KR102261103B1 - A device that uses laser beams to weld opaque and permeable plastics without annealing - Google Patents

Abstract

In a plastic welding apparatus for welding an impermeable first plastic and a transparent second plastic without an annealing process using a laser beam according to an embodiment of the present invention, the plastic welding apparatus comprises: the first plastic and Adhering the transparent second plastic, irradiating a laser beam to the adhered first plastic and the second plastic, at least a portion of the laser beam is first absorbed while passing through the second plastic, the first plastic and The remaining beam may be second absorbed in the first adhesion region of the second plastic, and the first adhesion region may be welded using the first absorption and second absorption.

Description

A device that uses laser beams to weld opaque and permeable plastics without annealing}

The present invention relates to an apparatus for welding an opaque plastic and a transmissive plastic using a laser beam without an annealing process. Specifically, the present invention relates to an apparatus and method for welding an impermeable plastic and a transmissive plastic without an annealing process using a laser beam having a wavelength range of 1400 to 3000 nm.

In general, as a method of bonding two members made of a thermoplastic resin, there is a method of applying an adhesive to any one of the upper and lower members to be joined, or bonding through ultrasonic welding or vibration welding.

However, this method causes environmental pollution according to the use of the adhesive, the joint is not smooth, and the joint strength is not constant, so damage to the inside of the product occurs when a mechanical external force is applied, and above all, the problem of water tightness was caused.

Based on this problem, a laser welding method that conducts heat locally and implements it in a non-contact manner has been proposed.

In the laser welding method, the edge of the transparent cover and the housing are welded together using a laser while the cover and the housing, which are the welding objects, are in close contact with each other, the laser passing through the cover is absorbed on the surface of the housing, and the absorbed laser is A method of welding the housing to the cover by heating and melting the housing at the interface between the cover and the housing.

However, in order to enable laser welding, the upper and lower members must be made of the same material. If a member of a different material is to be welded using a laser, the temperature characteristics are different depending on the material, so that the welding is not performed completely.

That is, with the general laser welding method, it is realistically possible to mutually weld a car lamp made of different materials, that is, a transparent cover made of PC and PMMA materials, and a non-permeable housing made of PP, PET or ABS material as it is fixed to the car body. There was a problem that it didn't.

Further, in the laser welding method described above, since the laser is absorbed from the surface of the housing after penetrating the cover, the temperature of the surface of the housing rises sufficiently and melts, but the temperature does not increase because the laser is transmitted through the cover.

Therefore, the temperature of the cover is considerably lower than that of the housing, and a large temperature difference occurs, and this temperature difference makes the welding between the housing and the cover not solid and at the same time, the welding quality is not uniform. Accordingly, a phenomenon in which the cover is partially separated from the surface of the housing by vibration applied while the vehicle is running often occurs.

In this case, rain, snow, or external moisture penetrated through the gap between the cover and the housing to form dew in the automobile lamp, and this dew corroded the electrode of the lamp and shortened the lamp life.

While solving the problem caused by such a large temperature difference, an annealing process may be applied to make the welding quality uniform.

The annealing process is a treatment method in which an alloy hardened by heat treatment is heated at a high temperature for a long time and then cooled to room temperature gradually to soften it. In a material whose phase change occurs as the temperature rises or falls, it is cooled slowly over a sufficient time to achieve a stable equilibrium state. say

However, when such an annealing process is applied, there is a big problem that a short circuit part occurs in the entire welding process, and the manufacturing cost is significantly increased.

Therefore, there is a growing need for a technology that enables high-quality welding without annealing process by melting and welding the lower material together while melting the upper transparent material based on the laser beam.

(1) US Patent Application No. 12/382633 (2) US Patent Application No. 12/551837 (3) Japanese Patent Application No. 2016-052587

The present invention has been devised in order to solve the problems of the prior art, and an object of the present invention is to provide a welding apparatus using a laser and a method for controlling the same to a user.

Specifically, an object of the present invention is to provide a user with an apparatus and method for welding an impermeable plastic and a transmissive plastic without an annealing process using a laser beam having a wavelength range of 1400 to 3000 nm.

On the other hand, the technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned are clearly to those of ordinary skill in the art to which the present invention belongs from the description below. can be understood

In a plastic welding apparatus for welding an impermeable first plastic and a transparent second plastic without an annealing process using a laser beam related to an example of the present invention for realizing the above object, the plastic welding apparatus of the first plastic and the transmissive second plastic, irradiating a laser beam to the adhered first plastic and the second plastic, and first absorption while at least a part of the laser beam penetrates the second plastic and the remaining beam is second absorbed in the first adhesion region of the first plastic and the second plastic, and the first adhesion region is welded using the first absorption and second absorption, and the laser beam is having a wavelength range of 1400 to 3000 nm, at least a portion of the laser beam passing through the second plastic is reflected on a reflective surface provided in at least a portion of the second plastic, and the reflected laser beam is different from the first adhesion region Absorbed into the second adhesion region of the first plastic and the second plastic, the first adhesion region and the second adhesion region are welded together, and at least a part of the first plastic and the second plastic is bent If present, the plastic welding device collects first information about the curved part before the first plastic and the second plastic are brought into close contact, and the laser beam is irradiated according to the first information Adjusts at least one of a focal length, an output value, a speed, and a separation distance between the first plastic and the second plastic of the laser beam, and the first information includes length, height change, and shape information for the curved part. and an intermediate surface formed with a step having an angle exceeding a critical angle through which the laser beam is introduced is formed on at least a portion of the first plastic and the second plastic, so that the laser beam is formed in an area other than the first adhesion area. The beam is prevented from entering, and the plastic welding Chi, before irradiating the laser beam to the first and second plastics in close contact, the first plastic and the second plastic in close contact are further brought into close contact using a jig, the jig is transparent, and the The output of the laser beam may be increased in a region in which the incident angle of the laser beam is equal to or less than a preset value or the incident energy density is increased among the first adhesion regions.

The present invention has been devised to solve the problems of the prior art, and it is possible to provide a welding apparatus using a laser and a method for controlling the same to a user.

Specifically, the present invention can provide a user with an apparatus and method for welding an impermeable plastic and a transmissive plastic without an annealing process using a laser beam having a wavelength range of 1400 to 3000 nm.

According to the present invention, by omitting the application of the annealing process, there is an effect that the short-circuit process part in the entire welding process can be eliminated, and the manufacturing cost can be significantly lowered.

Laser welding according to the present invention enables plastic bonding at low cost and high efficiency, and as a non-contact welding method, there is no external deformation of the product due to vibration, shock, or heat, and the bonding quality is excellent because no burrs or fluff occur. , 2D, 3D shape products can be applied, regardless of size or shape, easy to automate, and can provide system stability.

On the other hand, the effects obtainable in the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those of ordinary skill in the art to which the present invention belongs from the following description. will be able

The following drawings attached to the present specification illustrate a preferred embodiment of the present invention, and serve to further understand the technical spirit of the present invention together with the detailed description of the present invention, so the present invention is limited to the matters described in those drawings It should not be interpreted as being limited.
1 shows an example of a welding method using an adhesive, a welding method using vibration, and a welding method using an ultrasonic wave that can be used for welding plastics.
2 shows an example of a schematic diagram of a laser welding process in relation to the present invention.
3 is a view for explaining a welding method using a laser in relation to the present invention.
4 shows an example of a block diagram of a welding apparatus using a laser proposed by the present invention.
5 shows an example of using a laser beam of a wavelength band for preheating the transmissive cover and a laser beam of another wavelength band for melting the welding interface between the transmissive cover and the non-transmissive housing in relation to the present invention.
6 shows an example of preheating the transmission area of the transparent cover and melting the contact area by irradiating a laser beam having an infrared wavelength band toward the contact area of the housing in close contact with the edge of the transparent cover in relation to the present invention. did it
7 shows a table summarizing desirable condition values in laser welding for automobile lamps in relation to the present invention.
8 illustrates an example of performing welding of a desired area by placing a reflective surface therein in relation to the present invention.
9 illustrates an example of adjusting a focal length, an output value, etc. using height information from a reference point of a curved object based on one laser source in relation to the present invention.
10A and 10B show an example of forming a welding surface to have an angle perpendicular to the jig on the lower surface of the transparent plastic in contact with the opaque plastic in relation to the present invention.
11 illustrates an example of preventing the laser from entering the interior by forming an intermediate surface between the welding surface and the transmission part in relation to the present invention, and forming an angle exceeding the critical angle with respect to the laser.
12 shows an example of increasing the degree of adhesion by applying the pressing jig as transparent in relation to the present invention, and allowing the laser to reach through the jig.
13 shows an example of maintaining a state in close contact without a separate jig by inserting a defect in the seating part formed on the resin cover to which the welding machine part protruding from the housing is welded, in relation to the present invention.
14A to 14D show graphs for explaining the laser welding market related to the present invention.

Conventional Techniques Used for Welding of Plastics

1 illustrates an example of a welding method using an adhesive, a welding method using vibration, and a welding method using an ultrasonic wave that can be used for welding plastics.

The adhesive method shown in FIG. 1 (a) requires an adhesive, which is a third material to connect the parts of the joined seam.

The adhesive method is a very efficient bonding method that permanently 　bonds to the material, and a visible light/ultraviolet ray curing adhesive is widely used.

The vibration welding method shown in Fig. 1 (b) is a method of spreading the plastic melting while rubbing and pressing left and right by frequency and amplitude.

Vibration welding method. It is mainly used for plastic products that require pressure resistance and high strength, and is mainly used for welding of crystalline resins and engineering plastics.

In addition, the ultrasonic welding method shown in FIG. 1C is based on thermal conversion of friction and vibration energy.

In ultrasonic welding, high-frequency vibrations are transmitted along with pressure to the parts to be joined.

In the ultrasonic welding method, micro-melting due to frictional heat occurs at the vibrating interface.

However, the welding method using the adhesive, the welding method using vibration, and the welding method using ultrasonic waves cause environmental pollution, the joint portion is not smooth, the strength is not constant, and problems related to water tightness are frequently generated.

Therefore, in the present specification, a laser welding method that locally conducts heat and implements a non-contact method is proposed and applied.

laser welding technology

Welding refers to the technology of joining separated materials by applying heat, pressure, or heat and pressure at the same time. It is essential for manufacturing, repair, and maintenance of the product to be created.

In particular, laser welding using light generated from a laser is a welding method using thermal energy concentrated through a lens. High-strength steel, aluminum alloy, stainless steel, plastic, etc., thanks to high output, high quality, high efficiency, and high luminance of the laser generator. It is applied to welding various kinds of materials.

2 shows an example of a schematic diagram of a laser welding process in relation to the present invention.

Referring to FIG. 2 , after fixing the laser transmission material and the absorption material (transmitting body/absorber) under a clamping force, ① laser is irradiated and the laser beam passes through the laser transmitting body, and ② reaches the absorber. It is absorbed and converted into thermal energy. ③ The converted thermal energy melts the absorber and forms a molten pool with the permeate by transferring heat, and finally bonding is performed.

3 is a view for explaining a welding method using a laser in relation to the present invention.

Referring to FIG. 3 , adjustment of the output direction and focus of the laser is an important factor in order to increase processing precision.

That is, when the laser is output, it is expanded by a beam expander, the direction of the expanded laser is adjusted through a reflective mirror, and is focused through a focus lens and irradiated to the workpiece.

In such welding using a laser, the upper member and the lower member to be welded are brought into close contact, and then the edge portion of the closely adhered member is welded using a laser. At this time, the upper member is a material through which laser light is transmitted, and the lower member may be a material that generates heat by absorbing laser light.

At this time, after passing through the upper member, the laser beam is heated while being absorbed by the lower member, and the generated heat is transferred to the upper member, and the laser beam is thermally welded to each other.

As a factor affecting laser welding, in order to control laser welding, transmittance, compatibility of materials, thickness, etc., which are material aspects, are considered, and in terms of welding process, laser power, irradiation speed, clamping pressure, and presence of a dedicated jig, laser Wavelength, beam diameter, design shape of the product, and the like may be considered.

Regarding the welding process aspect, it is necessary to check the laser used because the diameter and wavelength, power, irradiation speed and frequency of the laser beam have a great influence on the welding quality of the product, and the above variables according to the size and thickness of the welding part is decided

In addition, the work (DOE: Design Of Energy) work to optimize the appearance so that there is no deformation and burning due to the heat of the absorber is essential, and the pressure of the clamp, that is, the jig used is equally important.

With respect to the technology of welding plastic materials with a laser, plastic bonding requires various requirements for mass production into actual products.

It should be possible to manufacture efficiently in mass industrial production, and in terms of cost, it needs to be simplified compared to the existing bolting process. Types of these bonding technologies include laser welding, rotational welding, vibration welding, ultrasonic / high-sonic welding, etc. In general, laser welding is suggested as an optimal method to solve the difficulties encountered in plastic welding.

The technology of welding plastic resin with a laser utilizes the property that the energy of the laser beam penetrates one part of the plastic resin and the other part is absorbed by the resin, and the absorbed laser energy is converted into thermal energy and an appropriate force is applied to the two parts. When applied, the principle of welding is applied.

The main application fields include plastic resin welding of automotive lamp housings, in vitro (in-glass tube) diagnostic tools, and micro-tube bonding such as microfluidic devices.

Laser welding is becoming an issue in plastic bonding due to its low cost and high efficiency. As a non-contact welding method, there is no external deformation of the product due to vibration, shock, or heat, and the bonding quality is improved because there is no burr or fluff. It has the advantage of being excellent.

In addition, laser welding on plastic materials can be applied to 2D and 3D shaped products, so it is not limited by size or shape, and can be easily automated and have excellent system stability.

Welding device using laser

Hereinafter, a detailed configuration of a welding apparatus using a laser proposed by the present invention will be described with reference to the drawings.

4 shows an example of a block diagram of a welding apparatus using a laser proposed by the present invention.

Referring to FIG. 4 , the welding apparatus 1 using a laser proposed by the present invention includes a laser emitting unit 10 , an extension unit 20 , a mirror unit 30 , a lens unit 40 , and a motor unit 50 . , a control unit 60 , a compression unit 80 , a power supply unit 91 , a communication unit 92 , a user input unit 93 , a memory 94 , an interface unit 95 , and the like.

First, the laser emitting unit 10 provides a function of emitting a laser.

The laser emitting unit 10 may be exemplarily installed on a horizontal axis to emit a laser, or alternatively, may be installed on a vertical axis.

Next, the extension part 20 provides a function of expanding the diameter of the laser output from the laser emitting part 10 , and the mirror part 30 adjusts the direction of the laser extended from the extension part 20 to align. Provides the ability to adjust the degree.

The laser emitted in the horizontal direction from the laser emitting unit 10 is converted to the vertical direction by the mirror unit 30 and passes through the extension unit 20 .

At this time, the cross-sectional area of the laser irradiated to the workpiece is changed according to the rate at which the diameter of the laser is expanded by the extension 20 .

The extension 20 may include a lens, a prism, and a collimator for making the enlarged laser into a parallel beam of light.

On the other hand, in the welding apparatus 1 using a laser, a plurality of mirror units 30 may be disposed at a position where a direction change of the laser emitted from the laser emitting unit 10 is required, and the direction is changed by the mirror unit 30 . The resulting laser may be in a state parallel to the laser axis emitted from the first laser emitting unit 10 .

The mirror unit 30 may be installed to change the direction of the laser so that the laser can be irradiated in the vertical direction to the workpiece.

In addition, the lens unit 40 provides a function of condensing the laser introduced through the laser emitting unit 10 to form a focus.

The lens unit 40 condenses the expanded laser again to form a focal point, and may be installed below the mirror unit 30 .

The lens unit 00 adjusts the focus by adjusting the position of the lens upward or downward. For this purpose, the motor unit 50 or the like may be used.

In addition, the motor unit 50 is used to change the positions of the mirror unit 30 and the lens unit 40 .

In addition, the control unit 60 includes a laser emitting unit 10 , an extension unit 20 , a mirror unit 30 , a lens unit 40 , a motor unit 50 , a compression unit 80 , a power supply unit 91 , It controls overall operations of the communication unit 92 , the user input unit 93 , the memory 94 , and the interface unit 95 .

The control unit 60 described herein may be implemented in a computer-readable recording medium using, for example, software, hardware, or a combination thereof.

According to the hardware implementation, the embodiments described herein are ASICs (Application Specific Integrated Circuits), DSPs (digital signal processors), DSPDs (digital signal processing devices), PLDs (programmable logic devices), FPGAs (field programmable gate arrays, It may be implemented using at least one of processors, controllers, micro-controllers, microprocessors, and other electrical units for performing functions.

According to the software implementation, the control unit 60 may be implemented as separate software modules. Each of the software modules may perform one or more functions and operations described herein. The software code may be implemented as a software application written in a suitable programming language.

In addition, the compression part 80 is also called a jig, and is a kind of auxiliary tool used when processing various parts. When a plurality of objects are to be welded, it refers to a mechanism for forcibly fixing the plurality of objects. .

The jig 80 refers to a special tool that attaches or attaches a work piece to the work piece to determine the position of the machining part and guide the machining at the same time. In recent years, many jigs and attachments are used due to the advancement of machining methods and rationalization of production methods. and includes an attachment hole in the jig.

In addition, the power supply unit 91 receives external power and internal power under the control of the control unit 60 to supply power necessary for the operation of each component.

In addition, the communication unit 92 may include one or more modules that enable wireless communication between the welding apparatus 1 using a laser and a wireless communication system or between a device and a network in which the device is located.

The communication unit 92 may communicate through short-range communication or wireless communication.

The short-distance communication may use at least one of Bluetooth, Radio Frequency Identification (RFID), Infrared Data Association (IrDA), Ultra-Wideband (UWB), and ZigBee technology.

In addition, wireless communication is CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), SC-FDMA (single carrier frequency division multiple access) technology At least one of them can be used.

In addition, the user input unit 93 generates input data for the user to control the operation of the welding apparatus 1 using a laser.

Here, the user input unit 130 may include a keypad, a dome switch, a touch pad (static pressure/capacitance), a jog wheel, a jog switch, and the like.

In addition, the memory 94 may store a program for processing and control of the controller 60, and for temporary storage of input/output data (eg, message, audio, still image, video, etc.) function can also be performed.

The frequency of use of each of the data may also be stored in the memory unit 94 .

The memory 94 may include a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (eg, SD or XD memory), and a RAM. (Random Access Memory, RAM), SRAM (Static Random Access Memory), ROM (Read-Only Memory, ROM), EEPROM (Electrically Erasable Programmable Read-Only Memory), PROM (Programmable Read-Only Memory), magnetic memory, magnetic It may include at least one type of storage medium among a disk and an optical disk.

In addition, the interface unit 95 serves as a passage with all external devices connected to the welding apparatus 1 using a laser.

The interface unit 95 receives data from an external device, receives power and transmits it to each component inside the welding device 1 using a laser, or transmits data inside the welding device 1 using a laser to an external device. to be sent

For example, wired/wireless headset ports, external charger ports, wired/wireless data ports, memory card ports, ports for connecting devices equipped with identification modules, audio input/output (I/O) ports, A video I/O (Input/Output) port, an earphone port, etc. may be included in the interface unit 170 .

The identification module is a chip that stores various information for authenticating the usage right of the welding device (1) using a laser, and includes a User Identify Module (UIM), a Subscriber Identify Module (SIM), and a general-purpose user. It may include an authentication module (Universal Subscriber Identity Module, USIM), and the like.

A device equipped with an identification module (hereinafter, 'identification device') may be manufactured in the form of a smart card. Therefore, the identification device may be connected to the welding device 1 using a laser.

The interface unit 95 is a passage through which power from the cradle is supplied to the welding apparatus 1 using a laser when the welding apparatus 1 using a laser is connected to an external cradle, or by a user. Various command signals input from the cradle may be a passage through which the mobile device is transmitted. Various command signals or the power input from the cradle may be operated as signals for recognizing that the mobile device is correctly mounted on the cradle.

The laser welding method based on the welding device 1 using a laser described above is a method of welding and bonding an edge portion of a transmissive cover and a housing using a laser in a state in which the cover and the housing, which are objects to be welded, are in close contact with each other, and the cover is penetrated. This is a method in which a laser is absorbed on the surface of the housing, and the absorbed laser heats and melts the housing at the interface between the cover and the housing, thereby welding the housing to the cover.

On the other hand, in order to enable laser welding, the upper member and the lower member must be made of the same material. If a member of a different material is to be welded using a laser, there is a problem that the welding is not performed completely because the temperature characteristics according to the material are different.

That is, with the general laser welding method, it is realistically possible to mutually weld a car lamp made of different materials, that is, a transparent cover made of PC and PMMA materials, and a non-permeable housing made of PP, PET or ABS material as it is fixed to the car body There was a problem that it didn't.

Further, in the laser welding method described above, since the laser is absorbed from the surface of the housing after penetrating the cover, the temperature of the surface of the housing rises sufficiently and melts, but the temperature does not increase because the laser is transmitted through the cover.

Therefore, the temperature of the cover is considerably lower than that of the housing, and a large temperature difference occurs, and this temperature difference makes the welding between the housing and the cover not solid and at the same time, the welding quality is not uniform. Accordingly, a phenomenon in which the cover is partially separated from the surface of the housing by vibration applied while the vehicle is running often occurs.

In this case, rain, snow, or external moisture penetrated through the gap between the cover and the housing to form dew in the automobile lamp, and this dew corroded the electrode of the lamp and shortened the lamp life.

While solving the problem caused by such a large temperature difference, an annealing process may be applied to make the welding quality uniform.

The annealing process is a treatment method in which an alloy hardened by heat treatment is heated at a high temperature for a long time and then cooled to room temperature gradually to soften it. say

However, when such an annealing process is applied, there is a big problem that a short circuit part occurs in the entire welding process, and the manufacturing cost is significantly increased.

Therefore, in this specification, based on a laser beam, by melting and welding the lower material together while melting the upper transparent material, it is intended to propose a technology that enables high-quality welding without an annealing process.

How to use a double laser beam

In order to solve the above problems, in the present specification, as a first embodiment, a laser beam of a wavelength band for preheating the transmissive cover and a laser beam of a different wavelength band for melting the welding interface between the transmissive cover and the impermeable housing are used. suggest

5 shows an example of using a laser beam of a wavelength band for preheating the transmissive cover and a laser beam of another wavelength band for melting the welding interface between the transmissive cover and the non-transmissive housing in relation to the present invention.

Referring to FIG. 5 , the laser welding method according to the present embodiment starts with the step of adhering the transparent cover 200 of a vehicle lamp made of a different material and the non-permeable housing 100 coupled to the transparent cover 200 . .

Thereafter, the second laser beam 12 of a second wavelength for preheating the transmission preheating region 210 of the transmissive cover 200 and the transmission preheating region 210 overlap the transmissive cover 200 and the non-transmissive housing. The first laser beam 11 of a first wavelength shorter than the second wavelength is irradiated to the welding interface 70 in order to weld the welding interface 70 therebetween.

At this time, the temperature of the first laser beam 11 irradiated to the welding interface 70 is detected and a corresponding temperature signal is generated, and the temperature signal is transmitted to the control unit 60 in real time and the temperature of the first laser beam 11 is generated. It is used to control the output.

Here, the transparent cover 200 transmits the light irradiated from the light source and is mainly made of a PC (PolyCarbonate) or PMMA (Poly Methyl Methacrylate) material.

In addition, the non-permeable housing 100 is generally made of PP (PolyPropylene), PET (Polyethylene Terephthalate), or ABS (Acrylonitrile Butadiene Styrene copolymer) material.

In addition, the second laser beam 12 is for preheating the transmission preheating region 210 to be transmitted. For this purpose, the first wavelength of the second laser beam 12 is in the range of 1600 to 2000 nm, preferably in the range of 1670 to 1960 nm. can be

About 50 to 70% of the second laser beam 12 of this second wavelength is absorbed while passing through the transparent PC or PMMA material transparent cover 200 made of a thermoplastic resin to preheat the transmission preheating region 210 . have

In addition, the first laser beam 11 is used to melt the welding boundary surface 70 after passing through the transparent cover 200 , and the welding boundary surface 70 is overlapped with the preheated transmission preheating area 210 .

To this end, the second wavelength of the first laser beam 11 is in the range of 750 to 1000 nm, preferably in the range of 808 to 980 nm.

The first laser beam 11 of this first wavelength is not absorbed by the transmissive cover 200 made of PC or PMMA material but is mostly transmitted, and is mostly absorbed at the welding interface 70 of the non-transmissive housing 100. and, accordingly, the welding interface 70 is melted.

That is, the second laser beam 12 preheats the transmission preheating region 210 overlapping the welding boundary surface 70 , so that when the first laser beam 11 melts the welding boundary surface 13 , the first It is to reduce the difference in temperature characteristics between the permeable cover 200 and the non-permeable housing 100 as much as possible.

In addition, the output of the first laser beam 11 is 20-40W, preferably 30W, and the second laser beam 12 has an output of 20-50W, preferably 40W.

Here, the output of the second laser beam 12 may be greater than that of the first laser beam 11 , because the second laser beam 12 has to preheat a larger area than the first laser beam 11 . to be.

In addition, the first laser beam 11 and the second laser beam 12 may be irradiated to overlap each other.

Method using a single laser beam in the infrared wavelength band

In addition, in order to solve the above problems, in the present specification, as a second embodiment, by irradiating a laser beam having an infrared wavelength band through the edge of the transparent cover toward the close contact area of the housing, the transmittance area of the transparent cover is preheated. and propose a method of melting the adhesion region

6 shows an example of preheating the transmission area of the transparent cover and melting the contact area by irradiating a laser beam having an infrared wavelength band toward the contact area of the housing in close contact with the edge of the transparent cover in relation to the present invention. did it

Referring to FIG. 6 , in the welding method using a laser according to the present invention, the transmissive cover 200 is in close contact with the housing 100 , and a portion is absorbed in the transmissive region 220 penetrating the transmissive cover 200 , and the transmissive A laser beam having a wavelength range of 1400 to 3000 nm is irradiated so that the rest can be absorbed in the adhesion region 70 between the cover 200 and the housing 100 to perform welding in the adhesion region 70 .

Here, the housing 100 may be fixed to a vehicle body, etc., a lamp may be built therein, and a mirror coating for reflection of light may be performed.

The housing 100 is a thermoplastic resin of an opaque material, PP (PolyPropylene), PET (Polyethylene Tere70thalate), A13S (Acrylonitrile 13utadiene Styrene copolymer), PMMA (Poly Methyl Methacrylate),

It may be any one material selected from the group consisting of COC (Cyclic Olefin Copolymer).

Meanwhile, the permeable cover 200 may be welded to the inlet of the housing 100 to block external water or moisture from flowing into the housing 100 .

The transparent cover 200 is a thermoplastic resin of a transparent material so that the light irradiated from the lamp of the housing 100 is transmitted without loss, and may be any one material selected from the group consisting of PC (PolyCar13onate), PMMA, and COC. have.

With respect to the step of adhering the permeable cover 200 to the housing 100 , the permeable cover 200 is attached to the housing by the jig 80 so that the edge of the permeable cover 200 can be completely in close contact with the housing 100 . It can be pressed to the (100) side.

In connection with the step of irradiating the laser beam 13 to the adhesion region 70 where the housing 100 and the transparent cover 200 are in close contact with the transparent cover 200 to proceed with welding, the transparent cover 200 is irradiated The laser beam 13 to be used is partially absorbed in the transmissive region 220 of the transmissive cover 200, and the surface of the housing 100 to which the transmissive cover 200 is in close contact, that is, the transmissive cover 200 and the housing 100 ) by allowing the remainder to be absorbed in the close contact area 70 between the housing 100 and the permeable cover 200 to weld the contact area between the housing 100 and the permeable cover 200 .

To this end, the laser beam 13 has a wavelength range of 1400 to 3000 nm, more preferably a wavelength of 1670 nm or 1940 nm.

The relationship between the transmittance (T) and the wavelength (λ) of the laser beam 13 with respect to the thermoplastic resin becomes smaller as the wavelength becomes longer.

In this case, the low transmittance means that the absorption for absorbing the laser beam 13 is increased, and accordingly, the temperature of the transmission region 220 through which the laser beam is transmitted increases.

Here, when the wavelength of the laser beam 13 is a wavelength of 1670 nm or 1940 nm, the absorbance of the transmissive region 220 increases exponentially as it approaches the adhesion region 70 from the surface side of the transmissive cover 12 . .

Accordingly, the temperature generated in the light-transmitting area close to the close contact area 70 and the temperature generated in the close contact area 70 form a relatively continuous relationship, so that the materials of the housing 100 and the transparent cover 200 are different. Even if it is a material, the welding bonding quality between the permeable cover 200 and the housing 100 by melting in the close contact area 70 is maximized.

In addition, since the temperature is gradually increased by absorbing the laser beam from the transmissive region on the surface side of the transmissive cover 200, the temperature on the surface side of the transmissive cover 200 and the temperature of the external environment outside the transmissive cover 200 are also relatively continuous. make up

Therefore, it is possible to prevent the surface of the permeable cover 200 from being deformed by the temperature difference between the surface of the permeable cover 200 and the outside environment during the welding process, and accordingly, high-quality welding can be performed even if the permeable cover 200 is a temperature-sensitive material. It is possible.

In this way, the laser beam 13 preheats the transmission region 70 while a part is absorbed in the process of passing through the transparent cover 200 , and then melts the adhesion region 70 while the rest is absorbed in the adhesion region 70 . make it

At this time, since the transmissive region 70 absorbs the laser beam and is preheated, the temperature rises, and accordingly, the temperature difference between the transmissive region 220 and the close contact region 70 becomes small, and thus the melting of the housing 100 . The surface is firmly welded to the permeable cover 200 to improve the weld quality.

In the present invention, a laser using thulium may be typically applied.

As described above, a laser having an infrared wavelength band of 1400 to 3000 nm, more preferably a wavelength of 1670 nm or 1940 nm is used.

Only when a laser in this range is used, the laser beam 13 preheats the transmission region 70 while a part is absorbed in the process of passing through the transparent cover 200, and then the adhesion region 70 as the rest is absorbed in the adhesion region. (70) can be melted.

According to the method proposed in the present specification, since the transmission region 70 is preheated by absorbing the laser beam, the temperature rises, and accordingly, the temperature difference between the transmission region 220 and the adhesion region 70 becomes small, and thus Since the surface of the molten housing 100 is firmly welded to the permeable cover 200 to improve the weld quality, the conventional annealing process can be omitted.

As such, in the present invention, by omitting the application of the annealing process, the short-circuit process part in the entire welding process is eliminated, and the manufacturing cost can be significantly reduced.

Laser welding conditions

In addition, the method of preheating the transmission area of the transparent cover and melting the contact area by irradiating a laser beam having an infrared wavelength band proposed as the second embodiment through the edge of the transparent cover toward the contact area of the housing in close contact with an automobile lamp Preferred conditions when applied to will be described.

The output of the laser beam is preferably 20 to 50 W, preferably 40 W.

If the output of the laser beam is less than 20W, the output is significantly weak while the laser beam passes through the transmission region 220 of the transparent cover 200 , so that the adhesion region 70 cannot be melted, so that the fusion is not performed well. .

And when the output of the laser beam 13 is 50W or more, the transmissive region 220 of the transmissive cover 200 melts and becomes opaque, and in this case, the laser beam is absorbed more and combustion occurs in the transmissive region 220 . Otherwise, the fusion reliability is reduced.

7 shows a table summarizing desirable condition values in laser welding for automobile lamps in relation to the present invention.

Referring to FIG. 7 as the most desirable condition, the best effect was obtained when the laser focal size was Φ 2.2 mm, the laser intensity was 25 W, and the welding speed was 29.5 mm/sec.

Furthermore, the weight of pressing through the jig 80 is 25 ± 5 kgf, the beam passing thickness of the laser is 7 mm, the circumference of the transmitted laser is 619.8 mm, and the radius is 32.9 mm. could

Welding using a reflective surface structure

In addition, in order to solve the above-mentioned problem, as a third embodiment, in the present specification, a method of performing welding of a desired area by placing a reflective surface therein is proposed.

8 shows an example of performing welding of a desired area by placing a reflective surface therein in relation to the present invention.

Referring to FIG. 8 , the first member 200 is a transparent resin member (hereinafter, optically transparent part) made of a thermoplastic resin, and the second member 100 is an opaque resin member (hereinafter, optically opaque) made of a thermoplastic resin. one part).

Reference numeral 340a denotes a junction at the rib wall (side surface), 340b denotes a junction at the bottom of the rib, and 13 denotes light energy introduced by the light energy generating device 10 .

Regarding the arrangement of the optical axis reflective surface, a reflective surface 350 of light energy is provided at the rib tip of the optically transparent component 200 .

This reflective surface is designed to reflect light energy as an inclined surface to the rib tip of the optically transparent component 200 .

The reflective surface 350 may select light energy suitable for the absorption wavelength region of the optically opaque component 100 and reflect the light energy,

In addition, the correction rib 330 is demonstrated. The fitting position correction rib 330 is disposed on the optically opaque part 100 side for the purpose of ensuring that welding is performed by interlocking the joint portion 330a on the rib wall surface.

As shown in FIG. 8 , for the joint portion 340b on the bottom surface of the rib, a joint portion 340b on the bottom surface to transmit some light energy to the bottom surface of the rib is provided.

In the setting of the optical axis reflective surface, as described above, the welding (welding) property is advantageous when the junction part 340a of the rib wall surface for welding (welding) is used as the rib wall surface. Therefore, the bonding surface becomes the bonding part 340a used as a wall surface.

In addition, light energy 13 is irradiated from the upper side of the optically transparent component 200 .

However, since the light energy 13 in a normal shape passes through the ribs due to wall reflection or the like and falls out to the lower side, the reflective surface 350 of the light energy 13 is provided at the tip of the ribs and the optical axis is bent by bending the housing wall surface. By irradiating light energy 13 to the junction 340a of the rib wall, welding (welding, 320) may be possible.

Through the reflective surface 350 , most of the light energy 13 irradiated from the optically transparent component 200 reaches the junction 340a 3 provided on the wall surface of the rib of the optically opaque component 100 .

In addition, by providing the joint portion 340b_ on the bottom surface of the rib, the cross section of the joint portion becomes an L-shaped structure, so the strength of the welding (welding) portion is higher than that of the conventional joint specification (cross-section is a straight line such as a letter or I letter). can be expected to increase.

Therefore, according to the proposed method, it is possible to provide a part shape with higher welding (welding) strength compared to conventional products while maintaining a stable, high-quality welding (welding) state while reducing design restrictions.

Here, the reflective surface is provided on the inclined surface shown in the cross-sectional view as the rib tip of the transparent resin member, and the bottom surface does not have a reflective surface.

In addition, when manufacturing the reflective surface, any means can be used as long as it can reflect light energy in a certain wavelength range.

For example, it is possible to coat an optically reflective material as a method for producing a reflective surface, and if it is an optically reflective film, it is also possible to coat by other means such as coating, vapor deposition or plating.

How to weld curved objects

In addition, in order to solve the above-mentioned problems, in the present specification, as a fourth embodiment, based on one laser source, a method of adjusting a focal length, an output value, etc. using height information from a reference point of a curved object is proposed. do.

9 illustrates an example of adjusting a focal length, an output value, etc. using height information from a reference point of a curved object based on one laser source in relation to the present invention.

As shown in FIG. 9 , when welding a curved object, a method of using a plurality of laser sources or rotating one laser source or an object receiving a laser is not used in the present embodiment.

Instead, in this embodiment, one laser source is used, information on the curved object is acquired in advance, and the focal length, output value, speed, etc. of the laser source are adjusted by using the change in height information from the reference point of the curved object. suggest how to

Referring to FIG. 9 , information on a curved object formed of the transparent member 100 and the opaque member 200 in advance, for example, information on length, height change, shape, and the like may be acquired in advance.

Thereafter, while changing the focal length, output value, speed, distance from the object, etc. of the laser emitting unit 10 under the control of the controller 60, using a plurality of laser sources or receiving one laser source or laser Welding can be performed on curved objects without rotating the object.

How to improve adhesion between objects and prevent internal damage by laser

In addition, in order to solve the above-mentioned problems, in the present specification, as a fifth embodiment, a welding surface is formed so that the lower surface of the transparent plastic in contact with the opaque plastic has an angle perpendicular to the jig, and an intermediate surface between the welding surface and the transmission part is formed. We propose a method of preventing the laser from entering the interior by forming it and forming it at an angle exceeding the critical angle with respect to the laser.

10A and 10B show an example of forming a welding surface to have an angle perpendicular to the jig with the lower surface of the transparent plastic in contact with the opaque plastic in relation to the present invention.

10A, 10B and 11 will be described on the assumption that welding is performed to make a vehicle lighting fixture.

10A and 10B, in the vehicle lighting fixture 1, the front opening of the container-shaped housing 100 with the front open is covered by the transparent cover 200, and the housing 100 and the transparent cover 200. The light source 10 is arranged in the light room partitioned by the

On the rear surface of the periphery of the transparent cover 200, a welding surface 70 is formed over the entire periphery, and the welding surface 70 is formed on the periphery of the front opening of the housing 100 by light welding. are joined

That is, the welding beam, which is a coherent or non-coherent electromagnetic wave such as laser, visible light, ultraviolet light, or infrared light, passes through the transparent cover 200 from the front side of the transparent cover 200 and is in close contact with the welding surface 70 . The welding surface 21 of (100) is irradiated.

That is, the point 32i corresponding to the welding surface 70 among the front surfaces 32 of the transparent cover becomes the light-incident surface.

By the irradiation of the welding beam, the welding surface 21 is in an excited state by irradiation of the welding beam, which is an electromagnetic wave, and heat is generated, and the welding surface 21 and the welding surface 21 are in close contact with the heat. The welding surface 70 of the transparent cover 200 melts together to become a commercial state, and the material resin of the housing 100 and the transparent cover 200 is integrated at the interface where the two welding surfaces 21 and 31 are in contact. .

Then, after the irradiation of the welding beam, which is the electromagnetic wave, is finished, the portion in the commercial state is cooled and solidified, whereby the transparent cover 200 is integrally joined to the housing 100 .

As described above, the transparent cover 200 needs to transmit a welding light beam, for example, a laser, and for that reason, it is required that the material of the transparent cover 200 has poor absorption of the welding light beam which is an irradiated electromagnetic wave. For example, a transparent synthetic resin such as PMMA (polymethyl methacrylate) is preferable.

In addition, since the housing 100 generates heat by being in an excited state when the welding surface 21 of the housing 100 is irradiated with a welding beam, which is an electromagnetic wave, the material is applied to radicals whose oscillation period coincides with the wavelength of the welding beam, which is an electromagnetic wave to be irradiated. It needs to have a molecular structure composed of

As shown in FIG. 10, the transparent cover 200 has a flat shape with an almost constant thickness as a whole, and the front surface 32 is greatly curved, and both ends in one cross section, for example, the upper and lower ends ( 32u and 32d are inclined in opposite directions (θu, θd) with respect to the reference line (line of the optical axis of the light source 10) XX.

Referring to FIG. 11 , an enlarged cross-sectional view of a portion surrounded by a circle III of FIG. 10 , that is, an upper end is shown.

In the case of light welding, as described above, if the two welding surfaces 21 and 31 are not in close contact, heat generated on the welding surface 21 of the housing 100 is transferred to the welding surface 70 of the transparent cover 200 . ), and causes poor welding in locations where the adhesion state is damaged.

In addition, in this specification, "adhesion state" means not only that two surfaces are in close contact, but also when there is a gap between the two surfaces, if the gap is 0.1 mm (millimeter) or less, welding is possible, so the two surfaces A state in which the two surfaces are in close contact with each other with a gap of 0.1 mm or less interposed therebetween is collectively referred to as a "adhesive state".

And, in order to bring the two welding surfaces 21 and 31 into a close contact state, a pressing force is applied from the front side of the transparent cover so that the welding surface 70 of the transparent cover 200 is connected to the welding surface 21 of the housing 100. pressed to

In this case, it is necessary to apply the compression force in the direction of arrow 10 of FIG. 11 in order to apply the compression force evenly over the entire circumference of the welding surface 70 .

The compression direction F is a direction in which an angle θf formed with a line perpendicular to the front surfaces (eg, 32u, 32d) of both ends in one cross section becomes substantially the same.

If the inclination angle of the welding surface 70 is the same as the inclination angle of the front surface 32, the welding surface 70 at the same inclination angle as the front surface 32 by the compression force F applied in the direction of the arrow 10, The surface pressure (Fs) acting in the vertical direction is equal to the following Equation (1).

Equation 1

That is, as θf increases, the surface pressure Fs decreases. And when the surface pressure Fs becomes small, the adhesiveness between the two welding surfaces 21 and 31 will fall.

Therefore, in the vehicle lighting fixture 1 of the present invention, the angle formed between the front surface 32 and the inner side by increasing the thickness of the portion that becomes the welding surface 70 among the rear surfaces of the transparent cover 200 is the inside, that is, the lighting fixture The angle θ31 formed by a line perpendicular to the welding surface 70 and the compression direction 10 by forming an inclination different from that of the front surface 32 so as to increase toward the center of (1) is the angle θf. make it smaller

In this case, the surface pressure F31 acting in the direction perpendicular to the welding surface 31 of the inclination angle θ31 by the compression force F applied in the direction of the arrow 10 is equal to the following Equation 2, and, Since θf > θ31, F31 > Fs.

Equation 2

That is, a greater pressing force is applied between the two welding surfaces 21 and 31 compared to the case where the inclination angle of the welding surface 70 is equal to the inclination angle of the front surface 32 , and the two welding surfaces 21 , 31) are firmly in close contact.

On the other hand, in relation to the present invention, by forming an intermediate surface between the welding surface and the transmission part, and forming an angle exceeding the critical angle with respect to the laser, it shows an example of preventing the laser from entering the interior.

In FIG. 11, the light incident surface (b) and the welding surface (c) have the same inclination angle, and thus, a transparent cover (a) having no thickened portion on the rear surface and no intermediate surface is applied to the housing (d). An example in the case of welding is shown.

By superimposing the welding surface (c) of the transparent cover (a) on the welding surface (e) formed on the periphery of the opening of the housing (d) in a close contact shape, the laser (f) is transmitted through the transparent cover from the light incident surface (b) Irradiate the welding surfaces (e, c).

At this time, although there is no problem if the laser f is irradiated to the welding surfaces e and c correctly, the irradiation position of the laser f may shift inward. Then, a part g of the laser f is irradiated to the inside of the luminaire further away from the welding surface e of the housing d, and there, another member disposed in the luminaire, for example, an extension h If there is such a thing, a part g of the laser f is irradiated to the member h, but there is a fear that the irradiated part i is burned.

So, as in the vehicle lighting fixture 1 of the present invention, if the intermediate surface 34 is formed between the welding surface 31 of the transparent cover 3 and the illumination light transmitting part 33, as shown in FIG. When the laser L is shifted inward and a part Lp of the laser L is shifted inward from the welding surfaces 21 and 31 , a part Lp of the laser is incident on the intermediate plane 34 .

And, since this intermediate surface 34 has an inclination which becomes an angle exceeding a critical angle with respect to a welding beam, the part Lp of this laser is totally reflected by the intermediate surface 34 and is directed outward.

Therefore, even if there is a member such as an extension in the rear of the intermediate surface 34, there is no fear that the member is damaged by a welding beam such as a laser that has departed from the target.

How to use a transparent jig

In addition, in order to solve the above-described problem, in the present specification, as a sixth embodiment, a method of increasing the degree of adhesion by applying a pressing jig as transparent and allowing the laser to reach through the jig is proposed.

12 shows an example of increasing the degree of adhesion by applying the pressing jig as transparent in relation to the present invention, and allowing the laser to reach through the jig.

Referring to FIG. 12 , in the light welding method according to the present embodiment, the first resin member 200 provided with the welding part 70 is transmitted through the irradiation light beam, and the transmittance to the first resin member with respect to the irradiation light beam. This is a light-beam welding method in which the second resin member 100 having a smaller transmittance and provided with a welding portion is welded by the irradiation light beam.

In particular, in this embodiment, the welding portion 70 of the first resin member 200 is pressed to the welding portion 70 of the second resin member 100 using a pressing jig 80 formed of a transparent material. The first resin member is formed of a transparent material while pressing the welding portion 70 of the first resin member 200 to the welding portion 70 of the second resin member 100 by the pressing process and the pressing jig 80 . A heating step of softening at least one of the welded portion of the first resin member or the welded portion of the second resin member by heating with a heating element provided in the pressing jig 8 so as to be in contact with each other to bring the welded portions into close contact with each other. The light source and the light source transmit the pressing jig 80 and the first resin member 200 to irradiate the welding portion 70 of the second resin member 100 to the first resin member 200 and the second A welding step of welding the resin member 100 is provided.

Therefore, there is no need to move the heating element for heating the welded portion before the pressing operation by the pressing jig in the direction in contact with the second resin member 100, and the pressing jig 80 formed of a transparent material so as to be in contact with the first resin member 200 ) is provided in

Through the transparent jig 80, the heating operation and the pressing operation can be continuously performed, and the workability is improved, and then good bonding property is ensured by welding the first resin member 200 and the second resin member 100. can do.

How to keep a tight fit without a jig

In addition, in order to solve the above-mentioned problems, in the present specification, as a seventh embodiment, a method of maintaining a state in close contact without a separate jig by inserting a defect in the seating part formed on the resin cover to which the welding machine part protruding from the housing is welded. suggest

13 shows an example of maintaining a state in close contact without a separate jig by inserting a defect in a seating part formed on a resin cover to which a welding machine part protruding from the housing is welded, in relation to the present invention.

Referring to FIG. 13 , it is a schematic cross-sectional view illustrating an enlarged bonding state between the housing 100 and the outer cover 200 .

The welding base 101 is fitted in the groove so that the outer peripheral side of the welding base 101 and the inner wall of the first welding leg are joined by laser welding.

The laser welding part 70 is positioned in a direction parallel to the fixing direction z'.

Even when the vehicle lamp 1 is viewed from the front direction of the laser welding part 70, the laser welding surface is hardly observed because the laser welding surface is parallel to the viewing direction.

Therefore, even if a non-uniform welding portion has been generated on the laser welding surface, the appearance may not be damaged.

Next, a method of bonding the outer cover 200 to the housing 100 by laser welding will be described.

The outer cover 200 is assembled to cover the concave portion in a direction parallel to the welding base 101 formed on the entire circumference of the housing 100 , that is, in the z' direction.

At this time, the welding base 101 is fitted so as to be inserted into the groove 201 .

The outer peripheral side surface of the welding base 101 and the inner wall of the first welding leg are formed to be parallel to each other, and the inner side of the welding base 101 and the inner wall of the second welding leg are parallel to each other, and the groove 201 is the same size as can be formed.

In addition, the welding base 101 may form a trapezoidal cross-sectional shape with a narrower width on the tip side.

Therefore, when the welding base 101 and the welding leg part are fitted, the welding base 101 makes surface contact within the groove|channel 201, and fixes it.

In addition, it is preferable to mold the housing 100 and the outer cover 200 so that they are always in surface contact over all directions, but when it is difficult for reasons of errors in injection molding and mold manufacturing, the laser welding part 70 of the groove 201 is It is desirable to have the person interview you.

Moreover, it is preferable to make the welding base 101 into the shape which has a side surface only inclined with respect to the fixing direction z'.

This is because, by tilting, the surface contact at the laser welding part can be strengthened using its own weight.

Moreover, it is preferable that either the side surface of the welding base 101 and the inner wall of the groove|channel 201 set it as a smooth surface.

It is because the laser welding surface can be set as clean bonding by setting it as a smooth surface.

Then, laser welding is performed in a state where the housing 100 and the outer cover 200 are fitted.

The laser light L (10) may be irradiated from the left side of the paper, that is, from the outer peripheral side of the vehicle lighting fixture (1).

Laser-beam L10 goes through the 1st welding leg and goes to the welding base 101, and the welding base 101 which received laser-beam L10 heat|fever-generates, and also the 1st welding leg also heat|fever-generates by heat conduction.

Thereafter, both are fused and welded in a molten state, but when the laser beam L (10) is not irradiated, it is cooled and the laser welding part 70 is bonded and fixed on the laser welding surface.

In this Example, when irradiating the laser beam L10, the operation|work which adds pressurization from the outside using the special jig|tool 80 is not performed.

In the conventional laser welding, it was necessary to press the bonding surface using the jig 80, but in this embodiment, since the welding base 101 is inserted into the welding leg or the groove 201, the housing 100 ) or the weight of the outer cover 200, even without using a special jig 80, the laser welding portion 70 is because the surface-contact bonding surface.

Accordingly, it is possible to solve the conventional problem that the central portion of the outer cover 200 is damaged or contaminated.

Additional Examples

According to another embodiment of the present invention, an intermediate surface is formed between the welding surface and the illumination light transmitting part in order to prevent the laser from being introduced into the interior and burning, and the layer is formed to be at an angle exceeding the critical angle with respect to the light beam to the inside. It is possible to prevent ingress.

In addition, according to another embodiment of the present invention, it is possible to increase the welding efficiency by increasing the scanning speed of the laser in a region where the incident angle is relatively small and the incident energy density is increased.

laser welding market

14A to 14D show graphs for explaining the laser welding market related to the present invention.

14A is a representation of the size of the global laser welding market in millions of dollars.

Referring to FIG. 14A , in the global market, the laser welding market is expected to grow from $1.425 billion in 2016 to $1.997 billion in 2022 at an average annual rate of 5.79%.

In addition, FIG. 14B shows the market size of each laser welding region in units of millions of dollars.

Referring to FIG. 14B , the Asia-Pacific market is expected to account for the largest share, and is expected to grow from USD 528 million in 2016 to USD 765 million in 2022.

In addition, FIG. 14c shows the market size of each laser welding application industry in units of millions of dollars.

Referring to FIG. 14C , the machine tool market is expected to occupy the largest share, and is expected to grow from $365 million in 2016 to $483 million in 2022.

Also, FIG. 14d shows the size of the global laser plastic welding market in units of billions of dollars.

Referring to FIG. 14D , it is expected to reach USD 1,543.2 million by 2025, growing at an average annual rate of 8.3% from USD 758.9 million in 2016, and the Asia-Pacific region is worth USD 342.8 million (42% share). It occupies the largest market share in the world.

The global laser plastic welding market is pursuing innovation in various methods such as welding method, laser source, and automation to enter the competitive manufacturing machinery market.

The laser plastic welding market is growing rapidly as the production of high-quality welded joints is possible with the development of laser plastic welding technology. In particular, as consumers’ preference for aesthetic products increases, welding on hidden surfaces is possible. There is a growing demand for laser welding that can do the job.

The rapid decline in the price of laser welding equipment is also affecting the market expansion.

Therefore, it is determined that the demand for the welding apparatus and the control method using the laser proposed by the present invention is high, and high marketability is guaranteed.

Effects according to the present invention

The present invention has been devised to solve the problems of the prior art, and it is possible to provide a welding apparatus using a laser and a method for controlling the same to a user.

Specifically, the present invention can provide a user with an apparatus and method for welding an impermeable plastic and a transmissive plastic without an annealing process using a laser beam having a wavelength range of 1400 to 3000 nm.

According to the present invention, by omitting the application of the annealing process, there is an effect that the short-circuit process part in the entire welding process can be eliminated, and the manufacturing cost can be significantly lowered.

Laser welding according to the present invention enables plastic bonding at low cost and high efficiency, and as a non-contact welding method, there is no external deformation of the product due to vibration, shock, or heat, and the bonding quality is excellent because no burrs or fluff occur. , 2D, 3D shape products can be applied, regardless of size or shape, easy to automate, and can provide system stability.

In addition, since the laser is used, it is possible to increase the focal length, thereby increasing the flexibility of the welding operation, and since the shape and focal size of the laser beam can be changed, welding on an object having a three-dimensional shape is possible.

In addition, according to the present invention, the temperature difference between the transmission area and the close contact area becomes small, so that the housing and the permeable cover are firmly welded together, and further, a constant welding quality can be expected.

In addition, since the preheating of the permeable area and the melting of the close contact proceed at the same time, even if the permeable cover and the impermeable housing are of different materials, there is an effect that a strong and fast welding connection is possible.

On the other hand, in the apparatus and method described above, the configuration and method of the above-described embodiments are not limitedly applicable, but all or part of each embodiment is selectively combined so that various modifications can be made. may be configured.

Claims (1)

A plastic welding apparatus for welding an impermeable first plastic and a transparent second plastic using a laser beam without an annealing process, the plastic welding apparatus comprising:

The plastic welding device,
Adhering the first plastic and the permeable second plastic into close contact,
Irradiating a laser beam to the first plastic and the second plastic in close contact,
At least a portion of the laser beam is first absorbed while passing through the second plastic, and the remaining beam is second absorbed in the first adhesion region of the first plastic and the second plastic,
using the first absorption and the second absorption to cause the first adhesion region to be welded,

The laser beam has a wavelength range of 1400 to 3000 nm,

At least a portion of the laser beam that has passed through the second plastic is reflected on a reflective surface provided on at least a portion of the second plastic,
The reflected laser beam is absorbed into a second adhesion region of the first plastic and the second plastic different from the first adhesion region,
the first and second adhesion regions are welded together;

When there is a part in which at least a portion of the first plastic and the second plastic is curved,
The plastic welding device,
Before the first plastic and the second plastic are brought into close contact, first information about the curved part is collected,
The laser beam adjusts at least one of a focal length, an output value, a speed, and a separation distance between the first plastic and the second plastic of the irradiated laser beam according to the first information,
The first information includes length, height change and shape information for the curved part,

At least a portion of the first plastic and the second plastic is formed with an intermediate surface formed with a step having an angle exceeding a critical angle through which the laser beam is introduced, so that the laser beam is directed to an area other than the first contact area. to prevent entry,

The plastic welding device,
Before irradiating the laser beam to the first plastic and the second plastic in close contact, the first plastic and the second plastic in close contact are further brought into close contact using a jig,

The jig is transparent,

Plastic welding apparatus, characterized in that the laser beam output is increased in a region in which the incident angle of the laser beam is less than or equal to a preset value or the incident energy density is increased among the first adhesion regions.

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