JPH0115444B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a conveyor control circuit in an article conveying device. In particular, distributing cigarettes or similar rod articles exiting an article-making machine at high speed in a continuous or semi-continuous stream to a packaging machine in sequence;
It relates to the control of a manufacturing process in which the production rate and packaging rate, or any one of them, changes from time to time in response to periodic suspension of operation of individual manufacturing machines or when products are determined to be defective. This type of equipment with multiple manufacturing machines and multiple packaging machines is commonly used in the cigarette manufacturing industry, so the invention will be described using cigarette manufacturing as an example, but it is equally applicable to other products. .

<Prior Art> When a device is in operation that includes a large number of manufacturing machines connected to a large number of packing machines by a tobacco conveyor, the number of good cigarettes produced and the packing machines used to pack these cigarettes are calculated. There is often an imbalance between the capacities. For this purpose, storage devices such as Molins "OSCAR" are usually provided, which act as a buffer storage between the manufacturing and packaging machines. This storage device takes in cigarettes when the production capacity is greater than the packaging capacity (for example, when a certain packaging machine is out of order), and when the capacity of the packaging machine is greater than the production capacity (for example, when the production machine stops, or if the (When a large number of cigarettes are not discharged from the production machine) the cigarettes are returned to the device.

<Problems to be Solved by the Invention> If the conveying device has one or several manufacturing machines and a large number of packaging machines, rational control of the distribution of tobacco to the packaging machines can be achieved relatively easily. that is, placing sensors at various points in the flow path, for example at the junction where a storage device connects to a conveying device;
When an excess of tobacco is detected, the tobacco is taken into the storage device, and when a shortage is detected, the tobacco is returned to the system. This is usually easily accomplished by changing the direction of the conveyor connecting the junction to the storage device.

However, when a large number of manufacturing machines and a large number of packaging machines are connected, it becomes difficult to avoid complex interferences between the conveyors that disrupt the flow that is transmitted around the equipment, resulting in prolonged unstable conditions. This makes it difficult to maintain a smooth flow of tobacco.
One of the reasons for this is that it takes some time for the cigarette to move from one sensing point to another, so a disturbance in the flow at one point will not be detected at the next point until a certain amount of time later. , it is conceivable that at that delay time, new disturbances will occur in the following points mentioned above.

The Applicant's co-pending application no. 20962/72 (and the corresponding German publication no. 2621564) discloses a means for defining a connection area and at least two tobacco conveyors, each conveying tobacco to and from the joining area. a first drive means for driving one of said conveyors, and a second drive means for driving the other conveyor.
The speed of the second drive means is such that the second drive means operates at a predetermined speed relative to the speed of the first drive means as long as the drive means and other factors determining the flow of tobacco into and out of the junction zone remain constant. and a second drive means responsive to the volume or pressure of the tobacco in the joining zone such that the speed of the second drive means varies from said predetermined value over a predetermined range in response to the volume or pressure of the tobacco. and a sensor for controlling an associated speed adjustment mechanism.

When controlling the speed of a conveyor in response to the volume or height of cigarettes (corresponding to the quantity of cigarettes), a control signal is sent from a sensing circuit that senses the volume or height to the conveyor drive means to determine the quantity of cigarettes. The speed is corrected to the desired value. Conventionally, this speed correction value had a linear relationship with the volume and height of the cigarettes, regardless of the operating speed of the conveyor. Therefore, if the sensitivity of the sensing circuit, that is, the relationship between the speed correction control signal and the volume or height of cigarettes, is suitable for relatively high speeds, the sensitivity would be too high when the conveyor or low speeds are used, and it would be difficult to keep the cigarettes at a predetermined amount. The control becomes jerky and the amount of tobacco never settles to the desired value. On the other hand, if the sensitivity is adjusted to the low speed side, when the conveyor speeds up, the control will not be able to keep up and the cigarettes will overflow or gaps will form. Therefore, it is necessary to change the sensitivity depending on the current conveyor speed.

<Means and effects for solving the problem> The conveying device to which the invention is applied comprises at least one device in which each joint region normally carries tobacco in and out of this joint region, and one of which is controlled according to flow conditions. a plurality of junction zones having an "upstream" conveyor and a "downstream" conveyor, a separate drive means connected to each conveyor, and a separate drive means provided in each junction zone and responsive to the volume or pressure of the tobacco in the junction zone; a sensor and a control that determines the speed or speed and direction of the conveyor to be controlled by combining a quantity signal of tobacco present in the tobacco stream upstream and/or downstream of the joining zone and a correction signal from the sensor; and control circuit means for generating a signal.

Normally, when there are no abnormal disturbances in the system, the sensor is in an equilibrium position in which the sensor has little or no function, so that the control signal is an algebraic sum of the quantitative input signals. The sensor preferably operates as an error correction device in that it senses changes from the desired conditions in the connection area and "feeds back" appropriate correction signals to the control circuit.

Here, "upstream of the connecting area" means an area from which tobacco flows into the connecting area. The tobacco may be supplied from a conveyor line connected to one or more production machines, directly from the production machine, or from a line downstream of other equipment, in which case the other equipment is connected to the Cigarettes are taken in and out of the line so that a certain number of cigarettes are normally fed into the area per unit time. And when there are many manufacturing machines connected to a common line, typically
A first signal is related to the sum of operating speeds of multiple manufacturing machines. Similarly, the "downstream" direction is the direction in which excess tobacco (if any) flows out of the splicing zone, although tobacco could also be returned to the splicing zone from downstream if there is a downstream storage device.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a conveyor control circuit for an article conveying device that optimally controls the amount of articles depending on the speed of the conveyor.
In order to achieve this object, the structure of the present invention is as follows. That is, a control circuit for a conveyor in an article conveying device, wherein the conveying device has a junction point where the conveyor joins at least one other conveyor, and the control circuit connects the other conveyor to the junction point. means for generating a signal representing the quantity of articles flowing into a point or flowing out from said junction point to said other conveyor per unit time; and a deviation signal responsive to a deviation of the quantity of articles at said junction point from a desired value. and a sensing circuit that generates
The sensing circuit generates a deviation signal of opposite polarity when articles flow from the junction to the other conveyor than when articles flow from the other conveyor to the junction; Sensitivity control means for the sensing circuit increases the sensitivity of the sensing circuit when the signal representing the quantity becomes large and decreases the sensitivity when the signal representing the quantity becomes small; and means for controlling the speed to be proportional to the sum of the speed.

The control circuitry may be configured to respond to a change in direction when one of the plurality of conveyors or other devices providing the input signal changes direction. That is, for example, one of the upstream conveyors
When it becomes necessary to reverse the table and eliminate the problem, so that the normal flow to the junction is abruptly changed to flow out of the connection, the control circuit can use any suitable method, e.g., by changing the direction of the downstream conveyor. By continuing to control the downstream conveyor at , tobacco can be fed into the splice instead of being taken from the splice. In this way, even in systems with a large number of junctions, suitable deposition conditions are maintained throughout the system, and tobacco is automatically removed from the storage device as needed to ensure uniformity at all conveyors and connections. This ensures sufficient accumulation, eliminating the occurrence of vacancies and traffic jams.

Therefore, in large and complex machines, signals representing the quantity per unit time at various positions of the machine are distributed to conveyor control circuits provided at connections at various other positions, and these control circuits are It also needs to be configured to work effectively.
In large-scale tobacco manufacturing factories, various machines are generally driven by separate power supply circuits to distribute the load. For example, they are connected to different phases of a three-phase power supply. Therefore, it is dangerous to connect the speed signal generator of one machine directly to the control circuit of another machine or conveyor.

Therefore, according to another aspect of the present invention, there is provided a control signal distribution device for use in a device in which a manufacturing machine and a packaging machine as described above are linked, the size of which is related to the quantity of articles per unit time. means for generating an AC conveying signal and modulating it with said DC signal; and insulating coupling means for connecting said modulated AC signal to an input of at least one conveyor controller. A control signal distribution device is provided.

Preferably, an isolation transformer is used as the coupling means. This is because each isolation transformer can be provided with a number of separate secondary sides so that a number of control circuits can be provided with mutually separate control signals. Preferably, an amplifier is provided in the primary circuit of the transformer to supply each control circuit with a signal of sufficient magnitude.

Further, it is preferable to set the frequency of the AC carrier signal to about 1 KHz and modulate the amplitude with the DC signal. When amplitude modulating, the incoming control signal can be detected by interconnecting the secondary sides of a pair of transformers through a phase sensitive detector such that the polarity of the rectified output from the detector changes in accordance with the incoming control signal. Determine the polarity of

In the case of a simple connection, in which the tobacco elevator is provided by two conveyors, it is advantageous to provide a simple control device. For example, the control device can be used to combine flows from one or more cigarette manufacturing machines when the manufacturing machines are operating at a much slower speed than the conveyor to which they are connected. For this purpose, conveyors of the "inverted T-connection" type are used, for example as shown in Figures 5 or 6 of applicant's co-pending application no. 52473/76.
Elevator bonding equipment is used. According to an example of a connecting device described in the above-mentioned application, a flow gap or gap occurs in one of the conveyors connected to the elevator, and the operating speed of the elevator is halved until this gap or gap is filled. controlled.

Moreover, since the speed control of the elevator needs to be continuously variable, according to yet another aspect of the present invention, there is provided an apparatus for controlling an elevator connected to a pair of conveyors for transporting tobacco from a manufacturing machine, comprising: means for forming a stack of tobacco on the input side of each conveyor; a transducer acting on each stack to provide a speed control signal to each conveyor proportional to the height of the corresponding stack; A controller is provided that includes a conveyor control circuit having a summing amplifier that produces a proportional output and an elevator motor control circuit that controls the speed of an elevator according to the sum of the conveyor speed control signals.

By providing an inspection device for each manufacturing machine downstream of the pile forming means of each conveyor, a small amount of tobacco can be taken out from the conveyor and the quality can be visually inspected, so that a gap is created in the flow at this portion. Therefore, downstream of the inspection device, a deposit detection means is provided for each conveyor, which is connected to the input side of the corresponding summing amplifier. The pile detection means provides a zero input in place of a corresponding pile height signal when a flow gap occurs.

<Examples> Hereinafter, the present invention will be explained in detail by examples with reference to the drawings.

FIG. 1 shows a production line which is connected to two cigarette manufacturing machines S1, S2 feeding via conveyors C1, C2 to a packing machine S3 and to a conveying device via a third conveyor C3. A storage device R is provided. This storage device R is provided to absorb excess product that cannot be processed by the packaging machine. As is clear from the figure, if two cigarette manufacturing machines each supply S1 and S2 cigarettes to the production line per minute at a constant rate,
The speeds of conveyors C1, C2 must correspond to S1 and S1+S2 per minute, respectively. Similarly,
If the packing machine packs at a rate of S3, the conveyor carrying the surplus to the storage machine must move at a speed corresponding to (S1 + S2) - (S3).

However, in reality, cigarette manufacturing machines do not operate at a constant speed, and some cigarettes are determined to be defective before being packaged, so the speed of the conveyor cannot be determined in advance and the speed at which the conveyor is fed to each connection point cannot be determined in advance. It is necessary to change the speed of the conveyor depending on the actual amount of tobacco (per minute). In the case of a simple conveying device, the above-mentioned speed change can be carried out by providing a space at each connection for a certain amount of tobacco to accumulate, and monitoring the height (level) of the accumulated tobacco there, for example, with a mechanical sensor. Ru. That is, as the height of the pile increases, the speed of the conveyor that draws tobacco from the connection increases, and the height of the pile causes a corresponding decrease in the speed of the conveyor. However, for more accurate control, a control circuit as shown in FIG. 2 may be provided at each connection.

This circuit receives two speed signals: a first speed signal from a second conveyor C2 "upstream" of the junction and a second speed signal also from a second conveyor S3 directly connected to the cigarette making or packing machine. and a signal indicative of the level of the articles to generate a control signal for controlling the first conveyor C3. Although the example shown here controls a conveyor that connects a junction to a storage device, it can of course be used as a circuit to control a conveyor between this junction and other connections with slight modifications. It is. In a system such as that shown in FIG. 1, the number of "first signals" is one or more depending on the number of conveyors upstream of the connection.

The circuit of FIG. 2 operates as follows. The first from two tacho-generators,
A second speed signal, i.e., a speed signal of the second conveyor C2 (representing the quantity of articles flowing into or out of the junction by the conveyor C2) as well as a speed signal of the second conveyor S3 (representing the quantity of articles flowing into or out of the junction by the conveyor C2)
(representing the amount of article flowing into or out of the junction) is supplied to terminals W14, W15. These signals are attenuated by a network consisting of resistors R1, R2 and R3, R4, respectively, and brush noise or ripple filtered by a network consisting of resistors R6, R9 and capacitor C3 and a network consisting of resistors R7, R10 and capacitor C4. and is supplied to voltage tracking amplifier A.

A pair of Zener diodes Z1, Z2 and Z3, Z4 prevent saturation of the amplifier input if an excessive input occurs that would reverse the polarity of the amplifier output.

Potentiometers VR1 and VR2 are used to adjust the distribution of each signal at the input of summing amplifier B1. The sum signal of the two signals is connected to the input of another summing amplifier D1 via a variable attenuator VR3 and a resistor R27.

The unattenuated output at pin 7 of said summing amplifier B1 is connected to a diode bridge D5-D6-D7-D8.
The diode D is directly supplied to the connection point of the diodes D7 and D8, and the
It is also supplied to the connections 5 and D6. As a result, terminal W18 is always positive with respect to terminal W19, regardless of the polarity of pin 7 of summing amplifier B1.
The voltage between terminals W18 and W19 is applied across an external level sensing potentiometer VR5.
The voltage of the slider of this potentiometer VR5 is connected to terminal W17. The slider slides as shown between the ends of the potentiometer VR5 depending on the level of the article, and its position is representative of the level of the article. Therefore, this potentiometer
The voltage across VR5 is proportional to the conveyor speed,
At very low speeds, the forward voltage drop across the diode is greater than the supply voltage. Therefore, resistor R12, diode D9, resistor R13, diode D10
A bias network consisting of the following is provided to provide sufficient bias to eliminate malfunctions at low speeds. By providing these bias networks, sufficient power is provided to the circuit even when the conveyor is "creeping."

The output of the sensor potentiometer is connected to the terminal W17 to provide a voltage for correcting the conveyor. This voltage is fed to a unity gain buffer E (resistor R21 prevents damage to the sensor potentiometer VR5 in the event of an amplifier failure), the output of which is passed through a resistor R37 to the input of the amplifier D1. It is added to the output of summing amplifier B1 via variable attenuator VR3 and resistor R27. The output of amplifier D1 is supplied to terminal WO5 via a filter consisting of resistor R35 and capacitor C5 to provide a field control signal for the conveyor motor. The output is also supplied to the unity gain inverting amplifier D2. Diodes D13, D14 form a gate circuit that selects the negative signal from pins 7, 1 of the two amplifiers D1, D2 (terminal WO5 is connected to terminal WO9 by means of a relay contact), the output of this gate is connected to the resistor. It is supplied to terminal WO7 via R36 to provide speed signals in both forward and reverse directions. terminal
When WO5 and terminal WO9 are disconnected, the motor is prevented from reversing.

Furthermore, the circuit described above provides rapid correction if the detected tobacco level is too low or too high. The correction operation will be described below when the first conveyor under control is moving in the forward direction. The voltage across the diode network is resistor R1
6. It is supplied to a resistor string consisting of variable resistor VR4 and resistors R17 and R18. Resistor R16, variable resistance
The connection point of VR4 and the connection point of resistors R17 and R18 provide two reference voltages for the level detection circuit. These two reference voltages are connected to resistors R23 and R2
5 to pins 6, 2 of amplifier C.
The output of pin 1 of buffer E (same as the sensing potentiometer voltage) is connected to the non-inverting input of the amplifier via resistors R22 and R24. The voltage W17 of the slider of the potentiometer VR5 is the resistor R16,
When the voltage is higher than the voltage at the connection point of variable resistor VR4, pin 5 becomes more positive than pin 6, giving a positive output to pin 7. Therefore, the diode D11 is forward biased, and through the resistors R38 and R29,
At the input of amplifier D1, the voltages are summed.
At the same time, pin 3 becomes more positive than pin 2 and diode D12 is reverse biased. When the voltage on slider W17 is lower than the voltage at the junction of resistors R17 and R18, pin 2 of amplifier C becomes more positive than pin 3, and the output at pin 1 drops to the negative supply voltage, forward biasing diode D12. do. This voltage is then added at the connection point between resistors R28 and R29. Similarly, pin 6 becomes more positive than pin 5 and the amplifier output switches to a negative supply potential, reverse biasing diode D11. When the voltage of the slider W17 is between the two reference voltages, both amplifiers are switched, so that the diodes D11 and D12 are reverse biased, and the outputs of these amplifiers no longer affect the summing point. When diode D11 becomes forward biased, the voltage at the input of the summing amplifier increases, thereby increasing motor speed. When diode D12 is conducting, summing amplifier D1
The voltage at the input of is decreased, reducing the motor speed. Conversely, when the first conveyor under control is moving in the opposite direction, the forward bias of diode D11 will decrease the motor speed and the forward bias of diode D12 will increase the motor speed.

As an example, the constants of each element in the circuit are as follows.

R1, R3, R12, R13, R21...2.2K
Ω R2, R4, R6, R7, R17, R37, R
38...1KΩ R8, R31, R35...4.7KΩ R16, R18...1.5KΩ R5, R9, R10, R11, R22, R2
3, R24, R25, R32, R33...10KΩ R30...22KΩ R14, R15, R19, R20, R27, R
28...47KΩ R26, R29, R34...100KΩ R36...68KΩ VR1, VR2, VR4...5KΩ VR3...1KΩ Z1, Z2, Z3, Z4...BZY38 type D5, D6, D7, D8, D9, D10, D1
1, D12, D13, D14...IS923 type C1, C2...100μF, 15V (operating voltage) C3, C4...0.1μF C5...1μF Integrated circuit...RC4558 type In addition, two or more input channels with amplifier "A" If provided, it is necessary to add two or more speed signals at the input of the circuit. If one or more signals are provided by a remote device operating from a separate power source, the circuits shown in FIGS. 3 or 4 may be used to provide appropriately separated signals.

The apparatus of FIG. 3 can be used if there is no need to detect changes in direction of the conveyor providing the input signal. The device shown in the figure includes a speed signal generator 2. For example, the generator is a simple tachometer that produces a DC output signal with a level proportional to the input speed. The output of the generator is preferably about 1KHz with a pair of FETs 4 and 6.
The signal is supplied to a chopper circuit having a multivibrator 8 operating at . The alternating current signal obtained from the chip is adjusted to the desired power level by a simple audio amplifier (selecting such an amplifier is easy).
The signal is amplified to drive the primary side of the transformer 12. Multiple fully separated secondary sides can be provided,
The input power is commensurate with the number of separate control circuits driven by the secondary, each control circuit having a suitable rectifier at its input.

If it is necessary to detect a change in direction of a conveyor providing an input signal, the circuit of FIG. 4 is used. This circuit is arranged in the same way as the circuit shown in FIG.
The output from the multivibrator, which has FETs 4 and 6, a multivibrator 8, and an amplifier 10 and supplies a modulated AC control signal to the primary side of the transformer 12, that is, a non-modulated "carrier wave" is transferred to the second transformer 14.
It is also supplied to the primary side. The second transformer includes a pair of diodes 16 and 18 connected in series with its secondary terminals 20 and 22, respectively. The diodes are coupled through a pair of capacitors 24,26. The secondary side of the transformer 12 is connected to the secondary side center tap 28 of the transformer 14 and the capacitor 2.
4 and 26 connection points. This configuration has the effect that when a signal is applied to the transformer 14, the charge on the capacitor 26 charged via the diode 16 is greater than the charge on the capacitor 24 charged via the diode 18. . Therefore, the rectified output terminal 30 of the device
becomes positive with respect to the output terminal 32. Conversely, when the signal applied to the transformer 12 and the signal applied to the transformer 14 are in opposite phases, charging of the capacitor 24 becomes dominant and the polarity of the output voltage between the terminals 30 and 32 is reversed. Obviously, the magnitude of the output is proportional to the level of the modulation signal, so terminals 30 and 32
The output of will represent the input from the tachometer 2, both in magnitude and polarity.

Although the transformers 12 and 14 are shown as each having one secondary winding, they actually have a plurality of windings like the transformer in FIG.
Therefore, multiple outputs are obtained which are separated from each other.

Under some circumstances, the provision of a single tachometer does not provide sufficient information for accurate control. For example, if a tachometer is associated with a cigarette making machine and the cigarettes are periodically rejected by an inspection device between the machine and the connection to be controlled, the signal obtained by the tachometer is It does not indicate the true speed of tobacco being fed to the connection.

In order to eliminate this problem, an additional detection device is provided downstream of the inspection device, and the additional detection device is configured to stop the tachometer after a predetermined time delay when the trail of tobacco flow ends. Alternatively, a detection device may be placed downstream of the inspection device to generate a pulse train corresponding to each good cigarette without using a tacho oscillator at all. These pulses are then fed into a frequency or pulse rate to voltage converter to generate the appropriate signal which will be zero when the flow ends.

In the embodiment shown in FIG. 5, a thread is provided in which a "stack" elevator 102 carrying a relatively wide stream 104 of tobacco is connected to conveyors 106,108. The junction 110 between the conveyor and the elevator is as shown in FIG. 6 or FIG.
Corresponds to Figures 5 and 6 of No. 52473/76.
According to the apparatus of FIG. 6, a conveyor 15 is constructed from two separate cigarette making machines (not shown).
2,153 tobacco deposits 150,
151 is pushed up to the lower end of the elevator.

As each pile approaches the elevator, it is separated by a corresponding band 152 or 153 and a pair of cooperating short bands 154 or 1.
55. The above band 154,1
55 are horizontally spaced lifter bands 158,1
It is stretched over the ends of lower pulleys 156 and 157 for 59.

The two tobacco stacks that have passed through the stationary transfer sections 160, 161 are moved obliquely upward by the bands 162, 163 and reach the push-up section 170 between the lower ends of the lifter bands. The bands 162, 163
One of the two bands is one wide band, while the other band consists of two narrow bands spaced apart on either side of the wide band. These bands 162, 163 are stretched over pulleys 164, 165 adjacent to the transfer section, and also stretched over another combined pulley 166, 167. The combination pulley is formed from a number of relatively self-rotatable parts that allow the band to be shifted in the appropriate direction. A triangular fixed cover is provided above the pulley 166, which prevents both bands from coming into contact with the tobacco at the same time in this area and assists in guiding the tobacco diagonally upwards.

FIG. 7 shows a modification of the device shown in FIG. In the figures, the same numbers represent equivalent parts. Separate pulleys 166A, 166B and 167A, 167 laterally spaced apart combination pulleys 166, 167
The difference is that it was replaced with B. In this example, each band 16
2,163 consists of a pair of laterally spaced narrow bands, these pairs of bands 152,15
3 around the ends of pulleys 164 and 165, respectively. Bands 152 and 153 also return around pulleys 164 and 165. Each band 162,
163 is driven by pulleys 167A and 167B which cooperate with pinch roller 169.

If the elevator needs to be emptied after each working period, elevator bands 158, 159 and 2
Set of bands 152, 154, 162 and 15
At least one of 3,155,163 may be reversed.

Tobacco supplied from and exiting each conveyor 106, 108 cigarette making machine (not shown) is deposited on the input side of the conveyor in a known manner.
A transducer for monitoring the height of the stack is a sensor 112 pivotally mounted to the top of the stack.
has. The sensor is also connected to a "rotational induction detector", a device in which a change in the position of the sensor causes a corresponding change in inductance. Therefore, Molins "Oscar"
(Molins “OSCAR”) A conveyor 106 that undergoes and responds to alternating current inputs to conventional conveyor speed control circuits, such as those used in storage equipment.
or 108 speeds are controlled.

The output signal from each speed control circuit 114 is also supplied to a separation buffer device for separating input and output, as shown in FIG. 8, for example. This buffer device consists of a pair of FETs 130 and 132 and preferably about 1KHz.
It is equipped with a chopper circuit consisting of a multivibrator 134 that operates at . The AC signal obtained from the chopper is amplified by a simple audio amplifier 136 to the power level required to drive the primary of a transformer 138. The secondary side of transformer 138 is connected to a rectifier 140 which provides the output of the buffer device. Apart from this, an optical coupling device may also be used. The output signal of buffer 116 is connected to the input of summing amplifier 118, the output of which is fed to elevator motor control box 120. Therefore, the speed of the elevator is equal to that of the conveyors 106, 108.
is controlled according to the sum of the inputs to.

A conveyor opening is provided downstream of the input side of each conveyor for inspection purposes. Therefore, if the operator manually removes some cigarettes, a gap is created in the cigarette stream. To provide the system with the ability to sense such flow changes, deposit detectors 122, 124, including, for example, photocells, are placed between the inspection station of each conveyor 106, 108 and the junction 110. . When one of the conveyors becomes vacant, the above-mentioned detector activates the switches 126 and 12.
8 and ground the corresponding input of amplifier 118, thereby reducing the speed of elevator 102.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a cigarette manufacturing line, Fig. 2 is a circuit diagram of a conveyor speed control circuit, Fig. 3 is a schematic circuit diagram of one embodiment of the control signal distribution device, and Fig. 4 is another embodiment of the dispensing device. An example circuit diagram, FIG. 5 is a simplified configuration diagram of the control device, FIG. 6 is a detailed diagram showing an example of the structure of the connection part near the cigarette elevator, and FIG.
This figure shows a modification of FIG. 6, and FIG. 8 is a circuit diagram of the control device section of FIG. 6. C1, C2, C3... Conveyor, S1, S2...
... Manufacturing machine, R ... Storage device, S3 ... Packing machine, 2 ... Tachometer, 4, 6 ... FET, 8 ... Multivibrator, 10 ... Audio frequency amplifier, 1
2, 14...Isolation transformer, 102...Elevator, 106, 108...Conveyor, 112...Sensor, 114...Speed control circuit, 116...Buffer, 118...Summing amplifier, 120...Motor control box , 122, 124...deposition detector,
130, 132...FET, 134...Multivibrator, 136...Audio frequency amplifier, 13
8...Isolation transformer, 140...Diode bridge, 150, 151...Tobacco stack, 152,
153...Band, 154,155...Band,
156,157...Pulley, 158,159...
...Elevator band, 160,161...Transit section, 162,163...Band, 164,165
...Pulley, 166, 166A, 166B, 1
67, 167A, 167B...Combination pulley,
168...Cover, 169...Pinch roller, 1
70...Pushing part.

Claims (1)

[Scope of Claims] 1. A control circuit for the first conveyor C3 in an article conveying device having a first conveyor C3 and a second conveyor C2, S3; The other second conveyors C2, S3
The control circuit has a junction point where it merges with the other second conveyor C2,
means for generating a signal representing the quantity of articles per unit time flowing into said junction from S3 or flowing out from said junction to said other second conveyor C2, S3; and the quantity of articles present at said junction; a sensing circuit that generates a deviation signal according to the magnitude of the deviation from a desired value; and a means for generating the signal that increases the deviation signal of the sensing circuit as the signal representing the quantity of the article increases. and a sensitivity control means of the sensing circuit that corrects the deviation signal by making it smaller when the symbol representing the quantity of the articles becomes smaller; means for controlling the speed to be proportional to the sum of the deviation signal, and thus the speed of the first conveyor is increased to a speed proportional to the sum which changes in response to a change in the deviation signal of the sensing circuit. 1. A control circuit for a conveyor in an article conveying apparatus, wherein the speed of the first conveyor is increased or decreased, and the speed increase or deceleration of the first conveyor is controlled in a direction in which the deviation signal decreases.