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Lesson 157 of Industrial Engineering ONLINE Course
This lesson is part of Analysis of Flow - Delays sub-module of process industrial engineering or process improvement. Reducing set up time will reduce batch sizes and therefore reduces delay in flow of material in a process. Hence analysis of setups and reducing setup time/cost is important for productivity improvement
Set up Time reduction was an issue of interest right from the Taylor's time. It was developed into a specific procedure by Shigeo Shingo.
F.W. Taylor on Quick Setups
Taylor want a foreman to be incharge of setup activities and gave him the responsibility for doing setups in quick time. Taylor advocated study of motions of men and eliminating unnecessary motions in all activities.
The gang boss has charge of the preparation of all work up to the time that the piece is set in the machine. It is his duty to see that every man under him has at all times at least one piece of work ahead at his machine, with all the jigs, templates, drawings, driving mechanism, sling chains, etc., ready to go into his machine as soon as the piece he is actually working on is done. The gang boss must show his men how to set their work in their machines in the quickest time, and see that they do it. He is responsible for the work being accurately and quickly set, and should be not only able but willing to pitch in himself and show the men how to set the work in record time.
H.B. Maynard on Setup Analysis
In this article, the issue of collecting drawings, materials and tools as well as instructions from appropriate persons are discussed. Then the machine set up and loading of the work piece are discussed. After the processing operation is over, the work piece has to be unloaded and it has to be moved to the next stage. At the end of the day, tools etc. are to be returned. In the process, care has to be taken to see that equipment is kept in proper order. All issues are raised in the check list of questions given below.
________________________
Before any work can be done, certain preliminary or "make- ready" operations must be performed. These include such elements as getting tools and drawings, getting material and instructions, and setting up the machine or laying out material and tools about the workplace. When the operation itself has been completed, certain clean up or " put-away " elements must be done such as putting away tools and drawings, removing finished material, and cleaning up the workplace or machine.
Questions on "Make-ready" and "Put-away" Elements. The procedure followed to perform the " make-ready" and "put- away" elements should be questioned closely, particularly on small-quantity work, for these operations are usually fairly long. Many of them carry the operator away from his workplace. This is undesirable for several reasons, and the necessity for trips to other parts of the department should be minimized. The arrangement of the setup or the workplace layout is of primary importance, and the simple rules governing efficient workplace layouts should be clearly understood.
Typical questions which will lead to suggestions for improvement in this connection are as follows :
1. How is the job assigned to the operator?
3. How are instructions imparted to the operator?
4. How is material secured?
5. How are drawings and tools secured?
6. How are the times at which the job is started and finished checked?
7. What possibilities for delays occur at drawing room, tool- room, storeroom, or time clerk's office?
8. If operator makes his own setup, would economies be gained by providing special setup men?
9. Could a supply boy get tools, drawings, and material?
10. Is the layout of the operator J s locker or tool drawer orderly so that no time is lost searching for tools or equipment?
11. Are the tools that the operator uses in making his setup adequate?
12. Is the machine set up properly?
13. Is the machine adjusted for proper feeds and speeds?
15. If vises, jigs, or fixtures are used, are they securely clamped to the machine?
18. Is material properly positioned?
19. Are tools prepositioned?
21. What must be done to put away all equipment used?
22. Can trip to return tools to toolroom be combined with trip to get tools for next job?
23. How thoroughly should workplace be cleaned?
24. What disposal is made of scrap, short ends, or defective parts?
25. If operation is performed continuously, are preliminary operations of a preparatory nature necessary the first thing in the morning?
26. Are adjustments to equipment on a continuous operation made by the operator?
27. How is material supply replenished?
28. If a number of miscellaneous jobs are done, can similar jobs be grouped to eliminate certain setup elements?
29. How are partial setups handled?
30. Is the operator responsible for protecting workplace over- night by covering it or locking up valuable material?
Make Ready. The methods followed in giving out jobs differ widely throughout industry. Where the same operation is worked day after day, the problem is not encountered; but on more miscellaneous work, some procedure for telling an operator what job he is to work upon next must be provided.
When the operator has received notification in one way or another of the job he is to do, he must next secure drawings, tools, and material. The way in which this is done also varies widely. In some cases, the operator must hunt everything for himself. In others, he goes to a tool- or drawing-room window and waits while an attendant gets what he requires. In still other cases, everything is brought to him, and he does not have to leave his work station.
The exact procedure that is followed will depend upon existing conditions; but if it is possible to work out an economical system for furnishing the operator with what he needs at his work station, it is desirable to do so. Besides reducing costs, this procedure increases the amount of time the equipment is utilized and thus increases the productive capacity of the plant. Often a low-rated worker can do the errands of the operators and bring tools, drawings, and materials.
Where the group system is used and no supply boy is available, the group leader commonly gets all necessary supplies and tools. By getting the necessary items for several jobs at one time, he is able to effect economies.
If a conveyer system specially designed is used, the jobs may be dispatched by the production department in the order wanted, and all material, tools, and drawings can be sent out at the same time on the conveyer. Thus the amount of time spent by the operator in getting ready to make the setup or workplace layout is reduced to a minimum.
The manner in which instructions are furnished with regard to how the job should be done is worthy of careful consideration. Instruction sheets can be used to instruct operators and, under certain conditions, their use is not too costly. It gives complete and detailed instructions.
Setup. The setup of the machine and of any tools, jigs, or fixtures used should be studied in detail. The correctness and the adequacy of the setup should first be considered, followed by a brief review of the methods employed to make it. The correct setup is fixed by the nature of the operation, the nature of the part, the requirements of the job, and the mechanical features of the machine. Sometimes, it is possible to do a job in more than one way, and care should be taken to ascertain that the best way is being used.
When the setup is being made, certain tools are usually required. These should be suitable for the purpose. If each operator must make his own setup, he should be provided with the necessary tools. If only one or two wrenches are furnished to a group of 10 operators, for example, the time lost in hunting the wrenches and in waiting for a chance to use them will usually far offset the cost of additional equipment.
If setup men are employed to setup machines ahead of the operators, their setup work is to them fairly repetitive work, because they are performing the same elements day after day. It will therefore be desirable to treat it as such and to furnish the setup men with special-purpose quick-acting tools.
Put Away. The put-away elements usually consume less time than the make-ready elements. Tools are put away, the setup is torn down, and the workplace is more or less thoroughly cleaned up. Usually, some of the put-away elements can be combined with some of the make-ready elements for the next operation.
Tools for one operation, for example, may be returned to the toolroom when the tools for the next operation are obtained. The procedure that will prove most economical for the put-away elements will depend to a large extent upon the manner in which the make-ready elements are performed.
Where a number of similar operations are performed on a machine, it is sometimes possible to use 'the same or part of the same setup on two or more jobs. A part that is common to several assemblies may be ordered separately for each and appear on several different orders. If these orders are grouped, one setup will care for them all. Again, in milling-machine work, for example, it may be possible to use the same cutter for several different jobs. The elements of "get cutter from toolroom" "place cutter on machine", "remove cutter from machine" and "return cutter to toolroom" will thus be performed but once for the several jobs.
Where possibilities of this sort exist, provision should be made when setting up the make-ready and put-away routine so that the economies will be made. If the operator does not know what job he is to do next, if he must completely tear down his setup before going for another job, and if neither the foreman nor the dispatcher attempts to group similar jobs, advantage cannot be taken of partial setups. This is wasteful, of course, and every attempt should be made to secure the benefit of partial setups. Whether or not the operator is paid for the complete setup or only for that part which he actually makes depends upon the difficulty in controlling setups and upon whether or not the saving is due to the operator's own initiative. In either case, more time is available for productive work which is a distinct gain.
Shigeo Shingo
The efficiency of setup requires two things on the part of operators:
1. Knowledge relating to the structure and function of the machinery and equipment, as well as a thorough acquaintence with tools, blades, dies, jigs, etc.
2. Skill in mounting and removing these items, and also in measuring, centering, adjusting, and calibrating after trial runs.
The History of SMED
In 1950, Shingo was conducting an efficiency improvement survey at Toyo Kogyo's Mazda plant. As the large body-molding presses of 350, 750 and 800 tons were declared as bottlenecks, Shingo did a production study.
There was an incident of a missing bolt and one hour was wasted in finding the bolt. Shingo had written that gave him the idea that external set operations have to set up as standard procedures and one has to make sure that all items required for set up are there before one starts the set up procedure. Shingo established the external set up procedure of making all items required for a set up and the efficiency was raised by 50% and the bottle neck problem disappeared.
The Second Idea
In 1957, Shingo was studying the operation of a large planer which is machining diesel engine beds. He noticed that centering and dimensioning of the engine bed had to be done and was being conducted on the planer table only. He came with the idea of buying an extra planer table on which this activity can be done while on the machine a job is getting machined. When the job was completed, the table was pushed out and the second table was pushed in ready with the job. This solution resulted in 40% increase in productivity.
The Third Important Event
In 1969, Shingo studied the set operation of 1,000 ton press at Toyoto Motor Company/s plant. The setup time was four hours and it was known that Volkswagen in Germany was doing the same set up in two hours. Shingo in association with Toyota engineers have identified the external setup operations and internal setup operations and improve the process to a time of 90 minutes. According to Shingo, it took six months of effort to reach that stage.
At this stage, Toyota management thought of a challenging goal. Can be reduced drastically to only three minutes? This challenge resulted in the inspiring insight in Shingo. Can we convert much more internal activity (setup activity that was being done on the machine) to external activity. So a search began for eliminating activities from internal setup activity to move them the external activity. Shingo had written that 8 ideas came in quick succession and they developed these 8 ideas in 3 months time to reach the single digit setup time. So Shingo remarked that it took 19 years of time to make a drastic improvement to the setup operations.
Foreword
SMED system is the most essential method for achieving Just-In-Time Production. SMED system will revolutionize existing production systems and I hope you will practice it after reading this book.
Introduction
In many factories, diversified low-volume production is a problem. The main difficulty is the setup operations and adjustments required - calibration, switching of tools or dies etc. Frequent setups of course are necessary to produce a large variety of goods in small lots.
But now I can tell you, you can cut your setup time and increase productivity. You can do setups in three minutes for tasks which had taken 3 hours earlier. The theory and techniques are made available to you in this book. Japanese industrial engineers have long understood the need to reduce setup times and many examples are made available by them in books. But in this book for the first time principles are provided so that you can apply them to your situation even though it does not match any of the previous examples or applications.
Why the setup times remained high for long. Managers and industrial engineers neglected the task and left it to the skill of workers.
People have to realize that high volume production and large lot production are the same. Even high volume production can be achieved through small lots and economy of manufacturing can be realized. Traditional production planning assumes inventory as inevitable but new production system based on SMED works on the concept of confirmed production and eliminates inventory.
It took 19 long years for me to develop the SMED system.
Production activities may best be understood as a process consisting of operations.
A process refers to a continuous flow by which raw materials are converted into finished goods. An operation is action performed by men, machine or equipment on raw materials, or intermediate or finished goods (for example packing). A process can have one or more operations.
Manufacturing processes can be further divided into four distinct phases (traditional IE categories)
1. Processing (termed as operation) 2. Inspection 3. Transportation 4. Storage.
The storage phase can be further categorised into:
1. Storage of raw materials.
2. Storage of finished goods
3. Lot waiting for process: The entire lot is in a queue before a machine
4. Waiting for a lot: Some of items of the lot are yet to be processed and some are processed.
Each operation on a lot will have preparation and clearing. These are termed setup operations.
The principal operation carried out on workpieces include essential operation, auxiliary operation like loading the workpiece and removing it and margin allowances (activities) that irregularly happen like sweeping up cuttings and personal activities of the operator like taking rest for fatigue and drinking water etc.
It is important to note that there are setup operations in inspection, transportation and storage also.
The blind spot: The unspoken assumption that drastic reductions in setup time are not possible. But with the development of SMED, the concept of economic lot size has diappeared from the profit-engineering agenda. Moreover, SMED has substantially reduced the level of skill required for setups and production operators themselves can do the setup.
In the spring of 1950, Shingo was conducting an efficiency improvement survey at Toyo Kogyo's Mazda plant. At the presses were bottleneck machines, Shingo conducted a production analysis and observed a die change. As he observed the time wasted after the machine was stopped for setup change, it dawned to him that setup operations fundamentally were two types: Internal setups which are to be done after a machine is stopped and external setups which can be conducted when the machine is in operation. The external set up were identified and only internal setups were done when the machine is stopped. The setup time reduced by 50%.
The first step of SMED was discovered and Shingo started advising companies on improving setups.
The second insight
Shingo was doing study of open-sided planer at the Mitsubishi Heavy Industries Shipyard for methods improvement. He observed that marking-off procedure for centering and dimensioning the engine bed ws being conducted on the planer table and it was taking significant time. The idea came came to install a second planer table and perform the setup operation on it separately. Then the table was shifted in less time and it saved time and increased productivity.
The third experience
In 1969, the divisional manager of body shop at Toyota Motor Company told Shingo that they were taking 4 hours to make a die change and they know that in Volkswagen they were doing in two hours. Shingo worked with them to separate internal and external setup items and got the die change time reduced to one and half hours.
After a month, Shingo was informed that management want the setup time to go to three minutes. Shingo was strartled but challenged. The thinking led to the idea that some more internal elements can be converted into external elements. In three months, three minute goal was reached and Shingo says, he named the method SMED.
This SMED concept then spread to all types of setups in Toyota.
Basic steps in the Setup Procedure
1. Preparation, checking of all required items, tools and materials 30%
2. Removing old tools and mounting new tools 5%
3. Centering, dimensioning and setting other conditions 15%
4. Trial runs and adjustments 50%
5. Returning Old tools - Negligible
The time taken for trail runs and adjustments can be shortened by improving the prior process of centering, dimension and setting.
Basic Steps of SMED
Separating Internal and External Setup
Converting Internal Operations to External Operations
Improving Internal Setup Operations
Improving External Operations
Separating Internal and External Setup
Doing External Setup Operations Efficiently - Preliminary Steps
Use a checklist
Make a list of all the parts required with names and specifications and make sure that they are there before the setup. For it to happen without any shortcoming, Shingo recommended that a drawing is made with all the parts pictures and keep the parts on those drawing.
Then there has to be one more list that specifies details of pressure, temperature and other settings that are part of external setup. One has to go through this checklist and ensure that every item is having the required specification and also functioning. These list of items and checklists have to be separate for every machine.
The old die and related items should be transported back either after the setup is completed or by people who are specific to transportation. The machine should not be made to idle due to the transport operation of old die and related items.
Converting Internal Operations to External Operations
The first step in converting internal operations to external operations is to create operating conditions of the dies externally. Then only internal operations are to push the dies and attach them to ram and body.
Preheating Dies
Old practice was to heat dies in die casting by injecting hot metal between them. Instead of that if dies were preheated using gas or electric heat externally, 30 minutes could be saved.
Standardization of dies of various sizes or items on a machine can be done by shape standardization to reduce setup time. But the dies of even small parts can be large because of that. Instead Shingo suggested function standardization.
Function Standardization
What are the functions in attaching die to machine? Clamping, centering, dimensioning, expelling,grasping, and maintaining loads.
Efficient function standardization requires that for each die, the function providing features are only standardized as required by examining the die feature by feature or element by element.
Clamping height can be changed by adding shims to smaller dies. Centering can be done centering jigs. The dies can be made as a set and they can be inserted and withdrawn like a casette so that die inserting time can be only 20 seconds. Various locating elements can be used to adjust the dies in the required positions externally.
Implementation of Parallel Operations
Die-change operations on plastic molding machines, and die-casting machines and large presses require work both at front and at the back of the machine. If two work parallelly one at the back and one at the front lot of time is saved.
The Use of Function Clamp
The length of the bolt should be determined such that only one turn is required for fastening or loosening. Such bolt will be called functional clamp.
Examples of One Turn Attachments
The Pear Shaped Hole Method
The U Shaped Washer Method
The Split Thread Method
The U-Slot Method
The Clamp Method
One Motion Methods
Cams and clamps
Wedges, tapered pins and knock pins
springs
Magnetism and Vacuum Suction
Interlocking Methods
(Punch and die assembly for making interlocking integral fasteners - Patent No. US2924312)
Instead of fastening, many times, two pieces can be interlocked and it is sufficient.
Interlocking Method for Press Dies
In a press, the upper die is attached to the machine ram and the lower die is attached to the machine tool. Why there should be same number and diameter of bolts in both sides. While the die attached to the ram has to be supported against gravity, the die attached to the machine bed need not be so supported. Shingo suggests holding plates and cradles for the holding plate to hold the die.
Seeing is believing. Watch in YouTube video die changes in less than 9 minutes
SMED - YouTube Videos
Related Development:
1. Knowledge relating to the structure and function of the machinery and equipment, as well as a thorough acquaintence with tools, blades, dies, jigs, etc.
2. Skill in mounting and removing these items, and also in measuring, centering, adjusting, and calibrating after trial runs.
The History of SMED
In 1950, Shingo was conducting an efficiency improvement survey at Toyo Kogyo's Mazda plant. As the large body-molding presses of 350, 750 and 800 tons were declared as bottlenecks, Shingo did a production study.
There was an incident of a missing bolt and one hour was wasted in finding the bolt. Shingo had written that gave him the idea that external set operations have to set up as standard procedures and one has to make sure that all items required for set up are there before one starts the set up procedure. Shingo established the external set up procedure of making all items required for a set up and the efficiency was raised by 50% and the bottle neck problem disappeared.
The Second Idea
In 1957, Shingo was studying the operation of a large planer which is machining diesel engine beds. He noticed that centering and dimensioning of the engine bed had to be done and was being conducted on the planer table only. He came with the idea of buying an extra planer table on which this activity can be done while on the machine a job is getting machined. When the job was completed, the table was pushed out and the second table was pushed in ready with the job. This solution resulted in 40% increase in productivity.
The Third Important Event
In 1969, Shingo studied the set operation of 1,000 ton press at Toyoto Motor Company/s plant. The setup time was four hours and it was known that Volkswagen in Germany was doing the same set up in two hours. Shingo in association with Toyota engineers have identified the external setup operations and internal setup operations and improve the process to a time of 90 minutes. According to Shingo, it took six months of effort to reach that stage.
At this stage, Toyota management thought of a challenging goal. Can be reduced drastically to only three minutes? This challenge resulted in the inspiring insight in Shingo. Can we convert much more internal activity (setup activity that was being done on the machine) to external activity. So a search began for eliminating activities from internal setup activity to move them the external activity. Shingo had written that 8 ideas came in quick succession and they developed these 8 ideas in 3 months time to reach the single digit setup time. So Shingo remarked that it took 19 years of time to make a drastic improvement to the setup operations.
The SMED System - Book by Shigeo Shingo - Chapter Summaries
Foreword
SMED system is the most essential method for achieving Just-In-Time Production. SMED system will revolutionize existing production systems and I hope you will practice it after reading this book.
Introduction
In many factories, diversified low-volume production is a problem. The main difficulty is the setup operations and adjustments required - calibration, switching of tools or dies etc. Frequent setups of course are necessary to produce a large variety of goods in small lots.
But now I can tell you, you can cut your setup time and increase productivity. You can do setups in three minutes for tasks which had taken 3 hours earlier. The theory and techniques are made available to you in this book. Japanese industrial engineers have long understood the need to reduce setup times and many examples are made available by them in books. But in this book for the first time principles are provided so that you can apply them to your situation even though it does not match any of the previous examples or applications.
Why the setup times remained high for long. Managers and industrial engineers neglected the task and left it to the skill of workers.
People have to realize that high volume production and large lot production are the same. Even high volume production can be achieved through small lots and economy of manufacturing can be realized. Traditional production planning assumes inventory as inevitable but new production system based on SMED works on the concept of confirmed production and eliminates inventory.
It took 19 long years for me to develop the SMED system.
Chapter 1 The Structure of Production
Production activities may best be understood as a process consisting of operations.
A process refers to a continuous flow by which raw materials are converted into finished goods. An operation is action performed by men, machine or equipment on raw materials, or intermediate or finished goods (for example packing). A process can have one or more operations.
Manufacturing processes can be further divided into four distinct phases (traditional IE categories)
1. Processing (termed as operation) 2. Inspection 3. Transportation 4. Storage.
The storage phase can be further categorised into:
1. Storage of raw materials.
2. Storage of finished goods
3. Lot waiting for process: The entire lot is in a queue before a machine
4. Waiting for a lot: Some of items of the lot are yet to be processed and some are processed.
Each operation on a lot will have preparation and clearing. These are termed setup operations.
The principal operation carried out on workpieces include essential operation, auxiliary operation like loading the workpiece and removing it and margin allowances (activities) that irregularly happen like sweeping up cuttings and personal activities of the operator like taking rest for fatigue and drinking water etc.
It is important to note that there are setup operations in inspection, transportation and storage also.
Chapter 2. Setup Operations in the Past
The blind spot: The unspoken assumption that drastic reductions in setup time are not possible. But with the development of SMED, the concept of economic lot size has diappeared from the profit-engineering agenda. Moreover, SMED has substantially reduced the level of skill required for setups and production operators themselves can do the setup.
3. Fundamentals of SMED
In the spring of 1950, Shingo was conducting an efficiency improvement survey at Toyo Kogyo's Mazda plant. At the presses were bottleneck machines, Shingo conducted a production analysis and observed a die change. As he observed the time wasted after the machine was stopped for setup change, it dawned to him that setup operations fundamentally were two types: Internal setups which are to be done after a machine is stopped and external setups which can be conducted when the machine is in operation. The external set up were identified and only internal setups were done when the machine is stopped. The setup time reduced by 50%.
The first step of SMED was discovered and Shingo started advising companies on improving setups.
The second insight
Shingo was doing study of open-sided planer at the Mitsubishi Heavy Industries Shipyard for methods improvement. He observed that marking-off procedure for centering and dimensioning the engine bed ws being conducted on the planer table and it was taking significant time. The idea came came to install a second planer table and perform the setup operation on it separately. Then the table was shifted in less time and it saved time and increased productivity.
The third experience
In 1969, the divisional manager of body shop at Toyota Motor Company told Shingo that they were taking 4 hours to make a die change and they know that in Volkswagen they were doing in two hours. Shingo worked with them to separate internal and external setup items and got the die change time reduced to one and half hours.
After a month, Shingo was informed that management want the setup time to go to three minutes. Shingo was strartled but challenged. The thinking led to the idea that some more internal elements can be converted into external elements. In three months, three minute goal was reached and Shingo says, he named the method SMED.
This SMED concept then spread to all types of setups in Toyota.
Basic steps in the Setup Procedure
1. Preparation, checking of all required items, tools and materials 30%
2. Removing old tools and mounting new tools 5%
3. Centering, dimensioning and setting other conditions 15%
4. Trial runs and adjustments 50%
5. Returning Old tools - Negligible
The time taken for trail runs and adjustments can be shortened by improving the prior process of centering, dimension and setting.
Basic Steps of SMED
Separating Internal and External Setup
Converting Internal Operations to External Operations
Improving Internal Setup Operations
Improving External Operations
4. Techniques for Applying SMED
Separating Internal and External Setup
Doing External Setup Operations Efficiently - Preliminary Steps
Use a checklist
Make a list of all the parts required with names and specifications and make sure that they are there before the setup. For it to happen without any shortcoming, Shingo recommended that a drawing is made with all the parts pictures and keep the parts on those drawing.
Then there has to be one more list that specifies details of pressure, temperature and other settings that are part of external setup. One has to go through this checklist and ensure that every item is having the required specification and also functioning. These list of items and checklists have to be separate for every machine.
The old die and related items should be transported back either after the setup is completed or by people who are specific to transportation. The machine should not be made to idle due to the transport operation of old die and related items.
Converting Internal Operations to External Operations
The first step in converting internal operations to external operations is to create operating conditions of the dies externally. Then only internal operations are to push the dies and attach them to ram and body.
Preheating Dies
Old practice was to heat dies in die casting by injecting hot metal between them. Instead of that if dies were preheated using gas or electric heat externally, 30 minutes could be saved.
Standardization of dies of various sizes or items on a machine can be done by shape standardization to reduce setup time. But the dies of even small parts can be large because of that. Instead Shingo suggested function standardization.
Function Standardization
What are the functions in attaching die to machine? Clamping, centering, dimensioning, expelling,grasping, and maintaining loads.
Efficient function standardization requires that for each die, the function providing features are only standardized as required by examining the die feature by feature or element by element.
Clamping height can be changed by adding shims to smaller dies. Centering can be done centering jigs. The dies can be made as a set and they can be inserted and withdrawn like a casette so that die inserting time can be only 20 seconds. Various locating elements can be used to adjust the dies in the required positions externally.
5 Applying SMED to Internal Operations
Improving Internal Operations or Reducing Time of Internal Operations
Implementation of Parallel Operations
Die-change operations on plastic molding machines, and die-casting machines and large presses require work both at front and at the back of the machine. If two work parallelly one at the back and one at the front lot of time is saved.
The Use of Function Clamp
The length of the bolt should be determined such that only one turn is required for fastening or loosening. Such bolt will be called functional clamp.
Examples of One Turn Attachments
The Pear Shaped Hole Method
The U Shaped Washer Method
The Split Thread Method
The U-Slot Method
The Clamp Method
One Motion Methods
Cams and clamps
Wedges, tapered pins and knock pins
springs
Magnetism and Vacuum Suction
Interlocking Methods
(Punch and die assembly for making interlocking integral fasteners - Patent No. US2924312)
Instead of fastening, many times, two pieces can be interlocked and it is sufficient.
Interlocking Method for Press Dies
In a press, the upper die is attached to the machine ram and the lower die is attached to the machine tool. Why there should be same number and diameter of bolts in both sides. While the die attached to the ram has to be supported against gravity, the die attached to the machine bed need not be so supported. Shingo suggests holding plates and cradles for the holding plate to hold the die.
Seeing is believing. Watch in YouTube video die changes in less than 9 minutes
SMED - YouTube Videos
Related Development:
SMED 2.0 - April 25, 2023 by Christoph Roser.
https://www.allaboutlean.com/smed-2-0/
Design for changeovers
http://etidweb.tamu.edu/hsieh/ENTC410/Design%20for%20Mass%20Customerization/DesignForChangeOver.pdf
The paper is on original equipment manufacturer making design of machine that facilitates quick setup changes
Design for changeovers
http://etidweb.tamu.edu/hsieh/ENTC410/Design%20for%20Mass%20Customerization/DesignForChangeOver.pdf
The paper is on original equipment manufacturer making design of machine that facilitates quick setup changes
Ud 29.4.2023, 10.10.2022, 9.10.2021
Pub 9,12.2013
