Vertical type forming, filling and closing machine for flexible package

A vertical type forming, filling and closing machine for a flexible bag for filling a fluid substance discharged from an injection nozzle to a predetermined height into a bag and packaging the same, comprising:

• an injection nozzle having a discharging opening for filling a bag with a fluid substance;
• upper surface height detecting means for detecting the height of the upper surface of the fluid substance filled in the bag;
• a cylinder connected to said injection nozzle for moving said injection nozzle upwardly and downwardly;
• and
• a controlling apparatus for controlling said cylinder in response to the result of detection of said upper surface height detecting means to move said injection nozzle upwardly or downwardly during filling;
• said controlling apparatus controlling said cylinder so that the discharging opening of said injection nozzle is always buried, during filling, to a predetermined level from the upper surface of the fluid substance filled in the bag.