JP7845321B2 - Laser processing machine - Google Patents

Description

This disclosure relates to a laser processing machine.

In laser processing machines that process workpieces by irradiating them with a laser, molten material generated by the laser irradiation may scatter and adhere to optical components such as lenses.
For example, Patent Document 1 discloses a technique for protecting optical systems from molten material splatter by supplying gas into a nozzle and generating negative pressure.

Japanese Patent Publication No. 2018-114542

The inventors identified the following problems with respect to laser processing machines.
If molten material is not completely recovered and remains, it may contaminate the optical system and workpiece, potentially leading to a decrease in laser processing efficiency. Furthermore, contamination of the nozzle interior and surrounding equipment may reduce the equipment's lifespan. Therefore, further suppression of molten material scattering is required.

This disclosure addresses these challenges and aims to provide a laser processing machine capable of further suppressing the scattering of molten material.

One embodiment for achieving the above objective is:
It is a laser processing machine,
A laser irradiation unit that irradiates the workpiece with a laser,
The system comprises a chamber having a hollow portion that connects the laser irradiation section to the processing point of the workpiece,
The aforementioned chamber contains,
An air inlet passage is provided in the middle of the inner wall forming the hollow portion of the chamber, and air flows into the chamber through the air inlet.
An air intake passage that communicates with an air intake port provided on the inner wall surface facing the inner wall surface on which the air inlet is provided, and draws air from inside the chamber through the air intake port,
A system is in place,
The hollow portion of the chamber has a rectangular cross-section when cut in a direction perpendicular to the direction of laser propagation.
At least two of the air inlets are provided on the longer side portion of the inner wall of the chamber.
In the inner wall of the chamber opposite to the inner wall where the air inlet is provided, the portion corresponding to the air inlet is a wall,
In the inner wall of the chamber facing the air intake, the portion corresponding to the air intake is a wall.
The air intake passage has an inclination that rises from the air intake port toward the outer end.

According to this disclosure, it is possible to provide a laser processing machine that can further suppress the scattering of molten material.

This is a plan view of the chamber provided in the laser processing machine according to the embodiment. This diagram shows the configuration of a laser processing machine according to an embodiment. This is a diagram showing the shape of the chamber. This graph shows the relationship between the shape of the chamber and the number of residual particles.

The embodiments of this disclosure will be described in detail below with reference to the drawings. In each drawing, identical or corresponding elements are denoted by the same reference numerals, and redundant explanations are omitted where necessary for clarity. Furthermore, in this specification, "substantially identical" refers to a state in which elements are perceived by a human eye as having the same shape and dimensions.

First, the configuration of the laser processing machine 10 according to this embodiment will be described with reference to Figures 1 and 2. As shown in Figure 1, the laser processing machine 10 comprises at least a chamber 100 and a laser irradiation unit 200. The laser processing machine 10 may further include peripheral members such as 600 and 700. Note that in addition to the laser processing machine 10, workpieces 300 and 400 are also shown in Figure 1.

The laser processing machine 10 is a device that processes workpieces by irradiating them with a laser. In the example shown in Figure 1, the laser processing machine 10 joins two workpieces 300 and 400 by laser irradiation. The processing point 500 shown in Figure 1 is the laser irradiation position. The laser irradiation unit 200 irradiates the laser toward the processing point 500. The workpieces 300 and 400 are melted and joined by the laser near the processing point 500. When the workpieces 300 and 400 receive the laser, they are rapidly heated, momentarily exceeding their melting or boiling points, and the molten material and molten vapor may diffuse into the surrounding area. Hereinafter, the molten material and molten vapor will be referred to as "molten material." Note that the laser processing machine 10 may perform processing other than joining workpieces. For example, the laser processing machine 10 may perform drilling, etc.

The peripheral members 600 and 700 are components positioned around the chamber 100 and the workpieces 300 and 400, and have various functions. In the example shown in Figure 1, the peripheral members 600 and 700 are components that position the chamber 100 and the workpieces 300 and 400.

The chamber 100 connects the laser irradiation unit 200 to the processing point 500. As shown in Figure 1, the chamber 100 is a hollow member, and the laser passes through the hollow portion provided in the chamber 100. Figure 2 is a view of the chamber 100 from the laser irradiation unit 200 side. As shown in Figure 2, the chamber 100 has a rectangular hollow. Specifically, the chamber 100 has a hollow whose cross-section is rectangular when cut in a direction perpendicular to the laser's direction of travel. That is, the inner wall 150 of the chamber 100 has two opposing long side portions 150a and 150b, and two short side portions (not shown) connecting the ends of these long side portions.

The chamber 100 is provided with at least two air inlet passages 130. In the example shown in Figure 2, the chamber 100 is provided with two air inlet passages 130a and 130b. The air inlet passages 130 communicate with the air inlet 110, and air flows into the chamber 100 through the air inlet 110. The air inlet 110 is provided in the middle of the inner wall 150 of the chamber 100, as shown in Figure 1. Specifically, at least two air inlets 110 are provided on the long side portion of the inner wall 150. In the example shown in Figure 2, two air inlets 110a and 110b are provided on the long side portion 150a of the inner wall 150.

The chamber 100 is provided with at least one air intake passage 140. In the example shown in Figure 2, the chamber 100 is provided with one air intake passage 140. The air intake passage 140 communicates with an air intake port 120 and draws in air from inside the chamber 100 through the air intake port 120. As shown in Figure 1, the air intake port 120 is provided in the middle of the inner wall 150 of the chamber 100. Specifically, the air intake port 120 is provided on the long side portion of the inner wall 150 opposite to the long side portion where the air inlet 110 is provided. In the example shown in Figure 2, one air intake port 120 is provided on the long side portion 150b of the inner wall 150. As shown in Figure 1, the air intake passage 140 has an incline that rises from the air intake port 120 toward the outer end of the chamber 100. In other words, the air intake passage 140 is angled such that the air intake port 120 faces the machining point 500. Furthermore, it is preferable that the air intake port 120 is provided at approximately the same height as the air inlets 110a and 110b, as shown in Figure 1. By providing the air intake port 120 at approximately the same height as the air inlets 110a and 110b, short-circuiting of the airflow within the chamber 100 can be suppressed, and a vertical swirling flow can be accurately generated within the chamber 100.

In the long side portion 150b opposite to the long side portion 150a where the air inlets 110a and 110b are provided, the area corresponding to the air inlets 110a and 110b is a wall. In other words, the area corresponding to the air inlets 110a and 110b in the long side portion 150b does not have an air intake port 120. Furthermore, in the long side portion 150a opposite to the long side portion 150b where the air intake port 120 is provided, the area corresponding to the air intake port 120 is a wall. In other words, the area corresponding to the air intake port 120 in the long side portion 150a does not have air inlets 110a and 110b. In the example shown in Figure 2, the air intake port 120 is provided in the long side portion 150b at the location corresponding to the two air inlets 110a and 110b.

The arrows in Figures 1 and 2 indicate the airflow within the chamber 100. As shown in Figures 1 and 2, the air flowing in from the air inlet passages 130a and 130b through the air inlets 110a and 110b generates a swirling flow that rotates in both the longitudinal and transverse directions within the chamber 100. The swirling air within the chamber 100 is drawn in through the air intake passage 140 via the air intake port 120. Because the swirling flow extends in the longitudinal direction, i.e., the direction of laser propagation, the airflow reaches the processing point 500. Because the swirling flow extends in the transverse direction, i.e., perpendicular to the direction of laser propagation, the molten material can be discharged from the chamber 100 even if the processing point 500 is linear in shape.

The molten material generated when the laser is irradiated onto the processing point 500 is carried by the swirling flow generated in the chamber 100 and discharged through the air intake passage 140 along with the air. Therefore, adhesion of the molten material to the workpieces 300, 400, and the various components constituting the laser processing machine 10 can be suppressed. Because the laser processing machine 10 discharges the molten material using airflow, its running costs are lower compared to devices that use inert gas to discharge the molten material. Furthermore, since the laser processing machine 10 does not require a mechanism to supply inert gas, its structure is simple and controllable. Because the molten material contained in the air has a greater mass than the air itself, there is a risk that it may deviate from the airflow due to inertial force within the air intake passage 140. Therefore, from the viewpoint of suppressing the adhesion of molten material within the air intake passage 140, it is preferable to provide the air intake passage 140 in a straight line.

Next, embodiments of the present invention will be described.
Figure 3 shows models of the chambers according to Example 1 and Comparative Examples 1 to 3. Figure 3 is a schematic diagram showing a model of the chamber cut along the direction in which the air inlet passages 130a and 130b extend. The chamber models according to Example 1 and Comparative Examples 1 to 3 are all provided with two air inlet passages 130a and 130b and one air intake passage 140.

Example 1 is a model in which air inlet passages 130a, 130b and an air intake passage 140 are provided on the long side portion of the inner wall of the chamber, and the air intake passage 140 has an inclination from the air intake port 120 toward the outer end. That is, it is a model corresponding to the chamber 100 described in the above embodiment. Comparative Example 1 is a model in which air inlet passages 130a, 130b and an air intake passage 140 are provided on the long side portion of the inner wall of the chamber, and the air intake passage 140 extends substantially horizontally from the air intake port 120 toward the outer end. Comparative Example 2 is a model in which air inlet passages 130a, 130b and an air intake passage 140 are provided on the short side portion of the inner wall of the chamber, and the air intake passage 140 extends substantially horizontally from the air intake port 120 toward the outer end. Comparative Example 3 is a model in which air inlet passages 130a, 130b and an air intake passage 140 are provided on the short side portion of the inner wall of the chamber, and the air intake passage 140 has a slope from the air intake port 120 toward the outer end.

The discharge performance was evaluated using the model shown in Figure 3. During the evaluation, virtual particles simulating molten material were placed near the laser processing point in the chamber, air was drawn in, and the number of virtual particles remaining in the chamber was measured. Initially, the virtual particles were assumed to be floating and to adhere upon impact with the inner wall surface. The evaluation results are shown in Figure 4. Comparing Example 1 and Comparative Example 1 with Comparative Examples 2 and 3, it was found that by providing air inlets 110 and air intake ports 120 on the long side of the chamber's inner wall, a large number of virtual particles could be discharged by the airflow. Furthermore, comparing Example 1 with Comparative Example 1, it was found that providing a slope in the air intake passage 140 allowed for even greater discharge of virtual particles. Thus, Example 1 demonstrated superior discharge performance compared to Comparative Examples 1-3, as it could discharge a large number of virtual particles in a shorter time.

Furthermore, this disclosure is not limited to the embodiments described above, and may be modified as appropriate without departing from its intent.

10 Laser processing machine 100 Chamber 110 (110a, 110b) Air inlet 120 Air intake port 130 (130a, 130b) Air inlet passage 140 Air intake passage 150 Inner wall 150a, 150b Long side portion 200 Laser irradiation section 300, 400 Workpiece 500 Processing point 600, 700 Peripheral components

Claims (2)

A laser irradiation unit that irradiates the workpiece with a laser,
The system comprises a chamber having a hollow portion that connects the laser irradiation section to the processing point of the workpiece,
The aforementioned chamber contains,
An air inlet passage is provided in the middle of the inner wall forming the hollow portion of the chamber, and air flows into the chamber through the air inlet.
An air intake passage that communicates with an air intake port provided on the inner wall surface facing the inner wall surface on which the air inlet is provided, and draws air from inside the chamber through the air intake port,
A system is in place,
The hollow portion of the chamber has a rectangular cross-section when cut in a direction perpendicular to the direction of laser propagation.
At least two of the air inlets are provided on the longer side portion of the inner wall of the chamber.
In the inner wall of the chamber opposite to the inner wall where the air inlet is provided, the portion corresponding to the air inlet is a wall,
In the inner wall of the chamber facing the air intake, the portion corresponding to the air intake is a wall.
The air intake passage has an inclination that rises from the air intake port toward the outer end.
Laser processing machine. The laser processing machine according to claim 1, wherein the air inlet is provided at approximately the same height as the air intake port.