RU225783U1 - DEVICE FOR AUTOMATICALLY CHANGING AIR PRESSURE DURING OPERATION OF CO2 LASER CNC MACHINE - Google Patents

Abstract

The utility model relates to the field of cutting and engraving of various materials on a CO ₂ laser machine with numerical control, in particular, to devices with automatic supply of pressure to the cutting area. The device is installed inside the machine and connected to the machine control through a system of two electromagnetic valves and air pressure adjustment, with the ability to select the required air pressure for cutting and engraving materials. This ensures high quality processing of materials, reduction of carbon deposits on products, reduction of post-processing time and a reduction in the amount of defects. 14 ill., 1 tab.

Description

The utility model relates to the field of cutting and engraving of various materials on a CO ₂ laser machine with computer numerical control (CNC), in particular, to devices with automatic supply of pressure to the cutting area.

The claimed technical solution will be part of a CO ₂ laser CNC machine; it serves to control the air pressure that is supplied to the material in the cutting zone, as a result of which the amount of carbon deposits on the material is reduced, and a lighter cut of materials is also ensured, as a result of which this speeds up the post-processing of materials and eliminates the need to stop the machine during operation to control the air pressure manually.

The prior art knows a method for cutting a brittle non-metallic material, predominantly glass, under the influence of thermoelastic stresses, including the initiation of a separating microcrack and its development by heating the cut line under the influence of a laser beam with relative movement of the beam and the material to a temperature not exceeding the softening temperature of the material, and local cooling the heating zone by supplying refrigerant. Patent BY 10022 C1 “Method of cutting brittle non-metallic material under the influence of thermoelastic stresses” application date 2005.07.11.

The patent for the invention of the Russian Federation RU 2172233 C2 “METHOD AND DEVICE FOR CUTTING MATERIALS WITH A LASER BEAM” was chosen as the prototype. A nozzle with a gap is placed above the surface to be cut, allowing it to cut uneven and rough surfaces, and an area of increased pressure is created above the cut by blowing auxiliary gas into it. Gas is injected into the area of high pressure with a velocity component directed along the cut towards its front. Air is used as an auxiliary gas. The nozzle for supplying auxiliary gas has an outlet section made elongated along the direction of the cutting front. The nozzle outlet section is equipped with guide baffles located at an angle of 45-60° to the direction of the cut front to obtain a component of the auxiliary gas velocity directed along the cut towards its front. This allows the laser beam to pass in front of the nozzle, simplifying the design of the device.

CO ₂ laser machines do not use regulation of the air pressure supplied to the cutting zone, or are partially regulated using a single solenoid valve. The device is used to turn on and off the air supply to the cutting zone of a certain pressure, which is regulated on the compressor or not regulated at all, the solenoid valve consists of the following elements: a body with a cover - cast from brass, stainless steel, cast iron or durable polymers; shutter - made in the form of a piston, ball or plate; coil with core (solenoid) - placed in a sealed housing, and the winding is made of high-strength copper wire, allowing the valve to be opened and closed tens of thousands of times; rod, return spring, plunger and diaphragm.

The disadvantages of this model of supplying air to the cutting zone using a single solenoid valve are: insufficient or excessive air pressure when processing materials, which leads to undercuts, severe charring of the edges of the workpiece, unclear engraving of the product, and heavy carbon deposits on the material. All this leads to reworking the workpieces, wasting time on post-processing of the product, or it is necessary to stop the machine during operation and adjust the air pressure, which also affects the quality of the resulting product, and also increases the manufacturing time, resulting in a decrease in productivity and quality.

If you turn off the air supply completely, this will lead to overheating of the focal lens inside the cutting head, and after a while it will crack (destroy), and the nozzle of the cutting head will become clogged with combustion waste (resins, plastic, etc.). Minimal airflow is required for operation.

The purpose of the utility model is to create a device that will supply the required air pressure to the cutting zone when cutting and engraving various materials; the air pressure for each material is selected individually.

Technical result is achieved by the fact that the device is installed inside the machine and connected to the machine control through a system of two electromagnetic valves and air pressure adjustment, with the ability to select the required air pressure for cutting and engraving materials, which will allow for higher quality processing of materials and reduce carbon deposits on products, will also reduce post-processing time and reduce the amount of scrap.

The utility model is a device made of the following elements: an air duct, two solenoid valves, two pressure gauges, two pressure regulators.

The device, connected in a circuit between the compressor and the machine head (cutting head), is controlled by a controller that sets the sequence in which the solenoid valves turn on and off. On pressure gauges, using pressure regulators, the required pressure is set on each of the valves, which will be supplied to the cutting or engraving zone for a specific material.

The dependence of the quality of cutting and engraving of a particular material on the air pressure of the ball was established through experiments. For example, the experiment was carried out on a CNC laser CO ₂ machine using a RECI 100W laser tube, a D20 focal lens, F50.8 mm, using double-sided plastic material 1.5 mm thick with a permissible air pressure error of 0.03-0.1 atmospheres due to various factors, for example, the length of the air path, the error of the pressure gauge, the height of the cutting head to the material due to the unevenness of the material. The results are summarized in table No. 1.

Table No. 1: dependence of the quality of cutting and engraving of the material on air pressure. Experience no. Air pressure in atm Machine operating speed in mm/s when cutting Emitter power in % when cutting Emitter power in % when engraving Machine operating speed in mm/s when engraving Positioning accuracy when engraving in mm Result, photo 1 1 25 35 17 370 0.07 Fig. 4 2 1.2 25 35 17 370 0.07 Fig. 5 3 1.4 25 35 17 370 0.07 Fig. 6 4 1.6 25 35 17 370 0.07 Fig. 7 5 1.8 25 35 17 370 0.07 Fig. 8 6 2 25 35 17 370 0.07 Fig. 9 7 2.4 25 35 17 370 0.07 Fig. 10 8 2.8 25 35 17 370 0.07 Fig. eleven 9 3 25 35 17 370 0.07 Fig. 12 10 4 25 35 17 370 0.07 Fig. 13 eleven 5 25 35 17 370 0.07 Fig. 14

The results of the experiments showed that the higher the pressure, the cleaner the cut, but up to a certain pressure of 2.8 Atm. (applies to plastic), therefore, the cleanest engraving with the least carbon deposits starts from 1 atm. up to 1.6 Atm. But at a pressure of 1 Atm. cutting cannot be done, since this is atmospheric pressure and the material ignites, which is unsafe, and high temperatures cause degradation of the lens without cooling. The best parameters for engraving are 1.1-1.4 atm, cutting 2.4-3.0 atm, fig. 12.

Checking indicators on the material, birch plywood Ш2, 3mm, grade 2/2

The experiment was carried out under the following parameters:

Engraving power 17%

Engraving speed 200 mm/s

Engraving pitch 0.05 mm

Cutting speed 20 mm/s

Cutting power 30%

Experience No. 1 shows that the lower the pressure, the better, brighter, and clearer the engraving, but the edges of the cut become black from soot.

Experiment No. 2 confirms Experiment No. 1, the engraving is less clear and dark, there is a lot of dust, but the cut is cleaner and better quality; if you look closely in Experiment No. 2, stripes of the laser pitch are visible in the inscription, which is not present in Experiment No. 1.

The essence of the proposed device is illustrated by the drawing.

Figure 3 is a diagram of a device for automatically changing air pressure.

A device for automatically changing air pressure when working on a CO ₂ laser machine with numerical control consists of:

1 - air duct; 2 - solenoid valve; 3 - pressure gauge; 4 - pressure regulator;

5 - compressor.

The proposed technical solution is unknown from the state of the art based on available sources of information, from which it clearly follows for a specialist in the field of cutting and engraving, and can be practically implemented in mass production using conventional technology, that is, it meets the patentability criteria.

Claims (1)

A device for automatically changing air pressure when working on a CO ₂ laser machine with numerical control, consisting of an air duct, two solenoid valves, two pressure gauges, two pressure regulators and designed to be connected to the machine compressor and controlled by numerical control.