Vibration device

An anti-vibration device comprising:

• a first anti-vibration rubber cylinder configured to connect a vibration generating portion and a vibration receiving portion to each other in a first direction;
• a second anti-vibration rubber cylinder configured to sandwich one of the vibration generating portion and the vibration receiving portion in the first direction between the first anti-vibration rubber cylinder and the second anti-vibration rubber cylinder;
• and
• a support member configured to sandwich the second anti-vibration rubber cylinder in the first direction between the one of the vibration generating portion and the vibration receiving portion and the support member, wherein
• the first anti-vibration rubber cylinder and the second anti-vibration rubber cylinder are provided with respective central axes thereof extending in the first direction,
• peripheral grooves are formed separately on an outer peripheral surface and an inner peripheral surface of at least one of the first anti-vibration rubber cylinder and the second anti-vibration rubber cylinder, and
• a communication hole is formed in the one of the vibration generating portion and the vibration receiving portion, the communication hole communicating an inside of the first anti-vibration rubber cylinder with an inside of the second anti-vibration rubber cylinder in the first direction,
• the anti-vibration device further includes
• a core cylinder configured to be inserted integrally into the first anti-vibration rubber cylinder and into the second anti-vibration rubber cylinder through the communication hole and configured to be sandwiched in the first direction between the support member and another one of the vibration generating portion and the vibration receiving portion, wherein
• the peripheral grooves are formed separately on the outer peripheral surface and the inner peripheral surface of the second anti-vibration rubber cylinder,
• a depressed portion is formed at an opening end edge of the second anti-vibration rubber cylinder that is located closer to the one of the vibration generating portion and the vibration receiving portion along the first direction, the depressed portion opening inward in a radial direction,
• the communication hole formed in the one of the vibration generating portion and the vibration receiving portion is provided, at an opening peripheral portion thereof, with a stopper cylinder portion that is inserted into the depressed portion, and
• in the second anti-vibration rubber cylinder, a count of peripheral grooves formed on the outer peripheral surface is larger than a count of one or more peripheral grooves formed on the inner peripheral surface.