Análisis Porqué5W1H
Clasificar el problema de acuerdo a las 5 Ws 1 H,
explicando características y tendencias
Quien Qué Cuando Donde Cómo
Problema
Patín de contacto
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Principio
Reglas Básicas Regla principal
Que el filamento reciba una corriente eléctrica
adecuada
Que la resistencia eléctrica del circuito sea baja
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Hacer un Análisis Porqué
El Análisis Porqué es un método que busca llegar a la causa del problema a través de repetirse el cuestionamiento ¿porqué? hasta en 5 ocasiones aproximadamente.
Medida
Fenómeno
×
×
×


Verificar los porqués del nivel W-1, y si hay problema, verificar entonces el W-2. Si no hay problema, allí termina la verificación.
W-
¡Problema!×
Una vez identificadas todas las posibles causas mediante el Análisis
Porqué, se estudia cada una y su relación con el sitio y el objeto
Problema. Se comienza analizando por el nivel W1. Si existe alguna causa
listada, poner N.G., si no la hubiera, poner un círculo
No requiere
Phenomenon
Why
Why
Why
After chucking, a product drops during transport.
Downward force on the product is stronger than the gripping force of the hand.
The gripping force of the hand is too weak.
The chucking force of the hand is weak.
Downward force on the product is too strong.
Contact surface between the hand and the product is small.
The product weight increased.
hand
bottle
After chucking, a product drops during transport. p196
Malfunction description: The hand holds a bottle but drops it when the elevator moves downward.
Phenomenon
Why
Why
Why
The bottle was gripped by the hand then dropped.
Downward force on the bottle is stronger than the hand gripping force.
The hand gripping force is too weak.
The hand is weakly pressed to the bottle.
Contact surface between the hand and the bottle is small.
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Why
Downward force on the bottle is stronger than the hand gripping force.
Downward force on the bottle is strong.
The bottle weight increased.
After chucking, a product drops during transport.
Malfunction description: The hand holds a bottle but drops it when the elevator moves downward.
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Contact surface between the hand and the bottle is small.
The bottle was held at a slant to the hand.
The hand was declined.
Why
OK
The top head of the bottle is low to the hand.
The bottle was gripped during upward movement.
The hand position was higher than the upward moving end of the bottle.
The bottle was not raised to the end.
Rubber with the hand was hardened.
Abnormal material was inserted between the hand and the bottle.
OK
OK
After chucking, a product drops during transport.
Malfunction description: The hand holds a bottle but drops it when the elevator moves downward.
OK
OK
Why
OK
Clearance between the top end of the bottle and the fixed side of the hand was too large.
The bottle was declined on the receiving stand.
The bottle top end interfered with the fixed side of the hand.
Recurrence prevention measures
Clearance between the receiving stand of the elevator and the bottle is large.
Why
Why
Why
Not exclusive for the bottle.
Make a special use stand. Alternatively, improve the receiving stand to be adequate for the bottle.
Why
NG
Resistance force was stronger than the upward force to the elevator.
The rod is bent.
Resistance acts between an inside wall of the air cylinder and the piston.
Air at the pressed side remains.
Piston pressing force is weak.
Resistance force to the elevator was strong.
Elevator upward moving force is weak.
OK
OK
OK
OK
OK
After chucking, a product drops during transport.
Malfunction description: The hand holds a bottle but drops it when the elevator moves downward.
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Package process
The cap head was collapsed at the press-fitting process of the cap.
Phenomenon
Why
Why
The cap head is collapsed at the press-fitting process of the cap.
The cap was pressed at the declined state.
Guide inside the press-fitting block failed to move the cap horizontally.
The cap was declined excessively.
The press-fitting block is declined to the bottle.
Resistance occurred between the cylindrical section of the cap head and the press-fitting block guide.
Diameter at the bottom side of the press-fitting block is smaller than the cap external diameter.
The center of the bottle is deviated horizontally to the center of the press-fitting block.
The press-fitting block is declined.
The bottle is declined
The press-fitting margin at the cap and the bottle was increased.
The cap surface is rough.
Elongation in the circumferential direction of the cap was insufficient.
Resistance between the cap and the bottle was strong.
The cap was forcedly pressed at stopping in the press-fitting process.
The press-fitting block is lowered excessively.
The cap did not touch the bottom of the press-fitting block.
Height of the bottle increased.
The cap was pressed over an allowable range.
Note
Fully observe collapsed cap head to classify phenomenon as shown in the figure for analysis.
When the state written in the column of phenomenon was not observed, start to analyze at the step just before (that is, cap head was collapsed.)
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Phenomenon
The cap head is collapsed at the press-fitting process of the cap. (Occurred before position to apply the pressure to the cap at normal condition.)
The cap was pressed to the press-fitting block at the declined state to the press-fitting surface of the block.
Guide inside the press-fitting block prevents the cap from moving horizontally.
Why
The press-fitting block was declined to the bottle.
The cap head is collapsed at the press-fitting process of the cap.
Malfunction description: The cap head is collapsed at the press-fitting process of the cap.
Star Wheel
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Guide inside the press-fitting block prevents the cap from moving horizontally.
Why
The cap was declined excessively.
The press-fitting block bottom diameter is too small for the cap external diameter.
Resistance occurred between the circumferential part of the cap head and the guide of the press-fitting block.
Why
The bottle center is deviated horizontally from the center of the press-fitting block.
The cap head is collapsed at the press-fitting process of the cap.
Malfunction description: The cap head is collapsed at the press-fitting process of the cap.
OK
OK
OK
The cap is scratched.
The press-fitting block is scratched.
OK
OK
OK
OK
Why
A mounting part of the press-fitting block has gotten rickety.
The bottle neck touches partially to the neck support area of the star wheel.
OK
The bottle is declined.
Radius R of the bottle neck is larger than R of the star wheel neck support area.
R of the bottle neck is large.
Why
Why
Why
Rework the star wheel fitting to the bottle standard.
When fabricating the star wheel, specify the standard value and then formulate the rule referring the standard.
Why
R of the star wheel is small.
The star wheel was fabricated by referencing sample bottle without reflecting the bottle standard.
NG
The cap head is collapsed at the press-fitting process of the cap.
Malfunction description: The cap head is collapsed at the press-fitting process of the cap.
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Phenomenon
Why
Why
Did not reach the specified value before filling process (insufficient measurement)
Viscosity of is high.
Filling pressure is low.
Gas generating (or vapor) is not removed.
adheres to the inside before filling port and is not removed.
leaks (splashed) before the filling port (or at the filling port, etc.)
filled to does not reach the specified value.
failed to fill into to the specified value.
Why
solidified at the filling port (or before not filled area)
Flow velocity of is slow.
Filling time was short.
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not filled into to the specified volume (insufficient filling).
Malfunction description: Unfilled area appeared near the gate of mold product.
Resin density near the gate is too small.
Unfilled area appears near the gate of mold product.
Filled resin volume itself is too little.
Measured volume is too little.
Reverse flow occurs in the cylinder.
The gate temperature of the mold is low.
Resin temperature is too low.
Injection speed is too slow.
Switch timing from injection to cooling was too quick.
Pressure lowered more quickly than pressure reduction in the specified time.
Specified value of the injection time is too short.
Injection time, if extended, causes generation of a burr on the molded product at the center of the mold.
Parting surface (mating surface) in the cavity at the mold center is deteriorated.
No standard for mold repair is specified.
The gate is solidified before filling resin.
Resin flows backwards before solidifying the gate.
Improve the parting surface (mating surface).
Extend the injection time.
Determine the standard to improve the mold when a certain amount of burr is generated at the cavity of the mold center.
Recurrence prevention measures
Unfilled area appears near the gate of mold product.
Resin involved gas generated from the resin.
Gas volume generated from the resin was too much.
Air at the spool is moved back to the cavity.
Resin absorbed water.
Originally resin has low molecular weight.
Air is difficult to blow from the air vent.
Resin involves air.
Air is leaked more slowly than filling speed of the resin in the cavity.
not filled into to the specified volume (insufficient filling).
Malfunction description: Unfilled area appeared near the gate of mold product.
OK