JPS6235779B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for sorting tablets after producing tablets by pressing while measuring the individual press pressures in the matrix of a tablet machine. It also relates to a device for actuating an exclusion device via a press rod proximity actuated switch depending on the press rod.

In known tablet machines, the production of tablets takes place in a matrix which is arranged on a rotating matrix disk, in which the powder is pressed by means of a press rod. To ensure that all tablets are of consistent quality, the press pressure applied during the production of individual tablets is constantly measured and compared to target values. If the measured press pressure of a tablet exceeds the upper target value and falls below the lower target value, the tablet must be classified. For this purpose, an exclusion device is used, which device is placed behind the press position and is activated when a defective tablet as described above approaches. The exclusion device is actuated in known devices via a signal applied to a shift register from a press pressure monitoring device and a first press rod proximity actuation switch.

The known devices have the following drawbacks. That is, because the so-called screening frequency is low, it is not suitable for high-capacity tablet machines. The sorting frequency refers to the number of possible sorting processes in a unit time, for example, one second. This is due to the following reasons. This is because, in the known device, no automatic transition of the release point for the sorting element is made as a function of the speed of the tablet press.

Known sorting devices have a sorting frequency of up to 30 Hz, i.e. the maximum number of sorting operations possible per second is 30.
It is times. A high-capacity tablet machine of modern construction already produces about 80 tablets per second.

The aim of the invention is to create a device for tablet sorting, which allows a substantially greater sorting frequency compared to known devices. The above objects are achieved by the present invention as follows. That is, the exclusion device is additionally controlled via the second press rod proximity-actuated switch and the electronic time selection element in a temporal relationship taking into account the rotational speed of the mother disk and the position of the mother mold relative to the exclusion device. This is accomplished through manipulation. In this case, the present invention provides for the tablets to be sorted to be lowered between two tablets revolving one behind the other, particularly from above, and to move the identified defective tablets in another direction. A guide wall that is lifted back to its original position after running is used, and the guide wall is actuated by an electromagnet. The lifting electromagnet is then released in a time-dependent manner as a function of the rotational speed of the master disk or the pressing frequency. That is, if the rotational speed is relatively high, the release time is selected in such a way that the lowering of the guide wall begins when the tablet traveling in front is still located below the guide wall. In contrast to the above, if the master disk runs at a smaller speed, the operation of the lifting electromagnet to make the next tablet travel in a different direction will require that the tablet traveling in front has already traveled under the guiding wall. This will be done when the process is finished. As a result of the above, on the one hand, when the rotation speed is slow, the tablet traveling in front collides with the guide wall and breaks, and on the other hand, when the rotation speed is high or the pressing frequency is high, the guide wall may cause the tablet to fail. is prevented from being lowered to its lowest position before hitting it.

The features described above are achieved by the present invention in the following manner. This means that the pulses generated when a defective tablet is measured are not sent from the press pressure monitoring device, which is implemented as an electronic logic circuit, to a shift register and used directly to operate the lifting magnet. , are first introduced into the time selection element, which transmits a signal to the delay time dependent on the press frequency, which is signaled to the time selection element by the second press rod proximity activated switch. Therefore, it is done by sending it first. Furthermore, among the time selection factors, the time for inertia when the exclusion device is operated is also taken into account. In order to minimize the time required for this inertia, it is expedient to move as little mass as possible when operating the exclusion device. It is therefore considered expedient according to the invention that the guide wall of the device is made of titanium. Having perforations in the guiding wall helps to reduce the mass. Sufficient rigidity can be obtained by arranging one or several ribs.

The connection between the guide wall and the lifting magnet is made via a rod that is connected to an iron core that is movably mounted in the lifting magnet.

The operation of the exclusion device via the electronic time selection element is further carried out as follows. In other words, when the number of rotations of the master disk is low, that is, when the pressing frequency is low,
The guide wall remains in the lowered sorting position for a longer period of time than would be the case if the rotational speed of the master disk was high, and therefore Not only is the activation of the lifting electromagnet dependent on the rotation speed, but also the duration of the activation cycle of the exclusion device is carried out in such a way that this cycle consists of raising and lowering the guide wall and then staying in the lowered position. .

The present invention will be explained by the following examples based on the drawings.

In FIG. 1, a master disk 1 is arranged to pass below a press position 2. In FIG. In the area of this press position 2, the tablet 3 in the matrix is pressed by a press rod. The press pressure applied when manufacturing each tablet 3 is measured,
If no defects are recognized in the tablet by this measured value, the tablet is removed from the matrix disk 1 by the ejection piece 4.
from there to the groove 5. Defective and defective tablets are guided into a groove 6 for defective tablets. For this purpose, a guiding wall 7 is used which is connected to a lifting electromagnet 8. By the lifting electromagnet 8, the guiding wall 7
is inserted between two tablets 3 that are lined up one after the other, and guides the next tablet recognized as a defective tablet in a different direction without contacting the tablet in front.

According to Fig. 2, the press pressure is measured by strain measuring device 1.
It is done with 0. A measuring amplifier 11, which is designed as a carrier frequency amplifier or a direct voltage amplifier, is connected to the measuring device. The measured press pressure is input from the measuring amplifier 11 to an electronic logic circuit 12 which is designed as a press pressure monitoring device.
This logic circuit 12 processes the input press pressure signal by comparing it with two set target limit values. The evaluation in the logic circuit or the press pressure monitoring device 12 is performed when the maximum value detection signal of the press pressure from the press rod proximity operation switch 13 is input. That is, the first press rod proximity actuation switch 13 signals the exact point in time when the measured press pressure has reached its maximum value. Furthermore, the first press rod proximity actuation switch 13 provides a signal to a shift register 14 located behind the press pressure monitoring device 12 indicating when a new shift movement of the exclusion device is to be made. The transition register accounts for a certain number of press operations until the tablet is conveyed from the press position to the position of the exclusion device. The number of actuations is determined by the arrangement of the press position and the position of the exclusion device, but is a value independent of the rotational speed of the master disk. The influence of the rotation speed or pressing frequency of the master disk is taken into account by the second press rod proximity actuated switch 15 and the electronic time selection element. That is, a signal is provided from the transition register 14 to the electronic time selection element 16 of the present invention, to which the second press rod proximity actuated switch 15 is also connected, and in addition, a signal is provided by the second press rod proximity actuated switch 15. The time selection element 16 is then provided with a signal defining the exact beginning of the selection time and the duration of the delay at which the time selection element issues the signal. This duration depends on the pressing frequency or the rotational speed of the master disk.

The second press rod proximity activation switch 15 begins to issue a signal when the approaching press rod reaches a predetermined distance, and the press rod that has passed by the switch moves a predetermined distance along the periphery of the master disk. The signal is continued to be emitted until the signal reaches the point. The duration of the signal is therefore related to the circumferential speed of the master disk or to the speed of movement of the press bar. That is, when the signal persists for a long time, the tablet machine operates slowly. In this case,
The quantity "X", which will be explained in detail below, is increasing. In one practical embodiment, the above "X" is
It is set by the electronic time selection element to last three times the duration of the signal provided by the second press rod proximity activated switch 15. This is done in the most favorable proportion to the amount of time "W" required due to the relatively short inertia of the exclusion device. It should be taken into account that in this case the so-called control time, i.e. the duration itself of the signal given by the second press rod proximity actuation switch 15, can in fact be shorter than the amount "W". . On the other hand, the quantity "X" must be greater than the quantity "W", so that the quantity "X" is selected to be three times as long as the signal duration of the second press rod proximity-actuated switch 15. However, adopting three times the duration as mentioned above is not necessarily necessary if the tablet machine is operating relatively slowly. This is because in such a case, the signal duration of the second press rod proximity actuated switch 15 is long. The time selection element 16 is fed on the one hand with a signal from the second press rod proximity actuation switch 15 and on the other hand with a signal from the transition register 14. Both signals are processed in the time selection element 16 in such a way that at time C an activation signal is applied to the lifting magnet 8.
At this time, amplification is performed in advance by the output amplifier 17.

Various temporal relationships are shown in the diagram of FIG. In FIG. 3, A = time of release of the time selection element 16 B = time of the guide wall 7 reaching the sorting position C = time of release of the lifting electromagnet 8 , this amount can be freely selected within a certain range.

W = activation time or time required for inertia of exclusion devices 7, 8 = 5 ms = constant Y = X - W (time from A to C) In this case X is given by the following formula:

X=(F・S)/(D・π・(rotation speed/second)) However, S=selected pitch distance (mm) of the press rod scale, determined by the second press rod proximity switch 15, for example. control distance F = multiple, for example 3 = delay time coefficient D = diameter of the circumference where the press rod is located (mm) revolutions/second = number of revolutions per second From the above formula, the delay time X is the control distance and the press rod position It is confirmed that there is a proportional relationship with the circumferential diameter and rotational speed at is the only variable. It is also clear that the larger the rotational speed, the smaller the value of the quantity X becomes.

The following is further recognized from the above equation. That is, the rotational speed or circumferential speed, the delay time factor F and the time W required for inertia must be processed in the electronic time selection element 16. In this embodiment, the examination of the rotation speed is carried out by the second press rod proximity actuation switch 15, and the control time (X/3) of the switch is one of the rotation speeds of the master disk. represents quantity. The pulses generated by the oscillator within the control time are counted in a counting register. The accounting is done in the forward direction. On the other hand, at one-third of the counting frequency, counting is done in the negative direction. After a certain amount of time has elapsed, there is a point in time when the state in the counting register becomes 0.
This time corresponds to three times the control time. As already mentioned, the exclusion devices 7, 8 must be released as early as the time W required due to their inertia. Therefore, W is subtracted from the triple control time. In the embodiment shown, therefore, the exclusion devices 7, 8 are not released when the state of the counting register becomes zero, but are released by the exclusion devices preselected by means of a coded switch. is released when a value corresponding to the time required for the inertia of is reached. Once the ejecting device 7, 8 has been moved to the ejecting position (UT), it remains in that position until a good tablet comes again. This is because, if defective tablets come in succession, it is not appropriate to repeat the operation shown in FIG. 3. In order to move the guide wall 7 upwards from the exclusion position (UT) to the non-exclusion position (OT), a rotation speed-dependent time selection is required. This is because in this case too, the inertia of the exclusion device must be taken into account. In this case, the rotational speed is examined as already described above. The time W required for the inertia of the exclusion device is also subtracted, but by logical connexion the release pulse serves to move from the exclusion position (UT) to the non-exclusion position (OT).

The lifting electromagnet 8 for moving the guiding wall 7 as a component of the exclusion device is a polarized lifting electromagnet with two fixed positions for the iron core using two permanent magnets. For this purpose, the iron core is guided movably in a coil between two permanent magnets. By energizing the coil, the core is pulled to one end and held by a permanent magnet. The iron core entrains the guide wall 7 via the rod 18.
When the polarity is changed, the core is pulled to the other end and held by another permanent magnet. The guiding wall 7 shown in FIG. 5 is made of titanium to reduce mass and is provided with reinforcement 19 and holes 20 to reduce weight.

FIG. 4 shows schematically how the temporal operation of the exclusion devices 7, 8 differs for different rotational speeds of the master disk. When the master disk rotates at a high speed _V1 , the guide wall 7 is lowered at a point when the tablet C traveling in front is still located under the guide wall 7.
Done in Z ₁ . The raising of the guide wall again begins at the time Z ₂ when the next tablet B to be excluded or its matrix reaches the guide wall 7 . If the rotational speed V ₂ is very low, the lowering of the guide wall 7 takes place at a time point Z ₁ when the tablet C traveling in front has already crossed the plane of the guide wall 7 and moved forward. In this case, the point Z ₂ at which the guide wall is raised is set after the matrix of the tablet B, which has been selected as defective, has passed under the plane of the guide wall. Activation of the exclusion device is therefore delayed at low working speeds or press frequencies. This is because the lowering and raising of the guide wall always takes place for equal duration. On the other hand, when the pressing frequency is low, the residence time is longer than when the working speed is high. This avoids that no sorting of the tablets takes place if the rotational speed of the master disk is extremely slow. A feature of the present invention is that the residence time changes from the start to the end depending on the rotational speed as shown in the two embodiments shown in FIG. The point of release of the electromagnet can be moved forward in the case of high working speeds or can be released at a suitable time, depending on the rotational speed of the master disk in relation to the position of the master mold generally being moved. clearly recognized.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a portion of the tablet machine; FIG. 2 is a schematic diagram of the exclusion device with measuring device and circuit; FIG.
The figure is a diagram showing the time course of the exclusion process, Figure 4 is a schematic diagram showing two temporally different exclusion processes, and Figure 5 is a diagram showing the time course of the exclusion process.
The figure is a side view of the guide wall. In the figure, 1...mother disk, 7...guiding wall, 8...lifting electromagnet, 15...second press rod proximity switch, 16...time selection element, 18...rod, 19...stripe, 20...hole, be.

Claims (1)

Claims: 1. Press pressure monitoring controlling an exclusion device via a transition register in cooperation with a first press bar proximity-actuated switch 13 which separates the tablets after press production in the matrix of the tablet machine. In the device comprising a device, the sorting device further comprises a second press rod proximity actuated switch 15 and an electronic time selection element 16, by means of which the exclusion devices 7, 8 are connected to the master disk 1.
The exclusion devices 7 and 8 are controlled based on the time dependence relationship between the circumferential velocity of the device and the position of the matrix with respect to the exclusion device, and the exclusion devices 7 and 8 are
1. A sorting device comprising a lifting electromagnet 8 operated by a lifting electromagnet 8 and a vertically slidable guide wall 7 having a rod 18 to which the iron core of the electromagnet is connected. 2. Device according to claim 1, characterized in that the guide wall 7 is made of titanium. 3. The device according to claim 1 or 2, characterized in that the guide wall 7 has striations 19. 4. Any one of claims 1 to 3, wherein the guide wall 7 has a hole 20.
The equipment described in section.