Hydraulic vibration damper piston with an integral electrically operated adjustment valve

A piston for a vibration damper that has a cylinder and a piston assembly with a rod extending out of the cylinder, the piston assembly includes a piston slideably received within the cylinder thereby defining a first chamber and a second chamber on opposite sides of the piston, with each chamber having fluid therein the piston comprising:

• a piston body having a bore, a first aperture extending from the bore to the first chamber, and a second aperture extending from the bore to the second chamber;
• a primary valve spool moveably received within the bore and defining a pilot chamber in the bore, wherein different positions of the primary valve spool in the bore control fluid flow between the first aperture and the second aperture;
• a fixed control orifice providing a path that enables fluid to flow continuously between the first chamber and the pilot chamber;
• a fixed pilot orifice providing another path that enables fluid to flow continuously between the first chamber and the pilot chamber;
• a variable orifice through which fluid flows between the second chamber and the pilot chamber;
• and
• an actuator operably connected to alter the variable orifice in response to a control signal.

A piston for a vibration damper that has a cylinder and a piston assembly with a rod extending out of the cylinder, the piston assembly includes a piston slideably received within the cylinder thereby defining a first chamber and a second chamber, the piston comprising:

• a piston body having a bore, a first aperture extending between the bore and the first chamber, a second aperture extending between the bore and the second chamber, and a pilot passage extending between the bore and the second chamber;
• a primary valve spool moveably received within the bore thereby defining a pilot chamber in the bore, the primary valve spool having a first position which allows fluid to flow between the first aperture and the second aperture, a second position which allows fluid to flow between the first aperture and the second aperture, and a third position that is between the first and second positions and in which flow is prevented from flowing between the first aperture and the second aperture;
• a first spring which biases the primary valve spool from the first position toward the third position;
• a second spring which biases the primary valve spool from the second position toward the third position;
• a control orifice that is directly connected between the first chamber and the pilot chamber;
• a pilot valve spool defining a variable orifice through which fluid flows between the pilot passage and the pilot chamber;
• and
• an actuator operably connected to move the pilot valve spool in response to a control signal.