One-time shaped mold for ball spline sleeve cold drawing

Abstract

The invention discloses a one-time shaped mold for ball spline sleeve cold drawing. The one-time shaped mode for ball spline sleeve cold drawing comprises an external mode and a mandrel. A forming hole is formed in the external mode. The forming hole comprises a cone shape inlet segment and a sizing segment. The length L1 of the inlet segment of the forming hole is (0.7-1.0) D, and D is the diameter of the periphery of a finished spline sleeve. The inclination angle alpha of the inlet segment is 10-13 degrees. The length L2 of the sizing segment is (0.2-0.3) D. A periphery of the mandrel comprises an external forming part and an internal forming part. The external forming part is coincident with a groove in the finished spline sleeve and has a cambered periphery. The internal forming partis matched with an internal round part of the finished spline sleeve and has the cambered periphery. A cambered internal forming part of the periphery of the mandrel is tangent to the internal round part of the finished spline sleeve. On the cambered surface of the external forming part, the arc length delta S from a point of intersection with the internal forming part to the point of intersectionwith a convex part in the spline sleeve is lambda.b / 4, wherein lambda is greater than or equal to 0.17 and smaller than or equal to 0.19, and b is the radius of the periphery cambered surface of theexternal forming part.

Description

technical field [0001] The invention relates to a primary molding die for cold drawing of a ball spline bushing. Background technique [0002] The ball spline pair is a linear motion component, and the spline sleeve and the spline shaft perform relative linear motion. When the steel ball in the spline sleeve moves linearly on the precision ground spline shaft, it can also transmit torque. The ball spline pair can control the clearance in the direction of rotation to zero clearance or interference, and can perform high-speed linear motion and high-speed rotary motion. Ball spline pairs are widely used in various automation equipment such as robot production lines to realize two-dimensional motions of rotation and straight line. [0003] Such as figure 1 As shown, the outer circumference of the cross-section of the ball spline bushing is circular, and the inner ring includes a number of arc-shaped grooves with a radius b and an inner circle with a radius d that are arranged...

AI Technical Summary

Problems solved by technology

However, when cold-drawing special-shaped tubes such as spline sleeves, due to the high requirements for the size of the internal spline, and due to various factors during the drawing process, the obtuse angle where the groove part and the inner circle part intersect generally cannot meet the size requirements.

If multi-pass drawing is used, it is easy to cause torsion, resulting in low yield (the material itself is not uniform, the mold may not be able to fix the pipe so that it does not twist during the drawing process), and the cost increases

Images