05-07-2012, 11:29 AM
Development of poke yoke device for gauging and sorting
Poke yoke is a Japanese concept presented by shiego shingo, the co founder of Toyota production system. Poke yoke means fool proof prevents error in a process and ensures defect free components with 100 percent inspection with minimum expenses. Though poke yoke concept is much familiar in Japan, it is still not adopted in our local industries like precision industries, automate industries, small scale industries where components are produced in batches. These components are inspected for dimensional accuracy like height, length, or diameter using conventional gauges on sampling basis, which does not ensures 100 percent inspection. The cost of inspection is increased due to wastage of time and labour. There is also risk of error in inspection due to human fatigue.
From literature survey it is found that the poke yoke devices available are designed for specific applications and not readily available in the market for the desired applications. It is also found that sorting of components on the basis of dimensional characteristics involves sophisticated inspection containing electronic sensors and computer processing. These devices are expensive and not affordable by small scale industries.
By knowing these difficulties, it is decided to develop a, poke yoke device with simple in design. The basic function of device is gauging and sorting the components by height. The critical part of the device is gravity feed chute which facilitate continuous flow of components and needs no power. Slope of the chute is adjustable to depending on the size of the components. The surface of the chute is machined and grinded to the highest accuracy, as it forms a reference for the gauge blocks. The device is equipped with three gauge blocks to sort the components. The gauge blocks carries inclined stoppers at the top.
The concept behind the project is when the oversize components hits the stopper under high velocity get sorted out and rest of the components move to the next stage. The stoppers are rigidly screwed to the gauge block to stay firmly when hit by components. Following are the features of this poke yoke device.
• Simple in design.
• Ensures 100 percent inspection.
• Inspection cost is reduced.
• Easy to operate and no maintenance.
• Defects are clearly visible to the operator.
• The rate of inspection is high.
• Components are defect free.
• Inexpensive quality control tool
The device hoping to create awareness in industries about the poke yoke device and its benefits and inspires them to develop different poke yoke devices for other physical characteristics like diameter, length or shape that’s suits to their application. Further this device can be made fully automatic and which works at high speed by introducing electronic sensors and motor driven conveyer system useful for mass production industries.
The device can be also used as a demonstrating poke yoke model in laboratories to explain the concept of poke yoke to the students and encourage them to take up projects on poke yoke devices. Lot of innovations needed in this area and to familiarize its benefits to the industries. By taking up this project an attempt is made in this direction.
Poke yoke is a Japanese concept presented by shiego shingo, the co founder of Toyota production system. Poke yoke means fool proof prevents error in a process and ensures defect free components with 100 percent inspection with minimum expenses. Though poke yoke concept is much familiar in Japan, it is still not adopted in our local industries like precision industries, automate industries, small scale industries where components are produced in batches. These components are inspected for dimensional accuracy like height, length, or diameter using conventional gauges on sampling basis, which does not ensures 100 percent inspection. The cost of inspection is increased due to wastage of time and labour. There is also risk of error in inspection due to human fatigue.
From literature survey it is found that the poke yoke devices available are designed for specific applications and not readily available in the market for the desired applications. It is also found that sorting of components on the basis of dimensional characteristics involves sophisticated inspection containing electronic sensors and computer processing. These devices are expensive and not affordable by small scale industries.
By knowing these difficulties, it is decided to develop a, poke yoke device with simple in design. The basic function of device is gauging and sorting the components by height. The critical part of the device is gravity feed chute which facilitate continuous flow of components and needs no power. Slope of the chute is adjustable to depending on the size of the components. The surface of the chute is machined and grinded to the highest accuracy, as it forms a reference for the gauge blocks. The device is equipped with three gauge blocks to sort the components. The gauge blocks carries inclined stoppers at the top.
The concept behind the project is when the oversize components hits the stopper under high velocity get sorted out and rest of the components move to the next stage. The stoppers are rigidly screwed to the gauge block to stay firmly when hit by components. Following are the features of this poke yoke device.
• Simple in design.
• Ensures 100 percent inspection.
• Inspection cost is reduced.
• Easy to operate and no maintenance.
• Defects are clearly visible to the operator.
• The rate of inspection is high.
• Components are defect free.
• Inexpensive quality control tool
The device hoping to create awareness in industries about the poke yoke device and its benefits and inspires them to develop different poke yoke devices for other physical characteristics like diameter, length or shape that’s suits to their application. Further this device can be made fully automatic and which works at high speed by introducing electronic sensors and motor driven conveyer system useful for mass production industries.
The device can be also used as a demonstrating poke yoke model in laboratories to explain the concept of poke yoke to the students and encourage them to take up projects on poke yoke devices. Lot of innovations needed in this area and to familiarize its benefits to the industries. By taking up this project an attempt is made in this direction.