AU2006345829B2

AU2006345829B2 - A method for joining a metal plate

Info

Publication number: AU2006345829B2
Application number: AU2006345829A
Authority: AU
Inventors: Takao Motohashi
Original assignee: HIROYASU KAWAMATA
Current assignee: HIROYASU KAWAMATA
Priority date: 2006-07-05
Filing date: 2006-07-05
Publication date: 2011-07-07
Anticipated expiration: 2026-07-05
Also published as: WO2008004285A1; JP5155859B2; HK1122089A1; CN101233329A; JPWO2008004285A1; CN101233329B; AU2006345829A1; NZ571701A

Abstract

[PROBLEMS] Provided are a method of joining metal sheets together, and a sander. The method is suitable for repairing a damaged part of a metal sheet of, for example, a vehicle body, and a damaged part of nonferrous metal of buildings and a machines or a damaged part of a nonferrous peripheral wall, is capable of two-dimensionally or three-dimensionally joining, in flush with each other, joined or repaired parts of sheet bodies having particularly complex curve surfaces, and precisely and beautifully finishing them, and is capable of reasonably and easily performing such joining operation. [MEANS FOR SOLVING THE PROBLEMS] Two plate bodies(5, 7) to be repaired and joined to each other are disposed so that their ends to be joined are separated from each other in the plate thickness direction or in the direction perpendicular to the plate thickness direction. In the method, joining pieces (6, 31) formed integrally with or separately from the metal sheet are disposed on one side of the ends to be joined. The ends to be joined are adhered to the joining pieces (6, 31). Before an adhesive agent (10) is cured, a pressing plate (12) is disposed on the other side surfaces of the ends to be joined. Attracting devices (15) each having magnetic force are installed on the surface of the pressing plate (12). The pressing plate (12) is fitted to the other side surfaces of the ends to be joined by the magnetic force of the attracting devices (15). The ends to be joined are attracted and displaced by the magnetic force, and as a result, the ends are disposed in flush with each other with reference to the pressing plate (12).

Description

DESCRIPTION A METHOD FOR JOINING A METAL PLATE TECHNICAL FIELD [0001] This invention relates to a method ofjoining a metal plate, which is suited to be used for repairing, for example, a damaged part of a metal plate of a vehicle body or a damaged part of a peripheral wall of a building, machine or the like. BACKGROUND ART [0002] For joining, for example, metal plates, it is a conventional method normally employed wherein metal plates are superimposed or abutted with each other or metal plates to be joined are abutted with a joint plate and joined together by means of welding, riveting or screwing. However, this conventional welding method has such shortcoming that the metal plates are thermally deformed or a remaining stress is produced. The riveting method has such a shortcoming that an impact twist and a remaining stress are produced around the rivet hole by instantaneous point pressure and joining stability is not good because joining accuracy or deformation afterjoining the metal plates is liable to occur. The screwing method has such a shortcoming that a troublesome screwing operation is required. Moreover, in the above methods, the appearance is not good 2 because a welding trace is left remained, or the rivet or machine screw is left exposed. Therefore, such normal joining methods as mentioned above are practically impossible to apply to an operation for repairing a damaged part, for example, of a vehicle body wherein a high surface uniformity is required. [0003] As one method to repair a damaged part of a vehicle, the damaged part is cut and the cut part is joined with a repair member. If, in this instance, the cut part is joined with a repair member by the above-mentioned conventional normal method, the surface of the repairing part is deformed, thus making it difficult to obtain a uniform surface or deteriorate the appearance. Therefore, the above-mentioned joining method is difficult to employ. What is normally practiced, in order to cope with the above mentioned shortcomings, is that a vehicle body part including the damaged part is replaced with a new one. According to this practice, however, it is required to remove and re-attach other parts adjacent to the damaged part, such as a window panel, a bumper and the like. Thus, much time and labor are required which results in high repairing cost and thus, this practice is unreasonable. [0004] In view of the above, the present applicant has developed a method capable of joining metal plates or the like comparatively easily and without deteriorating the uniformity of the surface by partially cutting a predetermined range of area of a vehicle body including the damaged part and attaching a repair member that is prepared beforehand and using an adhesive agent. This method is already proposed by the present applicant. [0005] 3 According to the metal plate joining method proposed by the present applicant, the end parts of one set of metal plates are tapered by chamfering, machine screw holes for tapping screw to be screwed therein, respectively, are formed in the vicinity thereof, and an opening part of each machine screw hole is formed in a cone shape. Then, the joining end parts of the metal plates are arranged in face-to-face relation and an adhesive agent is applied to the back surfaces of the joining end faces and attached to an abutment plate. When the adhesive agent is almost hardened, the tapping screws are screwed in the corresponding machine screw holes, and an adhesive agent is filled in the machine screw holes and a recess formed between the end parts of the metal plates to conceal the head part of the machine screw and to uniform the joining parts of the metal plates, so that a single plate having no joining part, in appearance, can be obtained (for example, see Patent Document 1). [0006] Another form of a metal plate joining method is simultaneously proposed by the present applicant, wherein an end part of one of the metal plates is tapered by chamfering, machine screw holes each for a tapping screw to be screwed therein is formed in the vicinity thereof, and a step part is formed on an edge part of the other metal plate. Then, the edge part of the other metal plate is bent toward the back surface side to form a superimposing part that serves as the above-mentioned abutment plate, this superimposing part is arranged on a back surface on the end part side of the first-mentioned metal plate, and an adhesive agent is applied to the back surface of the metal plate to attach the superimposing part thereto. When the adhesive agent is almost hardened, the tapping screw is screwed in the machine screw hole and an adhesive agent having the same quality is filled in the machine screw hole and a recess formed between the 4 chamfered part and the end edge of the metal plate to conceal the head part of the machine screw and to uniform the joining parts of the metal plates, so that a single plate having no joining part, in appearance, can be provided. [0007] However, the joining methods proposed by the present applicant have such shortcomings that since tapping screws are necessarily used and machine screw holes are also required to form in the metal plate, the number of component parts is increased and a process for machining the machine screw hole is required. Thus, the production efficiency is decreased. Moreover, such additional inconveniences arise when two thin steel plates are to be joined as in the case, for example, for the vehicle body of an automobile that tapping screws each having a length enough for the head parts to be embedded in the machine screw holes and the tapping screws are required to be arranged at a pitch of about 50 mm because otherwise, a favorable pressing condition cannot be obtained with respect to the joining margin. In order to satisfy the above-mentioned conditions, it is necessary to use tapping screws which are specially ordered. In addition, at the time of a sequence of joining operation, it is required to bore the machine screw holes, to screw the tapping screws therein and to fill the adhesive agent in the holes, etc. Thus, operation is complicated and much time and labor are also required for the operation [0008] Moreover, the above-mentioned methods have such an additional shortcoming that the joining parts of the end parts of the metal plates are difficult to be equally pressed by the tapping screws. When one of the metal plates is tightly screwed, its joining part is lowered than the joining part of the other metal plate and therefore, a step is formed between the left and 5 right joining parts. This makes it difficult to join the end parts of the two metal plates flush. In order to make uniform of the surfaces of the metal plates, a putty is applied to the lower part of the step including a space between the two metal plates. This means much time and labor are required. In addition, the joining trace is visually recognized from the outside, thus deteriorating the outer appearance. [0009] As one attempt to overcome the above-mentioned shortcoming, there is a metal plate repairing method (see, for example, Patent Document 2), in which a predetermined part of the vehicle body of an automobile including the damaged part is removed, an end part of the metal plate is tapered, and an bent part of the tapered part is formed in an R-shape. Then, a repairing member having a larger area than the removed part is prepared, an end part of the repairing member is bent by a suitable repairing tool, this bent part is joined with the back side of the end part of the metal plate by an adhesive agent, a putty is applied in a recess formed between the repairing member and the end part of the metal plate, and then, a coating is applied to the repairing member, the metal plate and the surface of the putty. [0010] This metal plate repairing method has such an advantage that the repairing trace can be prevented from appearance by forming the tapered part into a R-shape. However, since no attention is paid to temperature expansion of the filler, the repairing trace is appeared due to temperature expansion of the filler, for example, in summer, with the result that the outer appearance is deteriorated. Moreover, the above-mentioned repairing method has such an additional shortcoming that since the metal plate is merely joined to the bent part through an adhesive agent, flushness of the metal plate to be joined is 6 difficult to obtain due to irregularity of the dimension of the bent part or the increased/decreased amount of adhesive agent, and the production quality is not uniform. Thus, uniformity and beautiful appearance of thejoining part are difficult to obtain. Particularly, in case the joining part is a complicated and three-dimensionally curved surface, the flushness and uniformity of the joining part are significantly decreased. Thus, improvement is demanded. [0011] In general, a sander is used as putty polishing means adapted to polish a putty filled in a recess formed between a repairing member and an end part of a vehicle body when a damaged part of the vehicle body is repaired, in order to make the putty flush with the surface of the vehicle body in order to facilitate easy coating after the putty is hardened. [0012] Among many such sanders, there is a sander comprising a rough head and a finish head, each head including an endless grinding belt disposed around a pulley and driven for rotation, and a pad unit disposed within the belt, the pad unit comprising a bracket reciprocally movably disposed at the grinding belt, an air cylinder for actuating the bracket, a pad rotatably supported by the bracket and a motor for positioning the pad at a desired angle, the pad including two flat parts which are perpendicular to each other and a curvature surface part disposed at a corner part between the flat parts, the flat part of the pad being selected for a surface-to-be-ground having a flat surface or a convexly curvature surface and the curved surface part being selected for a concavely curved surface, and the surface-to-be-ground being ground by pressing the grinding belt with the selected part (see, for example, Patent Document 3). [0013] However, the above-mentioned belt sander has such a shortcoming that since the curvature of the pad is limited to one kind and such limited 7 pad is linearly moved by the air cylinder and the grinding belt is simply pressed against the surface-to-be-ground, the surface-to-be-ground is formed into a complicated curved surface. Thus, this curvature is unable to cope with the operation for grinding a curved surface part of a vehicle body which is variable in curvature. [0014] In order to overcome the above-mentioned shortcoming, there is another belt sander in which a pad is composed by superimposing two pad main bodies each formed of a flexible elastic material and relatively movably joining them in a longitudinal direction, the pad being held by hand and pressed against a grinding belt to grind a surface-to-be-ground (see, for example, Patent Document 4). [0015] However, the above-mentioned belt sander has such shortcomings. Since the pad is held by hand, the operator is much tired and difficult to work for a long time. Moreover, since the pad main body has flexibility, delicate finger operation is required to maintain the pad main body at a desired curvature. Thus, the operator's finger must withstand a large load and the operator is required to have much experience and skill. [0016] Patent Document 1: Japanese Patent No. 3187782 Patent Document 2: WO No. 00/323 52 Patent Document 3: Japanese Patent Application Laid-Open No. S59 53155 Patent Document 4: Japanese Patent Application Laid-Open No. 2001-300840 [0017] The discussion of documents, acts, materials, devices, articles and the like is included in this specification solely for the purpose of providing a 8 context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application. Throughout the description and claims of this specification, the word "comprise" and variations of the word, such as "comprising" and "comprises", is not intended to exclude other additives, components, integers or steps. SUMMARY OF THE INVENTION [0018] According to one aspect of the present invention, there is provided a method for joining a metal plate comprising arranging two metal plates to be joined such that joining end parts of the metal plates are spaced apart in their thick direction or in a direction orthogonal to the thick direction; arranging a joining piece that is integral with or separate from the metal plate at one side of one joining end part; applying an adhesive to a surface side of the joining piece and arranging the otherjoining end part on the adhesive; placing a single or a plurality of magnetic suckers over a surface of the two joining end parts directly or indirectly before the adhesive is hardened; sucking and displacing the two joining end parts to a surface side by a magnetic force of the sucker, making the surface of the two joining end parts flush, and joining the two joining end parts with the joining piece; the method further comprising: disposing a presser plate which is bendable in a thick direction over the surface of the two joining end parts before the adhesive is hardened; attaching a non-adhesive sheet to a back side of the presser plate and to face the adhesive; placing the magnetic sucker on the surface of the presser plate and intimately attaching the presser plate to the surface of the joining end parts by the magnetic force of the sucker; and sucking and displacing the 9 joining end parts by the magnetic force and making the surface on the side of the two joining end parts flush with respect to the presser plate. [0019] It is preferable that the two surfaces on the side of the joining end parts are made flush so that the two surfaces form a planar surface or a curvature surface. Owing to the foregoing arrangement, various joining surfaces ranging from a flat surface to a complicated curvature surface are made flush. It is also preferable that the presser plate is formed of a member having a small relative magnetic permeability. Owing to the foregoing arrangement, a magnetic force can be transmitted into the presser plate so that the magnetic force is prevented from being attenuated and flushness of the joining surface utilizing a magnetic force is realized. It is also preferable that the presser plate is bendable in the thick direction thereof. Owing to the foregoing arrangement, the presser plate is easily bent along the joining part so that flushness of the curved joining surface is realized. It is also preferable that a plurality of presser plates are disposed over the surface on the other side of joining end parts in adjacent relation. Owing to the foregoing arrangement, bending of the presser plate is promoted and a curved joining surface is easily made flush. It is also preferable that a non-adhesive sheet is attached to a back side of the presser plate. Owing to the foregoing arrangement, the adhesive agent pushed by the metal plate sucked and displaced is prevented from adhering to the presser plate and the metal plate is easily removed. [0020] It is also preferable that a single or plurality of suckers are placed on the presser plate. Owing to the foregoing arrangement, the presser plate is attached in place efficiently and correctly.

10 It is also preferable that the adhesive agent is hardened after the surfaces on the side of the joining end parts are made flush. Owing to the foregoing arrangement, the joining end parts are sucked and displaced surely and the joining end parts are made flush surely. It is also preferable that the presser plate is removed after the surfaces on the side of the joining end parts are made flush and after the adhesive agent is hardened. Owing to the foregoing arrangement, the adhesive agent is filled between the metal plates easily. It is also preferable that a filler is applied between the metal plates on the other side of the joining end parts after the presser plate is removed. Owing to the foregoing arrangement, the surfaces on the side of the joining end parts are maintained flush. [0021] It is also preferable that at least a corner part on the surface side between the metal plates to which the filler is applied is formed in a small curved shape before the filler is applied latest. Owing to the foregoing arrangement, the line of the corner part is prevented from appearance after repair and thus, the joining trace is difficult to be visually recognized. It is also preferable that the filler is preferably as small as possible in linear expansion coefficient. Owing to the foregoing arrangement, the filler is prevented from thermal outflowing due to thermal expansion of the adhesive agent, for example, in summer and thus, the joining trace is difficult to be visually recognized. It is also preferable that the sucker is formed by mounting a magnet block within a housing which is made of a steel plate and having a U-shape in section. Owing to the foregoing arrangement, a concrete construction of the sucker is proposed. It is also preferable that an end edge of the housing projects from an end face of the magnet block. Owing to the foregoing 11 arrangement, a magnetic force is emitted from the end edge efficiently and thus, the sucker is attached in place stably. It is also preferable that a grip part is provided on the sucker. Owing to the foregoing arrangement, the sucker is handled easily. It is also preferable that a plurality of suckers are connected by a handle. Owing to the foregoing arrangement, a plurality of suckers are handled easily. It is also preferable that the metal plate is ground smoothly after the filler is hardened by a sander. Owing to the foregoing arrangement, the surface of the filler is ground easily. [0022] There is also disclosed herein a method for joining a metal plate or the like comprising arranging two metal plates to be joined such that joining end parts of the metal plates are spaced apart in their thick direction or in a direction orthogonal to the thick direction; disposing a joining piece that is integral with or separate from the metal plate at one side of the joining end parts; and joining the joining end parts with a joining piece; and fixing at least one of the metal plates to the joining piece by a machine screw, wherein the machine screw is a tapping screw having a thin head part, the head part of the machine screw is ground after the adhesive agent is hardened and the machine screw remains in the joining end part of the plate member. Owing to the foregoing arrangement, the plate member is temporarily fixed by the tapping screw, and by utilizing the joining strength of the tapping screw, various plate members each made of a metal, nonferrous metal or nonmetal are joined rationally and firmly.

12 [0023] It is preferable that the head part of the machine screw is ground smoothly, and a grinding surface of the head part is made flush with the joining end part. Owing to the foregoing arrangement, the surface of the joining end part is readily subject to coating. It is also preferable that the grinding surface of the head part of the machine screw and the surface of the joining end part are applied with a coating after they are made flush. Owing to the foregoing arrangement, the surface of the joining end part is coated rationally. [0024] There is also disclosed herein a sander comprising a driver and a grinding plate that is operated in association with the driver and capable of holding a grinding sheet, wherein the grinding plate is bendable in a thick direction thereof. Owing to the foregoing arrangement, the grinding plate is easily curved along the curvature surface of the curvature surface-to-be ground to enhance easy grinding. It is preferable that the grinding plate is formed in an elongate shape in the grinding direction and the grinding plate is reciprocally linearly movable in a longitudinal direction thereof. Owing to the foregoing arrangement, the grinding plate is downsized and made light in weight, so that a favorable operability is obtained and a grinding in a small space is realized. It is also preferable that front end part of the grinding plate is pressed, so that the grinding plate is movable along the surface of a part to be ground. Owing to the foregoing arrangement, the grinding plate is workable along the curvature surface of the curvature surface-to-be-ground to enhance easy grinding. It is also preferable that a pivot frame on which the driver can be placed is provided, a pivot lever is pivotably connected to an opposing 13 position of the pivot frame, a holding plate is turnably connected to an end part of the pivot lever in a thick direction thereof and the grinding plate is bendably attached between the holding plates. Owing to the foregoing arrangement, the surface-to-be-ground is ground precisely by displacing the grinding plate in accordance with the surface-to-be-ground. [0025] It is also preferable that the grinding plate can be operated in a longitudinal direction and in a width direction thereof through operation of the pivot lever. Owing to the foregoing arrangement, precise and various grinding surface are obtained, which are met with various grinding directions and various grinding conditions. It is also preferable that the driver part is pivotably provided, and the driving frame and the pivot lever are operatively connected through vibration of the driver part. Owing to the foregoing arrangement, a grinding utilizing vibration is realized. It is also preferable that the driver part projects above the pivot frame so that the driver part can be gripped. Owing to the foregoing arrangement, the sander is enhanced in operability so that the sander is used easily. It is also preferable that the driver part is pressed so that the grinding sheet can be displaced along the surface of a part to be ground. Owing to the foregoing arrangement, various surfaces-to-be-ground are ground easily. EFFECT OF THE INVENTION [0026] A method for joining a metal plate according to one embodiment of the present invention ensures that the joining part of the metal plate is joined flush two-dimensionally or three-dimensionally, so that the joining part can be uniformed and a precise and beautiful outer appearance can be obtained.

14 Since, in one preferable mode of the invention, the two surfaces on the side of the joining end parts are made flush so that the two surfaces form a planar surface or a curvature surface, various joining surfaces ranging from a flat surface to a complicated curvature surface can be made flush. Since, in another preferable mode of the invention, the presser plate is formed of a member having a small relative magnetic permeability, a magnetic force can be transmitted into the presser plate so that the magnetic force is prevented from being attenuated and flushness of the joining surface utilizing a magnetic force is realized. [0027] Since, in still another preferable mode of the invention, the presser plate is bendable in the thick direction thereof, the presser plate is easily bent along the joining part so that flushness of the curved joining surface can be realized. Since, in still another preferable mode of the invention, a plurality of presser plates are disposed over the surface on the other side of joining end parts in adjacent relation, bending of the presser plate can be promoted and a curved joining surface can easily be made flush. Since, in still another preferable mode of the invention, a non adhesive sheet is attached to a back side of the presser plate, the adhesive agent pushed by the metal plate sucked and displaced can be prevented from adhering to the presser plate and the presser plate can easily be removed. [0028] Since, in still another preferable mode of the invention, a single or plurality of suckers are placed on the presser plate, the presser plate can be attached in place efficiently and correctly.

15 Since, in still another preferable mode of the invention, the adhesive agent is hardened after the surfaces on the side of the joining end parts are made flush, the joining end parts can be sucked and displaced surely and the joining end parts can be made flush surely. Since, in still another preferable mode of the invention, the presser plate is removed after the surfaces on the side of the joining end parts are made flush and after the adhesive agent is hardened, the adhesive agent can be filled between the metal plates easily. Since, in still another preferable mode of the invention, a filler is applied between the metal plates on the other side of the joining end parts after the presser plate is removed, the surfaces on the side of the joining end parts can be maintained flush. [0029] Since, in still another preferable mode of the invention, at least a corner part on the surface side between the metal plates to which the filler is applied is formed in a small curved shape before the filler is applied latest, the line of the corner part can be prevented from appearance after repair and thus, the joining trace is difficult to be visually recognized. Since, in still another preferable mode of the invention, the filler is preferably as small as possible in linear expansion coefficient, the filler can be prevented from thermal outflowing due to thermal expansion of the adhesive agent, for example, in summer and thus, the joining trace is difficult to be visually recognized.

16 Since, in still another preferable mode of the invention, an end edge of the housing projects from an end face of the magnet block, a magnetic force can be emitted from the end edge efficiently and thus, the sucker can be attached in place stably. Since, in still another preferable mode of the invention, a grip part is provided on the sucker, the sucker can be handled easily. Since, in still another preferable mode of the invention, a plurality of suckers are connected by a handle, a plurality of suckers can be handled easily. Since, in still another preferable mode of the invention, the metal plate is ground smoothly after the filler is hardened by a sander, the surface of the filler can be ground easily. [0030] [left blank] [003 1] [left blank] [0032] [left blank] [0033] Embodiments of the invention will now be described, by way of example only, with reference to the following drawings. BRIEF DESCRIPTION OF DRAWINGS [0034] FIG. 1 is a front view showing a vehicle having a damaged part at its vehicle body as an object to be repaired, to which an embodiment of the present invention is applied.

17 FIG. 2 is a perspective view showing, on an enlarged scale, an essential part of joining parts, to which an embodiment of the present invention is applied. FIG. 3 is a perspective view showing, on an enlarged scale, an essential part of a repairing state ofjoining parts, wherein a presser plate is arranged on surfaces of the joining plates. FIG. 4 is a perspective view showing, on an enlarged scale, a part of a repairing state of joining parts, wherein suckers are disposed at a presser plate which is arranged on surfaces of the joining end parts. FIG. 5 is a perspective view showing, on an enlarged scale, a sucker which is used for a joining method according to an embodiment of the present invention. [0035] FIG. 6 is a sectional view showing, on an enlarged scale, a part of a repairing state ofjoining parts, wherein, joining end parts ofjoining plates are arranged spaced apart in a thick direction of the joining plates, an adhesive agent is applied between the joining end parts, and a sucker is disposed at a presser plate which is arranged on surfaces of the joining plates. FIG. 7 is a sectional view showing, on an enlarged scale, a part of a repairing state of joining parts, wherein joining end parts of joining plates are arranged spaced apart in a thick direction of the joining plates. FIG. 8 is a sectional view showing, on an enlarged scale, a repairing state of joining parts according to an embodiment of the present invention, wherein joining end parts are arranged spaced apart in the thick direction of the joining plates and the joining end parts are spaced apart in an opposite direct to that of FIG. 7. [0036] FIG. 9 is a sectional view showing, on an enlarged scale, a part of a repairing state ofjoining parts according to an embodiment of the present 18 invention, wherein the joining end parts are arranged spaced apart in a thick direction of the joining plates and one of the joining end parts is formed in an abnormal shape. FIG. 10 is a sectional view showing, on an enlarged scale, a part of a repairing state ofjoining parts according to an embodiment of the present invention, wherein a presser plate disposed at surfaces of the joining end parts is removed and a filler is applied to the clearance. FIG. 11 is a sectional view showing, on an enlarged scale, a part of a repairing state ofjoining parts according to an embodiment of the present invention, wherein the filler filled in the clearance in the surfaces of the joining end parts is ground by a sander. FIG. 12 is a front view showing a sander that is applied to grinding of the filler. FIG. 13 is a plan view of FIG. 12. FIG. 14 is a sectional view showing a using state of a sander that is applied to grinding of the filler. [0037] FIG. 15 is a perspective view showing two metal plates arranged in abutting relation, a presser plate is disposed on surfaces of joining end parts of the metal plates and a sucker is placed on a surface of the presser plate. FIG. 16 is a cross sectional view of FIG. 15. FIG. 17 is a sectional view showing, on an enlarged view, a part of a repairing state of joining parts according to the arrangement, wherein the presser plate of FIG. 16 is removed and a filler is applied to the clearance. FIG. 18 is a sectional view showing, on an enlarged view, a part of a repairing state of joining parts according to the arrangement, wherein the filler of FIG. 17 is ground by the sander. FIG. 19 is a perspective view showing an arrangement, wherein two suckers are connected by a handle.

19 [0038] FIG. 20 is a perspective view showing an arrangement, wherein two plate members are arranged spaced apart, an adhesive agent is applied to back surfaces thereof, a joining piece is superimposed thereon, and a tapping screw is screwed in the back surface thereof so that they are temporarily fixed. FIG. 21 is an enlarged sectional view taken along line A-A of FIG. 20, wherein a flat head part of the tapping screw is ground by the sander and removed. FIG. 22 shows a state that after the head parts of the tapping screws are removed, a filler is applied to the clearance and the surface is made flush and a coating is applied thereto. FIG. 23 is a front view of a sander showing an arrangement, wherein the sander is in a using state. [0039] FIG. 24 is a sectional view showing, on an enlarged scale, a part of FIG. 23, wherein attachment between a pivot frame and a pivot lever and between a holding plate and a grinding plate is shown. FIG. 25 is a sectional view showing, on an enlarged view, a part of FIG. 23, wherein attachment between a pivot frame and a pivot lever and between a holding plate and a grinding plate is shown in detail. DESCRIPTION OF REFERENCE NUMERALS [0040] 2 . metal plate (on the vehicle body side) 4a, 4b, 9 . a fine curve part 5 . metal plate (repair member) 6, 31 . joining piece (joining margin) 20 10 . adhesive agent 12 . presser plate 13 . none-adhesive sheet 15 . sucker [0041] 16 . housing 17 . magnet block 18 ..... grip part 19 . filler 20 . sander 22 . grinding plate 28 . part to be ground 29 . grinding wheel [0042] 32 . handle 34 . tapping screw 34a ..... head part 35 . coating part 36 . pivot frame 37 . driver (vibrator) 39 . pivot lever 21 BEST MODE FOR CARRYING OUT AN EMBODIMENT OF THE INVENTION [0043] One embodiment of the present invention will be described hereinafter with reference to the drawings in which the present invention is applied to a method for repairing a damaged part of a vehicle body of an automobile. In FIGS. 1 through 11, reference numeral 1 denotes an automobile as an object to be repaired, wherein the automobile 1 has a damaged part 3 in an area of a plate member 5 on the side of its vehicle body 22 [Page 22 intentionally left blank] 23 2 which is to be repaired (this side shall be hereinafter referred to as the "to be-repaired side"). To repair the damaged part 3, first, the damaged part 3 is cut into a proper shape using a suitable tool, a periphery of the cut part is bent slantwise inward using a suitable tool (not shown), and a tapered opening surface 4 is formed in its surface. The opening surface 4 is bent to form a step part the height of which is equal to a sum of a thick dimension of the plate member 5 on the to-be repaired side and a coating thick dimension of an adhesive agent which will be described later, and its flat cut part on the end edge side bent generally parallel to the plate member 5 on the repair side to form an adhesive margin 5 which is a jointing piece integral with the plate member 5 on the to be repaired side. R-shaped small bending parts 4a, 4b are formed on an upper surface of the opening surface 4, i.e., on its outward bending part and on its inward bending part, respectively, using the above-mentioned or other tool. [0044] On the other hand, a repair side plate member 7, which is made of a metal plate having the same quality and the same thickness as the to-be repaired side plate member 5 of the vehicle body 2 is prepared, and the repair side plate member 7 is formed into a shape slightly smaller than a shape similar to that of the cut part or into a shape identical with that of a vehicle body part, excluding the cut part, of the damaged part 3. The repair side plate member 7 has a joining margin 8 on its end periphery, which margin 8 is generally equal in thick to the joining margin 6. A tapered opening surface 9 like the tapered opening surface 4 is formed on an end edge of the repair side plate member 7, and R-shaped small bending parts 9a are formed on an upper surface of the tapered opening surface 9 in the same manner as mentioned above.

24 [0045] The shape of the opening surfaces 4, 9 is not limited to a tapered shape. It is also accepted that corner parts on the surface side of the opening surfaces 4, 9 are each formed in a R-shape. It is also accepted that instead of forming the small bending parts 4a, 4b, 9a from beginning, the small bending parts 4a, 4b, 9a are formed before a filler is filled in a clearance 11 which will be described later. Moreover, in this embodiment, a bending part is formed on the to-be-repaired side plate member 5. It is also accepted a bending part is formed on the to-be-repaired side plate member 7. [0046] Then, an adhesive agent 10 is applied to an upper surface of the joining margin 6, the joining margin 8 is superimposed on the adhesive agent 10, the opening surface 4 of the to-be-repaired side plate member 5 on the side of the vehicle body 2 and the opening surface 9 of the joining margin 8 are arranged in opposing relation serving the clearance 11 as an intermediate member, and those states are retained through a presser plate 12 before the adhesive agent 10 is hardened. In this embodiment, an adhesive agent composed of a main agent mainly composed of an epoxy resin and of a hardening agent are used as the adhesive agent 10. [0047] The presser plate 12 used in this embodiment is a metal plate such as a small aluminum plate having a small relative magnetic permeability, or a synthetic resin. The presser plate 12 formed of a metal plate or the like is arranged along a flat surface of the repair side plate member 7 or formed in a bendable thin plate along the curvature surface. A non-adhesive sheet 13 such as a polyethylene film is attached to a back surface thereof An index line 14 is formed vertically in the center of an upper surface of the presser plate 12. By placing the index line 14 in the center of the 25 joining end part between the to-be-repaired side plate member 5 and the repair-side plate member 7, the repair plate 12 can be arranged uniformly left and right.. [0048] As means for bending the presser plate 12 along the curvature surface of the to-be-repaired side plate member 5 or the repair side plate member 7, a plurality of cuts or neck parts (none of them shown) may be formed vertically and laterally, or the presser plate 12 may be formed small in width or small in length and a plurality of such presser plates 12 may be arranged at plural places. [0049] Then, a plural or single number of sucker 15 is disposed on the presser plate 12 over the joining part between the to-be-repaired side presser plate 5 and the repair side presser plate 7. The sucker 15 is comprised of a housing 16 that is made of a steel plate and has a relative magnetic permeability and a magnet block 17 fixed to the inside of the housing 16. The magnet block 17 is formed, for example, of a permanent magnet that is light in weight and has a large magnetic force. The housing 16 is formed by bending a steel plate into a generally U-shape in section. An end edge of a bending piece 16a of the housing 16 is slightly protruded from the magnet block 17 so that a magnetic pole can be formed. Reference character e denotes a protruding amount of the bending piece 16a. In Figure, reference numeral 18 denotes a grip part projecting from the center of the housing 16. The grip part 18 is formed in a generally T shape and capable of holding the sucker 15. [0050] Owing to the above-mentioned arrangement, the sucker 15 is intimately adhered at the end edges of its bending pieces 16a, 16a to the presser plate 12, and the magnetic force emitted from the magnet block 17 26 penetrates the presser plate 12 from the end edges of the bending pieces 16a, 16a and forms a magnetic circuit extending from the to-be-repaired side plate member 5 on the backside of the presser plate 7 and the joining margin 8. During the time the adhesive agent 10 is hardened, the end part of the to-be-repaired side plate member 5 and the joining margin 8 on the back surface side are sucked and displaced by the sucker 15, so that the surfaces of the plate member-to-be-repaired 5 and the joining margin 8 are made flush with respect to the presser plate 12. [0051] Therefore, in case the bending part formed on the joining part of the to-be-repaired side plate member 5 is shallowly bent or a large amount of adhesive agent 10 is applied. so that the joining margin 8 of the to-be repaired side plate member 5 protrudes outward with reference to the to-be repaired side plate member 5 to form a small space S 1 between the to-be repaired side plate member 5 and the presser plate 12 as shown in FIG. 7 for example, the to-be-repaired side plate member 5 is sucked and displaced by the sucker 15 to move in a direction as indicated by arrows, i.e., toward the outer surface, and the joining margin 8 keeps the initial sucking state with the presser plate 12, thereby the surfaces of the to-be-repaired side plate member 5 and joining margin 8 are made flush. As a result, an adhesive layer 10 having a predetermined thickness is formed between the joining margins 6, 8. Thereafter, the adhesive agent 10 is hardened and the surfaces of the to-be-repaired side plate member 5 and the joining margin 8 are kept flush. Moreover, a predetermined adhesive strength can be obtained owing to the adhesive layer 10 having a predetermined thickness. [0052] 27 When the to-be-repaired side plate member 5 is sucked and displaced by the sucker 15, a part of the adhesive agent 10 is pushed into the clearance 11. However, since the adhesive agent 10 contacts the non-adhesive sheet 13 and avoids contact with the presser plate 12, it can be prevented that the presser plate 12 becomes non-removable after the adhesive agent 10 is hardened. Moreover, a part of the adhesive agent 10 is pushed by the end part of the joining margin 6 and the back surface of the plate member-to-be repaired 7 to enhance its adhesive force. However, since they are placed on the back surface of the plate member-to-be-repaired, the outer appearance of the plate members 5, 7 is not deteriorated. [0053] On the contrary, in case, for example, the bending part formed on the joining part of the to-be-repaired side plate member 5 is deeply bent or a small amount of adhesive agent 10 is applied, so that the to-be-repaired side plate member 5 protrudes outward with respect to the joining margin 8 to form a small space S 2 between the joining margin 8 and the presser plate 12 as shown in FIG. 8, the joining margin 8 is sucked and displaced by the sucker 15 in a direction as indicated by arrows, i.e., toward the outer surface side, and the to-be-repaired side plate member 5 keeps the initial sucking state with the presser plate 12, thereby the surfaces of the to-be-repaired side plate member 5 and joining margin 8 are made flush. [0054] Therefore, an adhesive layer 10 having a predetermined thickness is formed between the joining margins 6, 8. Thereafter, the adhesive agent 10 is hardened, the surfaces of the to be-repaired side plate member 5 and joining margin 8 are kept flush, and a predetermined adhesive strength is obtained by the adhesive agent 10 having a predetermined thickness.

28 Even if the to-be-repaired side plate member 5 is sucked and displaced in the manner as mentioned above, adhesion by the adhesive agent 10 is not disturbed unless the amount of application of the adhesive agent 10 is extremely small. [0055] Even in a case where the joining margin 6 and the joining margin 8 are not parallel due to inferior bending work of the joining margin 6 as shown in FIG. 9, the -t-be-repaired side metal plate 5 and the repair side metal plate 7 can be made flush by disposing the presser plate 12 over the entire length of the to-be-repaired side metal plate 5 and the joining margin 8, arranging the sucker 15 thereon and sucking and displacing the -to-be repaired side metal plate 5 and the joining margin 8. By hardening the adhesive agent 10 in that condition, the -to-re-repaired side metal plate 5 and the joining margin 8 can be made flush. [0056] The end part of the joining margin 8 facing the clearance 11 is preferably bent at right angles. By doing so, no burr is formed at the opening surface 9. This facilitates the subsequent operation for removing the presser plate 12 and filling a filler into the clearance 11 because there is no worry for the operator to touch the burr with his fingers and thus, he can carry out the operation safe. [0057] Normally, a plurality of suckers 15 are arranged at predetermined intervals on a single number of presser plate 12 However, in a case where the to-be-repaired side metal plate 5 is not uniformly bent or the adhesive agent 10 is not equal in application amount, the suckers 15 are arranged in place in their proper attitudes so that the to-be-repaired side metal plate 5 and the joining margin 8 are enhanced to be made flush. This state is as shown in FIG. 4.

29 [0058] After the adhesive agent 10 is hardened, the suckers 15 are removed and the presser plate 12 is detached. At that time, since the presser plate 10 is avoided from attachment of the adhesive agent 10 as previously mentioned, the suckers 15 can be removed easily by falling the grip part 15 or by other suitable means. [0059] Thereafter, the filler 19 is filled into the clearance 11. The filler 19 used herein is one having such an adhesive property as an epoxy resin-based filler. The filler 19 is preferably small in linear expansion coefficient, so that temperature expansion and contraction can be reduced as much as possible at the joining part. Particularly, swelling of the filler 19 in summer due to temperature expansion can be prevented and thus, the joining trace can be avoided from appearance. [0060] The filler 19 is initially filled in the clearance 11 in a build-up form as shown in FIG. 10 and the surface of the filler 19 is uniformly ground by the sander 20. The sander 20 is, as shown in FIGS. 12 to 14, comprised of a sander main body 21 and a grinding plate 22. The sander main body 21 is formed in an elongated cylindrical shape. A reciprocating linear movement mechanism and a driving mechanism (none of them shown) which are actuated by compression air are built in the sander main body 21. One end of the sander main body 21 is connected with an air hose 23 connected to a compression air source. One end of a control lever 24 is turnably connected to the outer peripheral surface of the sander main body 21. [0061] In the embodiment, the driving mechanism comprises a mechanism for transforming a rotational movement to a reciprocating linear movement.

30 The driving mechanism is capable of providing a reciprocating linear movement within a range of from 10 to 10 mm. Instead of a compression air, an electric power source may be used as the driving source for this mechanism. [0062] A connection rod 25 having a generally Z-shape projects from the other end of the sander main body 21. A basal end of the connection rod 25 is connected to the driving mechanism so that it can move simultaneously with the driving mechanism. A distal end part of the connection rod 25 is offset downward from the axial direction of the basal end part, thus expanding its shape into a rectangular shape. A retaining plate made of a synthetic resin and having a relatively rigid property is fixed to a distal end part of the distal end part by a machine screw. [0063] The retaining plate 26 is formed in a generally square shape. A basal end of the grinding plate 22 is attached to the retaining plate 26 through a double coated adhesive tape or adhesive agent. The grinding plate 22 is made of a synthetic resin such as a soft vinyl chloride having rich elastic and flexible properties, and it is formed in a laterally long square shape longer than the retaining plate 26. The grinding plate 22 can be bent in its thick direction by pressing its distal end part with a finger and thus, it is bendable in accordance with a curvature surface 28a of the surface-to-be-ground 28. A grinding sheet 29 coated with predetermined abrasive grains is detachably attached to an undersurface of the grinding plate 22 through a face fastener (not shown), so that the grinding sheet 29 can move simultaneously with the grinding plate 22. [0064] 31 Operation for uniformly grinding the surface of the filler 19 using the sander 20 will now be described. After the filler 19 is dried or hardened, the grinding sheet 29 having a predetermined grain size is attached to the undersurface of the grinding plate 22 and the air hose 23 is connected to the compression air source such as an air compressor. Then, the sander main body 21 is held and pressed with the surface of the filler 19, and the distal end part of the grinding plate 22 is lightly pressed with a finger 28 so that the grinding plate 22 or the grinding sheet 29 is disposed along the surfaces or curvature surface contours of the joining margins 6, 8. [0065] Thereafter, the control lever 24 is pressed to feed a compression air to the inside of the sander main body 21, so that the driving mechanism built in the sander main body 21 is actuated to reciprocally and linearly move the connection rod 25 connected to the driving mechanism. Thus, the reciprocating linear movement is transmitted to the grinding plate 22 from the connection rod 25 through the retaining plate 26 and the grinding sheet 29 is moved simultaneously with the retaining plate 26 to ground the surface of the filler 19. During that time, the finger 28 lightly keeps pressing the distal end part of the grinding plate 22, so that the grinding plate 22 or grinding sheet 29 is disposed along the surfaces or curvature surface contours of the joining margins 6, 8 [0066] Since not only the surfaces of the to-be-repaired side plate member 5 and repair side plate member 7 are flat but also the curvature surface 28a as shown in FIG. 14 can be ground, it is not necessary to grind the surfaces by varying the angle as in the conventional method, and the filler 19 can be ground easily and uniformly even by those who are not experts.

32 [0067] In case a part-to-ground of the to-be-ground side plate member 5 or repair side plate member 7 having a concavely curved surface is ground, the grinding plate 22 or the grinding sheet 29 is pressed with the part-to-be ground. Then, the grinding plate 22 is bent against elasticity thereof and its basal end part is supported by the retainer plate 26. Accordingly, the grinding plate 22 can be bent easily at a desired angle. Thus, in case a concavely curved surface of the type just mentioned is ground, the distal end part of the grinding plate 22 is, basically, lightly pressed with the finger 28 to perform a grinding operation along the curved surface contour of the part-to-be-ground. This state is as shown by an imaginary line of FIG. 12. [0068] When the finger 27 is taken off the distal end of the grinding plate 22 after the grinding operation is finished, the grinding plate 22 restores its original linear shape by its elasticity and the grinding sheet is moved simultaneously therewith. When the grinding sheet 29 is worn after long use or when the grinding sheet 29 is required to be replaced with other one having a different roughness, it can be replaced with a desired one by removing a fastener. [0069] The sander can be manually reciprocally moved. In that case, the reciprocating linear movement mechanism and its driving mechanism built in the sander main body 21 may simply be omitted. By doing so, the sander can be made light in weight and decreased in cost, and in addition, operability by hand is enhanced. [0070] After the surface of the filler 19 is ground, a primer surfacer is applied to the surfaces of the joining parts as primer coat and then, a finish coat 33 having the same color as the vehicle body 2 is applied thereon as finish coat after the primer surfacer is dried. By doing so, a series of repairing operations are finished. After repairment, since the joining parts including the grinding part of the filler 19 are repaired in uniformity with the peripheral surface and the curvature surface, the joining parts are felt integral with the periphery. Moreover, since the filler 19 used herein is smaller in linear expansion coefficient that the conventional one, expansion of the filler 19 in summer and contraction of the filler 19 in winter are reduced as much as possible. This makes it possible to prevent the filler 19 from peeling-off and swelling in winter and in summer. Thus, the joining trace is avoided from appearance and uniformity is maintained. [0071] FIGS. 15 to 25 show other embodiments of the present invention. Those parts corresponding to the parts of the above-mentioned embodiment are denoted by identical reference numerals. FIGS. 15 to 18 shows a second embodiment of the present invention. In this second embodiment, instead of arranging the joining parts of the to be-repaired side plate member 5 and the repair side plate member 7 in a superimposing relation in the thick direction, they are arranged in an abutment relation on the same plane through the clearance 11, and the adhesive agent 10 is applied to the back surfaces of them. Then, a joining piece 31 separate from the plate members 5, 7 is superimposed on the back surfaces through the adhesive agent 10. [0072] Before the adhesive agent 10 is hardened, the presser plate 12 is superimposed on the surfaces of the joining end parts of the to-be-repaired side plate member 5 and the repair side plate member 7, and a single or plural suckers 15 are set on the presser plate 12, so that the joining end parts 34 are sucked and displaced by the magnetic force of the suckers 15 and the surfaces of the joining end parts are made flush with respect to the presser plate 12. Accordingly, no tapping crews and no machine screw holes are required contrary to the conventional method. Thus, operation can be carried out easily and rapidly to that extent. Moreover, the surfaces of the joining end parts can be made flush with precision. Thereafter, as in the same manner mentioned above, the suckers 15 are removed, the presser plate 12 is detached, the filler 19 is filled in the clearance 11, and after the filler 19 is hardened, the surface of the filler 19 is ground by using the sander 20. [0073] FIG. 19 shows a third embodiment of the present invention. In this third embodiment, two suckers 15 are connect to each other through a handle 32 having a generally U-shape, so that the suckers 15 can be attached and detached easily. The suckers 15 are connected to each other with an interval slightly larger than the opening width of the clearance 11, so that they can cope with various joining end parts of the to-be-repaired side plate member 5 and the repair side plate member 7. [0074] FIGS. 20 to 22 show a fourth embodiment of the present invention. This fourth embodiment relates to a method for temporarily fixing the joining end parts of the to-be-repaired side plate member 5 and the repair side plate member 7 by using the adhesive agent 10 and the joining piece 31 during the time the adhesive agent is hardened. A plurality of like machine screw holes 33 are formed in the joining end parts of the plate members and joining piece 31 in the vertical direction. For temporarily fixing the joining 35 end parts, tap screws are screwed in the corresponding machine screw holes 33. Accordingly, the plate members 5, 7 can be applied to joining of not only metal plates but also various other plate members such as nonferrous metal plates and nonmetal plates. [0075] A head part 34a of each tapping screw 34 is flat. A slit or an engagement groove engageable with a tool (not shown) is formed in an outer surface of the head part 34a. The thickness of the head part 34a is about 1 mm or less. [0076] Operation for temporarily fixing the joining end parts of the to-be repaired side plate member 5 and the repair side plate member 7 by using the tapping screws 34 will now be described. The adhesive agent 10 is applied to the back surfaces of the joining end parts and the joining piece 31 is superimposed thereon Then, the machine screw holes 33 are position aligned and the tapping screws 34 are screwed in the corresponding machine screw holes by using a proper tool. [0077] After the adhesive agent 10 is hardened, a belt sander or the above mentioned sander is pressed with the head part 34a to sand off the head part 34a by actuating the sander. The head part 34a is formed very thin to facilitate easy temporary fixture of the two plate members 5, 7, and the thin head part 34a is sanded off rapidly by the sander. Thus, friction heat created by the sander is not accumulated in the two plate members 5, 7 nor in the threaded shaft of the tapping screw 34. In addition, the cutout part can be formed flush with the surfaces of the plate members 5, 7. This state is as shown in FIG. 21. [0078] 36 Thereafter, a primer surfacer is applied to the surfaces of the plate members as primary coat. After the primary surfacer is dried, a coating material 35 having the same color as the vehicle body 2 is applied to the top of the primary surfacer. By doing this, a series of repairing operations are finished. Thus, it is no more required to fill a filler or adhesive agent in the machine screw holes 33 contrary to the conventional method. Moreover, the tapping screws 34 are left remained in the two plate members 5, 7 of the joining parts and thus, the joining stress with the joining piece 31 is increased. [0079] FIGS. 23 to 25 show a fifth embodiment of the present invention. This fifth embodiment relates to an improvement of the sander 20, in which instead of pressing the distal end part of the grinding plate 22 by the finger 27, sanding operation is carried out while gripping the upper part of the sander 20. Specifically, the sander 20 is comprised of a pivot frame 36 having a generally U-shape, a vibrator 37 which is formed in a generally cylindrical shape for easy gripping and which is placed on the pivot frame 36, and a turbine (not shown) actuated by a compression air and disposed at the inside of the vibrator 37. The sander 20 is pivoted and vibrated spherically by the turbine. [0080] An upper part of a pivot lever 39 is turnably and pivotably connected to a pair of bending pieces 36a of the pivot frame 36 through a universal joint 38, and a square retaining plate 26 is vertically tumably connected to a lower end part of the lever 39 through a pin 40. The connection position is distributed on a two-to-one basis (LI : L2= 2 : 1) inward and outward along the longitudinal direction of the retaining plate 26. A grinding plate 22 and 37 a grinding sheet 29 are attached between the retaining plates 26, 26 such that they can be bent and moved simultaneously. [0081] Operation for grinding the surface of the filler 19 with the sander 20 will be described. The sander 20 is moved to a desired position by gripping the vibrator 37 and the grinding sheet 29 is pressed and abutted with a part to-be-ground 28 in such a manner as to enclose the surface of the filler 19. Then, the retaining plates 26, 26 are turned about the pin 40 along the surface contour of the part-to-be-ground 28, the grinding plate 22 between the retaining plates 26, 26 is gently bent and the grinding sheet 29 is bent simultaneously with the grinding plate 22. [0082] Under such conditions, when a compression air is fed to the vibrator 37, the vibrator 37 is pivoted and vibrated spherically, the pivot frame 36 and the bending piece 36a are moved simultaneously therewith, and the pivot lever 39 is turned and pivoted spherically about the universal joint 38. Thus, the retaining plates 26, 26 are pivoted in the longitudinal direction and in the width direction, and the grinding plate 22 and the grinding sheet 29 are moved simultaneously therewith to grind the surface of the filler 19 in multi-directions. Accordingly, since the operator may simply grip and lightly press the vibrator 37, the labor-load can be reduced. Moreover, since the sander 20 is not required to be moved forward and backward, operation can be carried out easily and rationally, and the surface of the filler 19 can be ground with precision by the grinding sheet 29 moving in multi-directions. [0083] In the above-mentioned case, when the grinding sheet 29 grinds the surface of the swelling of the filler 19, an upward-directing force is acted on the retaining plate 26 inside the pivot position and a downward-directing 38 force is acted on it outside the pivot position. The downward-directing force corresponds to twice of the upward-directing force due to the above mentioned distribution ratio, and this downward-directing force presses the surface of the swelling of the filler 19. Accordingly, in spite of that the retaining plate 26 outside the pivot position is 1/2 in its surface area than the retaining plate 26 inside the pivot position, a uniform grinding operation can be made. INDUSTRIAL APPLICABILITY [0084] As discussed above, a metal plate, or the like, joining method and a sander according to the present invention are particularly suited to be used for joining ajoining part or repairing part of a plate member having a complicated curvature surface flush in a two- or three-dimensional manner, finishing the same precisely and beautifully, and a joining operation of this type can be carried out rationally and easily. Thus, the invention is suited to be used for repairing, for example, a damaged part of a metal plate of a vehicle body or a damaged part of a peripheral wall of a building, machine or the like, which is made of a nonferrous metal or a nonmetal.

Claims

1. A method for joining a metal plate comprising arranging two metal plates to be joined such that joining end parts of the metal plates are spaced apart in their thick direction or in a direction orthogonal to the thick direction; arranging a joining piece that is integral with or separate from the metal plate at one side of one joining end part; applying an adhesive to a surface side of the joining piece and arranging the other joining end part on the adhesive; placing a single or a plurality of magnetic suckers over a surface of the two joining end parts directly or indirectly before the adhesive is hardened; sucking and displacing the two joining end parts to a surface side by a magnetic force of the sucker, making the surface of the two joining end parts flush, and joining the two joining end parts with the joining piece; the method further comprising: disposing a presser plate which is bendable in a thick direction over the surface of the two joining end parts before the adhesive is hardened; attaching a non-adhesive sheet to a back side of the presser plate and to face the adhesive; placing the magnetic sucker on the surface of the presser plate and intimately attaching the presser plate to the surface of the joining end parts by the magnetic force of the sucker; and sucking and displacing the joining end parts by the magnetic force and making the surface on the side of the two joining end parts flush with respect to the presser plate. 40

2. A method according to claim 1, wherein the two surfaces on the side of the joining end parts are made flush so that the two surfaces form a planar surface or a curvature surface.

3. A method according to claim 1, wherein the presser plate is bendable due to a plurality of cuts formed at an end part thereof.

4. A method according to claim 1, wherein the presser plate is formed small in length and a plurality of the presser plates are arranged over the surface of the two joining end parts.

5. A method according to claim 1, wherein the presser plate is flexible and magnetically permeable.

6. A method according to claim 5, wherein the presser plate is an aluminum or a synthetic resin.

7. A method according to claim 1, wherein the presser plate has a low relative magnetic permeability.

8. A method according to claim 1, wherein a width of the presser plate is identical with a length of the two joining end parts.

9. A method according to claim 1, wherein a width of the presser plate is longer than a length of a housing of the sucker.

10. A method according to claim 1, wherein the presser plate has an index line vertically in the center of an upper surface and the index line is placed in the center of the two joining end parts. 41

11. A method according to claim 1, wherein a plurality of presser plates are disposed over the surface of the two joining end parts in adjacent relation.

12. A method according to claim 1, wherein the presser plate is removed after the surface of the two joining end parts are made flush and after the adhesive is hardened.

13. A method according to claim 12, wherein a filler is applied between the joining end parts after the presser plate is removed.

14. A method according to claim 1, wherein the joining part of a first metal plate is sucked and displaced toward the surface by magnetic force of the sucker and the surfaces of two metal plates are made flush with respect to the presser plate when the joining piece, which is integrally formed by bending the joining end part of the first metal plate, is shallowly bent or when a space is formed between the presser plate and the first metal plate by applying a large amount of adhesive between the joining piece and the joining end part of the second metal plate.

15. A method according to claim 1, wherein the joining part of a second metal plate is sucked and displaced toward the surface by magnetic force of the sucker and the surfaces of two metal plates are made flush with respect to the presser plate when the joining piece, which is integrally formed by bending the joining end part of the first metal plate, is deeply bent or when a space is formed between the presser plate and the second metal plate by applying a small amount of adhesive between the joining piece and the joining end part of the second metal plate. 42

16. A method according to claim 1, wherein the joining end part of the second metal plate is inwardly bent at right angles, the presser plate is attached over the surfaces of the joining part of the first and the second metal plates, and the surfaces of two metal plates are made flush with respect to the presser plate by magnetic force of the sucker when the joining piece, which is integrally formed by bending the joining end part of the first metal plate, is not properly bent and is not parallel to the joining end part of the second metal plate.

17. A method according to claim 1, wherein the presser plate is removed after a filler is hardened, a grinding sheet is attached to a grinding plate which is bendable in the through-thickness direction, and the surface of the filler is ground by reciprocating linear drive.

18. A method according to claim 17, wherein the grinding sheet is disposed along the surfaces or curvature surface of the joining part of the metal plate by pressing the end of the grinding plate with fingers.

19. A method according to claim 17, wherein the grinding sheet moves with the vibrator in a through-thickness direction and a longitudinal direction of the grinding sheet to ground the surface of the filler.

20. A method according to claim 19, wherein the vibrator is held and the grinding sheet is pressed into contact with a part-to-be-ground for grinding.

21. A method for joining a metal plate substantially as hereinbefore described with reference to the accompanying drawings.