SU683681A1 - Device for preventing clogging of thrasher - Google Patents

Description

The invention relates to the field of agricultural machine building, mainly to devices for preventing disturbances of technological processes, and can be used with units having a threshing apparatus.

A device for the prevention and clogging of a threshing apparatus, including a lever connected by tamping, a sector with slots for fixing the position of the lever 1 is known.

The disadvantage of the device lies in the fact that it is controlled manually from the cab of the tractor driver, and the reliability of control is not ensured.

It is also known a device for preventing the clogging of a threshing apparatus, including a rotational speed sensor of the threshing drum, a threshold element, an amplifier power, connected to an expansion element of the actuating mechanism. The increase in gaps in this device is produced by a jump in a certain amount, as soon as the rotation frequency of the threshing drum is reduced to a predetermined value. The large changes in the gaps are set large enough to (with a HIGH probability to prevent clogging in a wide range of changes in the feed and fpsi. With the mechanical properties of the plant mass 2.

Although in this device the loss of grain increases dramatically, only the damage caused by the increase in threshing gaps (up to 17-20%), these losses due to frequent device trips;: on cleaning in difficult conditions become very significant.

The purpose of the invention is to reduce the loss of grain under the ground when the device is activated.

The goal is achieved by the fact that in the proposed device, between the output of the threshold element and the input of the power amplifier, two one-shot are installed ;;. clock generator, element); AND, OR, and a controllable level switch of the threshold element and the actuator is made with a self-locking device. The output of the threshold element is connected to the first inputs of the AND elements OR, the second input of the element OR is connected to the output of the element AND, and the second input of the element AND to the output of the clock generator; -: pulses. The output of the element OR is not connected to the inputs of one-shot, the output of one of them is connected to the power amplifier, and the output of the other is connected to the switch of the threshold element.

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In addition, the actuator self-actuator consists of an electromagnet, which is coupled to a moving rod, a moving cam and a position lock, with the moving rod having a socket.

FIG. , 1 shows a block diagram of the device; in fig. 2 - a variant of the constructive EXECUTION of the executive mechanism.

The device for preventing the clogging of the threshing device (Fig. 1) contains a sensor / frequency in the threshing drum that is connected to the input of threshold element 2. U: the right threshold triggering level switch is designed as an electromechanical relay 3. The threshold threshold action level is set by connecting To its input one of the D1 two-way direct voltage Ll or U via the moving contact 4 of relay 5 and through the normally closed 5 or normally open 6 contacts. The output of the threshold element 2 is connected to the inputs of the elements OR 7 and AND 8. The second input of the element AND 8 is connected to the generator 9 clock pulses, and the output of the element AND 8 is connected to the second input of the element OR 7. The output of the element OR 7 is connected to the combined inputs of the one-shot JO and 11, generating pulses of a given duration, respectively, Ui and t / 2.

The output of the one-shot // is connected to the relay 3 for switching the level of the drive, and the output of the one-shot 10 by the power amplifier 13. The output of the power amplifier is connected to the actuator 13.

The executive mechanism 13 (Fig. 2) saddle the lever 14 connected by means of 15 to concave 75. Sector 77 has a number of cavities 75 for fixing the position of the lever .14 on the sector using the lock 79. The clamp is fixed on the movable rod 20, which passes through the handle 27, and is provided with a return spring 22 with a spring lock 23. On the stem 20 there is a seat 24 for the lock. Below sector 17 is a movable cam 25 for displacing the rod 20 from a fixed position. On the lever 14 is fixed to the electromagnet 26, -the core of which is connected to the movable rod 20. The winding of the electromagnet 26 is connected to the output of the power amplifier 12. A threshing drum 27 is fixed above the concave 16.

The device works as follows. The threshing mass is fed into the gap between concave 16 and the threshing drum 27. The gap is set by manual movement of the lever 14 along sector 77. In this case it is necessary to press the upper end of the movable

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75 sector 77. Since the movement of the rod 20 when pressing on its upper part is less than the movement caused by the movement of the electromagnet core when the device is triggered, the rod 20 is not locked in the depressed state when the working gap is set.

In normal operation, the speed sensor 7 of the threshing drum generates a signal that exceeds the trigger levels Ui and U of the threshold element 2. This corresponds to the start of operation of the device.

The triggering level U is equal to the voltage produced by the sensor 7 at the frequency of rotation of the threshing drum 27, corresponding to the start of clogging of the threshing apparatus.

The triggering level t / 2 is lower than the triggering level Ll by an amount corresponding to the possible reduction of the voltage at the output of sensor 7 due to a decrease in the frequency of rotation of the threshing drum 27 during the response time of the actuator 13.

In the initial state, the threshold element 2 and. Has an actuation level f / j set via normally closed contacts 5 and 5. In the case of overload of the threshing apparatus caused by an increase in the supply and / or moisture of the vegetable mass, the frequency of rotation of the threshing drum 27 decreases. output of sensor 7 is reduced to the level of operation L / i of the threshold element 2. The output voltage of threshold element 2 abruptly changes from zero to the maximum value and through the OR 7 element enters the launch of one-shot .10 and 77.

The impulse of the single vibrator 10 with the duration and, is supplied to the power amplifier 12 and after amplification to the winding of the electromagnet 26 of the actuator 13. The electro / magnet 26 triggers and displaces the measles (not shown in Fig. 2) associated with the movable rod 20 by the amount necessary for the latch jack 24 on the rod 20 to move to the latch 23. The pulse duration (/ 1 is 0.3-0.5 s and does not much exceed the time required for fixing the rod 20, so that the winding of the electromagnet 26 de-energizes after a reliable fixing st 20. When moving 20, retainer 19 is released from engagement with sector 77 and concave 16 is lowered under the action of its own weight and the reaction forces of the compressed vegetable mass. The golden gaps increase.

When lowering the drum 16, the lever connected to the concave 75 and 75 slides along sector 77 until the latch 19 reaches the inclined slipping of the inclined surface the latch 19 and the rod 20 connected with it move along the axis of the lever 14 on the honeycomb 25. This pin 20 leaves the fixed position and the return spring 22 moves the rod 20 along lever M upwards, the lock 19 enters the next depression after 18 of the cam 25, 18 u sector 17, the movement of the lever and the concave stop. In general, the value of the threshing gap is established.

If the initial increase in clearance is insufficient to prevent clogging, the rotational speed of the threshing drum will continue to decrease. In this case, the launch of the one-shot 10 will receive another signal, which will cause the initial actuation of the actuator 13, the concave 1b will move to the extreme lower position, providing maximum gaps between the bottom-half and the threshing drum 27.

The device works as follows.

Simultaneously with the launch of the one-shot 10, a single-shot 11 is started, which, while the pulse duration t / a, turns on the level-switching relay 4. The pulse duration t / 2 is set so that when the threshing apparatus is blocked by an initial increase in the gap, the rotational speed of the threshing drum has time during the pulse (2 increase to a value higher than the triggering level U. Relay 4 closes normally open contacts 3 and b, and thus sets a new level of operation of 1/2 1/2 threshold element 2. Since before this threshold element 2c worked at a level and less than t / 2, then after switching the voltage at the output of the threshold element 2 and abruptly decreases to "Str.

Further two cases are possible:

the voltage at the output of sensor 1 decreases to the level of operation U after the end of the pulse t / i;

the voltage at the output of the sensor / reaches the operation level L / g before the end of the pulse Ui.

In the first case, after a repeated jump of the voltage of the threshold element 2, the signal arrives at the start of the one-shot 10 through the element OR 7.

In the second case, the one-shot 10 is triggered by a pulse of the generator 9 through the elements AND 8 OR 7 after the end of the pulse fyi.

In all cases, when the frequency of rotation of the threshing drum to a value lower than the set operating level t / i, the sound and light signals (not shown) are turned on.

Restoration of gaps to the nominal value is performed after elimination of the risk of clogging.

Claims (2)

1. A device for preventing the threshing apparatus from clogging, comprising a threshing drum rotation frequency sensor connected to the input of the threshold element and a power amplifier connected to the control element of the actuating mechanism, characterized in that, in order to reduce grain losses under the ground when the device is triggered, the output the threshold element and the input of the power amplifier are equipped with two single vibrators, a clock generator, AND, OR elements and a controllable actuation level switch The second element is connected to the output of the threshold element connected to the first inputs of the elements AND and OR, the second input of the element OR is connected to the output of the element AND, and the second input of the element AND to the output of the clock generator, “the output of the element OR is connected to the inputs of one-shot, the output of one of them is connected to the power amplifier, and the output of the other is connected to the switch of the trigger level of the threshold element. 2. The device according to claim 1, characterized in that the actuator self-actuator is made in the form of an electromagnet, kinematically connected with a movable rod, a movable cam and a position lock, the movable core having a socket. t Sources of information taken into account. When expertise: 1.Patent of France No. 2250467, cl. A 01 F 12/28, 1974. 2.Patent of France No. 2201818, cl. And 01 D 41/12, 1974 (prototype).