Heat treatment apparatus, useful for hardening and tempering sheet metal parts made of steel, comprises a hardening device operated with a coolant for rapidly cooling sheet metal parts, which are heated to an austenitizing temperature

摘要

The heat treatment apparatus comprises a hardening device operated with a coolant for rapidly cooling sheet metal parts (25), which are heated to an austenitizing temperature. The hardening device comprises receiving surfaces that are formed at outer sides of the sheet metal parts, and cooling channels, which are passed through the coolant. Throttle elements are arranged immediately before or in the hardening device, and are connected with the cooling channels directly or via internal coolant lines. The coolant is present in gaseous state under normal conditions of 0[deg] C and 1013.25 hPa. The heat treatment apparatus comprises a hardening device operated with a coolant for rapidly cooling sheet metal parts (25), which are heated to an austenitizing temperature. The hardening device comprises receiving surfaces that are formed at outer sides of the sheet metal parts, and cooling channels, which are passed through the coolant. Throttle elements are arranged immediately before or in the hardening device, and are connected with the cooling channels directly or via internal coolant lines. The coolant is present in gaseous state under normal conditions of 0[deg] C and 1013.25 hPa. The hardening device further comprises two bodies that are arranged between the sheet metal parts. The coolant flows into the throttle element with an excess pressure. The cooling channel is bounded into a closed cooling circuit. The closed cooling circuit comprises first and second pressure reservoirs, a compressor, and a heat exchanger. The first and second pressure reservoirs are operable as the heat exchangers. A flow direction of the coolant is switchable in the cooling circuit. The cooling channel is formed as an open cooling channel and bounded into the open cooling circuit, which is equipped with a collection container. The hardening device is formed as shaping device, which comprises a lower forming tool (22) and an upper forming tool (21). The forming tools are mounted on a pressing carrier. The cooling channel is arranged into the body of the forming tools. The apparatus further comprises a first apparatus for hardening a sheet metal part, and a second apparatus for tempering the sheet metal parts hardened in the first apparatus. An independent claim is included for a method for hardening sheet metal parts made of steel.