1. Field of Invention
This invention relates to a system for manufacturing an instrument panel which is primarily used in the interior construction of an automobile.
2. Description of the Relevant Art
In general, an instrument panel is constructed such that a foamed resin of polypropyrene or the like is placed between a hard core material (aggregate) of ABS resin or the like and a soft covering material such as polyvinyl chloride. In a conventional manufacturing process for such an instrument panel, beads of a foaming resin material are filled in a space between the core member and the covering material when formed, and are then heated and foamed. Due to this process, the prior art has various attendant problems in as much as a longer period of operation is required for making a foamed resin, and further, irritating gas is produced when the resin is foamed. In order to resolve such problems, proposals have been made by the present applicants in Japanese Patent Laid-Open No. 54-144, 478.
In the aforesaid known system a composite sheet having a semi-hard covering material and a foamed sheet adhered to each other in advance is cut to a desired length of a unit sheet and the unit sheet is guided to the heating station where it is heated to its softening point, thereafter the heated unit sheet is fed to the forming station where it is pressed against the core member set on the lower die in advance, through adhesive, and then finally it is pressed between the upper and lower dies. Further, in this prior art system of manufacturing an instrument panel, endless conveying chains are arranged to run through the feeding, heating and forming stations, respectively, and during this passage of the sheet panel, the sheet is spiked by some needles formed on the running chain the conveyed through each of the stations in sequence while being spiked. Due to this operational arrangement, the sheet should be conveyed through each of the stations with its positional relation to each of them being retained therein, and thus an independent processing of the sheet in each of the stations cannot be performed. Because the conveying chains pass through the heating station, they are always required to be cooled thus influencing the durability of the conveying chains. Further, an arrangement of the conveying chains in the forming station causes problems in that a sheet forming process is restricted and the like. With such arrangement as set forth above, two devices, one for drying the adhesive applied to the surface of the core member and the other for additionally heating the dried adhesive to melt it, are installed for processing the core member before the forming of the sheet material due to different temperature conditions therebetween.
Due to this fact, an additional process for taking the core member from the drying device and transferring it to the melting device is required, and the area occupied by these devices is excessive, resulting in a decreased efficiency of the entire system. Further, because the heater, etc. should be arranged for each of the devices, the prior art system has the problem that a desirable thermal efficiency cannot be retained.
Further, in such a prior art system, the feeding station has a suction device for sucking the unit sheet cut to a desired length and a bogie device for transferring said unit sheet to the subsequent heating station at respective different locations. Due to this fact, an operation required for transferring the unit sheet to the bogie additionally requires time for transferring the sheet from the suction device to the bogie device, and further occupies an excessively large area the feeding station.
Further, in such a prior art system, problems arise in that the conveying chains themselves cannot be lifted up and down, and alternatively the upper and lower dies are required to be moved up and down and the lower die should be movable, resulting in a complex and large-sized device.
In the forming station, in order to set the core member on the lower die, an operator sets the core member while he enters a space between the dies and also in case of taking out the formed product of the instrument panel upon completion of the forming process, the product is pushed up by the ejector and the operator enters the space between the dies to take the product. Therefore, this is undesirable in view of workability and safety of the operator.
The present invention effectively overcomes the above problems found in a conventional type of an instrument panel manufacturing system as described above.