PLC Automation of Cartoning Machine IC 150

(PLC Automation of Cartoning Machine IC 150)

2. Introduction

A Programmable controller is a solid state user programmable control system with

functions to control logic, sequencing, timing, arithmetic data manipulation and counting capabilities. It can be viewed as an industrial computer that has a central processor unit, memory, input output interface and a programming device. The central processing unit provides the intelligence of the controller. It accepts data, status information from various sensing devices like limit switches, proximity switches, executes the user control program store in the memory and gives appropriate output commands to devices like solenoid valves, switches etc.

Input output interface is the communication link between field devices and the controllers; field devices are wired to the I/O interfaces. Through these interfaces the processor can sense and measure physical quantities regarding a machine or process, such as, proximity, position, motion, level etc. Based on status sensed, the PLC issues command to output devices such as valves, motors, alarms, etc.

Programmer unit provides the man machine interface. It is used to enter the application program, which often uses a simple user-friendly logic.

BENEFITS OF PROGRAMMABLE CONTROLLERS

Programmable controllers are made of solid state components and hence provide high reliability.

They are flexible and changes in sequence of operation can easily be incorporated due to programmability. They may be modular in nature and thus expandability and easy installation is possible.

Use of PLC results in appreciable savings in Hardware and wiring cost.

They are compact and occupy less space.

Eliminate hardware items like Timers, counters and Auxiliary relays. The presence for timers and counters has easy accessibility.

PLC can control a variety of devices and eliminates the need for customized controls.

Easy diagnostic facilities are provided as a part of the system. Diagnosis of the external systems also becomes very simple. Thus easy service/maintenance.

Programming devices provide operator friendly interface with the machine. Being an outcome of the latest art of electronics technology, Programmable controllers provide higher level of performance with computers is possible. Useful management data can be obtained and maintained.

It has total protections against obsolescence and has wide scope for upgrade

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Cartoning Machine IC 150

GENERAL

The IC 150 is fully automatic intermittent horizontal cartoners that automaticallyopen/fold cartons, infeed products, insert leaflet into the cartons, coding and thenautomatically close the carton. The IC 150 can be fitted with a wide range of feeding units which automatically separate and orientate the product before it is carefully introduced into the previously opened and erected carton. The PLC automatically controls and manages all packaging steps with any malfunction being indicated on the display, stopping the machine if necessary so in order for any remedial action to be taken

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Machine Layout

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3. Process Description

3.1 Product Infeed

Blister Dispensing

Blister Magazine: Here blister arrives in blister magazine through adjustable extension conveyor of Blister forming machine. The extension conveyor mounted on blister magazine & it is fixed with knob. Blister magazine is equipped with two capacitive sensor ‘Blister minimum load sensor’ & ‘Blister maximum load sensor’

Keyence PLC: A Keyence KV 10T PLC used here which controls various operation of Blister dispensing .It works on 24V dc supply. Input to Keyence PLC is given by main PLC through alleged connector. Blister dispensing works due to proper synchronization of Keyence PLC & main PLC. Keyence PLC has four outputs two of which are further connected to four EM coils & remaining two are connected to sensors.

Electromagnetic Coils: Four EM coils holds blister inside blister magazine when it gets energized it allow dropping blister inside each pocket of bucket conveyor. At time only one blister is dropped. Number of blister fall inside each packet is decided by settings made on control panel.

Bucket Conveyor

This bucket conveyor is just below the blister magazine having fixed number of bucket whose sizes can be changed as per pack size. While moving along the blister conveyor ‘Product check sensor’ check weather exact number of blisters fell inside each bucket or not

3.2Carton FeedingThe machine is equipped with carton magazine where the carton is picked up on conveyor. The carton magazine is equipped with a carton minimum load photocell called as ‘Minimum carton load sensor’

Carton is moved by conveyor to the line parallel to pocket conveyor called carton line. While being moved by carton chain rack carton is formed & prepared to receive the product.

Other photocells are fixed in the magazine they check for proper carton pick up.

3.3Carton Forming

Carton is formed while being moved along the line parallel to pocket chain.

Carton forming process is pneumatically operated. Two suction paths pick up & set the two carton sides apart further mechanical components fold the side flaps

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The chain transport & forming conveyor are equipped with two photocells ‘Upper forming check’ & ‘Lowe forming check’

Carton above the conveyor is guided at the top by mobile guide here an inductive sensor called as ‘Carton guide up sensor’ is attached for this.

3.4Product Insertion

Products are inserted into the carton by pusher.

Pusher is equipped with safety device which move back the pushers guide in case the product is harmed to be inserted.

Safety system is controlled by the sensor’ Pusher Safety Sensor’ that avoid further damages to the machine. If blisters are not placed properly or they are not present inside pocket or bucket pusher comes in contact

Leaflet is also inserted along with blisters inside the carton by the pusher. Mobile plate plays important role in this process. Mobile plate catches the leaflet meanwhile pusher pushes the fixed number of blisters inside mobile plate in such away that leaflet holding all blisters moves inside carton.

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3.5 Side Flap Closing & Numbering

For proper side flap closing each carton (whether properly formed or not) are mounted on carton carrying conveyor guide before that every carton has to through central numbering device. Flaps are closed by simultaneous movement of central comb located in between two side comb. While carton moved along conveyor carton code is read by carton code reader then with the help of flap closure flap A , A’& B,B’ are closed further lower flap numbering & upper flap numbering is performed.

Knives placed along side of central gripper comb folds the flap C, C’ & tuck in closer perform final closing.

At the end rejected cartons are diverted to different direction & properly formed cartons are come out through outlet.

OPERATION SEQUENCE

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4. Proximity Sensors Used in Machine Tools

A proximity sensor is a sensor able to detect the presence of nearby objects without any physical contact. A proximity sensor often emits an electromagnetic or electrostatic field, or a beam of electromagnetic radiation (infrared, for instance), and looks for changes in the field or return signal. The object being sensed is often referred to as the proximity sensor's target. Different proximity sensor targets demand different sensors. For example, a capacitive or photoelectric sensor might be suitable for a plastic target; an inductive proximity sensor requires a metal target.

The maximum distance that this sensor can detect is defined "nominal range". Some sensors have adjustments of the nominal range or means to report a graduated detection distance.

4.1 CAPACITIVE SENSOR

4.1.1Principle

Capacitive dimensional measurement requires three basic components:

• A probe that uses changes in capacitance to sense Changes in distance to the target,

• Driver electronics to convert these changes in capacitance into voltage changes,

• A device to indicate and/or record the resulting voltage change.

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http://en.wikipedia.org/wiki/Inductance

http://en.wikipedia.org/wiki/Photoelectric

http://en.wikipedia.org/wiki/Capacitive

http://en.wikipedia.org/wiki/Electric_field

http://en.wikipedia.org/wiki/Infrared

http://en.wikipedia.org/wiki/Electromagnetic_radiation

http://en.wikipedia.org/wiki/Electrostatic

http://en.wikipedia.org/wiki/Electromagnetic

http://en.wikipedia.org/wiki/Sensor


A continuous 50-kHz excitation square wave applied to the source (SRC) side of the sensor, to set up the electric field in the capacitive sensor. The stimulus creates an electric field in the sensor that partially protrudes through the overlay plastic. The capacitance-input side is connected to the input of the capacitance-to-digital converter

4.1.2 Blister minimum/ maximum load sensor

Blister magazine is equipped with two capacitive sensor called as ‘Blister minimum load sensor’ & ‘Blister maximum load sensor’. Blister minimum load sensor gets off if no. of blister in magazine goes below minimum level & blister maximum load sensor takes care of that number of blister should not go beyond predetermined limit

4.2 INDUCTIVE SENSOR

Inductive proximity sensors are noncontact proximity devices that set up a radio frequency field with an oscillator and a coil. The presence of an object alters this field and the sensor is able to detect this alteration. An inductive proximity sensor comprises an LC oscillating circuit, a signal evaluator, and a switching amplifier. The coil of this oscillating circuit generates a high-frequency electromagnetic alternating field. This field is emitted at the sensing face of the sensor. If a metallic object (switching trigger) nears the sensing face, eddy currents are generated. The resultant losses draw energy from the oscillating circuit and reduce the oscillations. The signal evaluator behind the LC oscillating circuit converts this information into a clear signal. The measurement of proximity, position and displacement of objects is essential in many different applications: valve position, level detection, process control, machine control, security, etc.

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Important specifications for proximity sensors, inductive include operating distance, repeatability, field adjustable, and minimum target distance. Rated operating distance is the distance at which switching takes place. Repeatability is the distance within which the sensor repeat ably switches. It is a measure of precision. Field adjustable sensors can be adjustable while in use. Depending on the sensor's technology, there can be minimum target size requirements.

Load configurations are also important parameters to consider. Inductive proximity sensors may switch an AC load or a DC load. DC load configurations can be NPN or PNP. NPN is

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a transistor output that switches the common or negative voltage to the load; load connected between sensor output and positive voltage supply. PNP is a transistor output that switches the positive voltage to the load; load connected between sensor output and voltage supply common or negative. Wire configurations are 2-wire, 3-wire NPN, 3-wire PNP, 4-wire NPN, and 4-wire PNP. Switch types can be normally open (NO) or normally closed (NC). Switch specifications include whether or not the switch is normally open or normally closed. Switch repeatability and maximum switching frequency are important parameters to consider. The switch may be a NAMUR type switch, a specialized switch for switching a resistive load. Requires an external amplifier.

4.2.1 Pusher Safety Sensor

Pusher is equipped with safety device which move back the pushers guide in case the product is harmed to be inserted.

Safety system is controlled by the sensor ’Pusher Safety Sensor’ that avoid damages to pusher. If blisters are not placed properly in bucket of pocket conveyor or they are not present inside pocket or bucket, pusher comes in contact in that case pusher moves backward. In this case alarm condition is occurred & machine stops

4.2.2 Product check sensor

While moving along the blister conveyor ‘Product check sensor1’ check weather exact number of blisters are present inside each bucket or not whereas ‘Product check sensor2’ senses extra blister in pocket of blister conveyor. If such condition occurs blisters are rejected form blister rejection outlet here machine does not stop

4.2.3 Carton magazine right/left safety sensor

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They are the carton guide up sensors. It ensures proper alignment of the cartons.

4.2.4Clutch machine safety sensor

The operation of this sensor is mainly in two stages:

1). ON: When this sensor is ON, then the main motor works properly.

2). OFF: When this sensor is OFF, then either the main motor is not working properly or a load fault had occurred in the working of the motor. Hence this clutch moves outwards.

4.2.5 Hand wheel sensor

This senor is mainly used for manual machine check. This sensor mainly operates in two modes:

ON: When this sensor is ON, the machine works automatically.

OFF: When this sensor is OFF, the machine is working in manual mode.

4.3 FIBER OPTIC SENSOR

4.3.1 Principle

A fiber optic sensor is a sensor that uses optical fiber either as the sensing element ("intrinsic sensors"), or as a means of relaying signals from a remote sensor to the electronics that process the signals ("extrinsic sensors"). Fibers have many uses in remote sensing. Depending on the application, fiber may be used because of its small size, or the fact that no electrical power is needed at the remote location, or because many sensors can be multiplexed along the length of a fiber by using different wavelengths of light for each sensor, or by sensing the time delay as light passes along the fiber through each sensor. Time delay can be determined using a device such as an optical time-domain reflectometer.

4.3.1 Leaflet Check Sensor

It checks that leaflet magazine has properly released the leaflet & gripper has picked it up if it is not pusher does not push blister into carton & at finally carton is rejected

4.3.2 Carton upper/lower forming check

It is mainly used to check the carton is properly formed or not i.e. it is fully opened or not & is ready to accept blisters along with leaflet

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4.5 PHOTOELECTRIC SENSOR

Photoelectric Sensors detect objects, changes in surface conditions, and other items through a variety of optical properties.A Photoelectric Sensor consists primarily of an Emitter for emitting light and a Receiver for receiving light. When emitted light is interrupted or reflected by the sensing object, it changes the amount of light that arrives at the Receiver. The Receiver detects this change and converts it to an electrical output. The light source for the majority of Photoelectric Sensors is infrared or visible light (generally red, or green/blue for identifying colors). These Fibers Units can be used in a variety of applications, such as detecting the presence of work pieces and positioning

4.5.1 Minimum carton load sensor

The carton magazine is equipped with a carton minimum load photocell called as ‘Minimum carton load sensor’ checks for presence of carton inside magazine. It gets off if number of cartons goes below minimum level or magazine is empty.

4.5.2Minimum leaflet load sensor

The leaflet magazine is equipped with a ‘Minimum leaflet load sensor’ checks for presence of leaflet inside magazine. It gets off if number of leaflet goes below minimum level or magazine is empty.

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5. Control Elements

5.1 Solenoid valve

5.1.1 Pusher Forward.

This sensor when activated is mainly used to push the blister along with the leaflet into the carton with the help of a pusher. However when it is deactivated, the pusher returns to its original position.

5.1.2 Carton Rejection.

These two sensors are mainly used to reject the carton in any case of deformity in the carton or the blister or the leaflet.

5.1.3 Pusher Backward.

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This sensor is mainly used to push the pusher backward after the blister along with the leaflet enters the carton.

5.1.4 Leaflet Suction.

This is used to pick up a single leaflet from the leaflet magazine and push it along with the blister into the carton.

5.1.5 Carton Suction.

This is used to pull up the carton from the carton magazine into which the blister and leaflet enters.

5.1.6 Carton Forming.

This sensor is mainly used to form the carton by suction method.

6. ENCODER FUNCTION

Encoder is electronic device, which is responsible to step-by-step execution (on degree basis) of entire process of IC 150.

7. INDUCTION MOTOR & DRIVE

7.1 MOTOR:

Induction motor works on the principle of magnetic effect of electric Current. There is a shaft made up of soft iron core, which is attached to electric supply via iron brushes. The shaft is attached surrounded by strong electro magnets. When we apply current to motor assembly due to interaction of two electromagnets torque forces gets developed, perpendicular to shaft of motor, this makes motor shaft to start rotating. Mechanical assembly attaches the motor shaft to machine drive.

7.2 MOTOR DRIVE:

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In IC 150 single motor is used to drive entire machine. This is used to get perfect synchronization of entire unit of IC 150.Drive is a complex mechanical part of machine, which is responsible for distribution of mechanical power to the various parts of IC 150.

Drive takes input power from motor & with the help of gears & chain assembly it distributes the power to other devices as output.

The various parts which are connected to drive assembly as follows:

1> Tucker assembly.

2> Carton conveyor.

3> Blister conveyor.

4> Leaflet assembly.

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PLC Automation of Cartoning Machine IC 150