Title of Invention

VIBRATION WELDING TOOL AND METHOD

Abstract

A vibration welding tool in which not less than three thermoplastic workpieces are integrally vibration welded into sandwich structure, which comprises an upper jig means supporting a first workpiece so that micro-vibration of crosswise direction can be applied thereto from a vibrating means and a lower jig means to hold plural second workpieces to be welded to at least both surfaces of the first workpiece, the lower jig means being operated so that the second workpieces are moved in the height direction by an elevating means to align with the first workpiece and slid in the lateral direction toward the first workpiece by a sliding means to come into contact therewith.

Full Text

BACKGROUND OF THE INVENTION Field of the Invention [0001] This invention relates to technology of vibration welding in which plural thermoplastic workpieces are subjected to relative vibration to weld them by means of frictional heat relative vibration. Prior Art [0002] [Patent Reference No. l] Japanese Patent Kokai 9-85833 There is disclosed vibration welding technology in embodiments in which two thermoplastic workpieces are met in an opposed situation. [0003] [Patent Reference No. 2] Japanese Patent Kokai No. 9-151723 There is disclosed another vibration welding technology in which two workpieces are brought into contact with each other by a contacing side jig and a vibrating side jig to meet them each other. Disclosure of the Invention Problems to be solved by the Invention [0004] It is impossible to weld not less than three workpieces to form sandwich structure all at once by the use of conventional technology disclosed in the references No. 1 and 2 above. [0005J It has been difficult, and thus is an object of this invention, to develop welding technology in which not less than three workpieces are sequentially processed to form integral structure. [0006] In addition, conventional products of thermoplastic material would cause problems as in the following. [0007] For example, because of intricate structure of a center console box arranged between the driver's and passenger's car seats, an intricately shaped mold is required to carry out one-piece molding all at once, thereby sometimes causing defective molding. [0008] When plural worfcpieces are joined by means of screws, there might cause loosening of the screws, an increase in processing steps and instability of strength properties of the product. [0009] The conventional problems as described above will be solved in the following manner according to this invention. [0010] Accordingly, it is an object of this invention to provide a method and tool for integrally vibration-welding not less than three workpieces of thermoplastic material into sandwich structure. [0011] Another object of this invention is to provide a method and tool for vibration-welding not less than three workpieces of thermoplastic material to form a product of high strength. [0012] Still another object of this invention is to provide an intricately structured thermoplastic product of high quality without causing any failure in production. [0013] Yet another object of this invention is to improve quality of a welded product by controlling relative distance and space of movement of a lower jig support block by a slide stabilizing means to stabilize a change of level in the direction of height. [0014] A further object of this invention is to improve quality of a welded product by controlling an up-and-down level of lower jig blocks. [0015] A still further object of this invention is to provide a method and tool for vibration welding without using an intricate and expensive mold. [0016] A specific object of this invention is to provide a method and tool for vibration welding in which workpieces are integrally joined without using joint means of different material such as metal screws, thereby reducing production man-hour and effectively avoiding classified waste disposal. tOO17] A still specific object of this invention is to provide a method and tool for vibration welding in which workpieces are vibration welded in a sequential process so that the production time is greatly reduced. Means to Solve the Problems (00181 These and further objects of this invention will be accomplished as in the following; (1) A vibration welding tool in which not less than three thermoplastic workpieces are integrally vibration welded into sandwich structure, which comprises an upper jig means supporting a first workpiece so that micro-vibration of crosswise direction can be applied thereto from a vibrating means and a lower jig means to hold plural second workpieces to be welded to at least both surfaces of the first workpiece, the lower jig means being operated so that the second workpieces are moved in the height direction by an elevating means to align with the first workpiece and slid in the laretal direction toward the first workpiece by a sliding means to come into contact therewith. (2) A vibration welding tool described in the item (l) above which further comprises a slide stabilizing means to synchronize relative and movement of right and left lower jig blocks in the lateral direction. (3) A vibration welding tool described in the item (l) which further comprises a slide stabilizing means is used to stabilize relative and lateral movement of right and left lower jig blocks in the height direction. (4) A vibration welding tool described in the item (1) which further comprises a distance sensor to control a space between the right and left lower jig blocks. (5) A vibration welding tool described in the item (l) which further comprises an elevation control rod and a frame stopper to control a vertical level of an elevation frame. (6) A vibration welding method in which not less than three thermoplastic workpieces are integrally vibration welded into sandwich structure, which comprises the following sequential processes' (A) Workpiece fitting process A first workpiece and plural second workpieces to be welded to both surfaces of the first workpiece are fitted to azTupper jig means and plural lower jig means, respectively, the upper and lower jig means being arranged apart; (B) Workpiece contacting process The first workpiece and the second workpieces are brought into contact with each other while allowing the plural lower jig means to elevate and come close; (C) Vibration welding process Lateral micro-vibration is applied to the first workpiece through the upper jig means to weld to the second workpieces, followed by generation of frictional heat between two workpieces to partially melt them; and (D) Workpiece cooling process After application of lateral micro-vibration is halted, the welded product is cooled spontaneously. Effects of Invention (00191 Characteristic effects of this invention are as in the following: 1. Not less than three thermoplastic workpieces can be integrally vibration welded into sandwich structure; 2. The vibration welded product is strong enough! 3. The welded product of high quality can be formed without using an intricately shaped mold; 4. As the welded product comprises no disparate material such as a metal piece, waste thereof can be disposed without classified collection; and 5. Productivity of vibration welding is improved due to its high-speed sequential production process. THE PREFERRED EMBODIMENTS [0020] Referring now to the appended drawings, Figs. 1 to 11, the preferred embodiments of this invention will be described. [0021] A vibration welding tool 1000 shown in Fig. 1 is an embodiment for forming a console box arranged between a driver's seat and an adjacent passenger's seat of a car. [0022] 1. Outline of vibration welding tool 1000 A frame means 100 comprises a fixed frame 110 and an elevating frame 120 as well as other means as will be described below. * [0023] The elevating frame 120 moved by a hydraulic drive means 200 is equipped with a lower jig means 500 which is slid by a sliding means 300 and used to hold a central box as a first workpiece, while the fixed frame 110 vertically carries an upper jig means 700 which is applied with micro-vibration through a vibrating means 600 and used to hold right and left panels as second workpieces. Action of the frame means 100 is controlled by a control means 800 as will be described below. [0024] 2. Constitution of each means (1) Upper jig means 700 When the center box CB and the right and left panels RP and LP are vibration welded to form a center console box CC as shown in Fig, 12, the upper jig means 700 for holding the central box CB vertically carries a pair of two upper jig blocks 720 under an upper jig plate 710 located close to the fixed frame 110 as shown in Fig. 1. A first shock-resisting material 721 is lined on the outer surface of the blocks 720 where the center box CB comes close, while a vacuum cup 410 is arranged in an adsorbing means 400 to adsorb the center box CB wfieri the upper jig blocks are inserted thereto. [0025] The upper jig plate 710 further comprises a vibrating means (vibrator) 600 to apply micro-vibration thereto. [0026] (2) Lower jig means 500 A lower jig means 500 comprises opposingly arranged right and left jig blocks 510 and 520. The blocks 510 and 520 are reciprocally slidable in the lateral direction on an elevating frame 120 and moved in close or kept apart by a sliding means 300 as will be described below. Second and third shock-resisting materials 511 and 512 are lined on the opposing surfaces of these blocks to hold right and left panels ( RP and LP) of the center console box CC, while vacuum cups 420 and 430 are arranged in the adsorbing means 400 to adsorb these panels RP and LP. [0027] The sliding means 300 comprises first and second air cylinders 310 and 320 provided with piston rods 311 and 321 on the elevating frame 120, while outer ends of these rods are connected to left and right flanges 513 and 523 mounted on and under base frames 512 and 522 of the lower jig blocks 510 and 520. [0028] Each of base frames 512 and 522 is connected to respective racks 514 and 524 interlocked with a pinion 530, while a slide stabilizing means 560 comprises sliders 515 and 125 protruded from under surfaces of the base frames 512 and 522 and put on rails 123 of the elevating frame 120. [0029] There ia arranged a distance sensor 900 between the right and left jig blocks 510 and 520 to detect spaces between right and left jig blocks 510 and 520 coming close or apart each other during the welding operation by sensing, for example, changes in eddy current on a metal surface. [0030] A run-away preventing means 920 comprises a support plate 921 fixed on the top of a piston rod 923 of a hydraulic cylinder 922 to guard against falling down of the center box BC held by the upper jig blocks 720, thereby the center box being held stable during the welding operation. [0031] (3) Hydraulic elevating means 200 The elevating frame 120 is connected to a piston rod 211 of a hydraulic cylinder 210 to move the lower jig means up and down during the welding operation. A vertical level of the elevating frame 120 is controlled when an elevation control rod 121 thereof meet up with a frame stopper 122 of the fixed frame 110, thereby operational safety being improved. [0032] (4) Control means 800 A control means constituted as CPU is connected to each means as shown in Fig. 2. Each means is actuated and stopped timely depending on commands from an operation commanding section 810. [0033] When a hydraulic actuating means 200 activates in response to the control means 800, elevation of the elevating frame 120 is controlled so that the center box CB and right and left panels RP and LP are held by the upper jig blocks 720 and the right and left lower jig blocks 510 and 520, respectively, with the aid of an adsorbing means 400. [0034] The right and left lower jig blocks 510 and 520 are slid by the sliding means 300 to come into contact the center box CB wjth the right and left panels RP and LP, followed by vi&ration welding with the aid of the vibrating means 600. Spaces between the right and left lower jig blocks 510 and 520 are controlled by the distance sensor 900 to stabilize the welding operation, while vertical levels of the elevating frame 120 are safely controlled by the frame stopper 122. [0035] The center box CB is held stable by controlling the run-away preventing means 920. [00361 3. Workpiece Each of three workpices as a component of the center console box CC as shown in Fig. 12 is made of thermoplastic material such as ABS and PP resins. (0037] The center box CB to be treated in a sandwiched situation by vibration welding is in the shape of box. [0038] The right and left panels RP and LP to be treated by vibration welding as side parts of the sandwiched center box CB are provided with meltable ribs LIB as internally extended and laterally paralleled protrusions. (0039] 4. Vibration welding method Referring to Figs. 3 to 11, each process of a vibration welding method using . the vibration welding tool 1000 will be described in the following. [0040] (1) Preliminary process The elevating frame 120 stays on a lowered level, while the right and left lower Jig blocks 510 and 520 as well as the upper jig blocks 720 are arranged in a separated or standby situation as shown in Fig. 3. [0041] (2) Workpiece fitting process The center box CB as a workpiece is fit on the upper jig blocks 720, while the right and left panels RP and LP are inserted to the right and left lower jig blocks 510 and 520 as shown in Fig. 4. Then, the adsorption means 400 is started so that the center box CB as well as both panels RP and LP are adsorbed to the upper jig blocks 720 and the right and left lower jig blocks 510 and 520 are adsorbed by the vacuum cup 410 and those cups 510 and 520 for the Lower jig blocks, respectively, to hold them stable. [0042] (3) Elevating process for lower jig means 500 The hydraulic cylinder 210 is started to raise the elevating frame 120 together with the lower jig means 500 to a level where the right and left panels RP and LP align oppositely to the center box CB as shown by an arrow in Fig. 4. [0043] Elevation of the elevating frame 120 is secured safely until the elevation control rod 121 reaches a level to be halted by the flame stopper 122. [0044] The support plate 921 connected to the piston rod 923 of the hydraulic cylinder 922 in the run-away preventing means 920 is raised in the direction of arrow B to support the center box CB from the bottom, thereby a run-away movement thereof being prevented. [0045] (4) Workpiece contacting process The piston rods 311 and 321 of the first and second air cylinders 310 and 320 are slid as shown by an arrow in Fig. 6 to come close the right and left jig blocks 510 and 520 with each other, thereby the center box CB being sandwiched between the right and left panels RP and LP to bring the meltable ribs LIB into contact with the central box CB. [0046] As the slide stabilizing means 560 is arranged between each piston rod 311 and 321, the right and left lower blocks 510 and 520 are slid the same distance and kept stable with the aid of the rail 123 and the sliders 515 and 525. [0047] (5) Vibration welding process Lateral micro-vibration is applied to the upper jig blocks 720 in the direction at right angles to the plan by the vibrator 600 connected to the upper jig plate 710 as shown in Fig. 7 to generate friction heat between the meltable ribs LIB and the center box CB and melt the end part of LIB, thereby the right and left panels RP and LP being welded to the center box CB. [0048] Melted LIB depth is detected by the distance sensor 900 based on a melted amount thereof during the welding operation, while the right and left jig blocks 510 and 520 come closer a little (about 3 mm) by additionally activating the first and second air cylinders 310 and 320 to further promote the welding operation. [0049] (6) Cooling process The vibrator 600 is halted by the control means according to a signal from the distance sensor 900 in a situation of the above mentioned process (5), which is kept there only for few seconds (about 3 sec.) for cooling and hardening. [0050] (7) Move-down process of run-away preventing means 920 The supporting plate 921 is moved down, a a shown by an arrow in Fig. 8 to separate it from the bottom of the center box CB. [00511 (8) Center box CB releasing process The vacuum cup 410 of the adsorbing means 400 is deactivated, while the elevating frame 120 is moved down to release the upper jig blocks 720 from the center box CB as shown in Fig. 9. [00521 (9) Releasing process for right and left panels RP and LP The vacuum cups 420 and 430 of the adsorbing means 400 are deactivated, while the first and second air cylinders 310 and 320 are driven in a reverse manner as shown by an arrow to release the right and left panels RP and LP from the right and left lower jig blocks 510 and 520 as shown in Fig. 10. 10053] (10) Center console box CC ejecting process The thus treated center console box CC is ejected from the vibration melting tool 1000 to complete all processes as shown in Fig. 11. Example [0054] An exemplary vibration welding is conducted in a manner as will be described below. 1. Micro-vibration frequency: 100 to 240 Hz; 2. Pressure added to workpiece: about 50 to 1,000 kg; 3. Melted width: about 3 mm; 4. Welding time: about 3 sec.; 5. Cooling time* about 3 sec. [0055] Workpiece used" 1. Starting material ABS resin, acrylic resin, polycarbonate resin, polyethylene and polypropylene; 2. Dimensions-Thickness of center box: about 2 to 5 mm; Thickness of right and left panels: about 2 to 5 mm. Industrial Applicability [0056] According to this invention, it is possible to yield a welded thermoplastic product of intricate shapes by a reduced production process. The product can be quite compact with increased rigidity and applicable as various kinds of plastic products. From this point of view, applicability of this invention is greatly tremendous. Brief description of the drawings [0057] Fig. 1 is a sectional side view of an embodiment of this invention. Fig. 2 is a functional block diagram. Fig. 3 is a process diagram before welding. Fig. 4 is a process diagram for fitting workpieces. Fig. 5 is a process diagram for elevating lower jig means. Fig. 6 is a process diagram for contacting workpieces. Fig. 7 is a process diagram for vibration welding. Fig. 8 is a process diagram for moving down a run-away preventing means . Fig. 9 is a process diagram for releasing a center box. Fig. 10 is a process diagram for releasing right an d left panels. Fig. 11 is a process diagram for ejecting a center console box. Fig. 12 is a perspective view of workpieces of a center console box. Description of Numerals 1000: Vibration welding tool; 300: Sliding means; 500- Lower jig means; 600: Vibration means (vibration generating means, vibrator); 700: Upper jig means. Summary There is provided a tool and method for integrally vibration welding not less than three thermoplastic workpieces to sandwich structure. A vibration welding tool in which not less than three thermoplastic workpieces are integrally vibration welded into sandwich structure, which comprises an upper jig means supporting a first workpiece so that micro-vibration of in the lateral direction can be applied thereto from a vibrating means and a lower jig means to hold plural second workpieces to be welded to at least both surfaces of the first workpiece, the lower jig means being operated so that the second workpieces are moved in the height direction by an elevating means to align with the first workpiece and slid in the lateral direction toward the first workpiece by a sliding means to come into contact therewith. SPECIFICATION VIBRATION WELDING TOOL AND METHOD What is claimed is- 1. A vibration welding tool in which not less than three thermoplastic workpieces are integrally vibration welded into sandwich structure, which comprises an upper jig means supporting a first workpiece so that micro-vibration of crosswise direction can be applied thereto from a vibrating means and a lower jig means to hold plural second workpieces to be welded to at least both surfaces of the first workpiece, the lower jig means being operated so that the second workpieces are moved in the height direction by an elevating means to align with the first workpiece and slid in the lateral direction toward the first workpiece by a sliding means to come into contact therewith. 2. A vibration welding tool claimed in claim 1 which further comprises a slide stabilizing means to synchronize relative movement of right and left lower jig blocks in the lateral direction. 3. A vibration welding tool claimed in claim 1 which further comprises a slide stabilizing means to stabilize relative and lateral movement of right and left lower jig blocks in the height direction. 4. A vibration welding tool claimed in claim 1 which further comprises a distance sensor to control a space between the right and left lower jig blocks. 5. A vibration welding tool claimed in claim 1 which further comprises an elevation control rod and a frame stopper to control a vertical level of an elevation frame. 6. A vibration welding method in which not less than three thermoplastic workpieces are integrally vibration welded into sandwich structure, which comprises the following sequential processes' (A) Workpiece fitting process A first workpiece and plural second workpieces to be welded to both surfaces of the first workpiece are fitted to an upper jig means and plural lower jig means, respectively, the upper and lower jig means being arranged apart! (B) Workpiece contacting process The first workpiece and the second workpieces are brought into contact with each other while allowing the plural lower jig means to elevate and come close; • (C) Vibration welding process Micro-vibration of lateral direction is applied to the first workpiece through the upper jig means to weld to the second workpieces, followed by generation of frictional heat between two workpieces to partially melt them; and (D) Workpiece cooling process After application of lateral micro-vibration is halted, the welded product is cooled spontaneously.

Documents:

378-CHE-2005 FORM-6 24-03-2008.pdf

378-che-2005-abstract.pdf

378-che-2005-claims.pdf

378-che-2005-correspondnece-others.pdf

378-che-2005-description(complete).pdf

378-che-2005-drawings.pdf

378-che-2005-form 1.pdf

378-che-2005-form 3.pdf

378-che-2005-form 5.pdf

378-che-2005-priority document.pdf