CH650167A5 - MACHINE FOR SHREDDING BULKY MATERIAL. - Google Patents

Description

The invention relates to a machine for shredding bulky material by means of a cutting mechanism, which consists of at least two shafts driven in opposite directions and equipped with cutting tools and can be fed with the material to be shredded via an inlet shaft directed towards the working area of the cutting tools, the cutting mechanism drive being subjected to excessive loads in Dependence on a predetermined drive parameter from the forward run to the reverse run and back to the forward run is controlled.

In known machines of this type, the so-called reversing mode, in which the cutting mechanism motor is switched from the forward run to a temporary reverse run and then back to the forward run,

is a possibility to automatically remove possible blockages of the cutting unit, which result in a correspondingly high load on the cutting unit motor, by the machine. Practice shows, however, that the cutting unit can often not work freely because material falling from the chute will hinder the loosening and loosening of the material already in the working area of the tools. In such cases, the operator is therefore usually forced to intervene by hand and free the cutting tools from jammed comminution material.

It has also been shown that the cutting unit motor is not adequately protected against overload, unless extensive monitoring of the mains voltage is used to switch off the motor, for example, in the event of a dangerous single-phase run.

The object of the invention is to provide a comminution machine which operates largely without problems and which is not damaged when overloaded.

To achieve this object, the machine mentioned at the outset is designed in accordance with the invention in such a way that the inlet chute can be shut off with a blocking element. In the case of a machine which is already equipped with a rocker arm working in the area of the chute for re-stuffing material lying loosely in the chute, the rocker arm expediently serves as a blocking element.

The possibility of being able to shut off or push off the chute, directly above the working area of the cutting tools, has the particular advantage that if the tools have already become blocked or the cutting unit drive has been subjected to high thermal loads, e.g. a motor, a further falling of crushing material can be avoided by shutting off the chute so as to give the machine the opportunity to work freely, for example in reverse operation, without intervention by the operator.

To avoid damaging the cutting unit motor in the event of a critical single-phase run, certain times and minimum speeds can be specified for the run-up of this motor in reverse and also in forward run. If the cutting unit motor has not reached the relevant minimum speed within the respective set time, the motor is switched off immediately.

In addition, there is the option of working with a controller that takes the winding temperature of the cutting unit motor into account and to have the drive of the locking element or the rocker controlled so that the locking element stops and then stops when a pre-selected winding warning temperature is reached in the position just reached is controlled in the locked position.

In the accompanying drawing, an embodiment for the controls of the shredding machine is shown in simplified form in the form of a block diagram. The left part A in the illustration relates to the control for the cutting unit motor, the middle part B the control for the

2nd

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

3rd

650 167

the swing arm serving as a gate valve and the right part C a controller which monitors the cutting unit motor with regard to its operating temperature and triggers control and display processes when a warning temperature is reached. By pressing the start button S, all three controls A, B and C can be put into operation or made ready for operation at the same time.

Insofar as certain control, regulation, measurement and display blocks occur several times in one of the controls or belong to several of the three controls and also have to perform the same tasks and functions, these blocks have the same reference symbols in the illustration for reasons of simplification. Before a more detailed explanation of the structure and mode of operation of the controls is given, a list of the various circuit blocks with associated reference numerals and brief information on their task and function is given below:

S

Start by switching on the machine

1

“Blocking” lamp OFF

2nd

Flasher OFF

3rd

Break

4th

Cutting tool - reverse running ON

5

Cutting tool drive - ramp-up time

6

Minimum speed reached or exceeded?

7

Preselected time for reverse running ended?

8th

Cutting tool - reverse run OFF

9

Cutting tool - forward run ON

10a

Preselected minimum speed reached or exceeded

ten?

10b

Preselected minimum speed maintained or still

exceeded?

11

Cutting tool - forward run OFF

12

“Blocking” light ON

13

Flasher unit ON

14

“End of program by blocking” lamp

15

Cutting tool - forward run ON?

16

Swing arm manual switch ON?

17th

Swing arm pushing inwards

18th

Hydraulic unit ON

19th

Swing arm «pushing movement» - reversing pressure

enough?

20th

Cutter motor - warning temperature reached?

21st

Time program switched on?

22

Material available in the shaft?

23

Program working hours expired?

24th

System OFF

25th

Swing arm - outward movement

26

Swing arm - end position «outward movement»?

27th

Swing arm STOP

28

Hydraulic unit OFF

29

Program ends after automatic shutdown

30th

Cutter motor - limit temperature exceeded?

31

Is there a blockage?

32

Release the cutting unit drive

33

Lock the cutting unit drive

With reference to the respective explanations for the control blocks 1 to 33, the control circuit A for the motor of the cutting unit will now be described. After pressing the start button S, the cutting unit should always start running in reverse in order to loosen up the material to be shredded, which may have jammed in the cutting unit at the end of the previous shredding operation. In addition, among other things, the initial reverse run should always take place with the swing arm retracted, in order to always ensure a relieved run-up of the drive motor so that the run-up time itself can be used as a parameter determining the control processes.

Under the action of control block 1, the "Blocking" indicator light will normally not light up at the start of the program, unless there has been a blockage that has not yet been cleared at the end of the previously completed program. With the timer 3, a pause is switched on before the start of the reverse run, which is in principle only important in the event that the cutting unit motor is switched from the forward run to the reverse run in order to allow a period of time for the rotating masses to run out of the forward rotation direction in the To provide standstill.

After this time or pause has elapsed, under the action of the control block 4, the motor contactor for the reverse running of the cutting unit motor is activated, so that it starts up in reverse. The timer 5 specifies a time which can be set via the actuator r 1 for the masses to ramp up in reverse, up to a predetermined minimum speed. After this preselected time, the signal continues to the control block 6. The respective engine speed is measured or counted with a tachometer belonging to the control block 6. It is constantly queried whether the minimum speed has been reached or is still present during the reverse run. If applicable, the control block 6 develops an output signal “yes” that comes to the timing element 7, with which the total time for the reverse run is specified via the actuator r 2. This timer 7 controls via line a 1 the input of control block 6 with an output signal “no” until the set time for the reverse run has expired, so that the cutting mechanism will definitely have the opportunity to catch material that has not yet occurred have resulted in a block.

However, if the specified time for the reverse run has ended and the drive has not reached a minimum speed, this can only mean high mechanical overload or even blocking or possibly even breakage of the drive belt or other drive elements, in which case the control block 6 outputs an “no” output signal. or "Minimum speed not reached in the specified ramp-down time" and passed on via line a 2 to the control block 8 for the motor contactor, which then drops and immediately switches off the cutting unit motor. Subsequently, the control block 12 for the “blocking” indicator light and the “end of program by blocking” light 14 are put into operation via line a 3, so that the operator is optically indicated that there is a blockage in the reverse run, which they have determined after Remedy the cause. An automatic switchover of the motor to forward running does not take place in the event of this fault, since it can be expected that the motor will not reach the required minimum speed even in forward running.

The monitoring of the engine speed during the reverse run by the control blocks 5 and 6 results in addition to the shutdown in the event of a fault, and above all an extremely safe early shutdown of the single-phase run, which is thermally dangerous for the engine, without the network having to be monitored specifically. The same applies analogously to the speed monitoring described later when running forward.

If the minimum speed in reverse run has been reached within the specified run-up time and the set time for operation in reverse run has elapsed, a «yes» signal is generated at the output of control part 7 for «end of reverse run time»; The motor contactor drops out via the control block 8 and the cutting unit motor is disconnected from the mains. With the following timer 3 there is a pause for the mass outflow from the reverse run to si5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

650 167

4th

Cheren standstill, then the motor contactor for forward running occurs via the control block 9. The motor now starts forward, i.e. in the working direction of the cutting unit.

With the actuator r 1, a time is set on the subsequent timer 5 in which the motor must have run up to a predetermined minimum speed in the forward run. After the specified time has elapsed, the signal is forwarded to the speed measuring device 10a. If the motor has not reached the minimum speed within the specified ramp-up time, the control circuit 10a develops an output signal “no”, which leads via line a 4 to the shutdown 11, which stops the motor immediately, which in this case also involves the control block 12 actuated lamp and the lamp 14 comes to the display in the manner described above. This display will generally mean that the cutting unit could not work freely in the previous reverse run or that material was jammed in the cutting unit in the forward run.

If, on the other hand, the cutting unit motor has reached the minimum speed in the specified ramp-up time, the control circuit 10a generates an output signal "yes", which arrives at the input of a further control circuit 10b, which then takes over the monitoring of the drive speed in normal forward running operation, for example by queries with a frequency of 5 Hz whether at least the specified minimum speed is still maintained. Only if this is not the case is an output signal "no" generated, which causes the motor contactor for forward running to drop out via control block 9 in order to switch off the motor from forward running. Via line a 5 a signal then arrives at the circuit described above for the operation of the motor in reverse, namely at the input of the timing element 3. In this case, the cutting tool then performs a reversing process by following the motor in a previously explained manner the pause given by the timer 3 is first switched to reverse and then back to forward in the expectation that the cutting mechanism has cleared itself and that the motor can finally reach the required minimum speed during forward run within the specified ramp-up time. In principle, this reversing process can be repeated automatically any number of times if the operator does not switch off the drive or the control.

The control circuits 10a and 10b for monitoring the speeds in the forward run fulfill the task of a safe early shutdown in the event of a single-phase run, without the need for the otherwise expensive and quite complex devices for monitoring the symmetry of the three-phase network. If a mains phase fails during normal operation, i.e. when the cutting unit motor is running forward, the torque-speed characteristic curve of the motor receives a greatly changed profile. The tipping moment decreases sharply and the tightening torque even goes to zero. However, this means that the constantly monitored minimum speed is not reached and the machine is switched to reverse. Since the torque is now zero at a speed of zero, the motor can no longer start, which immediately triggers the mains shutdown. Thus, only the currentless pause time set by the timing element 3 and the ramp-up time set by the timing element 5 pass until the early shutdown. This time period of approximately 5 s by the timing element 5 is relatively short, so that the motor cannot be damaged due to a single-phase run.

The control B shown in the middle in the drawing for the used as a gate valve and before

The swinging arm of the cutting tools in the chute is designed in such a way that the swing arm only works with normal cutting device forward running, but with reverse running it blocks the chute, i.e. it should be retracted. After pressing the start button S, it is therefore first queried with the control element 15 whether the forward run for the cutting unit is switched on. If the cutting unit motor is stationary or running backwards, the control member 15 will avoid an output signal “no” at its input via line b 1 and will not start the swing arm drive, which works, for example, with a hydraulic unit to open the swing arm. In order to facilitate the forward run-up of the cutting unit motor and thus to create clear conditions for the setting of the run-up time and not to be hindered by material falling immediately from the chute, a pause of about 10 s is first switched on with the timing element 3 and via the subsequent control element 15 the reinsurance has been obtained that the forward running for the cutting unit is still maintained even after this break. If «no», this is reported back to the input via lines b 2 and b 1 in order to repeat the process described. If the answer is yes, that is, if the cutting unit is actually still running forwards, the control element 16 asks whether the additional manual selector switch for the swing arm is switched on, i.e. whether the swing arm should work at all.

If this selector switch is not switched on, the control element 16 outputs an “no” output signal to the control line b 3 via the control element 15 to the input of the control element 16 so that the rocker does not work. When the selector switch is switched on, on the other hand, the control element 16 sends a “yes” signal to the control 17 in order to release the rocker for an inward pushing movement. The swing arm should always start with a retracting movement.

After release of this rocker movement, the hydraulic unit is supplied with energy by the ON circuit 18 and the rocker is driven in the retracting direction of movement until an obstacle ends this movement, i.e. the rocker is obstructed, for example, by an unfavorable material or has finally reached an end stop. As a result, an increased pressure builds up in the hydraulic system of the swing arm drive, which is queried by the end position controller 19 working with a pressure gauge as to whether the predetermined maximum value of the working pressure or the end pressure for reversing the swing arm in the other direction of movement has been reached. If the answer is “no”, this is continuously reported to the control 17 via the line b 4, so that the rocker is still pressed in the retracting direction. Otherwise, when the specified pressure value is reached, the output signal "yes" from the controller 19 is processed in the downstream control blocks, i.e. it is checked whether additional material can or can be replanted.

These include a controller 20 that takes the winding temperature of the cutting unit motor into account. When the specified but still permissible warning temperature of the motor has been reached, no further material should fall into the working area of the cutting tools. This means that the swingarm should not be retracted from the retracted position to open the chute. When the warning temperature has been reached, the controller 20 sends a signal to the STOP control 27 via the line b 5 and the latter sends a STOP signal to the control element 15 via the control line b 3. Intermediate positions shut down and then moved to the locking position via control parts 15, 16, 17, 18 and 19, provided the warning temperature has been reached.

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

If, on the other hand, the temperature of the cutting unit motor is below the predefined warning temperature, the controller 20 develops the signal “no” that comes to the control element 15 and activates it in order to make a precautionary request whether the cutting unit motor is still operated in the forward direction. If no, the hydraulic unit is depressurized as described via the control parts 27, b 3 and 14 and the rocker is then moved into the locked position via the control parts 16, 17, 18 and 19. If "yes", that is, when the cutting unit motor runs forward, a corresponding signal comes from the control element 15 to a control circuit 21, which takes into account a program for certain blocking hours during which the machine may not run, for example due to noise pollution or for other reasons. If this control circuit 21 is not on the. If blocking hours are set, he develops a “no” signal which, via control line b 6, arrives at a control 25, which then triggers a pulling movement of the rocker to open the chute, as will be explained later in another connection.

However, if the control circuit 21 is switched on, which will normally be the case, an output signal "yes" comes to a test circuit 22, which checks whether there is still material to be shredded in the chute. If «no», the circuit 24 is immediately actuated via the line b 7 to avoid unnecessary operation, with which the entire system is switched off automatically, which is indicated visually as the «program end» with the display 29.

If, on the other hand, there is still material in the chute, the test circuit 22 outputs an “yes” output signal to a control circuit 23, which will check whether a blocking time which is not permitted for the operation of the comminution machine has been reached. If applicable, the system is switched off via the circuit 24 which receives a “yes” signal. If “no”, the controller 25 is activated.

This now controls the rocker from the retracted position backwards in an opposite working direction by reversing the hydraulic unit accordingly. The end position control 26 then checks via a limit switch whether the rocker has already reached the other possible end position. If the answer is “no”, feedback is given via line b 8 to the input of the control 25, so that the outward pulling movement of the rocker is continued into the release position. When the rocker is finally extended to the end position and the end position button is actuated, the end position controller 26 sends a “yes” signal to the control element 16 already mentioned in order to ask whether the manual selector switch for the rocker is still switched on. If applicable, a "yes" signal is given via the control line b 4 to the input of the control 17, so that the rocker arm is retracted for stuffing again and the processes explained are repeated with the respective alternative control options.

However, should the selector switch have been switched off for any reason in the course of the swinging operation, the control element 16 develops a signal "no" for the STOP control 27, which controls the control valves of the swinging hydraulics for unpressurized circulation and the

650 167

Swing drive with the OFF circuit 28 is turned off.

The control C shown in the right part of the drawing is influenced by the temperature of the drive motor for the cutting unit.

After pressing the start button S, the controller 30, which works with a temperature sensor, asks whether the permissible limit temperature of the motor has been exceeded. If this is the case, a "yes" signal is sent via line c 1 to a circuit 33 for immediate engine shutdown, and this is indicated by control block 13 with a flasher unit.

If the limit temperature of the cutting unit motor is not exceeded, the test circuit 31 is triggered by a signal “no” in order to then determine whether the motor may be blocked due to its speed monitoring. If applicable, the control block 13 for the flasher unit is activated via the line c 1 with the output signal “yes” then generated. If, on the other hand, there is also no blockage, the test circuit 31 sends a “no” signal to the release circuit 32, which then releases the drive for the cutting unit motor.

With the connected control 20, which is also included in the function of the control B and takes the winding temperature of the cutting unit motor into account,

it is still checked whether the warning temperature has been exceeded. If “yes”, the control block 13 for the flasher unit 13 is put into operation. In addition, the swing arm does not open any further, but shuts off the material supply as a slide after the next tamping movement until the warning temperature falls below again. In this context, reference is made to the controller B, in which the function of the controller 20, which operates in a temperature-dependent manner, is described.

If the warning temperature has not been exceeded, the controller 20 develops an output signal “no”, which leaves the flasher unit switched off via the display circuit 2 or switches off again via the control block 13 if a signal was given beforehand, but in the meantime the warning temperature has fallen below again . This operating state is reported back to the input of the control 30 via the line c 2, so that the display and test process is continuously repeated in connection with the warning temperature.

Finally, the following should be pointed out. The shredding machine can also work with more than two shafts driven in opposite directions and equipped with tools, in which case two adjacent shafts are then normally driven in opposite directions.

If a locking device is used in the manner described, its functions should be taken over by the swing arm, which is usually provided anyway. Instead of the rocker, however, a separate shut-off device could also be provided, such as a locking slide or a locking flap. Incidentally, the term “chute” should be understood to mean a structure that feeds the material to be shredded directly to the cutting tools. This can be, for example, a funnel-like shaft as part of the machine or a building.

5

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

S

1 sheet of drawings

Claims (8)

650167 PATENT CLAIMS 1.Machine for the shredding of bulky material by means of a cutting mechanism, which consists of at least two shafts driven in opposite directions and equipped with cutting tools and can be loaded with the material to be shredded via an inlet shaft directed towards the working area of the cutting tools, the cutting mechanism drive being subjected to excessive load depending on a predetermined drive characteristic value can be controlled from the forward run into the reverse run and back again into the forward run, characterized in that the chute can be shut off with a blocking element. 2. Machine according to claim 1 with a swinging arm working in the area of the chute for stuffing loose material lying in the chute towards the cutting mechanism, characterized in that the rocker serves as a blocking member. 3. Machine according to claim 1 or 2, in which the cutting mechanism drive is controlled at the beginning of a program first in the reverse run and a predetermined time for the reverse run is specified, characterized in that a minimum speed for the reverse running cutting mechanism drive is specified that the respective Speed of the cutting unit drive is monitored and that the cutting unit drive is switched off from the reverse run if it has not reached the minimum speed within a specified time. 4. Machine according to one of claims 1 to 3, characterized in that a run-up time and a minimum speed are specified for the operation in the forward run, that the speed of the drive running in the forward run is monitored and that the cutting mechanism drive is switched off when the drive within the The target time has not reached the minimum speed. 5. Machine according to one of claims 1 to 4, characterized in that the locking member is moved into the locking position when the cutting mechanism drive runs backwards. 6. Machine according to one of claims 2 to 5, characterized in that a rocker drive is controlled so that the rocker first executes an inward pushing movement at the start of a cutting program. 7. Machine according to one of claims 2 to 6 with a hydraulic drive for the rocker, characterized in that the working pressure prevailing in the hydraulic system is monitored with an end position control which permits a further inward pushing movement of the rocker when a predetermined maximum value of Working pressure has not yet been reached, and the above-mentioned pushing movement is ended and an outward pulling movement of the rocker is effected when the said maximum pressure is reached. 8. Machine according to one of claims 2 to 7, characterized in that a control is provided which takes into account the winding temperature of a motor provided as a cutting mechanism drive, that a motor warning temperature is specified and that the control controls the rocker drive in such a way that the rocker at When the warning temperature is reached in the position just reached, it is stopped and then moved to the locked position and remains there until the engine warning temperature has fallen below again.