CS260239B1 - Device for evaluating the force or moment of the working part of the machine - Google Patents

Abstract

The device is intended for evaluating the magnitude of the force or moment acting on the moving working part of the machine equipment, especially in forming machines. The device consists of a sensor connected via a speed measurement block and a slope converter to a slope measurement circuit. The sensor output can be connected via a position measurement block to a slope measurement circuit.

Description

The invention relates to a device for evaluating the force or torque of a working part of a machine.

At present various methods are used for sensing forces or moments acting in particular on the working part of the machine. It is the strain-gauge method. The disadvantage of the method is low long-term stability of measuring strain gauges and low resistance to external influences; furthermore, the high complexity of the wiring using a large number of transmission conductors, which limits their use for measuring forces on the rotating part, especially in difficult operating conditions, such as forming machines operating in forming operations. Another disadvantage is the low voltages and currents of the sensors, which gives rise to the possibility of interference with electric drives, especially in high power operations.

Another method is the use of piezoelectric sensors. The disadvantage is the low load current of the sensors, which may affect interference immunity, as well as low shock and vibration resistance.

To indicate the braking torque or force in forming machines, especially presses, a limit switch with a flexible design of the elements, for example a brake, causing

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260 239 torque or force * The disadvantage is the high structural complexity of the mechanical part and the impossibility of actual evaluation of force or torque, but only reaching a certain limit *

The above-mentioned disadvantages of the prior art largely eliminate the device for evaluating the force or torque of the working part of the machine according to the invention, which is based on the fact that the output of the sensor is connected to. the input of the velocity measurement block, the output of which is connected to the input of the slope converter, the output of which is connected to the first input of the slope measurement circuit. A further feature of the invention is that the sensor output is coupled to the input of a position measuring block, the output of which is connected to a second input of the slope measurement circuit *

An advantage of the device according to the invention is a substantial improvement in the evaluation of the torque or force, e.g. the braking torque of the forming machines, thereby increasing the safety of the work. It is possible to detect wear of brake linings or machine clutches. Another advantage is the simple construction of the machine and higher reliability, because the device contains no contact elements *

BRIEF DESCRIPTION OF THE DRAWINGS The invention is illustrated in greater detail by the accompanying drawing, in which a device for evaluating the force or torque of a working part of a machine is shown in block.

The output of the sensor 1 is connected to the input of the speed measuring block 2, the output of which is connected to the input of the slope converter J. The output of the slope converter 2 is coupled to the first input of the slope measurement circuit 6. Suitably, the output of the sensor 1 is coupled to the input of the position measuring block 2, the output of which is connected to the second input of the slope measuring circuit 6.

Sensor 1 output signal is processed in speed measurement block 2 * The signal value at the output of measurement block 2

The speed is dependent on the speed of the moving part at which the force or torque acting on the moving body is detected. As soon as the force or torque is applied to the body, the velocity changes. This change in velocity is dependent on the force exerted on the body and its mass or its moment of inertia. The signal corresponding to the velocity change is at the output of the slope converter 2 The 4-slope converter converts the velocity changes at the output of the velocity measuring block 2 into a signal whose value corresponds to the velocity change at a certain time interval. The amount of this slope is measured by the position measuring block 6. In the position measuring block j, the slope signal is further converted to a torque value or force acting on the body. In some cases, the moment of inertia of the body may vary depending on the position of the body. achieves greater accuracy of force or torque measurement.

The device according to the invention can be used wherever it is necessary to ensure the amount of force or torque acting on the movable, in particular the working part of the machinery, in particular in forming machines.

Claims (2)

Device for evaluating the force or torque of a working part of a machine, characterized in that the output of the sensor (1) is connected to the input of a speed measuring block (2), the output of which is connected to the input of the slope converter (3) with the first input of the slope measurement circuit (4). Device for evaluating the force or torque of a working part of a machine according to claim 1, characterized in that the output of the sensor (1) is connected to the input of a position measuring block (5) whose output is connected to the second input of the slope measuring circuit (4).