Insert piece for inserting into a rapid connector device for fluid lines

A system for connecting fluid lines, comprising:

• a quick-action connector device having an entry opening and an inner wall extending from the entry opening into the quick-action connector device;
• a fluid line having an end piece;
• and
• an insert piece comprising:
• a hollow-cylindrical main body, wherein the hollow-cylindrical main body:
• extends along a cylinder axis between
• a front ring surface and
• a rear ring surface,
• has a passage opening extending along the cylinder axis, and
• has an outer lateral surface arranged in a depression arranged on the inner wall of the quick-action connector device such that the insert piece is arranged on the inner wall by way of the outer lateral surface,
• wherein the passage opening has a passage section which widens in the direction of the front ring surface,
• wherein the passage opening extends through the entire hollow-cylindrical main body and connects a ring opening of the front ring surface to a ring opening of the rear ring surface,
• wherein the passage section has a rounded edge on the front ring surface,
• wherein the hollow-cylindrical main body has a bevel which extends in a ring-shaped manner around the passage section and which delimits the passage section radially at the hollow-cylindrical main body,
• wherein the bevel is a surface defining the passage section at the hollow-cylindrical main body,
• wherein the bevel converges conically from the front ring surface to a section of the passage opening arranged outside the bevel,
• wherein, when the fluid line is introduced into the quick-action connector device, the end piece of the fluid line is arranged on the bevel of the insert piece by way of an upper surface of the fluid line,
• wherein, upon contact with the insert piece, the end piece of the fluid line transmits a force to the insert piece,
• wherein the contact between the end piece of the fluid line and the insert piece is realized at the rounded edge, and
• wherein the end piece has an outer diameter whose magnitude is between a maximum diameter at the passage section and a minimum diameter of the passage opening.