| 摘要 |
<p>The present invention relates to a hot press to manufacture a substrate in which a printed circuit is provided. The hot press comprising at least one of vertically movable heating plates, a freely elevating movable platen which elevates the heating plates to press a plate to be treated between the heating plates, and a detecting means for detecting the movement of the uppermost heating plate when said uppermost heating plate starts to be elevated, in which the elevating speed of the movable platen is changed to lower speed by the signal generated from the detecting device. This low speed control is carried out as follows. Relief valves and direction control valves are provided at a primary side and secondary side, respectively, of a clamping cylinder into which a ram for elevating the movable platen is insertedm and due to the difference of pressures between the primary and secondary sides of the clamping cylinder, it is made possible to successively change the clamping force from zero by elevating the ram at low speed, whereby giving an optional clamping force to the ram.</p> |
