Adhesive bonding and miscellaneous chemical manufacture – Methods – Surface bonding and/or assembly therefor
Reexamination Certificate
1999-07-08
2001-07-03
Ball, Michael W. (Department: 1733)
Adhesive bonding and miscellaneous chemical manufacture
Methods
Surface bonding and/or assembly therefor
C219S121640, C248S562000, C267S140120, C156S272800
Reexamination Certificate
active
06254706
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a manufacturing process of a cylindrical vibration isolating rubber device used for an engine mount of a vehicle and the like.
1. Description of the Prior Art
Various types of such a cylindrical vibration isolating rubber device are known. For example, such a device discloses an inner cylinder secured to one side of an engine or a vehicle body, an outer cylinder secured to another side thereof through a bracket, and a vibration isolating rubber connecting the inner cylinder and the outer cylinder, wherein the vibration isolating device is formed by means of molding including the steps of: laying the inner cylinder and the outer cylinder within a molding die such that the inner cylinder is arranged concentrically or eccentrically inside the outer cylinder, pouring liquid rubber into the die, tightening the die, and vulcanizing the rubber.
In a case that a bracket is welded to an outer cylinder, if vibration isolating rubber has been beforehand baked on an inside of the outer cylinder, the vibration isolating rubber suffer a harmful influence. Hence, it is required that the bracket is welded at first to the outer cylinder and then the vibration isolating rubber is baked on the inside of the outer cylinder. However, when such a process is adopted, since the bracket, a shape of which is apt to be complex, have to be housed in a die with the outer cylinder, such a problem occurs that it is unavoidable to use a complex and large die for formation of the vibration isolating device. Therefore, such a manufacturing process is required that a vibration isolating functional member including an inner cylinder, an outer cylinder and vibration isolating rubber is beforehand formed and thereafter the bracket is molded to the outer cylinder without giving thermal influence to the vibration isolating rubber.
2. Disclosure of the Invention
In order to solve the above subject, there is provided a manufacturing process of a cylindrical vibration isolating device comprising a vibration isolating functional member including a metal-made outer cylinder, a metal-made inner cylinder provided inside the outer cylinder and a vibration isolating rubber combined between the outer cylinder and the inner cylinder, and a fixing bracket welded to the outer cylinder, comprises the steps of forming the vibration insulating functional member, placing the bracket on an axial end portion of the outer cylinder projecting toward a position to give no thermal damage to the vibration isolating rubber and laser-welding the joint portion of the axial end portion of the outer cylinder and the bracket.
By thermal damage to the vibration isolating rubber, we mean such a harmful damage as detaching the rubber from the outer cylinder or denaturalization of the rubber such as lowering the required physical property on account of the vibration isolating rubber suffering from heat more than the upper temperature limit. And giving no thermal damage to the vibration isolating rubber means not effecting such a harmful damage to the vibration isolating rubber.
The axial end portion of the outer cylinder projects toward the position to give no thermal damage to the vibration insulating rubber. Hence, when the axial end portion and the bracket are joined and the joint portion of both members is laser-welded, the bracket is welded to the outer cylinder and the welding heat in this time gives no influence to the vibration isolating rubber.
Therefore, it becomes possible to weld the bracket to the outer cylinder after forming of the vibration isolating function member and to utilize a simple and small die for forming. Which make it much easy to manufacture the vibration isolating device. Moreover, since a common vibration insulating function member can be combined with various kinds of a bracket, the vibration isolating device can be manufactured advantageously.
Furthermore, since laser- welding makes it possible to weld in an extremely narrow width and a range to give thermal damage to the vibration isolating rubber becomes exceedingly narrow, the welding portion can be correspondingly approached to the vibration isolating rubber. Accordingly, the vibration isolating device as a whole can be made in a small-size and a light-weight.
The axial end portion of the outer cylinder may extend axially outwardly to the place to give no thermal damage to the vibration isolating rubber and the joint portion of an end face of the extending portion may be welded to the bracket, thereby it becomes possible to miniaturize the vibration isolating rubber device so as not to be expanded toward the radial direction. Moreover, by way of adopting the laser welding, it is possible to weld easily and with sufficient strength even in the narrow area such as the end face at the axial end portion of the outer cylinder.
The flange may be formed so as to bend radially outwardly at the end portion of the outer cylinder and to position a tip end face of the flange in a position to give no thermal damage to the rubber, and the joint portion of the end face of the flange may be welded to the bracket. Accordingly, it becomes easy to position the end portion of the outer cylinder at the place to give no thermal influence to the vibration insulating rubber, and in addition, it is possible to miniaturize the vibration isolating device so as not to expand a size thereof in an axial direction.
The step may comprise, setting melting depth by welding so as to be more than the thickness of a welded material; determining a laser output power and adequate welding speed according to the melting depth by an experiment; deciding a surface temperature limit determined through an experiment according to composition of the vibration isolating rubber; deciding an adequate distance from a welding line to a point to become less than the surface temperature limit when being welded with the selected laser output power and adequate welding speed by an experiment; and determining a position to keep the adequate distance from the vibration isolating rubber as said position to give no thermal damage to the rubber.
The laser output power and the welding speed are determined on the basis of the melting depth decided as the depth more than the thickness of the welded material. On the other hand, the surface temperature limit is determined by composition of the vibration isolating rubber. Thereafter, the adequate distance is determined according to the laser output power, welding speed and the surface temperature limit allowing for safety margin and is decided as the distance from the rubber to the position to give no thermal influence to the rubber. Therefore, even in a case that conditions are changed variously, the position to give no thermal damage to the rubber is decidable experimentally.
In this case, the adequate welding speed signifies a speed determined by means of the selected laser output power and the melting depth. The surface temperature limit signifies the maximum surface temperature not effecting harmful influence to the vibration isolating rubber, which is determined by the experiment according to composition of the vibration isolating rubber. The adequate distance means a distance from the vibration isolating rubber to a position to give no thermal influence to the rubber. These figures are determined allowing for safety margin.
REFERENCES:
patent: 4626653 (1986-12-01), Sciaky et al.
patent: 5769380 (1998-06-01), Hibi et al.
patent: 61-112142 (1986-07-01), None
patent: 7-75843 (1995-03-01), None
Ball Michael W.
Birch & Stewart Kolasch & Birch, LLP
Tolin Michael A.
Yamashita Rubber Kabushiki Kaisha
LandOfFree
Method of producing cylindrical vibration-proofing rubber... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of producing cylindrical vibration-proofing rubber..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of producing cylindrical vibration-proofing rubber... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2529056