Method and apparatus for producing battery pack
AssigneePanasonic Corporation
InventorsYoshio Goda, Yoshinori Koyanagi
Life of this patent
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Abstract
A tensile stress is applied to solidified resin. The tensile stress is so small that the solidified resin formed in the sprue by solidification of molding material does not break and is so large that the solidified resin formed in the sprue is separated from the inner surface of the sprue due to a reduction in the diameter of the cross sectional area thereof. For the application of such a tensile stress, the runner stripper plate holding the solidified resin is moved away from the nozzle and sprue bushing. This state is maintained for a predetermined time to separate the solidified resin from the inner surface of the sprue.
Claims18
A method for producing a battery pack, comprising a step (a) of forming a molded part between an end face of a secondary battery on a seal plate side and a circuit board disposed so as to face the end face thereof, to produce a battery pack intermediate product comprising the secondary battery and the circuit board which are joined integrally,
- wherein the step (a) includes:
- a step (b) of bringing a nozzle into contact with a molding material injection inlet of a mold for forming the molded part, the nozzle being provided for feeding a molding material comprising a resin of polyamide adhesive or polyurethane adhesive to the mold;
- a step (c) of, after the formation of the molded part, moving the nozzle away from the molding material injection inlet to cut off, from the nozzle, solidified resin that is formed by solidification of the molding material in a runner system of the mold connected to the molding material injection inlet;
- and
- a step (d) of applying a predetermined tensile stress to the solidified resin and maintaining this state for a predetermined time to separate the solidified resin bonded to an inner surface of the runner system therefrom, the step (d) being performed as a pretreatment for the step (c);
- wherein the runner system comprises a sprue connected to the molding material injection inlet and a plurality of runners branching off from the sprue,
- the step (d) is a step of separating solidified resin formed in the sprue by solidification of the molding material and bonded to an inner surface of the sprue therefrom, and
- the step (d) is performed by moving a sprue bushing having the sprue and the nozzle away from a runner stripper plate holding solidified resin formed in the runners by solidification of the molding material for a predetermined distance, and maintaining this state for a predetermined time.
An apparatus for producing a battery pack, the battery pack production comprising forming a molded part between an end face of a secondary battery on a seal plate side and a circuit board disposed so as to face the end face thereof, to produce a battery pack intermediate product comprising the secondary battery and the circuit board which are jointed integrally,
- the apparatus comprising:
- a plurality of nozzles capable of moving forward and backward in predetermined directions, each of the nozzles being provided for feeding a molding material comprising a resin of polyamide adhesive or polyurethane adhesive to one or more cavities for forming the molded part;
- a cavity plate provided in the direction the nozzles move forward, the cavity plate having the cavities and runners communicating with the cavities;
- a sprue bushing provided between each of the nozzles and the cavity plate, the sprue bushing having a sprue therethrough corresponding to each of the nozzles, the sprue communicating with the runners, the sprue having at one end an opening against which the nozzle is to be pressed,
- a bushing holder provided between the sprue bushings and the cavity plate, the bushing holder capable of moving forward and backward in directions parallel to the directions in which the nozzles move forward and backward, the bushing holder holding the sprue bushings in such a manner that the sprue bushings are capable of moving toward and away from the nozzles in the directions;
- means for biasing the respective sprue bushings from the bushing holder toward the nozzles;
- and
- a runner stripper plate provided between the sprue bushing holder and the cavity plate, the runner stripper plate capable of moving between a molding position for forming the molded parts, in which position the runner stripper plate closely adheres to the cavity plate, and a cut-off position which is a predetermined distance away from the molding position toward the nozzles, the runner stripper plate being configured to move from the molding position to the cut-off position while holding solidified resin formed in the runners by solidification of the molding material, thereby cutting off the solidified resin forted in the runners from the molded parts,
- wherein the runner stripper plate holding the solidified resin is moved away from the nozzles and the sprue bushings, so as to apply a tensile strength that is small so as not to cause breakage of solidified resin formed in the sprues by solidification of the molding material and that is so large as to separate the solidified resin formed in the sprues from inner surfaces of the sprues due to a reduction in the diameter of the cross sectional area of the solidified resin, and this state is maintained for a predetermined time.
Dependencies are inferred from the claim text.