RU109033U1 - TOOL FOR FRICTION WELDING WITH MIXING OF ALUMINUM ALLOYS - Google Patents

Abstract

 A tool for friction welding with stirring of aluminum alloys, comprising a holder and an executive unit in the form of a shoulder and a pin, characterized in that a cavity is made on the working end of the holder, in which a collet is placed with a pin mounted coaxially to the collet and fixed with two pins in the collet, while the collet is fixed in the holder with a union nut screwed onto the working end of the holder by thread, and a shoulder is made on the end of the union nut facing the welding zone.

Description

The utility model relates to tools for friction welding with stirring of the extended joints of aluminum alloys with a thickness of 4 ... 10 mm.

Known friction welding tool with stirring aluminum alloys (UK patent No. 2306366A, V23K 20/12 from 10/17/1996). The tool has a cone part in the form of a Morse cone at one end. At the opposite end of the tool is its working part in the form of a shoulder and a pin. During welding, the tool rotates, and the shoulder is brought into contact with the surface of the welded workpieces. In this case, the pin is immersed in the workpiece material along the axis of their joint. As a result of the action of friction forces, heat is generated that warms the metal in the joint zone of the workpieces to a plastic state. In the process of moving the tool along the joint, the pin destroys the oxide film on the end surfaces of the welded edges of the workpieces and, thereby, ensures the formation of an integral connection.

However, in the welding process there is an interaction of the metal being welded with the metal of the tool. This interaction is accompanied by the penetration of aluminum into the pin material and the formation of a network of microcracks. The presence of microcracks leads to breakage of the pin even with a slight ripple in the load on the tool during welding. Experience shows that the tool service life when welding parts 3-5 mm thick does not exceed 20-25 m of the weld.

Tool replacement is associated with the manufacture of a new kit. In this case, the main material consumption is the manufacture of the conical part of the tool in the form of a Morse cone for fixing in the machine pins. Therefore, the replacement of the tool is associated with additional costs for its manufacture.

The closest in technical essence to the claimed utility model is a composite tool for friction stir welding (RF Patent for Utility Model No. 45955 IPC 7 V23K 20/12, Application No. 2004138746 dated December 28, 2004). This tool contains an installation part in the form of a Morse cone and an actuating unit in the form of a shoulder and a pin. The shoulder and pin form a single piece. At the working end of the holder there is a cylindrical channel in which the actuating unit is placed. The executive unit is fixed in the holder by means of a locking screw and a pin.

This tool allows you to quickly change the Executive unit when the pin breaks without the need for a new installation part.

A significant disadvantage of the prototype is the need to manufacture a new actuator unit even with a slight increase in the thickness of the welded workpieces, for example, when switching from a thickness of 4 mm to a thickness of 5 mm.

The technical effect to which the claimed utility model is directed is that it eliminates the need to manufacture a new tool (executive unit) while increasing the thickness of the welded workpieces.

The technical effect is achieved by the fact that on the working end of the holder there is a cylindrical cavity in which the collet is placed with a pin mounted coaxially to the collet and fixed with two pins in the collet, the collet is mounted in the holder with a union nut screwed onto the working end of the holder, and at the end of the cap the nut facing the weld zone has a shoulder.

The essence of the claimed utility model is illustrated in the drawing. Figure 1 shows the inventive tool assembly; figure 2 - shows the design of the inventive tool assembly (left) and disassembled (right).

The tool consists of a holder 1 and an actuator unit. The actuating unit is formed by a collet 2, a pin 3 and a union nut 4. The collet 2 is mounted in the holder 1 by means of pins 5. In this case, the actuating unit is installed in the cavity 6 in the holder 1 coaxially to the holder.

To fix the collet 2 in the holder 1, a cap nut 4 is screwed onto the holder on an external thread. A shoulder 7 is made on the end of the cap nut 4 facing the welded part. A hole is made in the shoulder 7 along the nut axis 4 through which the pin 3 is released relative to the end of the shoulder at a distance equal to the thickness of the welded workpieces.

With an increase in the thickness of the workpieces being welded, the union nut 4 is screwed from the holder 1. The collet 2 with the fixed pin 3 is removed from the cylindrical cavity 6 in the holder 1. The pins 5 are loosened and the pin 3 extends from the collet to the required distance. Then the pins 5 are screwed into the collet 2, fixing the pin 3. After that, the collet 2 is installed in the cavity 6 and fixed with a union nut 4. The tool is ready for welding.

The inventive tool was tested in friction welding with stirring of butt joints of alloy V-1469T with a thickness of 5 mm. The tool had the following parameters (figure 2):

- holder length 150 mm

- diameter of the holder at the installation site of the executive unit 36 mm

- shoulder diameter 15 mm

- diameter of the pin at the transition to the shoulder 4 mm

- pin diameter in the working area 3 mm

- pin height 5 mm

The collet was fixed in the holder using a lock nut screwed onto the holder using M36 × 2 threads. The holder was made of steel 30HGSA. The union nut and pin are made of tool steel P18.

Experiments have shown that the durability of a composite tool is similar to the durability of a tool made as a whole. The main cause of tool failure is aluminum frozen on its surface. Aluminum penetrates the tool material to a considerable depth, forming a sublayer. Such interaction leads to the formation of microcracks in the tool material, contributing to its breakage at a certain operating time.

Additional features of the specified composite tool design is to vary the size of the pin and the diameter of the shoulder. This allows us to practically cover a wide range of thicknesses of welded aluminum alloys and welding modes, since the geometric dimensions of the tool are one of the parameters of the friction stir welding mode.

Claims (1)

A tool for friction welding with stirring of aluminum alloys, comprising a holder and an executive unit in the form of a shoulder and a pin, characterized in that a cavity is made on the working end of the holder, in which a collet is placed with a pin mounted coaxially to the collet and fixed with two pins in the collet, while the collet is fixed in the holder with a union nut screwed onto the working end of the holder by thread, and a shoulder is made on the end of the union nut facing the welding zone.