1. Field of the Invention
The present invention relates to a vibration damping device to be used, for example, for engine mounts and the like on motor vehicles.
2. Description of the Related Art
Conventionally, there has been known a vibration damping device interposed between members constituting a vibration transmission system to link or support the members each other in a vibration damping manner, which has been considered for application to engine mounts and the like on motor vehicles. This vibration damping device, as shown in Japanese Unexamined Patent Publication No. JP-A-11-311291 and others, has a structure where a first mounting member and a cylindrical second mounting member are elastically connected by a main rubber elastic body.
By the way, in the vibration damping device described in JP-A-11-311291, the first mounting member is arranged on the upper side of the second mounting member to be attached to the vibration source such as a power unit, while the second mounting member is attached to the member to be vibration-damped such as a vehicular body. In contrast, Japanese Patent No. JP-B-4755147 proposes an inverted vibration damping device, wherein the first mounting member is arranged on the lower side of the second mounting member to be attached to the member to be vibration-damped, while the second mounting member is attached to the vibration source.
However, since a massive bracket is fixed by press-fitting to the second mounting member constituting the upper portion of the vibration damping device in the vibration damping device shown in JP-B-4755147, the center of gravity thereof is positioned in the upper portion, which posed a risk of developing problems such as lack of rigidity of the vibration damping device in the falling direction.
In addition, in the structure of JP-B-4755147, since an axis-perpendicular stopper member that restricts relative displacement between the first mounting member and the second mounting member in the axis-perpendicular direction (front-back direction of the vehicle) is provided on the upper portion of the vibration damping device, there were some problems such as further deviation upward of the center of gravity position and a risk of adverse effects on the load bearing performance or ride comfort caused by a stopper load of the axis-perpendicular stopper member acting on the upper portion of the vibration damping device during acceleration and deceleration of the motor vehicle.