SU967734A1 - Friction welding machine - Google Patents

Description

The invention relates to welding, in particular to devices for friction welding.

A known friction machine comprising an electromagnetic drive axial force of compressing parts during welding and a device for creating a pulsating axial force of compression.

In this machine, the pulsary axial force is generated by the definition. divided form the ends of the core and. electromagnet core

Depending on the required pulse frequency, they can be made in the form of a polyhedron, ellipse, etc.

When the core rotates relative to the core, a change in magnetic resistance occurs, which leads to a pulsation of the magnetic flux and, consequently, axial force.

The pulsing axial force acting on the joint of the parts to be welded contributes to the improvement of the quality of the welded joints f1J.

However, this method of creating a pulsating axial force reduces the efficiency of the electromagnetic drive.

Closest to the proposed technical solution is a machine.

for welding, containing an electromagnetic drive axial force and energy accumulator, made in the form of an elastic element installed between the core of the electromagnet and the clamping device of one of the parts, the force of which at a given deformation is sufficient for forging.

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In this machine, the force during the heating of parts is created with the help of an electromagnet, and during the forging, at the expense of. energy accumulator, made in the form of an elastic element, compressed previously in the process of heating parts with an electromagnet f 2J.

A disadvantage of the known construction is the additional energy consumption for compressing the elastic element.

Since the force of the elastic element in the forging section (stroke 2-3 mm) should be almost constant, it is necessary either to choose an electromagnet 25 with oversized dimensions, the force of which, with zero clearance, considerably exceeds the spring force, or work on the section of the magnetization curve close to to saturate the material

30 magnetic circuit.

The choice of an electromagnet with large dimensions entails an increase in the moment of inertia of the rotating core of the electromagnet and, consequently, higher energy costs for acceleration and deceleration of the spindle,

The operation of an electromagnet on the saturation regimes of the material of a magnetic circuit requires much larger magnitudes of magnetizing force, i.e. large values of toa, and consequently, high energy consumption.

The aim of the invention is to reduce energy consumption by applying a pulsating force to the details and improving the quality of the welded joint.

This goal is achieved by the fact that the machine is equipped with an additional coil installed coaxially with the core, created by an alternating magnetic field, the pulse frequency of which is equal to the frequency of free oscillations of the elastic element and the inertial mass of the core associated with it.

In addition, in order to ensure reliable fixation of the core on the magnesium body, a latch is installed on the conductor of the magnesium, which interacts with the core.

In this case, when an additionally installed device is switched on, for example, a coil, in which the frequency of the pulsations of the magnetic flux is equal to the frequency of free oscillations of the elastic element, and the inertial mass of the core associated with it, a resonance of the system containing the elastic element and the core, i.e. a sharp increase in the amplitude of the oscillations of the core of the electromagnet, which leads to its closure on the body-magnetic circuit of the electromagnet and the compression of the elastic element.

To tune in to the resonant frequency, the machine is equipped with a thyristor frequency converter with a smooth adjustment of the frequency of the alternating current at the input of the power supply circuit. i.e. get a resonance system.

At the same time, the energy consumption is much lower than if the compression was carried out by increasing the magnetizing force of the electromagnet or increasing the dimensions of the electromagnet.

When the core closes on the body of the magnetic circuit of the electromagnet, the pull-off force of the core may exceed the force developed by the electromagnet with a zero gap. In the case where the force of the elastic element exceeds the force of the electromagnet, an additional fixer, for example a mechanical one, is needed for the Zero gap.

Figure 1 shows schematically the proposed friction welding machine; Fig. 2 is a graph of the force variation at the junction of the parts to be welded depending on the welding time.

The machine consists of a bed 1, on which is fixed the body-magnetic circuit 2 of the electromagnet, which creates an axial force during welding.

The core 3 is mounted with the possibility of axial displacement relative to the spindle 4. The clamping device 5 for the rotating part is mounted on the core with the possibility of axial displacement. The housing of the clamping device 5 is supported on the spring 6. The clamping device 7 for a non-rotating child is mounted on the body of the magnetic circuit 2..

The magnetic flux of the electromagnet is created by a coil 8 connected to a direct current power circuit. To create a pulsating axial force, a coil 9 is used, connected to an alternating current supply circuit with a pulsation frequency equal to the frequency of free oscillations of the spring 6 and core 3.

To fix the core 3 in a closed position on the magnetic core 2, a mechanical lock 10 is installed on the magnetic core 2, which is automatically activated when the core 3 is closed.

The machine works as follows

After the parts are installed in the clamping devices 5 and 7, the rotational drive of the spindle 4 is turned on. When the rated speed is reached, the toggle switch T closes, and the welding pressure of the heating is created at the junction. After a certain jipoMejxvTKa time has elapsed (a time relay not specified in Fig. 1 is installed in the machine), the T / j toggle switch closes, and coil 9 generates a pulsating magnetic flux and, therefore, a pulsating axial force. Since the frequency of the axial force pulsations coincides with the natural frequency of oscillation of the system consisting of spring b and core 3, core 3 begins to wobble along the axis of rotation, falling into resonance, and closes on the body-magnetic circuit 2, compressing it. spring 6. When the core 3 is closed, the rotational drive is turned off, the spindle 4 with the core 3 is sharply braked, and the core 3 is fixed in the closed position to the mechanical locks 10. The release spring 6 creates a forging pressure. Welding is finished.

The proposed technical solution allows to obtain the required amount of forging pressure with less energy and is recommended for use in machines designed for friction welding of tool and heat-resistant steels, where the piercing-force should be 3 times higher than the heating gain.

Claims (2)

1. A friction welding machine containing an electromagnetic drive force, comprising a body of a magnetic wire with a coil, a rotating core and an energy accumulator, made in the form of an elastic element located between the core and the clamping device of one of the parts, characterized in that, in order to reduce energy intensity by applying to the parts a pulsating axial force and improving the quality of the welded joint, it is equipped with an additional coil installed coaxially with the core, creating an alternating magnet th field pulse frequency equal to the frequency of free vibrations of the elastic member and its associated core inertial mass. 2. Machine pop. 1, characterized in that, in order to ensure reliable fixation of the core, on the body of the magnetic circuit installed latch, interacting with the core. Sources of information taken into account in the examination 1. USSR author's certificate No. 715261, cl. At 23 K 20/12, 1977. 2.Avtorskoe SEIdedelstvo USSR | 742080, class B 23 K 20/12, 1978 (prototype). five. - FIG. The closing time of the Preamp core Kar-ka Yi Sheis Prutiny Time offapKU, t Tv Fi. g