SU959250A1 - Method of controlling electromagnetic reciprocation motor - Google Patents

Description

(5k) METHOD OF MANAGEMENT OF ELECTROMAGNETIC ENGINE OF RETURN-AND-TRANSITIONAL MOTION

This invention relates to methods for controlling a reciprocating electromagnetic motor. A known method of controlling an electromagnetic motor of reciprocating motion is by applying current pulses to the motor windings. However, in this method there is an excessive heating of the coils, a strong vibration of the body and a low efficiency of the engine. The purpose of the invention is to increase the true power and reliability. This goal is achieved by the fact that current pulses corresponding to one cycle of operation are served with a period not less than; total time of direct and reverse cor. Figure 1 shows the timing diagram of the duty cycle fed in a known manner; on IG.2- - time diagrams of the duty cycle supplied by the proposed method (and Fig.2 - with a delay of one half-wave of the mains current; in Fig. 3 - with a delay of two half-waves of the mains current; in Fig. 4 with a delay of three half-waves of the mains current) . FIG. The following symbols are taken: i.f, is the current impulse supplied to the forward travel coils; IQ is the impulse of the current supplied to the reverse coils; S is the striker stroke (the lower Totika line is the position of the striker at the moment of impact, the upper point of the LINE is the position of the striker at the end of the return stroke); T is the period of current oscillations in the network; t - current% rem. The current 1 and i flowing in the coils for the sake of simplicity in FIG. l-i is conditionally assumed to coincide with phase voltage. In fact, the current continues to flow for some time after the voltage passes through zero, i.e. due to coil inductance

the half-wave current is longer than the half-wave voltage.

As can be seen from the diagrams (Fig. 2, when a current pulse is fed into the return coil, the striker starts moving towards the buffer (in fig. Up). After the pulse is terminated, one or several half-current currents are delayed and the unit continues to compress by inertia without electromagnetic braking Buffer spring. After stopping in the rear dead center, the hammer begins to move in the direction of the tool under the action of the spring. At this moment, a half-wave current iff enters the forward travel coil, under which the striker accelerates its movement. strikes the tool. Then in the flyback coil enters The next (i.e., without pause) halfwave current I,

the duty cycle is repeated. If there is a pause (after the ip impulse), the back stroke time tjj increases, and its average speed VQ decreases, which leads to a decrease in the load on the buffer spring, oscillation frequencies of the striker and pressure, on the engine body through the spring, and consequently, increase in durability and reduce vibration. Elimination of electromagnetic braking increases the efficiency of the engine. The duration of the operating cycle of the TC is in the following dependence on the number of delayed half-waves m in the pause :.

T T (1 + W-), and the frequency of beats per minute

BO BO -,

.n

m

t (.

-f)

1+

u,

where T and f - respectively the period

and the frequency of current oscillations in the network.

So when powering the industrial frequency (f 50 Hz) with a pause of m 1 half-wave, the engine will work with the frequency

pg. 2000 A / min. (Fig ;,

with m 2

n P50 (xoo NR / mmi (Figure 4),

i

at m y

bQ-SO. --- -LOOO liAll wH. etc.

 H

A decrease in the frequency of the supply of current pulses by introducing a pause into the working cycle leads to a proportional reduction in the power of heat losses with the same energy of a single unit speed in the same engine efficiency. As a result

heating of the coils can be reduced to a predetermined value or the engine can be operated without overheating when. given HB.

Introducing a pause between pulses

current and Q is a necessary but not sufficient condition for obtaining all the indicated positive effects. The proposed method also provides for a certain sequence of alternation of current and pause pulses, namely: the current in the forward travel coil K. - the current in the return coil KQ - the pause -VTOK in the forward travel coil Kr, etc.

If the flow of the workflow is reversed, i.e. in direction

TO,

 pause

and

P

That is, the introduction of a pause will only reduce the frequency of impacts, and the electromagnetic braking during the back stroke of the striker, the load on the buffer, the efficiency and the vibration of the engine remain the same as with the known method of feeding.

The proposed method can be implemented using, for example, a synchronous non-spark switch type BP, which allows a large number of options for the inclusion of coils.

Claims (1)

Claims The method of controlling the electromagnetic motor by reciprocating motion by applying current pulses to the motor windings, characterized in that, in order to increase the power density and reliability, the current pulses corresponding to one cycle of operation are served with a period not less than the total time of the direct and reverse cor. xx Fcg.3 g, 5T FIG. four