CS265309B1 - Device for influencing the clamping forces of the chucks - Google Patents

Abstract

The solution concerns a device for influencing the clamping forces of chucks with a mechanism for eliminating centrifugal jaws. The essence of the solution is that between the control device and the source of the working medium there is a regulator, the control member of which is interconnected with an electronic control unit.

Description

265309 2

BACKGROUND OF THE INVENTION The present invention relates to a device for influencing the chucking forces of a chuck with the mechanism of eliminating centrifugal forces of a jaw. D of the chucks with the mechanism of centrifugal force elimination of the jaws is reflected by the self-locking of the tightened force mechanism from the side of the acting clamping forces by the increase of the clamping forces realized under the rest. In some cases, the clamping force increases by 60%, which causes deformation and consequent loss of precision when machining flexible workpieces. There are solutions where the influence of the so-called hysteresis is already calculated to the choice of lower working pressure in the actuating cylinder and after the increase of the speed above the working room and the consequent reduction to the working speed, the required clamping force is present. However, after stopping and in these cases, it is partially increased. Furthermore, solutions are known where the self-locking of the force mechanism is disturbed by the vibrator, but it also affects the roughness of the machined surface, adversely affects other machine mechanisms, and in some cases is poorly effective.

The above disadvantages are alleviated by the device for influencing the chucking forces of the chuck by the centrifugal force elimination mechanism of the jaw, the principle being that there is a controller between the control device and the working medium source, the actuator of which is connected to the electronic control unit. The solution by simply changing the operating pressure in the control device, depending on the increment of the clamping force, also reduces this working pressure. As a result, substantially constant clamping is maintained over the entire operating range of the chuck. Since the pressure reduction sensitivity of the force mechanism is in some cases less than the pressure drop required by the preteoretical loss of clamping force given by the hysteresis, it is preferred that the device is provided with a force transducer by which the change in clamping force of the jaw is directly measured and controlled by changes in working pressure and / or control force. on the tow bar of the power mechanism.

Reducing the working pressure at speed reduction. in the said chuck type, the overload force mechanism is avoided.

In the accompanying drawing, Fig. 1 illustrates the influence of the clamping force of the invention according to the invention and Fig. 2 shows an example of a device for carrying out this method in a schematic arrangement.

The apparatus for influencing the chucking forces of the chucks of the present invention comprises a chuck 100, a control device 20, a source 300, a controller 400, an electrical control unit 500, a tachometer 700 and a force sensor 800 The chuck 100 has a centrifugal force elimination mechanism 110 and a power mechanism 120 coupled to the control device 200 which is a distributor 210 through a distribution 220, a controller 400, and an actuator 410 connected to a pressure medium source300. The controller 400 is connected via an actuator 410 to an electronic control unit 500 which is connected to a rotary drive 7 00 and to a force sensor 600a, optionally to a speed sensor 800b.

The device operates as follows: after clamping the workpiece 600 under the chuck 100 with a sosil mechanism 120, for example, a known wedge and elimination mechanism 110, for example, a known lever and an increased speed n to the upper speed nn of the tightened power mechanism 120 by the actuator 200 by axial force. the mechanism 120 changes in the direction of its clamping motion. As a result of this, when the revolutions of the self-locking force mechanism 120 are destroyed, the clamping force of the hysteresis increases the Fuh, which can be read with any of the known stiffness dynamometers 600. It is important that the increase in the clamping force of the hysteresis corresponds to the increase in force when clamping. However, methods are known for recalculating the nature of the change in the course of these forces as a function of the speed n of the dynamometer stiffness to another rigidity of the workpiece 600. In the memory of the electronic control unit, a set of clamping force waveforms of Funh for the stiffness of the dynamometer of the workpiece 600 is inserted. by varying the working pressure, for example, the hydraulic oil and the pressure gauge distribution 220, adjusts the working pressure of hysteresis xp at which the clamping

Claims (4)

OBJECT OF THE INVENTION An apparatus for influencing the clamping forces of a chuck comprising a chuck with a centrifugal force elimination mechanism of the jaws, a control device coupled to a chuck force mechanism and connected to a working medium source, characterized in that between the control device (200) and the working medium source (300) is a controller (400) whose actuator (410) is coupled to an electronic control unit (500). 2. Device for influencing the clamping forces of the chucks according to claim 1, characterized in that the electronic control unit (500) is electrically connected to the force sensor (800a). 3. Device for influencing the clamping forces of the chucks according to claim 1, characterized in that the electronic control unit (500) is electrically connected to the speed sensor (800b). 4. Device for influencing the clamping forces of the chucks according to claim 1, characterized in that the electronic control unit (500) is electrically connected to the force sensor (800a) and to the speed sensor (800b).