The present invention relates to a novel welding method using a heating plate and a welding apparatus using a heating plate, and more particularly to a technique with which two synthetic resin parts supported by upper and lower jigs are previously heated by a heating plate and pressing and welding the two synthetic resin parts and which enables tact time to be shortened.
As a means for joining two synthetic resin parts to each other, a welding method using a heating plate is known. The foregoing method has steps for preparing one pair of jigs, that is, an upper jig and a lower jig; making two synthetic resin parts, which must be joined to each other, supported by the corresponding jigs; heating the synthetic resin parts by a heating plate; making the two jigs approach each other in order to press joining portions of the two supported synthetic resin parts against each other so that the pressed portions are welded to each other.
The schematic structure of the foregoing welding method using a heating plate is shown in FIGS. 1 to 6.
An upper jig 2 and a lower jig 3 are disposed in a working region 1 so as to be joined to corresponding elevating means (not shown). Moreover, a heating plate 5 is disposed in a heating-plate standby region 4. The heating plate 5 is previously heated in the heating-plate standby region 4. Then, synthetic resin parts 6 and 7 are supported by the jigs 2 and 3, respectively (see FIG. 1).
Then, the heating plate 5 is moved to the working region 1 so as to be disposed between the upper jig 2 and the lower jig 3 separated from each other in the vertical direction (see FIG. 2).
Then, the upper jig 2 and the lower jig 3 are moved to approach each other, and then the synthetic resin parts 6 and 7 supported by the jigs 2 and 3 are brought into contact with the heating plate 5 (see FIG. 3). Thus, the synthetic resin parts 6 and 7 are heated.
After the synthetic resin parts 6 and 7 have sufficiently be heated, the jigs 2 and 3 are separated from each other in the vertical direction. Moreover, the heating plate 5 is returned to the heating-plate standby region 4 (see FIG. 4).
Then, the upper and lower jigs 2 and 3 are moved to approach each other, and the joining portions of the synthetic resin parts 6 and 7 are pressed with melted and joined against each other (see FIG. 5).
Finally, the upper and lower jigs 2 and 3 are separated from each other in the vertical direction to extract the joined synthetic resin parts 6 and 7 (see FIG. 6) left on the lower jig 3. Thus, the welding operation is completed.
The welding operation using the heating plate is performed as described above. In the conventional method, a working region a and a heating-plate standby region b are arranged as shown in FIG. 14. That is, a very simple arrangement has been employed in which the heating-plate standby region b is disposed at a deep position as compared with the working region a.
In an actual manufacturing site, plural types of products, not only one type of products, are manufactured. Therefore, one welding apparatus using a heating plate is operated to perform welding of parts of a plurality of products. If parts of a next product are welded after parts of one product have been welded, the jigs and the heating plate must be changed to those for the parts of the next product.
Hitherto, the following process must be performed such that the jigs 2 and 3 and the heating plate 5 for use to weld the parts of the previous product are removed from the working region a and the heating-plate standby region b by an operator c so as to be moved to a storage portion by using a carrier car or the like. Then, jigs 2 and 3 and the heating plate 5 for use to weld the parts of a next product are carried by similarly using the carrier car so as to be disposed in the working region a and the heating-plate standby region b. The foregoing operation is a complicated operation. Moreover, the heating plate 5 must be joined to a predetermined position of the heating-plate standby region b before the heating operation is started. Since a long time is required to heat the heating plate 5, a wasteful operating time cannot be omitted.
In view of the foregoing, an object of the present invention is to improve the working efficiency and shorten tact time.
To overcome the foregoing problems, according to the present invention, there is provided a method of welding a plurality of parts comprising the steps of: setting a first and second jigs in a working region; putting the first and second jigs in a standby position; moving the heating plate corresponding to the first and second jigs and previously heated from a heating-plate stocker adjacent to a heating-plate standby region to the heating-plate standby region during setting the first and second jigs in the working region, and the parts supported on the first and second jigs in a working standby condition; heating the parts supported on the first and second jigs with the heating plate after moving the heating plate to the working region; welding the heated parts after removing the heating plate from the working; and conveying the heating plate from the heating-plate standby region and conveying the first and second jigs from the working region.
The welding method using a heating plate according to the present invention has the step for moving the heating plate corresponding to the jig and previously heated from a heating-plate-stocker disposed adjacent to a heating-plate standby region to the heating-plate standby region during a period of time for introducing the upper and lower jigs into the working region and putting the jigs on operation standby.
Therefore, a welding step using the heating plate can immediately be started after the jigs have been put on operation standby. Therefore, the working efficiency can be improved and the tact time can be shortened.
To overcome the foregoing problems, there is provided an apparatus for welding a plurality of parts comprises a plural pairs of jigs, a plurality of heating plates, a working region, a heating-plate stocker, a heating-plate standby region, and a heating-plate slider. The pairs of jigs supports a plurality of parts, and each pair of the jigs has a shape different from another pair of the jigs. The heating plates respectively correspond to each pair of the jigs. The working region is for welding the parts with the jigs and the heating plates. The heating-plate stocker stocks and heats the heating plates. The heating-plate standby region is for standing by for moving the heating plates with heating between the working region and the heating-plate stocker. a heating-plate slider is for sliding the heating plates between the heating-plate standby region and the heating-plate stocker.
Therefore, the welding apparatus using a heating plate according to the present invention has the structure that the heating-plate stocker is disposed adjacent to the heating-plate standby region and the heating-plate is moved from the heating-plate stocker to the heating-plate standby region by the sliding means. Therefore, change of the heating plates can be quickly performed. Hence it follows that the working efficiency can be improved and the tact time can be shortened.