AU2013100701A4 - Three-jaw Chuck Convenient for Concentrically Positioning Center Hole of Axis Workpiece - Google Patents

Abstract

Title: Three-jaw Chuck Convenient for Concentrically Positioning Center Hole of Axis Workpiece Abstract The invention a three-jaw chuck convenient for concentrically positioning a center hole of an axis workpiece, comprising three jaws mounted on a machine tool, the three jaws being uniformly distributed in a radial shape along a peripheral surface. Ends of the three jaws pointing at the circle center are provided with arc-shaped raised heads, and intermediate surfaces of the three arc-shaped raised heads intersect on a same straight line. This straight line coincides with the axis of the clamped axis workpiece.

Description

Description Three-jaw Chuck Convenient for Concentrically Positioning Center Hole of Axis Workpiece Technical Field The invention relates to a three-jaw chuck convenient for concentrically positioning a center hole of an axis workpiece. Background of the Invention Generally, as for a three-jaw chuck applied in a lathe in the mechanical industry, an end face thereof pointing at a workpiece to be clamped is a plane. When an axis workpiece is clamped by a three-jaw chuck with such structure, the axis of the axis workpiece shifts each time, resulting in errors of positions of center holes drilled on the axis workpiece, thereby increasing both the scrap rate of products and the manufacture cost. Summary of the Invention The invention provides a three-jaw chuck convenient for concentrically positioning a center hole of an axis workpiece. The above technical problem of the invention is mainly solved by the following technical solution. A three-jaw chuck convenient for concentrically positioning a center hole of an axis workpiece is provided, comprising three jaws mounted on a machine tool, the three jaws being uniformly distributed in a radial shape along a peripheral surface; and ends of the three jaws pointing at the circle center are provided with arc-shaped raised heads, and intermediate surfaces of the three arc-shaped raised heads intersect on a same straight line. This straight line coincides with the axis of the clamped axis workpiece. The axis workpiece is put into a gap surrounded by the three jaws, and the three 1 jaws slowly move in the radial direction from outside to inside until clamping the axis workpiece. After the axis workpiece is clamped, the highest part of each arc-shaped raised head comes into contact with the axis workpiece, and the positioning is accurate; therefore, the position of a center hole drilled on the axis workpiece is accurate, the scrap rate of the products is low, the working efficiency is improved, and the manufacture cost is reduced. Preferably, the arc-shaped raised heads are made of copper and connected with the jaws by welding. The arc-shaped raised heads may be manufactured conveniently. The invention has the following advantages: arc-shaped raised heads are welded on the heads of the three jaws, the highest part of the arc-shaped raised heads come into contact with the axis workpiece when the axis workpiece is clamped by the heads of the three jaws, and the position of the axis will not shift each time when different axis workpieces are clamped, so that the position of the center hole drilled on the axis workpiece is accurate, the scrap rate of products is low, the working efficiency is improved and the manufacture cost is reduced. Brief Description of the Drawings Fig. 1 is a front structure view when an axis workpiece is clamped by the three-jaw chuck provided in the invention; and, Fig. 2 is a working state diagram of a machine tool mounted with the three-jaw chuck provided in the invention. In the figures: 1-Machine tool; 2-Jaw; 3-Arc-shaped raised head; 4-Axis workpiece; 5-Drill; 6-Intermediate surface; 7-Straight line Detailed Description of the Invention 2 The technical solutions of the invention will be further described in details as below by specific embodiments with reference to drawings. Embodiment 1 As shown in Fig. 1 and Fig. 2, a three-jaw chuck convenient for concentrically positioning a center hole of an axis workpiece of the embodiment comprises three jaws 2 mounted on a machine tool 1, the three jaws 2 are uniformly distributed in a radial shape along a peripheral surface, ends of the three jaws 2 pointing at the circle center are welded with arc-shaped raised heads 3 made of copper, intermediate surfaces 6 of the three arc-shaped raised heads 3 intersect on a same straight line 7. This straight line 7 coincides with the axis of the clamped axis workpiece 4. An end of the machine tool 1 opposite to the three jaws is mounted with a drill 5. In use, an axis workpiece 4 to be machined is put into a gap surrounded by the three jaws 2, and the three jaws slowly move in a radial direction from outside to inside until clamping the axis workpiece 4, and then the drill 5 moves towards the axis workpiece until the drill 5 drills a center hole on the axis workpiece 4. 3

Claims (2)

1. A three-jaw chuck convenient for concentrically positioning a center hole of an axis workpiece, comprising three jaws (2) mounted on a machine tool (1), the three jaws (2) being uniformly distributed in a radial shape along a peripheral surface, characterized in that ends of the three jaws (2) pointing at the circle center are provided with arc-shaped raised heads (3), and intermediate surfaces (6) of the three arc-shaped raised heads (3) intersect on a same straight line (7).

2. The three-jaw chuck convenient for concentrically positioning a center hole of an axis workpiece, characterized in that the arc-shaped raised heads (3) are made of copper and connected with the jaws (2) by welding. 4