JP2010089137A - Manufacturing method, cutting method, and laser beam machining apparatus of workpiece - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method and a laser beam machining apparatus of a workpiece by which a workpiece is free from burning even if a laser beam penetrated a cut section of the workpiece should come in contact with the reverse side of the workpiece. <P>SOLUTION: This is a manufacturing method of a cut workpiece, including a process of placing on a table the inner face of a workpiece along the surface shape of the table and a process of cutting the workpiece by scanning and emitting a laser beam toward the table. In the manufacturing method of a cut workpiece and the laser beam machining apparatus, the light quantity A1 of the laser beam in the workpiece cut section is within the range of A0×1.2 to A0×3.0, and the light quantity A2 of the laser beam, when it cuts off the workpiece to pass through a through-hole, and then passes through the through-hole again to reach the reverse side of the workpiece, is less than A0×0.90 (provided A0 is the minimum light quantity of the laser beam required for cutting the workpiece). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a workpiece cutting method, a workpiece manufacturing method, and a laser beam machining apparatus for cutting a workpiece by laser beam machining.

In the method of cutting a workpiece by laser beam processing, the laser beam penetrating the workpiece cutting site is reflected on the workpiece support base and touches the back surface of the workpiece to burn out the workpiece. Therefore, the ground contact surface between the workpiece and the support platform is minimized. However, there is a problem in that it is reflected by chips or the like below the workpiece, and again passes through the cutting portion and is scattered to the surroundings to burn out the optical path forming component. As a method for preventing this, in Patent Document 1, the first support plate is installed so as to be inclined with respect to the surface of the workpiece support table (table) that intersects perpendicularly with the perpendicular axis of the workpiece medium (workpiece). The first support plate reflects the processing medium penetrating the workpiece, and the second support plate reflects the processing medium reflected by the first support plate, A method of attenuating the energy of the processing medium by alternately reflecting the processing medium between the first support plate and the second support plate, and a support plate inclination angle for arbitrarily selecting the angle of the support plate It is described that the angle of the support plate can be easily changed by providing the adjusting means.
However, in the method described in Patent Document 1, when the work has a complicated three-dimensional shape or when the work is easily deformed due to low rigidity, the work cannot be firmly fixed.

Further, in Patent Document 2, a plurality of through holes are formed in a table for bringing a workpiece into close contact with each other so as to expand outwardly by a taper surface. It is described that reflection can be reduced.
However, in the method described in Patent Document 2, since the ground contact area of the workpiece and the table at the laser cutting site is large, a general-purpose resin molded body with low heat resistance, or when it is easily deformed due to low rigidity, It is not possible to prevent the workpiece from being burned out or deformed due to direct reflection at the grounding part or temperature rise at the grounding part. In addition, in the case of a complicated three-dimensional shape, it may be difficult to set the through hole.
JP-A-08-108291 JP 2005-297032 A

  The problem to be solved by the present invention is that when a workpiece is cut by laser beam machining, the reflected light or penetrating light of the laser beam penetrating the workpiece cutting portion may burn the workpiece even if it contacts the back surface of the workpiece. An object of the present invention is to provide a method for manufacturing a workpiece, and a laser beam processing apparatus for cutting the workpiece.

  As a result of intensive studies, the present inventors have found a table on which a workpiece having a surface shape similar to the inner surface shape of a workpiece made of a resin molded body and having a through groove provided at a position coinciding with the laser cutting site of the workpiece is placed. When the workpiece is placed and scanned with a laser beam to cut the workpiece, the amount of the laser beam at the workpiece cutting section and the workpiece cut through the through groove and then through the through groove again to reach the back of the workpiece The problem was solved by specifying the amount of laser beam at the time.

That is, the present invention has a surface shape similar to the shape of the inner surface of a workpiece, which is a resin molded body, and is provided with a through groove provided at a position coinciding with the laser cutting site of the workpiece, A process of placing the inner surface along the surface shape of the table;
A method of manufacturing a cut workpiece, comprising a step of cutting a workpiece by scanning and irradiating a laser beam toward the table,
The amount of laser beam A1 at the workpiece cutting site is in the range of A0 × 1.2 to A0 × 3.0,
In addition, when the workpiece is cut and passed through the through groove, the laser beam light quantity A2 when passing through the through groove again and reaching the back side of the workpiece is less than A0 × 0.90 (however, A0 is for cutting the workpiece) A method of manufacturing a cut workpiece that is the minimum amount of laser beam required).
Here, the minimum light amount A0 of the laser beam is the minimum value of the light amount of the laser beam that can completely cut the workpiece when the workpiece and the laser beam are vertical using a carbon dioxide laser processing machine when the scanning speed is 1000 mm / min. Say that.

Further, the present invention provides a table for placing a workpiece having a surface shape similar to the inner surface shape of the workpiece, which is a resin molded body, and having a through groove provided at a position coincident with the laser cutting portion of the workpiece. A process of placing the inner surface along the surface shape of the table;
A method of cutting a workpiece, comprising a step of scanning a laser beam toward the table and cutting the workpiece.
The amount of laser beam A1 at the workpiece cutting site is in the range of A0 × 1.2 to A0 × 3.0,
In addition, the amount of laser beam A2 when the workpiece is cut and passed through the through groove and then again passes through the through hole and reaches the back side of the workpiece is less than A0 × 0.90 (however, A0 is for cutting the workpiece) Provided is a method for cutting a workpiece, which is the minimum light amount of a necessary laser beam.

  Further, the present invention provides a table for placing a workpiece having a surface shape similar to the inner surface shape of the workpiece, which is a resin molded body, and having a through groove provided at a position coinciding with the laser cutting portion of the workpiece, In order to perform laser beam processing, laser beam processing includes a laser oscillator that scans and irradiates a laser beam toward the table, and a shielding plate that reflects or absorbs the laser beam that has cut the workpiece and passed through the through groove. Providing equipment.

  According to the present invention, a workpiece made of a resin molded body can be cut cleanly without being burned or deformed by the reflected light of the laser beam penetrating the workpiece or the influence of the penetrating light. In particular, when the workpiece is a sheet-like three-dimensional molded body, the above-described burnout and deformation can be effectively prevented, and thus the effect of the present invention is high.

Below, with reference to drawings, the manufacturing method of the cut work of the present invention is explained.
The method of manufacturing a cut workpiece according to the present invention places a workpiece having a surface shape similar to the inner surface shape of the workpiece, which is a resin molded body, and having a through groove provided at a position coinciding with the laser cutting portion of the workpiece. A step of placing the inner surface of the work along the surface shape of the table on the table for cutting, and a step of cutting the work by scanning and irradiating a laser beam toward the table, and the amount of laser beam at the work cutting site The amount of laser beam A2 when A1 is in the range of A0 × 1.2 to A0 × 3.0, and when the workpiece is cut and passed through the through hole, then again passes through the through groove and reaches the back side of the workpiece. Is less than A0 × 0.90 (where A0 is the minimum amount of laser beam necessary to cut the workpiece).
FIG. 1 shows an example 1 of a specific embodiment of the present invention. In FIG. 1, a through groove 4 is provided in a table 3 having a surface shape similar to the inner surface shape of a work 2 made of a resin molded body. The through groove 4 is provided so as to coincide with the cutting part of the workpiece 2.

The workpiece 2 used in the present invention is a resin molded body. Among these, a molded product of a resin mainly composed of a thermoplastic resin is preferable because the effects of the present invention can be exhibited well, and the thin molded product of the resin is particularly suitable for the method of the present invention. Conventional cutting with a laser processing machine melts and cuts the material by local heating of the laser irradiation part, so that a material having low heat resistance, such as a thermoplastic resin, particularly a thin wall, is likely to be thermally deformed. However, according to the production method of the present invention, it is possible to cut well even if it is a molded body of a resin mainly composed of a thermoplastic resin and has a thin wall thickness.
Specifically, the wall thickness is preferably within a range of up to 5 mm where laser cutting can be easily performed, and it is possible to effectively prevent burnout and deformation due to the reflected light of the laser beam penetrating the workpiece 2 or the influence of the penetrating light. More preferably within the range of 1 to 1 mm. For the above-described reason, the tensile elastic modulus of the work 2 is preferably in the range of 100 to 5000 MPa. The tensile elastic modulus is an elastic modulus measured by a method according to JIS K-7127.

  The shape of the workpiece 2 is not particularly limited, but is usually a shape that requires cutting before becoming a finished product, and is often a flat plate (sheet) shape or a three-dimensional solid shape, for example. For example, a molded article having a three-dimensional solid shape obtained by thermoforming a sheet-like thermoplastic resin has a part of the sheet three-dimensionally molded, and only the three-dimensionally molded part is often a finished product. It is necessary to cut the unmolded sheet portion. The method of the present invention is particularly suitable for cutting a resin molded body having a three-dimensional solid shape obtained by thermoforming such a sheet-like thermoplastic resin.

Specifically, the thermoplastic resin as the main component of the workpiece 2 is mainly a thermoplastic resin having a softening point in the range of 30 to 300 ° C. in order to perform heat molding such as vacuum molding or injection molding. It is preferable. For example, polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, acrylic resins such as polymethyl methacrylate and polyethyl methacrylate, ionomer resins, polystyrene, polyacrylonitrile, acrylonitrile-styrene resins, acrylonitrile-butadiene- Styrene resin, acrylonitrile-acrylic rubber-styrene resin, acrylonitrile-ethylene rubber-styrene resin, methyl methacrylate-styrene resin, styrene-butadiene-styrene resin, styrene-isoprene-butadiene-styrene resin, polyamide resin such as nylon, ethylene-acetic acid Vinyl resin, ethylene-acrylic acid resin, ethylene-ethyl acrylate resin Ethylene-vinyl alcohol resin, chlorine resin such as polyvinyl chloride and polyvinylidene chloride, fluorine resin such as polyvinyl fluoride and polyvinylidene fluoride, polycarbonate resin, cyclic polyolefin resin, modified polyphenylene ether resin, methylpentene resin, cellulose resin, Further, thermoplastic elastomers such as olefin elastomers, vinyl chloride elastomers, styrene elastomers, urethane elastomers, polyester elastomers, polyamide elastomers and the like can be used alone or in admixture of two or more.
In addition, conventional additives may be added to these thermoplastic resins as long as the moldability is not inhibited. For example, plasticizers, light-resistant additives (ultraviolet absorbers, stabilizers, etc.), antioxidants, Ozonization inhibitor, activator, antistatic agent, lubricant, antifriction agent, surface conditioner (leveling agent, antifoaming agent, antiblocking agent, etc.), antifungal agent, antibacterial agent, dispersant, flame retardant and vortex You may mix | blend additives, such as a promoter and a wake-promoting auxiliary. Moreover, you may add an inorganic filler suitably for the purpose of improving a heat deformation. Moreover, you may add a coloring material in order to provide the designability. These additives may be used alone or in combination of two or more.

When the workpiece 2 is in the form of a sheet, a single sheet or a mixture of two or more of the thermoplastic resins can be used. In addition, an ink or a paint may be spread on the surface of the sheet by a conventional method, or a metal thin film may be formed by a vacuum deposition method, a sputtering method, or the like.
Furthermore, a transparent or translucent surface protective layer is provided on the outermost surface of the sheet for the purpose of imparting characteristics such as friction resistance, abrasion resistance, weather resistance, stain resistance, water resistance, chemical resistance, and heat resistance. One or more layers may be provided. For such a surface protective layer, in addition to thermoplastic resins and thermoplastic elastomers, thermosetting bridge resins using isocyanate groups and epoxy groups, UV and EB curable resins using acrylate monomers and oligomers, etc. are used. can do.

  When the workpiece 2 is a three-dimensional molded body, there are a method of thermoforming the sheet by a conventional method, a method of thermoforming a molten or pellet-shaped thermoplastic resin by a method such as injection molding, and the like. As a method of thermoforming the above-mentioned sheet by a conventional method, for example, a hot plate pressure forming method, a vacuum forming method, an ultrahigh pressure forming method, a pressure forming method, a pressure forming method, a match mold forming method, a press forming method, It can be obtained by an existing thermoforming method such as a vacuum lamination press molding method. If necessary, a straight method using a plug, a drape method, a plug assist method, an air slip method, a snap back method, or the like may be used in combination. As the heating method, either an indirect heating method such as radiant heat or dielectric heating, or a direct heating method in which heating is performed in contact with a hot plate or the like may be used. In this case, since it is easy to design a surface shape similar to the inner surface shape of the workpiece in the table to be used, it is preferable that the table is thermoformed by a convex mold.

Of the workpieces 2 that are resin molded bodies, the thin workpiece 2 has a low rigidity and is easily deformed, so that a table having a surface shape similar to the inner surface shape of the workpiece 2 is required. Therefore, the table 3 in FIG. 1 has a surface shape similar to the inner surface shape of the workpiece 2, and the dimensional error is preferably less than 1%. As a method for producing the table 3, a method for producing the table 3 having a surface shape similar to the inner surface shape of the workpiece 2 in consideration of the molding shrinkage ratio inherent to the workpiece 2 is taken into consideration for the inner surface shape of the mold for molding the workpiece 2. Can be given. Specifically, when the molding shrinkage specific to the workpiece 2 is a%, the X-axis, Y-axis, and Z-axis directions are respectively (100−) with respect to the CAD data of the inner surface shape of the mold for molding the workpiece 2. a) It is preferable to produce the table 3 by cutting, casting, resin reversal, or the like using CAD data reduced to ± 0.5%. In addition, when the work 2 has a certain degree of rigidity, the table 3 may be manufactured by a casting process in which a curable resin or gypsum is poured directly into the inner surface of the work 2.
Moreover, it is preferable to hold | maintain the table 3 with the table support | pillar 7, the side plate 5, etc. so that laser beam processing may be performed easily. By doing this, the height can be adjusted. In order to prevent the laser beam entering the table 3 from leaking from an unexpected part, the side plate 5 preferably has a shape covering the entire lower part of the table.
The material of the table 3 is not particularly limited, but it should be a thermosetting resin or a steel material such as aluminum or iron from the viewpoint of maintaining durability even when the laser beam penetrating the workpiece 2 contacts the inside of the table 3. Is preferred. The thickness of the table 3 is preferably in the range of 5 to 25 mm from the viewpoint that durability can be maintained even when the laser beam comes in contact and heat generation can be prevented. In addition, when there is a possibility that the laser beam contacts the inside of the table 3 and generates heat to significantly increase the temperature of the workpiece 2 itself, a cooling mechanism (not shown) may be provided inside the table 3. The cooling mechanism is not particularly limited, and water or air that is usually used as a cooling medium can be appropriately used.
Further, the width of the through groove 4 provided in the table 3 is preferably within a range of 1 to 10 mm from the viewpoint of shape retention of the workpiece 2 and radiation cooling of the laser beam cut surface. That is, if the width of the through groove 4 exceeds the range, the workpiece 2 near the cutting site is easily deformed, and if it is smaller than the range, the workpiece 2 cut by the laser beam is insufficiently cooled and easily deformed. .
Moreover, when providing the below-mentioned shielding board (FIG. 28) inside the table 3, it is preferable to make it easy to install a shielding board by making this inside into a cavity.

When cutting the workpiece 2 by scanning with a laser beam, it is necessary to place the workpiece 2 on the table 3 and bring the table 3 and the workpiece 2 into close contact with each other. For this purpose, a method using a holding jig (not shown) similar to the outer shape of the workpiece 2 and a method of sucking the workpiece 2 from the table 3 side with a vacuum pad or the like (not shown) can be mentioned.
The method of installing the vacuum pad is not particularly limited, but it is necessary to install the vacuum pad so as not to impair the surface shape of the table 3. For example, a concave shape is provided on the surface of the table 3 so that the vacuum pad does not protrude from the surface of the table 3. It is preferable to install. Moreover, although the installation site | part of a vacuum pad is not specifically limited, When the workpiece | work 2 is a sheet-like three-dimensional molded object, when a vacuum pad adsorb | sucks to the workpiece | work 2 which is a sheet-like three-dimensional molded object, it may deform | transform. Therefore, it is necessary to consider the deformation of the workpiece 2 due to suction. For example, it is preferable to install the workpiece 2 at a position 5 mm or more away from the laser cutting part. Moreover, the shape and suction | attraction force of a vacuum pad are not specifically limited, What is necessary is just to select suitably by the thickness and rigidity of a workpiece | work.

The step of cutting the workpiece 2 by scanning with a laser beam toward the table 3 will be specifically described below.
The type of the laser beam is not particularly limited, and a carbon dioxide laser, a YAG laser, an excimer laser, a harmonic laser, a semiconductor laser, or the like can be used, but the workpiece 2 mainly composed of the thermoplastic resin can be cut. It is preferable to use a carbon dioxide laser because of its versatility and high versatility. When the laser cutting part has a three-dimensional shape, it is preferable to use a three-dimensional laser processing machine. The three-dimensional laser processing machine has a function of allowing the laser oscillation head to freely move in three dimensions, and specifically refers to a laser processing machine in which the laser oscillation head is arranged at the tip of a robot arm that can move three or more axes. .
The distance between the tip of the laser oscillation head 1 in FIG. 1 and the surface of the workpiece 2 is not particularly limited, and may be adjusted as appropriate according to the focal length of the laser condenser lens. As mentioned above, it is preferable to be within the range of the focal position of the laser condenser lens +10 mm. The angle between the surface of the work 2 and the laser beam is most preferably 90 degrees (perpendicular) with respect to the work 2 because the cut surface of the work 2 is clean. When it is difficult to maintain 90 degrees due to the shape of the oscillation nozzle 1, it is preferable to be within a range of 30 to 90 degrees with respect to the workpiece 2, and 45 to 90 degrees is more preferable. . The laser scanning speed needs to be adjusted as appropriate depending on the material and thickness of the workpiece 2, but it is preferably in the range of 500 to 10,000 mm / min since the cut surface is clean.

  Usually, a compressed gas called assist gas is blown out from the tip of the laser oscillation head 1, and has a role of removing the melted product by the laser beam from the work 2 and protecting the condenser lens from the melted scattered material. In this invention, since the workpiece | work which consists of a resin molding is used, as assist gas, nitrogen gas, air, or argon gas is preferable. In addition, when oxygen gas is used as the assist gas, combustion of the material can be promoted and cutting efficiency can be improved. However, since the laser cutting part may be oxidized and deteriorated, when a thermoplastic resin that is easily oxidized and deteriorated is used. Should be careful. Further, the assist gas ejection pressure and the air volume are not particularly limited, but need to be appropriately adjusted depending on the material and thickness of the workpiece.

In the present invention, the amount of laser beam A1 at the workpiece cutting site is in the range of A0 × 1.2 to A0 × 3.0, and after cutting the workpiece and passing through the through groove, it passes through the through groove again. The amount of laser beam A2 when reaching the back side of the workpiece is less than A0 × 0.90 (where A0 is the minimum amount of laser beam necessary to cut the workpiece).
By setting the amount of laser beam in this way, the workpiece made of a resin molded body can be cut cleanly without being burned or deformed by the influence of reflected light or penetrating light of the laser beam penetrating the workpiece. In particular, when the workpiece is a sheet-like three-dimensional molded body, the above-mentioned burnout and deformation can be effectively prevented.

The minimum amount A0 of the laser beam necessary for cutting the workpiece varies depending on the type or film thickness of the thermoplastic resin that is the main component of the workpiece material. Therefore, it is necessary to set the minimum light amount A0 every time the workpiece material changes or every time the film thickness changes even if the material is the same. At this time, the minimum light quantity A0 depending on the type of the thermoplastic resin often depends on Tg.
On the other hand, the minimum amount of light A0 of a plurality of works having the same material and different film thicknesses is often small when the difference in film thickness is small. For example, there is almost no difference in the minimum light amount A0 of each workpiece having a film thickness difference of 500 μm or less. Therefore, for example, when the workpiece is a three-dimensional molded body obtained by thermoforming a sheet mainly composed of a thermoplastic resin by vacuum forming or the like, the sheet before vacuum forming and the sheet after vacuum forming should be cut. If the difference in film thickness at the part is 500 μm or less, the minimum light amount A0 set in the sheet before thermoforming can be used. Specifically, if the maximum expansion ratio of the cut portion of the three-dimensional molded body obtained from the sheet having a thickness of 1 mm is within 200%, the difference in film thickness within the cut portion is 500 μm or less. It is possible to use the minimum light amount A0 set by the sheet. As described above, the method of setting the minimum light amount A0 by calculating backward from the sheet thickness before forming and the maximum unfolding magnification is an easy method for setting the minimum light amount A0 of a workpiece having a complicated three-dimensional shape.

A0 × 1.2, which is the lower limit of the laser beam light amount A1 at the workpiece cutting site (specifically, 1.2 times the minimum light amount A0 of the laser beam necessary for cutting the workpiece). 2 is a lower limit value of the output light amount for neatly cutting 2. If the value is less than this value, the workpiece can be cut, but an uneven step is formed on the laser cutting surface, and the market value is lowered. Further, A0 × 3.0 (specifically, 3.0 times the minimum light amount A0 of the laser beam necessary for cutting the workpiece), which is the upper limit of the laser beam amount A1 at the workpiece cutting site, This is the upper limit value of the output light amount for cutting the workpiece 2 cleanly, and exceeding this range is not preferable because the melt of the workpiece adheres to the laser cutting surface and foreign matter is easily generated.
In addition, when the workpiece is cut and passed through the through groove and then again passes through the through groove and reaches the back side of the workpiece, the laser beam quantity A2 is less than A0 × 0.90. The laser beam after cutting is reflected in the table for some reason and is again a through groove (in this case, the through groove may be a through groove at an incident place or a through groove at another place) The amount of light that does not cause burnout or deformation of the back surface of the work is shown even if such a situation occurs. (Specifically, it represents less than 0.9 times the minimum light amount A0 of the laser beam necessary for cutting the workpiece). If the above range is exceeded, when the above situation occurs, when the laser beam after cutting the workpiece 2 and passing through the through groove 4 passes through the through groove 4 again and reaches the back side of the workpiece, the workpiece is burned and deformed. Is not preferable.

(Measurement method of laser beam quantity)
In the present invention, the laser beam quantity is a three-dimensional carbon dioxide laser machine “VZ-1” manufactured by Mitsubishi Electric Corporation as a laser beam machine, and “Laser Power Probe” manufactured by Macken Instruments, Inc. as a laser beam quantity measuring device. The laser beam quantity was measured according to the following procedure. Further, the minimum light amount A0 of the laser beam was measured as follows. However, unlike cutting with a normal laser processing machine, it is necessary to continue irradiating the laser beam measuring device with a laser beam for 20 seconds, so the laser oscillation head and the laser beam measuring device are fixed and the workpiece is moved while cutting. Measurements were made.

(Minimum amount of laser beam A0)
While changing the set output of the laser processing machine, the distance between the workpiece and the tip of the laser oscillation head is 3 mm, the scanning speed of the laser oscillation head is 1000 mm / min, and dry air with a set pressure of 0.03 MPa is used as an assist gas. The laser beam is oscillated to determine the minimum set output at which the workpiece can be cut (see FIG. 3-1). Next, the laser light quantity measuring device is fixed at a position 3 mm from the laser oscillation head with the above-mentioned minimum set output, the laser beam is oscillated for 20 seconds, and the laser beam quantity A0 is measured (see FIG. 3-2).

  The measurement of the laser beam light amount A1 at the workpiece cutting site is based on the measurement method A0. In addition, the measurement of the laser beam light amount A2 when the workpiece is cut and passed through the through groove and then again passes through the through groove and reaches the back side of the workpiece is performed as follows.

(Laser beam light quantity A2)
The measurement method of the laser beam quantity A2 is different depending on whether the shielding plate 8 in FIG. 2 is provided or not. Specifically, it was measured by the following method.

(When there is no shielding plate Measuring method (1) of laser beam quantity A2)
As shown in FIG. 4, the laser oscillation head and the laser light quantity measuring device are fixed, and a sheet-like workpiece placed at a position 3 mm from the head tip is moved at a speed of 1000 mm / min, while the set pressure is 0.03 MPa as an assist gas. Using dry air, the laser beam is oscillated for 20 seconds, and the laser beam quantity A2 penetrating the workpiece is measured. Note that the distance between the laser oscillation head and the laser light quantity measuring device is assumed to be “when the workpiece is cut and passed through the through groove and then again passes through the through groove and reaches the back of the workpiece”. The longest distance connecting multiple through-grooves of the workpiece, or preparing a test workpiece in advance, cutting with an excessive laser beam, checking the back side of the test workpiece, causing burnout and deformation There is a method of identifying the part that is present and making it the distance. The latter method is preferable because it is simple and reliable.

(When having a shielding plate Measuring method (2) of laser beam light quantity A2)
As shown in FIG. 5, the laser oscillation head, the laser light quantity measuring device, and the shielding plate are fixed, and the set pressure 0 is set as the assist gas while moving the sheet-like workpiece placed at a position 3 mm from the head tip at a speed of 1000 mm / min. A laser beam is oscillated for 20 seconds using 0.03 MPa of dry air, and the amount of laser beam A2 that has passed through the workpiece and reflected by the shielding plate is measured. Note that the distance between the laser oscillation head and the laser light quantity measuring device or the position of the laser light quantity measuring device is assumed to be “when the workpiece is cut and passed through the through groove and then again passes through the through groove and reaches the back of the workpiece”. Therefore, it is the longest distance connecting multiple through-grooves of workpieces to be used through a shielding plate, or a test workpiece is prepared in advance and cut with an excess laser beam for testing. There is a method of confirming the back surface of the workpiece, identifying a part where burnout and deformation have occurred, and setting the distance or position thereof. The latter method is preferable because it is simple and reliable.

  As a specific method for setting the amount of laser beam passing through the through groove 4 and reaching the back side of the work 2 again after cutting the work 2 and passing through the through groove 4 within the range of A2, the laser beam A method of providing a shielding plate (see FIG. 2) 8 for reflecting or attenuating the light in the table 3 is preferable. Examples of the material of the shielding plate include carbon or a metal steel material having a relatively high melting point. Further, the laser beam tends to be attenuated more greatly when the distance from the tip of the laser oscillation head 1 exceeds a certain value. Therefore, if the distance from cutting the workpiece 2 and passing through the through groove 4 to reaching the back side of the workpiece again after passing through the through groove 4 is 30 mm or more, the laser beam is attenuated and still falls within the range of A2. It is possible to fit in.

Hereinafter, the present invention will be described with reference to examples.
Example 1
(Manufacturing method of a cut workpiece using workpiece (1))
Using a glittering decorative sheet “Metallare” (average thickness 0.49 mm, manufactured by DIC Corporation) and vacuum forming at a sheet temperature of 140 ° C., the length is 154 mm × width 160 mm × depth 30 mm (concave mold, corner : A workpiece (1) (see FIG. 6) having a box shape of 15 mmR) was produced. The maximum expansion ratio for this work was 150%.
In addition, as a layer structure of the metallare, from the surface layer side, (1) polyethylene-based cover film (50 μm), (2) acrylic urethane-based surface protective layer (10 μm), rubber-modified PMMA film layer (125 μm), (4) glitter Ink layer (1 μm), (5) Polyester urethane adhesive layer (5 μm), (6) Polypropylene backing sheet (300 μm), vacuum forming so that the surface layer side (1) is in contact with the concave mold did.

(Laser beam light quantity measurement and back surface damage evaluation by penetrating light)
For the workpiece (1), a three-dimensional carbon dioxide laser processing machine “VZ-1” manufactured by Mitsubishi Electric Corporation is used as a laser processing machine, and a “Laser Power Probe” manufactured by Macken Instruments, Inc. is used as a laser light quantity measuring device. The minimum light amount A0 of the laser beam was measured.

(Minimum amount of laser beam A0)
The distance between the workpiece (1) and the tip of the laser oscillation head is 3 mm, the scanning speed of the laser oscillation head is 1000 mm / min, and dry air with a set pressure of 0.03 MPa is used as the assist gas. The laser beam was oscillated while changing, and the minimum set output that can cut the workpiece at the workpiece cutting site (11 in FIG. 6) was determined. Next, the laser light quantity measuring device was fixed at a position 3 mm from the laser oscillation head with the above-mentioned minimum set output, the laser beam was oscillated for 20 seconds, and the laser beam quantity A0 was measured. As a result, the laser beam quantity A0 of the work (1) was 70W.

  The setting output of the laser processing machine “VZ-1” is set so that the laser beam light amount A1 (W) is 130 W (A0 × 1.6) and the laser beam light amount A2 (W) is 60 W (A0 × 0.86). The workpiece (1) was cut at 160 W without using a shielding plate. The measurement position of the laser beam light quantity A1 (W) is 11 in FIG. 6, and the measurement site of the laser beam light quantity A2 (W) is 12 in FIG.

  Evaluation criteria A for the cut surface at the workpiece cutting site and evaluation criteria B when the workpiece is cut and passed through the through hole and then passed through the through groove again to reach the workpiece back side are shown below.

[Evaluation criteria A]
○: The cut surface is smooth and can be cut cleanly.
(Triangle | delta): The jagged-shaped level | step difference generate | occur | produced on the cut surface, or the flaw-like level | step difference fuse | melted on the cut surface has generate | occur | produced.
N: Cannot be cut

[Evaluation criteria B]
○: Backside burnout due to penetrating light △: No burning due to penetrating light but deformation ×: Burnout due to penetrating light

As a result, the cut state of the workpiece was smooth and clean. Moreover, the back surface burnout by the through-groove was not seen. The results are shown in Table 1.

(Comparative Examples 1-4)
Except for the laser beam light amount A1 (W), the laser beam light amount A2, and the setting output of the laser processing machine “VZ-1” as described in Table 1, the shielding plate is not used in the same manner as in Example 1. The work (1) was cut. The results are shown in Table 1.

(Example 2, Comparative Example 5)
Example 1 except that the laser beam light amount A1 (W), the laser beam light amount A2, and the setting output of the laser processing machine “VZ-1” are described in Table 1, and the shielding plate is installed as shown in FIG. Then, the workpiece (1) was cut using a shielding plate. The measurement position of the laser beam light quantity A1 (W) is 11 in FIG. 7, and the measurement site of the laser beam light quantity A2 (W) is 12 in FIG.
The results are shown in Table 1.

In Examples 1 and 2, the laser beam light amount A1 is A0 × 1.2 to A0 × 3.0 (= 84 W to 210 W) and the laser beam light amount A2 is less than A0 × 0.9 (= 63 W). The setting output of the laser processing machine is set so as to be. In this case, the workpiece cutting state was good, and even when the workpiece was cut and passed through the through groove and then again passed through the through groove and reached the workpiece back side, no burning or deformation of the workpiece back surface occurred.
In Comparative Examples 1 and 2, the set output of the laser beam machine is set so that the laser beam light amount A1 does not satisfy A0 × 1.2 (= 84 W). In this case, since the laser output was low, a part that was not cut was generated, and a jagged step was generated on the cut surface.
In Comparative Example 3, the set output of the laser beam machine is set so that the laser beam light amount A2 is A0 × 0.9 (= 63 W) or more. In this case, backside burnout due to penetrating light occurred.
In Comparative Examples 4 and 5, the set output of the laser beam machine is set so that the laser beam quantity A1 is A0 × 3.0 (= 210 W) or more and A0 × 0.9 (= 63 W) or more. is there. In this case, a flaw-like step melted on the cut surface occurred on the cut surface, and burnout occurred on a part of the back surface of the workpiece. Moreover, the back surface burnout by penetrating light has also occurred.

(Example 3)
(Manufacturing method of the cut workpiece using the three-dimensional workpiece (2) after vacuum forming)
The “metallare” is heated to 140 ° C. with a vacuum forming machine, and vacuum forming is performed using a predetermined shape mold (convex shape mold) so that the back surface side (6) of the sheet is in contact with the mold. This gave a three-dimensional workpiece (2). The molding shrinkage rate of the workpiece (2) was 0.4%, the expansion ratio was 140 to 165%, and the film thickness of the cut portion of the workpiece (2) was in the range of 300 μm to 350 μm. From this, A0 = 70 W measured with the workpiece (1) was taken as A0 of the workpiece (2) as it was.

(Table preparation method for placing the workpiece (2))
The CAD data for the table surface shape is reduced to 99.6% in the X-axis, Y-axis, and Z-axis directions with respect to the CAD data of the mold (convex mold) for the workpiece (2). Created. Using this data, a table for mounting a work having a through groove having a width of 5 mm at the laser cutting site was prepared. In addition, a vacuum pad was used so that the inner surface of the workpiece could be firmly attached to the surface of the table.

  Next, after placing the test work (2) in close contact with the table, the set output of the three-dimensional laser processing machine is 160 W as in Example 1, and the laser beam light amount A1 at the work cutting site is 130 W (A0 × 1.6), the distance from the head tip to the workpiece is 3 to 5 mm, the laser output direction and the workpiece angle are in the range of 50 to 90 degrees, the laser oscillation head scanning speed is 1000 mm / min, the assist gas The workpiece (2) for testing was laser-cut using dry air with a set pressure of 0.03 MPa. Check the back side of the test work (2), identify the part where burnout and deformation occurred, and 2 mm thick inside the table so that the amount of laser beam at this part is less than 63 W (A0 × 0.9) A shielding plate which is an iron plate was installed.

  Using the workpiece (2) and the table, the workpiece (2) was cut with a three-dimensional laser beam machine in the same manner as the laser machining conditions described in the previous section, except that the scanning speed of the laser oscillation head was changed to 6000 mm / min. As a result, there was obtained a work in which the back surface of the work was not burned and deformed, and the cut surface was smooth and clean.

Example 4
(Manufacturing method of cut workpiece using workpiece (3))
The same as in Example 1 except that a rubber-modified PMMA sheet having a thickness of 0.5 mm (trade name: Technoloy S001G, manufactured by Sumitomo Chemical Co., Ltd.) was used as the sheet. A workpiece (3) (see FIG. 6) having a box shape of a mold and corners: 15 mmR was created and the workpiece was cut. The maximum expansion ratio for this work was 150%.

The workpiece (3) was measured for the amount of laser beam A0 using the laser beam measurement method described above. As a result, A0 = 95W.
The setting output of the laser processing machine “VZ-1” is set so that the laser beam light amount A1 (W) is 130 W (A0 × 1.37) and the laser beam light amount A2 (W) is 65 W (A0 × 0.68). The workpiece (3) was cut without using a shielding plate at 160 W. The results are shown in Table 1. As a result, the cut state of the workpiece was smooth and clean. Moreover, the back surface burnout by the through-groove was not seen.

(Comparative Examples 6-9)
Except that the laser beam light quantity A1 (W), the laser beam light quantity A2 and the setting output of the laser processing machine “VZ-1” are described in Table 2, the shielding plate is not used in the same manner as in Example 4. Work (3) was cut. The results are shown in Table 2.

(Example 5, Comparative Example 10)
The laser beam light amount A1 (W), the laser beam light amount A2, and the setting output of the laser processing machine “VZ-1” are described in Table 2, and the shield plate is installed as shown in FIG. Then, the workpiece (3) was cut using a shielding plate. The results are shown in Table 2.

In Examples 4 and 5, the laser beam light amount A1 is A0 × 1.2 to A0 × 3.0 (= 114 W to 285 W), and the laser beam light amount A2 is A0 × 0.9 (= 85.5 W). The set output of the laser processing machine is set so as to be less than. In this case, the workpiece cutting state was good, and even when the workpiece was cut and passed through the through groove and then again passed through the through groove and reached the workpiece back side, no burning or deformation of the workpiece back surface occurred.
In Comparative Examples 6 and 7, the set output of the laser processing machine is set so that the laser beam light amount A1 is less than A0 × 1.2 (= 114 W). In this case, since the laser output was low, a part that was not cut was generated, and a jagged step was generated on the cut surface.
In Comparative Example 8, the set output of the laser beam machine is set so that the laser beam light amount A2 is A0 × 0.9 (= 85.5 W) or more. In this case, backside burnout due to penetrating light occurred.
In Comparative Examples 9 and 10, the setting output of the laser processing machine was set so that the laser beam light amount A1 was A0 × 3.0 (= 285 W) or more and A0 × 0.9 (= 85.5 W) or more. Is. In this case, a flaw-like step melted on the cut surface occurred on the cut surface, and burnout occurred on a part of the back surface of the workpiece. Moreover, the back surface burnout by penetrating light has also occurred.

It is an example which shows sectional drawing of the specific aspect of this invention. It is an example which shows sectional drawing of the specific aspect of this invention, and is an example which has a shielding board. This is a measuring method of the laser beam light amounts A0 and A1. This is a method of measuring the laser beam light quantity A2 (when no shielding plate is provided). This is a measurement method of the laser beam light amount A2 (when a shielding plate is provided). It is sectional drawing which shows the specific aspect of the Example of this invention. It is sectional drawing which shows the specific aspect of the Example of this invention.

Explanation of symbols

1: Laser oscillation head 2: Work piece 3: Table 4: Slit (through hole)
5: Side plate 6: Bottom plate 7: Table column 8: Shield plate 9: Laser light quantity measuring device 10: Box-shaped workpiece 11: Measurement position of laser beam quantity A0 and A1 12: Measurement position of laser beam quantity A2

Claims (5)

The surface of the work is the surface of the table, which has a surface shape similar to the shape of the inner surface of the work, which is a resin molded body, and has a through groove provided at a position that coincides with the laser cutting part of the work. A method of manufacturing a cut workpiece, comprising a step of placing along a shape, and a step of cutting a workpiece by scanning and irradiating a laser beam toward the table,
The amount of laser beam A1 at the workpiece cutting site is in the range of A0 × 1.2 to A0 × 3.0,
In addition, the amount of laser beam A2 when the workpiece is cut and passed through the through hole and then again passes through the through groove and reaches the back side of the workpiece is less than A0 × 0.90 (however, A0 is for cutting the workpiece) A method for manufacturing a cut workpiece, characterized in that the minimum light intensity of a necessary laser beam. The method for manufacturing a workpiece according to claim 1, wherein a shielding plate for reflecting or absorbing a laser beam cut through the workpiece and passed through the through groove is provided inside the table. The manufacturing method of the workpiece | work of Claim 1 or 2 whose workpiece | work is a sheet-like three-dimensional molded object. The surface of the work is the surface of the table, which has a surface shape similar to the shape of the inner surface of the work, which is a resin molded body, and has a through groove provided at a position that coincides with the laser cutting part of the work. A process of placing along the shape;
A method of cutting a workpiece, comprising a step of scanning a laser beam toward the table and cutting the workpiece.
The amount of laser beam A1 at the workpiece cutting site is in the range of A0 × 1.2 to A0 × 3.0,
In addition, the amount of laser beam A2 when the workpiece is cut and passed through the through groove and then again passes through the through hole and reaches the back side of the workpiece is less than A0 × 0.90 (however, A0 is for cutting the workpiece) A method for cutting a workpiece, characterized in that the minimum amount of laser beam required). A table for placing a workpiece having a surface shape similar to the inner surface shape of the workpiece, which is a resin molded body, and provided with a through groove at a position coinciding with the laser cutting portion of the workpiece, and laser beam machining of the workpiece A laser oscillator that scans and irradiates a laser beam toward the table; and a shielding plate that reflects or absorbs the laser beam that cuts the workpiece and passes through the through groove. Processing equipment.

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