Vibration insulating device

A vibration insulating device interposed between an engine and a vehicle body, the vibration insulating device comprising:

• a main fluid chamber;
• an elastic support partly defining the main fluid chamber;
• a partition wall for changing a volume of said main fluid chamber, said partition wall partly defining said main fluid chamber, said partition wall being formed into a disc shape having a center axis;
• an actuator for generating a displacement force for displacing said partition wall toward the center axis of said partition wall;
• a magnetic path member for transmitting said displacement force to said partition wall, a magnetic path member wall of said magnetic path member being formed into a disc shape having a center axis;
• a clearance spacer for making clearance between said partition wall and said magnetic path member, said clearance spacer being formed into a disc shape having a center axis;
• a seal ring elastically connected with said partition wall so that said partition wall is allowed to move, said seal ring fixed so that the center axis of said partition wall is in alignment with the center axis of said displacement force;
• an elastic plate elastically supporting said partition wall to generate a force according to said displacement force, said elastic plate being placed within said clearance;
• a bolt for fastening said partition wall, magnetic path member and clearance spacer;
• wherein said partition wall has an internal thread hole which is in the center of said partition wall;
• wherein said clearance spacer has an opening for inserting said bolt, where said opening is in the center of said clearance spacer;
• wherein said magnetic path member has a first hole for inserting said bolt, where said first hole is in the center of said magnetic path member;
• wherein said bolt comprises a bolt head on an external thread, said bolt head contacting said first hole as the bolt is inserted;
• wherein said bolt head pushes said magnetic path member in the first hole until the center of the magnetic path member is put in alignment with the center of the partition wall,
• wherein said first hole has a first opening and a second opening on the respective surfaces of said magnetic path member;
• wherein said first hole has an inner diameter which tapers off from the first opening to the second opening with a taper angle θ1;
• wherein said bolt head has an outer diameter which tapers off from the top of the head to the external thread with a taper angle θ2;
• wherein the taper angle θ2 is at least the same or larger than the taper angle θ1.

A movable construction part for use in a vibration insulating device interposed between an engine and a vehicle body, the movable construction part comprising:

• a partition wall at least partly defining a main fluid chamber, said partition wall having an internal thread hole;
• a magnetic path member to receive a displacement force of an actuator, said magnetic path member having a first hole;
• a bolt to fasten said partition wall and said magnetic path member, said bolt being inserted in said internal thread hole and said first hole;
• wherein said bolt comprises a bolt head on an external thread, said bolt head contacting said first hole's internal surface as the bolt is inserted;
• wherein said bolt head pushes said first hole's internal surface until the center of the first hole is put in alignment with the center of the internal thread hole;
• wherein said first hole has an inner diameter which tapers off from the first opening to the second opening with a taper angle θ1;
• wherein said bolt head has an outer diameter which tapers off from the top of the head of the external thread with a taper angle θ2;
• wherein the taper angle θ2 is at least the same or larger than the taper angle θ1.