SU1471025A1 - Method of safeguarding press die working area - Google Patents

Abstract

The invention relates to the field of engineering, in particular, to equipment to protect the die space from the hands of an operator or an extraneous object. The purpose of the invention is to increase the reliability of protection. To do this, an ultrasonic field is created in the protection zone by periodically moving the signal by rotating the emitters. One by one receives the reflected signals from the opposite surface of the protected zone. Generate a signal to turn off the press in case of a decrease in the acoustic signal. The method allows to exclude the dead zone, to reduce the influence of interference and diffraction effects, since an object caught in the protective field creates a shadow zone on one of the acoustic receivers while maintaining the rest of the protective floor. 1 il.

Description

one

FIELD OF THE INVENTION The invention relates to mechanical engineering, in particular, to equipment for protecting the die space of a press from falling into the hands of an operator or an extraneous object.

The aim of the invention is to increase the reliability of protection.

The drawing shows a functional diagram of the device that implements the proposed method.

The device contains acoustic emitters 1, located on a rotating drum 2, mounted on the axis of the engine and connected to the output of the generator 3 through a rotating transformer (not shown), a reflective surface 4, on the opposite side of which is placed a line 5 with acoustic receivers 6 located on it , signal processing unit, including elements. You are NOT 7-11, the number of inputs and outputs of which are determined by the number of acoustic receivers, i.e. the length of the protected zone, the executive node 12.

The method is carried out in a skinny manner.

The drum 2 with the acoustic radiators 1 attached to it is rotated by an electric motor with the help of an electric motor in the direction of arrow A at a speed that provides

N5 SL

necessary inertia protective device.

When the drum rotates, each radiator irradiates the alternately reflecting surface with 4 acoustic oscillations with a smoothly varying (increasing) location angle (reflections).

In this case, the acoustic oscillations that are reflected from the surface 4 are alternately received by each of the acoustic receivers located on the ruler 5 in a geometrical line on the opposite side of the reflecting surface 4.

For example, the right-most receiver (at the drum) corresponds to the angles of location and reflection oi,, and to the extreme left - oSp

Acoustic receivers located between the extremes will alternately receive acoustic oscillations with the angles of location (reflection) of „„ ot L,

The rotational speed of the engine is chosen from the expression

 T,

N-N, where N is the speed in 1 s;

N is the number of radiating transducers on a rotating drum;

T is the probing time, t, e, the time of running around of all receivers by the reflected acoustic beam, should not exceed 10 s.

If a drum of acoustic emitters is placed on the drum, the engine revolutions per second is I

N

6 -10

1-2

16.6 (996 rpm)

If the periodic shift mode. Since the waves of the irradiating acoustic beam are generated by the electron scanning method, the scanning frequency is also chosen from the indicated expression

The electrical signals from the output of the receiver are amplified, detected, and in the form of DC voltages are fed to the inputs of the AND-NE elements 7-10, and from the outputs of the latter also to the AND-NOT element; JJ with four inputs and an output connected to the input of the actuating unit 12,

In the absence of a foreign object or hand operator in the protective field SO

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five

about

five

0

five

0

.

;

SO

55

At each of the six inputs of the NAND 7-10 elements, and consequently, at each of the four inputs of the NAND 11 elements, signals are present and through the execution unit 12 an enabling signal is given to activate the press with manual or automatic controls.

When a foreign object appears in the protective field and when the signal at the output of at least one of the acoustic receivers disappears or decreases, the signal at the output of one of the AND-NE elements 7-10 disappears, which leads to the disappearance of the signal at the output of the IS-NOT element 11, after As a result, a prohibitive signal is supplied to the press control system through the actuating unit 12 and the press cannot be turned on either by manual or automatic controls.

To increase the reliability of protection and increase the size of the protected area, the device can be equipped with a second drum at the opposite end of the area. Then, for each foreign object that has fallen into the protective field, two shadow zones are observed, which leads to a change in the signal not on one, but on two input elements of NAND.

The resolution of the method is determined by the minimum possible (constructive) distance between the centers of the acoustic receivers.

The advantages of the proposed method are to create a continuous acoustic protective floor, where there is no point, where the foreign object would not affect the attenuation of the acoustic signal, which essentially eliminates dead zones, as well as reducing the effects of interference and diffraction effects. e. A foreign object caught in the protective field necessarily creates a shadow zone at least on one of the acoustic receivers, while maintaining the remaining sections of the protective floor.

Claims (1)

Formula from. gaining A way to protect the die space of a press, which consists in creating an ultrasonic floor in a protective zone by emitting ultrasound5 1471025 of oscillations, reception of both reflected oscillations and off-press with a decrease in intensively received signals, which is characterized by the fact that with me They are created by periodically placing ultrasound tinges along the reflecting surface, and the reception of reflected vibrations is performed alternately on the opposite surface of the protected area.   U / U / /  V u l / a NWS  h a / / Protected area X f // f / f Protected area ./