Temperature control fluid supply system for injection tools used to produce CDs and DVDs has fluid channels to the cavity area fed by branch lines including separately controlled valves

摘要

Channels(28,30,32,34) close to both sides of the molding cavity(16) form an independent temperature control circuit for the cavity area and are connected with branch lines(80,82;88,90) of the supply and return lines(64,70) of the temperature control flow circuit. Separately controllable valves(84,86) are located in the branch lines(80,82) of the feed line(64) or the return line(70). A balancing valve(76) between the feed and return lines opens and closes in opposition to the valves in the part lines. In parallel with the balancing valve(76) between the supply(64) and return(70) of the fluid circuit(36,48,64,70) there is a connecting line(66) with a throttle(68). A heater(42) and/or a heat exchanger(38) for cooling the fluid are included in the circuit. Feed lines(92,94) branch off from the feed of the inner circuit and run to channels(20,22,24,26) controlling overall tool temperature of the tool. Outlets(24,26) from the latter channels are connected via return lines(112,114) with the return side of the main flow circuit. Each return line is connected directly to the appropriate feed line(92,94) via lines(120,122) containing heaters(124,126). A circulating pump(62) is positioned upstream from the branch lines(80,82) on the feed side.