SU904912A1 - Device for turning non-rigid parts - Google Patents

Description

(54) DEVICE FOR TURNING TREATMENT OF SMOOTH PARTS

one

The invention relates to a machine tool industry, in particular to devices for machining rotary parts on lathes.

A device for turning non-rigid parts is known, which includes two turning chucks facing one another, one of which is used to stretch a part with the help of an axial movement drive of the cartridge 1.

A disadvantage of the known device is the low quality of the treated surface due to the presence of longitudinal vibrations of the front headstock - part - rear headstock when stretched by a drive in the form of an elastic element, as well as the complexity and low accuracy of adjustment of the longitudinal stretching forces due to small movements of the tail headstock with significant changing the tensile force, which complicates the precise adjustment of the tensile force as the caliper moves.

The aim of the invention is to increase the quality of the treated surface by increasing the accuracy of the adjustment of the longitudinal tensile force.

The goal is achieved by the fact that in a device for turning non-rigid parts containing two turning chucks facing one another, one of which is equipped with an axial displacement drive, the latter is made in the form of a pneumatic cylinder, the bore of which is connected to the chuck, while the pressure chamber of the pneumatic cylinder communicates with a pressure source through a pressure regulator, the device being equipped with a sequentially connected instrument position sensor and a follow-up drive, the actuator of which is kinematically ki is associated with a pressure regulator.

The drawing shows the scheme of the proposed device for turning non-rigid parts.

15 The caliper 1 of the machine moves from the screw 2 by the drive 3. On the screw 2 there is a 4 position sensor of the cutting tool, which determines the amount of movement of the caliper. Signals proportional to the magnitude of the longitudinal movement of the caliper go to block 5 of the digital computing device, which monitors the implementation of a certain functional relationship between the tensile force of the part 6 and the movement of the caliper 1 and produces

the signals supplied to the control unit 7 of the follower engine 8, which causes the guide screw 9 to rotate through the gearbox 10. A sensor AND feedback is mounted on the screw 9. The screw 9 moves the actuator of the next drive, the carriage 12 of the pressure regulator 13. In the cavity of the pressure regulator, a grid 14 with openings is installed, relative to which the carriage 12 moves while adjusting the pressure in the pneumatic cylinder 15, which is controlled by a pressure gauge 16. Part 6 is fixed in turning chucks 17 and 18, the last of which is mounted with the possibility of axial movement on the tailstock (not shown) on the same axis with the piston 19 mounted on the rolling bearings 20 and 21.

The device works as follows

After fixing the part 6 in the turning chucks 17 and 18, applying an overpressure to the pneumatic cylinder 15 (shown by arrow a) creates the required tensile force of the part 6, and the value of the required force is determined by the pressure gauge 16. During machining of the part 6 with the cutter 22, the caliper 1 moves to the left. In this case, the deformations of the workpiece, measured in close proximity to the front and rear heads, have different deflection values, i.e. deflection of the headstock below the corresponding deflection measured at the tailstock. The discrepancy between the stiffness of the front and rear headstock of the machine is regulated by changing the force of the longitudinal stretching, its linear decrease, for example, starting from the middle of the workpiece. The caliper is driven by a driver, on whose shaft a position sensor 4 is installed, which determines the amount of movement of the caliper. Signals proportional to the magnitude of the longitudinal movement of the caliper 1 are received in block 5, which monitors the fulfillment of a certain functional relationship between the force of stretching the part 6 and moving the caliper 1 and produces signals arriving in the control unit 7 of the following engine 8, which leads

during rotation the guide screw 9 through the reducer 10. The feedback sensor 11 serves to maintain the constant rotational speed of the screw 9 through which the carriage 12 of the pressure regulator 13 moves. Moving the carriage 12 relative to the grid 14 of the pressure regulator performs a pressure change in the pneumatic cylinder and, in proportion to the pressure change, a change in the tensile force. The use of the proposed device for turning non-rigid parts makes it possible to increase the accuracy of the geometry in the longitudinal direction, the quality of the machined surface due to the damping of the longitudinal and transverse oscillations of the system of the headstock - part - tailstock. The application of the proposed device also allows smoothly, with high accuracy and according to an arbitrary law (in accordance with the shape of the workpiece) to process non-rigid parts.

Claims (1)

Invention Formula A device for turning non-rigid parts containing two turning chucks facing one another, one of which is equipped with an axial displacement drive, characterized in that, in order to improve the quality of the machined surface by increasing the accuracy of adjusting the longitudinal tensile force, the axial displacement drive is made a pneumatic cylinder, the bore of which is connected to the chuck, the pneumatic cylinder’s pressure chamber communicating with the pressure source through a pressure regulator, the device being provided with included been consistent tool position sensor and the follower actuator, the actuating element which is kinematically coupled with a pressure regulator. Sources of information taken into account during the examination 1. USSR author's certificate No. 686821, cl. B 23 B 1/00, 1978.