Laser welding method

• US 20030196750A1
• Filed: 04/11/2003
• Published: 10/23/2003
• Est. Priority Date: 04/23/2002
• Status: Active Grant

• Current Assignee: Aisan Kogyo Kabushiki Kaisha, Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Aisan Kogyo Kabushiki Kaisha, Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Sakai, Tomohiro, Nakamura, Hideo, Hirata, Masami, Fukaya, Kanehiro
• Granted Patent: US 6,989,070 B2
• Time in Patent Office: Days
• US Class Current: 156/272.8
• CPC Class Codes: B01D 29/01 with flat filtering elements B01D29/39 takes precedence
• CPC Class Codes: B01D 29/012 Making filtering elements making bag, cage, hose, tube, sleeve or like filtering elements B01D29/111
• CPC Class Codes: B29C 2035/0822 using IR radiation
• CPC Class Codes: B29C 65/08 using ultrasonic vibrations non-plastics element to plastics elements B29C65/645
• CPC Class Codes: B29C 65/1612 Infrared [IR] radiation, e.g. by infrared lasers
• CPC Class Codes: B29C 65/1616 Near infrared radiation [NIR], e.g. by YAG lasers
• CPC Class Codes: B29C 65/1635 at least passing through one of the parts to be joined, i.e. laser transmission welding
• CPC Class Codes: B29C 65/1654 scanning at least one of the parts to be joined
• CPC Class Codes: B29C 65/1674 making use of laser diodes B29C65/167 takes precedence
• CPC Class Codes: B29C 65/1687 making use of light guides
• CPC Class Codes: B29C 65/169 being a part of the joined article
• CPC Class Codes: B29C 65/1696 making use of masks
• CPC Class Codes: B29C 65/7841 Holding or clamping means for handling purposes clamping means for the purpose of applying pressure on the parts to be joined, in the area to be joined B29C66/81; work holders in general B25B; devices for holding or positioning work for welding metal B23K37/04
• CPC Class Codes: B29C 66/022 Mechanical pre-treatments, e.g. reshaping
• CPC Class Codes: B29C 66/112 Single lapped joints
• CPC Class Codes: B29C 66/131 Single flanged joints, i.e. one of the parts to be joined being rigid and flanged in the joint area
• CPC Class Codes: B29C 66/30325 making use of cavities belonging to at least one of the parts to be joined
• CPC Class Codes: B29C 66/53461 joining substantially flat covers and/or substantially flat bottoms to open ends of container bodies
• CPC Class Codes: B29C 66/5412 said substantially flat extra element being flexible, e.g. a membrane B29C66/5416 takes precedence
• CPC Class Codes: B29C 66/61 Joining from or joining on the inside for making tubes by bending sheets and joining from the inside B29C53/387
• CPC Class Codes: B29C 66/71 : characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/712 : the composition of one of the parts to be joined being different from the composition of the other part
• CPC Class Codes: B29C 66/7294 : Non woven mats, e.g. felt
• CPC Class Codes: B29C 66/7392 : characterised by the material of at least one of the parts being a thermoplastic
• CPC Class Codes: B29C 66/7485 : Natural fibres, e.g. wool, cotton
• CPC Class Codes: B29C 66/80 : General aspects of machine operations or constructions and parts thereof
• CPC Class Codes: B29C 66/8242 : Pneumatic or hydraulic drives using fluid pressure directly acting on the parts to be joined B29C66/8266
• CPC Class Codes: B29C 66/8322 : Joining or pressing tools reciprocating along one axis
• CPC Class Codes: B29C 66/863 : Robotised, e.g. mounted on a robot arm
• CPC Class Codes: B29K 2067/00 : Use of polyesters or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2077/00 : Use of PA, i.e. polyamides, e.g. polyesteramides or derivatives thereof, as moulding material
• CPC Class Codes: B29L 2031/14 : Filters optical filters B29L2011/0066, sieves or screens B29L2031/737

Abstract

To weld a filter made of a laser beam-transmittable fiber material to a case 2 made of a laser beam-nontransmittable resin material by a laser beam LB, the filter 4 is first placed on the case 2; subsequently, the filter 4 is pressurized by a jig 19 to increase the fiber density of a welding portion B2; and then the welding portion B2 is irradiated by the laser beam LB. In the step of increasing the fiber density, a periphery of the welding portion B2 is pressurized by the jig 19 to increase the fiber density of the filter 4 in a larger area than the welding portion B2. Accordingly, the laser beam LB transmitting through the filter 4 melts a part of the case 2, and the melted resin material permeates through gaps between the fibers constituting the filter 4, thereby welding the welding portion to the case 2.

Claims

1. A laser welding method for welding a fiber filter to a resin base member by a laser beam, the method including the steps of:

placing the filter made of a laser beam-transmittable fiber material on the base member made of a laser beam-nontransmittable resin material;

increasing the fiber density of a welding portion of the filter; and

irradiating the laser beam to the welding portion;

wherein the base member will partially be melted by the laser beam transmitting through the filter and a melted material of the base member will permeate through gaps between the fibers constituting the filter so that the welded portion is joined to the base member.

2. The laser welding method according to claim 1, wherein the step of increasing the fiber density is performed to increase the fiber density of the filter in a slightly larger area than the welding portion.

3. The laser welding method according to claim 2, wherein the step of increasing the fiber density is performed to press a periphery of the welding portion against the base member to thereby indirectly compress the welding portion.

4. The laser welding method according to claim 2, wherein the step of increasing the fiber density is performed to press a periphery of the welding portion against the base member to thereby indirectly compress the welding portion and directly compress the welding portion from the base member side.

5. The laser welding method according to claim 2, wherein the step of increasing the fiber density is performed to insert the welding portion and its periphery in a tucked state into a recess previously formed in the base to thereby compress the welding portion and its periphery inside the recess.

7. A canister provided with the base member and the filter welded by the laser welding method according to claim 1.

6. A laser welding method for welding a fiber filter to a resin base member by a laser beam, the method including the steps of:

placing the filter formed of a nonwoven fabric made of a laser beam-transmittable fiber material on the base member made of a laser beam-nontransmittable resin material;

pressurizing a welding portion of the filter by a jig having a slit to increase the fiber density of the welding portion; and

irradiating the laser beam to the welding portion through the slit of the jig;

wherein the base member will partially be melted by the laser beam transmitting through the filter and a melted material of the base member will permeate through gaps between the fibers of the filter so that the welded portion is joined to the base member.

8. A canister provided with the base member and the filter welded by the laser welding method according to claim 6.