What's the working principle of a packing machine (packing up the cartons)

[phatcreators]

What's the working principle of a packing machine (packing up the cartons) ?

with a strip .... that joins the strip over the cartons

 

[kak111]

Do you mean
Automatic Pressure Strapping Machine & Automatic Strapping Machine

 

[tpetar]

Semiconductors or cornflex?

 

[phatcreators]

what do you mean by cornflex ?
I think its not the semiconductor type .......... its an very old kind of mahcine .......
it has 220 V input supply ...... there are 3 limit switches ...... one is used as a single & other two used in a pair and attached or lean to the cam shaft when its rotated ..... there is a solenoid valve ........ a transformer ..... these kinds of things are there

---------- Post added at 21:24 ---------- Previous post was at 21:20 ----------

there's a single phase motor ........ there's a belt pulley system also ....... there's a clutch also

the problem is that when we push the button then the supply goes ahead and the heating tool (that makes the join by heating the strip) comes forward to join the strips but it stops in the midway ...... although it should have done automatically ....

manually as we keep the button pressed the heating tool makes the join of the strip to pack the cartons .........

I have checked the limit switches when the power is off & they are working fine ........ showing the NC contacts & NO contact ........

what could gone wrong ?

 

[kak111]

Without knowing machine construction and control schematic
i would say....

If the symptoms are as described
ie. when you manually keep run command valid
machine is carried out the work sequence from beginning to end.

but the auto sequence is interrupted

I would assume that some limit switch , relay contact or coil does not work
because the sequence of functions does not remain connected on ,
until the normal end of sequence.
( or the sequence stop contact is allways on , depends on : how the circuit is designed )

 

[munzir]

yes its a strapping machine and it has the limit switches
but as he says that he already cheked the limit switches , it means there's a mechanical fault of actuator (problem in actuating of the heating tool i.e. cutting tool)

 

[phatcreators]

i have already checked the limit switches all of the three are fine ........
there's no relay or its contact are visible to me inside the machine

 

[kak111]

manually as we keep the button pressed the heating tool makes the join of the strip to pack the cartons .........

How is that possible, seems like everything works properly mechanically ??...

 

[phatcreators]

if the coil is not working then how to figure it out ? How to proceed it ?

 

[ibrar]

phatcreators can u tell the machine name and model no. look if there any name plate on it.

 

[wa1kij]

You say there is no relay. So there is a switch that is supposed to remain closed until the cycle is completed. My guess is that something has worn out and is no longer holding that switch closed.

 

[munzir]

its basically a strapping machine

---------- Post added at 21:05 ---------- Previous post was at 21:00 ----------

what's the circuitry basically other than limit switches ?
What type of transformer & heating element (tool) is used ?

thank

 

[kak111]

In old strapping machines the partial and sequential movements are indicated and controlled with limit switches ( mechanical or inductive )
Execution of some sequences may be required some relays or discrete transistor logic circuit or -modules.

Usually thiskind simple sequence controlled machine working principle is.
- push start button
-some limit switch , when 1. move starts lock the sequence on ( or relay is used to lock this start sequence on)
- 1. move activates another limit switch, this stops 1. sequence and start 2. move and this goes on until next
limit switch stops this 2. sequence and starts 3. move........ etc......
- when all sequeces are moved from limit sw. to limit sw. the last switch stops last move and release start button
for new sequence.

Usually transformer for heating is line isolated type with low voltage secondary
Heat element is resistance wire or resistance plate type heater.
New machines can be some times equipped with piezo welding head.

 

[phatcreators]

so what could be the problems then ? i already checked all the 3 limit switches .....

discrete transistor logic circuit or modules ? Could it be some transistor logic or module fault ???

which transistors and modules are used & how to test them out ??

the process is stopped in the midway ..... only heating element (tool) just comes forward only half way not till the end limit neither it returns back to complete the sequence

 

[kak111]

so what could be the problems then ? i already checked all the 3 limit switches .....
discrete transistor logic circuit or modules ? Could it be some transistor logic or module fault ???
which transistors and modules are used & how to test them out ??

Impossible to answer, without knowing this machine better......

the process is stopped in the midway ..... only heating element (tool) just comes forward only half way not till the end limit neither it returns back to complete the sequence

Recommendation:
inspect all activities related to the mechanical parts when this movement is performed
-power transmission slip
-high friction between the parts of the movement
-whether mechanical parts or fixing loose
-some part is broken
-too large clearances

check all electrical components that operate or should operate when this movement is performed

Try to find or make circuit drawnings

 

[wa1kij]

You said a while back: "manually as we keep the button pressed the heating tool makes the join of the strip to pack the cartons" So I take it that everything works as it should if you hold the button down. There is either a relay or a switch that is in parallel with that pushbutton switch. What it does is the same thing as holding the button in. Find it.