JP2619274B2 - Plasma cutting method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma cutting method, and more particularly, to a plasma cutting method for perforating a cut material and starting cutting from the position.

<Prior Art> There is a plasma cutting method as a method of cutting a cutting material such as steel or stainless steel. In the plasma cutting method, a cutting start method for a cutting material includes a running start method in which a cutting is performed from an end face of the cutting material by a plasma torch adjusted to a predetermined speed, and a drilling (hereinafter, referred to as “piercing”). ), And a piercing start method in which cutting is performed from the position.

The running start method is generally employed when cutting a material to be cut, and the piercing start method is generally employed when performing die cutting.

When the die cutting is performed by using the piercing start method, as shown in FIG.
The torch speed is increased to a predetermined cutting speed from the point to the figure 2 to be cut, and the transition path of the torch is set so that the incident angle with respect to the figure becomes small.

The cutting speed in the plasma cutting method is set to a standard speed which is the optimum speed for the material and the thickness of the cut material. When the cut material is cut at a standard speed set for the cut material, it is possible to obtain a cut surface of constant quality without dross adhered to the lower surface of the cut material.

<Problems to be solved by the invention> When cutting a cutting material by the above-mentioned plasma cutting method,
Dross containing a melt or oxide of the cutting material is generated. The dross may be discharged from a kerf formed in the cut material and adhere to the lower surface of the cut material.

Adhesion of dross to the cutting material is likely to occur when the actual cutting speed is lower than the standard speed, especially when using the piercing start method, the cutting speed at the piercing position is approximately 0 mm / min, While this speed is raised to the standard speed, dross continuously adheres to the cutting material, and even when the cutting speed reaches the standard speed, newly generated dross adheres to the dross already attached to the cutting material. A so-called dross drag phenomenon that continues continues.

For this reason, there is a problem that dross adheres to the product after the cutting is completed, and extra steps are required for post-processing.

An object of the present invention is to provide a plasma cutting method in which such disadvantages are improved.

<Means for Solving the Problems> In order to solve the above problems, the plasma cutting method of the present invention perforates a cutting material and forms at least one closed circuit from the position to a figure as a product. And cut it.

<Operation> According to the above means, at least one closed circuit is formed and cut from the piercing position to the figure as a product, thereby cutting off the continuous attachment of dross, that is, the dragging phenomenon of dross, As a result, a product free of dross can be obtained.

That is, when cutting a figure to be a product from the piercing position, by forming a closed circuit between the piercing position and the figure, the cutting speed is increased from the piercing position without substantially making a single stroke. While cutting to the intersection of the closed circuit, and making a cut by the running start method using the cut groove already cut at the intersection as the end face of the cut material, the cut material adheres to the cut material from the piercing position to the intersection of the closed circuit. The dross is cut off at the intersection at the intersection with the kerf. When cutting is performed by the running start method using the kerf as an end face of the cutting material, dross does not adhere even if the cutting speed is the same.

<Example> An example of a plasma cutting method to which the above-described means is applied will be described with reference to the drawings.

FIG. 1 is an explanatory view of an embodiment of the present cutting method, and FIG. 2 is a view showing a dross-free speed range.

When cutting a cut material by the plasma cutting method, there is a so-called dross-free speed range in which dross does not adhere to the cut material according to the thickness of the cut material. As shown in FIG. 2 as a result of the experiment, this speed range is different between the case where running is started from the end face of the cut material and the case where piercing is started from the surface of the cut material. It turned out that the case was wider than with a piercing start.

That is, in the case of the running start in FIG. 2, the vehicle becomes dross-free in the speed range surrounded by the curve and the case of the piercing start.
The speed range surrounded by the curves and becomes dross-free.

The reason is that if the cut material is cut at a speed lower than the standard speed, dross adheres to the cut material, and once the dross adheres, the dross is already attached due to the viscosity and surface tension of the newly generated dross. This is because a so-called dragging phenomenon of dross that adheres to the dross that occurs one after another occurs, and as a result, the dross adheres even if the cutting speed reaches the standard speed.

Therefore, in order to start cutting stably in the dross-free state of the cut material and to continue the cut, a cutting is performed from the end face of the cut material by a running start method using a plasma torch adjusted to a standard speed. Is most effective. However, when performing a cutting start from the end face when cutting the cutting material, distortion occurs due to thermal effects or release of internal stress of the cutting material, and it is possible to cut the figure into an accurate shape. Absent.

Therefore, in the plasma cutting method of the present invention, as shown in FIG.
A predetermined position 3 on the cutting material 1 is pierced, a closed circuit 4 is formed before reaching the figure 2 with the piercing position 3 as a starting position of cutting, and cutting is already performed at an intersection 5 of the closed circuit 4. By intersecting with the cut groove 6, the cut is made substantially by the running start method using the cut groove 6 as an end face of the cutting material 1.

That is, at the piercing position 3, the cutting speed is approximately 0 mm /
Perform piercing in the state of min, after the end of the piercing,
The cutting groove 6 is formed while increasing the cutting speed, and the closed circuit 4 is cut. When the cutting of the closed circuit 4 is completed and the intersection 5 is reached, the cutting speed is set so as to be in a dross-free range at least in the running start shown in FIG.

When the cutting path intersects the kerf 6 at the intersection 5, continuous cutting from the piercing position 3 to the intersection 5 is cut off, so that the dragging of the dross attached to the lower surface of the cutting material 1 is cut off. . And the intersection 5
Thereafter, a new cutting by the running start method is started with the kerf 6 as an end face of the cutting material 1.

At this time, since the cutting speed is in the dross-free range in the running start, the dross generated by the newly started cutting is discharged from the kerf 6 and does not adhere to the cut material 1.

<Effects of the Invention> As described in detail above, according to the plasma cutting method of the present invention, at least one closed circuit is formed and cut between a piercing position and a figure to be a product, so that a dross is formed. Is cut off, thereby obtaining a dross-free product.

That is, by substantially cutting the cut at the intersection of the closed circuit, the dross dragging phenomenon of the dross adhering to the cut material is cut off, and the dross is newly cut at the intersection by the running start method. Free shapes can be cut.

As a result, a product without dross can be obtained,
Therefore, it has the feature that the number of steps for post-processing can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an embodiment of the present cutting method, FIG. 2 is a view showing a dross-free speed range, and FIG. 1 is a cutting material, 2 is a figure, 3 is a piercing position, 4 is a closed circuit, 5 is an intersection, and 6 is a kerf.

Claims (1)

(57) [Claims] 1. A plasma cutting method, wherein a hole is made in a cutting material, and at least one closed circuit is formed and cut from the position to a figure as a product.