JPH0246342B2 - KIRIKUZUSAIDANHOHO - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a chip shredding method for efficiently shredding chips generated during cutting and significantly improving chip disposal.

Particularly in chip machining, turning, boring, etc., continuous chips are generated and wrap around the tool or workpiece, worsening the surface roughness of the machined surface and damaging the tool. This is a quality control issue at the work site. , has become an important problem in production technology. Continuous chips are also dangerous for operators and can cause accidents. Furthermore, with the recent promotion of automation and labor-saving, there is a trend toward unmanned machining, but the generation of continuous chips described above has the possibility of wrapping around tools, workpieces, and even machine parts such as tool rests. Since this can cause various troubles, operator monitoring is required and is the biggest obstacle to achieving unmanned operation.

Conventionally, in order to improve chip disposal, a method has often been adopted in which an obstacle called a chip breaker is attached to a cutting tool to bend and break the chips to cut them into small pieces. The chip breaker has a depth of cut of 1 like during rough machining.
It can be said that when the thickness of the chips is thick, such as several mm, the bending strain and stress on the surface layer of the chips become large, making them relatively easy to break, which is effective. However, if the depth of cut is
In the case of cutting conditions in which the chip thickness is thin, such as 0.5 mm or less, even if the chip is bent by a chip breaker, the chip breaker will not be effective because the chip is thin and the bending strain of the chip is small, making it difficult to break.

In view of the above-mentioned problems in cutting processing, the present invention aims to reliably and efficiently cut chips even when the thickness of the chips generated is thin, and to shred the chips in an easy-to-handle manner. An object of the present invention is to provide a method of cutting chips by cutting while intermittently injecting high-pressure fluid or periodically varying fluid pressure.

Examples according to the present invention will be described in detail below. FIG. 1 shows a schematic diagram of a cutting machine embodied for carrying out the invention. In the figure, a rotating cylindrical workpiece 1 is being cut by a tool 2, and a fluid 5, which is a liquid such as water, cutting oil, or a gas such as air or nitrogen, is injected from a nozzle 4 toward the rake surface 3 of the cutting edge. The current state is shown. Further, the fluid 5 has a structure in which it is injected periodically and intermittently, and in this example, in order to enable intermittent injection, the fluid 5 supplied from the pump 6 is intermittently supplied by the electromagnetic switching valve 7. It has a method of opening and closing. The electromagnetic switching valve 7 is provided with a timer 8 so as to be able to open and close continuously at an adjustable period, and is supplied with an electric signal that turns on and off at a required frequency. The frequency at this time should be set mainly depending on the size of the chips to be separated and the cutting speed. As will be explained later, chips are cut once per cycle of the intermittent jet flow. For example, at a cutting speed of 100 m/min, chips with a total length of about 1.7 m flow out per second, so the total length is 34 cm (chip curl diameter). If you want to obtain chips that are separated by approximately 15 turns (if it is 7 mm), the injection period may be set to 5 Hz. The higher the fluid pressure, the more effective it is, but it is usually 10Kg/cm ²
or more is required.

Next, regarding the chip shredding mechanism according to this method, as shown in the enlarged view of the cutting part in Fig. 2, when the fluid 5 is injected onto the rake face of the cutting edge of the cutting tool 2, the area of the cutting point S becomes plastic. Therefore, if a bending moment due to the jet flow is applied to the chips C, the direction of shear slip changes and bending deformation occurs. Since the above action is performed continuously while the injection is being performed, the chips C are curled and spiral chips are generated. The generation process of chips C at this time is shown in Figure 31.
2.

Next, when the jet stream is stopped, as shown in Fig. 3,
Since the external force caused by the jet disappears, the chips no longer curl and begin to flow out almost linearly. Next, when the jet is applied again, the chips collide with the workpiece 1 due to the impact of the start of the jet, as shown in Fig. 3,
In the process, the part of the chip that is not curled and extends almost linearly is reversely bent and cut. Figure 3 4
Fig. 4 shows a view taken along the line A-A. FIG. 4 shows a pattern in which the chips are reversely bent and cracks are generated at this time. By periodically opening and closing the injection, the generation of chips and the cutting action shown in FIGS. 3, 1 to 4 are performed continuously. From a practical standpoint, it is more effective to make the injection time in one cycle longer than the non-injection time. Further, instead of using the injection-non-injection on-off cycle as described above, the same effect can be expected by varying the injection pressure in a sinusoidal manner or the like.

As described above, according to the present invention, it is possible to effectively shred relatively thin chips generated during light cutting such as finishing, which was difficult to break with conventional chip breakers, and to facilitate chip disposal. This method eliminates the dangers of manufacturing and is also advantageous in terms of quality control, making it an effective method for unmanned processing.

[Brief explanation of the drawing]

Fig. 1 is a schematic front view showing an embodiment according to the present invention, Fig. 2 is an enlarged view of cutting points, Figs. 3 1 to 4 are explanatory views showing the chip shredding process, and Fig. A
-A arrow view. 1... Work material, 2... Cutting tool, 4... Nozzle, 5... Fluid, 7... Solenoid switching valve.

Claims (1)

[Scope of Claims] 1. A chip shredding method characterized by cutting while intermittently jetting high-pressure fluid toward the rake face of a cutting tool to make the generated chips finer. 2. A chip shredding method characterized by cutting while jetting a high-pressure fluid whose pressure is controlled to periodically fluctuate toward the rake face of a cutting tool, thereby making the generated chips finer.