SU686867A1 - Band saw - Google Patents

Description

(54) BAND SAW MACHINE

The invention relates to the timber and woodworking industry and can be used in the production of sawn timber and sleeper. Known band sawing machines, including the leading and driven pulleys, the shearer feed mechanism and the control unit (1. Also known as band-sawing machines, including the leading and driven pulleys, the control unit and the drive pulley and feeder 2 mechanisms connected to it, the disadvantage of such devices is the low reliability of the machine and the quality of the sawn timber. The purpose of the invention is to improve the reliability of the machine and the quality of the sawn timber by controlling the feed rate depending on the speed of the saw movement. so that the machine is equipped with a pulse generator and two delay lines connected in series with it, a two-input OR NOT circuit, a pulse counter connected through a switch with matching circuits, a valve and a driven pulley speed sensor, and the output of the first delay line is connected to one of the inputs of the OR-NOT circuit and the second inputs of the coincidence circuits, the output of the second delay line is connected to the second input of cxevtt OR-NOT and to the input of the zero-setting of the counter and 1 I1 pulses, the outputs of the coincidence circuits are connected to the control unit, and the outputs are yes The speed switch and the OR-LE circuits are connected via a valve to the input of a pulse counter. In addition, the sensor obsfotov alpine in the form of a converter angle. FIG. 1 given the functional scheme of the machine; in fig. 2 - in the belt diagram of the scheme; in FIG. 3, side view. The band saw machine includes a band saw 1, a led 2 and a leading 3 pulleys, a pulley drive 4, a feed mechanism 5, a control unit 6, a pulse generator 7, a delay line 8, an OR-NOT circuit 9, a pulse counter 10, a valve 11, a sensor 12 revolutions of the driven pulley in the form of the angle-code converter, the switch 13 and the coincidence circuit 14. The machine works as follows.

The feed mechanism 5 feeds the wood for cutting into the sawing machine 1 included in the work of the machine, begins to be introduced into the wood.

In the process of sawing timber when an overload occurs, the band saw 1 starts to creep relative to the driven pulley 2, causing it to freeze, while the drive pulley 3 fails to transfer the overload to the drive 4.

At the moment when these phenomena occur, the functional diagram comes into play (Fig. 1 and 2).

In the device, the pulse generator 7 is made with synchronization from the AC network and when turned on, it generates square-wave pulses, the pulse duration being longer than the pause duration, for example, by a factor of 1.

The angle-code converter 12 consists of a wheel, mounted on the driven pulley shaft, and a contactless sensor fixedly attached to the base of the feed mechanism, with ehms protrusions of the impeller entering into the groove of the contactless sensor. When the impeller rotates, the square impulses are removed from the output of the contactless sensor with a frequency that is proportional to the rotational speed of the impeller.

After switching on from the control unit 6, driving the pulley 4 and reaching the nominal speed of the pulleys 2 and 3 of the control unit, a command is generated to turn on the power supply circuits of the device elements. Pulses U are generated from the generator output, and the angle-code converter output, AC, to the input of the valve 11 receives pulses with a frequency proportional to the rotation speed of the driven pulley.

The valve 11 is open with a single potential of the circuit OR-LE 9, since there are no signals at its inputs. Through the open valve 11, the pulses U. arrive at the counting input of the counter pulses 10, where they are not heated. On the trailing edge of the pulse C of the generator of the pulses 7, at the output of the 1st delay line 8 a pulse is formed and which, through the OR-LE 9 circuit, records; ate valve 11.

The pulse Ug opens the first inputs cxet / si of coincidences 14. At the nominal mode, the pulse counter during the pulse duration U accumulates the number of pulses in which there are no signals on the commutator outputs of the pulse counter Ycom / tator 13, therefore the coincidence circuits 14 do not open and The control unit 6 signals are not received.

When a pulse is formed by the 2nd delay line 8 and the input of the zero setting of the pulse counter, a signal is received to reset the information and to prohibit the opening of the valve 11 through the OR-NO 9 circuit.

With the beginning of the slowing down of the movement of the band saw, the disk 1 1st disk 2 slows down, consequently, the pulse frequency of the angle-code converter 12 decreases (during the clock and). The pulse counter 10 for the measured time interval accumulates a smaller number of pulses, therefore one of the coincidence schemes is 14 at the moment.

the action of the pulse Ug opens, since at its inputs, commutated by the switch 13, the signals of the outputs of the pulse counter 10 appear. This signal is transported in a block

control 6, for example, in the feed rate change signal. If in the further work of the machine the revolutions of the driven pulley fall, then the next coincidence circuit in the manner described above

will generate a signal to the control unit 6 to turn off the drive of the pulley 4 and the feed mechanism 5 using the switch 6,

It is possible to switch the circuits from the outputs of the pulse counter 10 to the inputs of the coincidence circuits 14, thereby deconfiguring

possibility is baked

three or other matching schemes for a given number of revolutions.

Claims (2)

1. Band-sawing machine, which includes the driving and driven pulleys, the control unit and the drives of the driving pulley and the feed mechanism connected to it, characterized in that, in order to increase the reliability of the machine operation and the quality of the saw through materials movement of the saw, the machine is equipped with a pulse generator and two successively connected delay lines with it, a two-input ILII circuit, a pulse counter connected via a switch to the coincidence circuits, a gate and a speed sensor comrade 5 of the driven pulley, where the output of the first delay line is connected to one of the inputs of the OR-NOT circuit and the second inputs of the coincidence circuits, the output of the second delay line is connected to the second input of the OR-NOT circuit, and to the input of the zero setting of the pulse counter, the outputs of the coincidence circuit are connected to control unit, and the outputs of the speed sensor and the circuit OR are NOT connected via a valve cp to the counter input to them. pulses. 2. The machine according to claim 1, characterized by the fact that the speed sensor is designed as an angle-code converter .. Sources of information accepted in the examination 1, USSR Author's Certificate 150221, cl. B 27 B 13/10, 1966. 2. Automatic band saw LO-43, Technical description and operating instructions LO-43,00,00.000.TO, TsNIIME, Khimki, 1977, p. 4-74, rice, 1-24 (prototype).