changes (such as a material with a hardened surface), it is necessary to change the cutting speed according to the material. By sequentially changing the cutting speed by frequency conversion, it is possible to handle any workpiece material.

In addition, conventional machines with a speed change function have a multi-step speed change function, and the speed is set in advance, so it is not possible to automatically change speed during cutting as in the present invention, and the speed change range is also narrow. However, according to the automatic cutting speed conversion method of the present invention, it is possible to change the cutting speed steplessly, so it is possible to process all kinds of workpieces. It can be said that it is extremely practical.Furthermore, the transition from break-in cutting (low speed) to normal cutting (high speed) can be done automatically by setting the time using a timer, etc., and the saw blade can be changed. You can improve your work efficiency by eliminating the hassle of doing this.

(Example) Embodiments of the present invention will be described below based on the drawings.

Figure 1 is a schematic side view showing changes in cutting area when cutting a cylindrical material with a circular saw, Figures 2 and 3 are schematic side views showing the speed change stages when cutting a cylindrical material with a circular saw and a band saw. FIG. 4 is a schematic side view showing a speed change stage when cutting a round tube material with a band saw.

As shown in Fig. 1, when cutting a cylindrical material (2) with a circular saw (1), the cutting depth (not shown) is constant for a constant feed rate 1 (S), but the cutting length (aa to bb, c
Since d to dd') changes from time to time, the cutting area (S) (S') in the shaded area increases and decreases from time to time, and if the circular saw (1) cuts at the same speed, the load per blade will remain constant. This causes the life of the blade to be shortened.

Therefore, the present invention aims to automatically change the cutting speed of the saw blade according to an increase or decrease in the cutting area, keep the load on the blade almost constant, extend the life of the saw blade as much as possible, and improve work efficiency. This method divides the increase or decrease in the cutting area of the workpiece into small sections over time, automatically converts the frequency for each section using inverter control, and changes the cutting speed appropriately during the cutting process, thereby increasing the depth of cut per cut. The amount and load are kept approximately constant. An example of the speed change process when cutting a cylindrical material 2) with a circular saw (1) is shown in FIG.

At the stage of sending the circular saw (1) from the A line position to the B line position.

Cut at low speed (approximately 50%), and after passing the B line position, 10
The speed is accelerated to 0%, the speed is reduced at the C line position, and the cutting operation is completed by cutting at a speed of 10% from the C line position to the 1) line position. Similarly, when cutting a cylindrical material (2) with a band saw <1f, the distance from the A line position to the B line position is 7
0%, 90% from B line position to C line position, 100% from C line position to D line position, ■) 80% from line position to B line position and perform cutting work. It is something. Also, when cutting a round pipe <2)° with a band saw (1), the cutting rate is 70% from the A line position to the B line position, 120% from the B line position to the C line position, and from the C line position to the D line position. Until then, the speed will be changed at a rate of 100%, and the ratio of each speed described in 2 is an example and should not be specified. Also, when there is a change in material, the rate of change may be changed as appropriate.

(Effects of the Invention) As explained above, according to the present invention, the load on the blade is made constant by appropriately changing the cutting speed during the cutting operation (cutting operation), thereby extending the life of the saw blade. Furthermore, there is no need to change the feed rate as in the conventional method, which reduces cutting time.11) The conversion from leveling cutting to normal cutting can also be performed automatically, increasing work efficiency. A dramatic improvement can also be obtained from this aspect.

[Brief explanation of drawings]

Figure 1 is a schematic side view showing changes in cutting area when cutting a cylindrical material with a circular saw, Figure 2 is a schematic side view showing the speed change stages when cutting a cylindrical material with a circular saw, and Figure 3 is a band saw. FIG. 4 is a schematic side view showing a speed change stage when cutting a cylindrical material with a band saw, and FIG. 4 is a schematic side view showing a speed change stage when cutting a round pipe material with a band saw.

Claims (1)

[Claims] In cutting work in which a workpiece is cut using a circular saw, band saw, etc., the cutting area, which changes as the saw blade is fed, is subdivided in time, and the cutting speed is continuously variable using inverter control. Based on the subdivided data, the cutting speed is controlled in conjunction with the saw blade drive motor so that the cutting speed changes slowly according to changes in the cutting area, and the depth of cut and load per blade are kept approximately constant. Features an automatic saw blade cutting speed conversion method.