Primary piston assembly for a master brake cylinder of a braking system of a vehicle, manufacturing method for a braking unit, and method for operating a braking unit

A braking unit for a braking system of a vehicle, comprising:

• an input rod;
• a master brake cylinder that is fillable with liquid;
• and
• a primary piston assembly that includes:
• a first primary piston component that includes a first piston element to which is transmittable a driver braking force generated by the input rod, to thereby move the first piston element in a manner that the first piston element reduces a pressure chamber volume of a pressure chamber of the master brake cylinder;
• and
• a second primary piston component that includes a second piston element that is movable under a force towards the pressure chamber in a manner that the second piston element reduces the pressure chamber volume of the pressure chamber;
• wherein:
• the first primary piston component and the second primary piston component are arranged relative to each other such that:
• when the second piston element is moved in the manner that the second piston element reduces the chamber volume of the pressure chamber, the first piston element is also movable in the manner that the first piston element reduces the chamber volume of the pressure chamber;
• and
• when the driver braking force is transmitted to the first piston element, the first piston element is movable in the manner that the first piston element reduces the chamber volume of the pressure chamber without applying any force to the second piston element in a direction towards the pressure chamber and without effecting any movement of the second piston element in the manner that the second piston element reduces the chamber volume of the pressure chamber;
• and
• at least one of:
• an end face of the second primary piston component that faces the chamber forms a first portion of a boundary wall of the chamber and an end face of the first primary piston component that faces the chamber forms a second portion of the boundary wall of the chamber;
• a portion of the second primary piston component that is nearest to the chamber is housed within an interior of a portion of the first primary piston component that is nearest to the chamber;
• and
• (i) the braking unit further comprises a booster rod and an at least partially elastic force transmission component, (ii) the input rod is arranged to transmit the driver braking force to the at least partially elastic force transmission component, (iii) the first primary piston component contacts the at least partially elastic force transmission component in such a way that the driver braking force is transmittable to the first primary piston component, and (iv) the booster rod (a) contacts the second primary piston component to apply to the second primary piston component the force towards the pressure chamber by movement of the booster rod, and (b) contacts the at least partially elastic force transmission component to apply to the first primary piston component the force towards the pressure chamber by movement of the booster rod.

A braking system for a vehicle, comprising:

• at least one brake circuit;
• and
• a braking unit including:
• an input rod;
• a master brake cylinder that is fillable with liquid;
• and
• a primary piston assembly, the primary piston assembly including:
• a first primary piston component that includes a first piston element to which is transmittable a driver braking force generated by the input rod, to thereby move the first piston element in a manner that the first piston element reduces a pressure chamber volume of a pressure chamber of the master brake cylinder;
• and
• a second primary piston component that includes a second piston element that is movable under a force towards the pressure chamber in a manner that the second piston element reduces the pressure chamber volume of the pressure chamber;
• wherein:
• the first primary piston component and the second primary piston component are arranged relative to each other such that:
• when the second piston element is moved in the manner that the second piston element reduces the chamber volume of the pressure chamber, the first piston element is also movable in the manner that the first piston element reduces the chamber volume of the pressure chamber;
• and
• when the driver braking force is transmitted to the first piston element, the first piston element is movable in the manner that the first piston element reduces the chamber volume of the pressure chamber without applying any force to the second piston element in a direction towards the pressure chamber and without effecting any movement of the second piston element in the manner that the second piston element reduces the chamber volume of the pressure chamber;
• and
• at least one of:
• an end face of the second primary piston component that faces the chamber forms a first portion of a boundary wall of the chamber and an end face of the first primary piston component that faces the chamber forms a second portion of the boundary wall of the chamber;
• a portion of the second primary piston component that is nearest to the chamber is housed within an interior of a portion of the first primary piston component that is nearest to the chamber;
• and
• the second primary piston component includes a booster rod and is arranged relative to the first primary piston component such that the booster rod is configured to move the first primary piston component in the manner that the first primary piston component reduces the pressure chamber volume of the pressure chamber of the master brake cylinder when the second primary piston component is moved under the force towards the pressure chamber in the manner that the second primary piston component reduces the pressure chamber volume of the pressure chamber of the master brake cylinder.