The clamping method of the piston ring has two aspects, one is to overcome the clamping from the free state to a perfect circle, and the other is to overcome the cutting force. Due to the large batch production, the clamping method should be accurate, efficient, convenient and labor-saving. In actual production, manual, electric and pneumatic clamping are used according to different processes.
1) The method of clamping the ellipse into a perfect circle
There are two basic methods for the free state of the piston ring to be folded into a perfect circle state, one is the tapered sleeve retracting the perfect circle method, and the other is the semi-circular sleeve retracting the perfect circle method.
a) Taper Sleeve Receiving Perfect Circle Method
The method of rounding the taper sleeve is the clamping method used when turning or milling the inner shoulder. After the piston ring is installed in the cone sleeve, the pressure plate is pressed down, and the ring will be elastically deformed after entering the cone part, and the diameter will gradually decrease until it is pressed into the tire sleeve. It should be noted here that the diameter of the upper cylindrical part of the taper sleeve should be larger than the diameter of the long axis of the ring in the free state.
In addition, this method of closing a perfect circle is also used in processes such as finishing openings and boring inner circles. The advantages of this method are simple tooling, simultaneous feeding and clamping, short auxiliary time and low labor intensity.
b) Semi-circle sleeve to close circle method
The method of closing the half circle to the perfect circle. Two semi-circular clamps are hinged together, the inner diameter of the semi-circular sleeve is slightly smaller than the workpiece tire cover, after a set of piston rings is installed, the movable clamp body is closed and clamped by pneumatic force, so that the workpiece is folded into a perfect circle, and the tire cover is placed on the workpiece. On the semi-circle sleeve, press the ring into the tire sleeve after pressing. This method is used for coarse and fine inner turning operations.
The process of finishing the outer circle, turning the oil groove and milling the oil return hole also adopts this method of closing the circle, but when closing the circle, the eccentric wheel is used for manual clamping. Rotating the eccentric will cause the change of the distance h, and the range of h is from (R-e)→(R+e), so the maximum working stroke of the eccentric is 2e. During the clamping process, the eccentric wheel rotates counterclockwise to gradually close the workpiece (ring). To facilitate adjustment of the closing size, a spacer is installed on the clamping body. After the work is folded to the required size, loosen the handle and keep it closed by the self-locking performance of the eccentric wheel.
