Accumulation type fuel injection system for engine

In an accumulation type fuel injection system for an internal combustion engine, a common rail (1) is formed with an accumulation chamber (22) inside a peripheral wall portion (21) so that a central axis of the accumulation chamber (22) is deviated from that of the common rail (1), which has a cross section in the shape of a complete round. Thus, a thick wall portion having thicker wall than other portion of the peripheral wall portion (21) is formed in the peripheral wall portion (21). A plurality of pipe connecting portions (25, 26) is formed radially inside the thick wall portion. A plurality of pipe connectors is formed separately from the common rail (1) and is connected to the common rail (1) at the pipe connecting portions (25, 26). As a result, machining of an outer periphery of the common rail (1) is simplified.