Fixture Changeover faster and easier to hold multiple workpieces

Quarter-Turn are used for

Our mold production team manufactures cases and covers for our products with
injection molding machines.
The post-molding products are pulled out by the take-out robot and they are carried
away from the injection machine. Then we cut the resin burr on back of the injection
molded products by a nipper.
We have 15 injection machines in our plant:

• 4 are used as dedicated machines

• 11 are used as general-purpose machines for manufacturing a wide variety of
  products in small quantities.

As for the general purpose machines, mold change is necessary depending on a
product to be formed. For some of the machines, we change the mold more than 50
times per month. In addition, the position of the burr is different product by product,
so a change of the nipper and its position is needed at every mold change.
Previously, we used the general-purpose nipper units for all our products but a great
deal of time was spent to loosen screws, change nippers and adjust positions.
Now we are using nipper units (highlighted by blue box on fig.1) dedicated for each
product and we exchange the units at every mold change. QUARTER-TURN
CLAMPS (highlighted by red circle on fig.1) of SpanClamps are used for positioning and
clamping these nipper units.

SpanClamp Quarter-Turn SCQT-P

Plastic Wing Head: SCQT0614-P
Receptacle: SCQTRBI12

What are the added values ​​of SpanClamps quarter-turn?

Now the clamp units can be replaced with a single press of a button. The installation time is only 1 minute, while it has elapsed between 15 and 30 minutes.
Another advantage is that the unit can be changed easily by anyone.
Previously, the clamp had to be adjusted for each product so that only the trained person could make the change. Now everyone can do it easily because the units can be locked simply by turning the knob 90 degrees to the ON position and inserting two air tubes into the joints.
Recent output robots are slaved, so only the NC program change is needed when changing the product to be molded. In addition to this, the quarter turn allowed us to shorten the installation time of the dump units. With the help of power-assisted extraction robots and quarter-turn, the machine's downtime for mold change was greatly reduced and we achieved a clear improvement in productivity.

What is the most important point in improving your production system?

" Reduce installation time " is the challenge of everything.
Regarding the burr cutting process, we had done by hand a long time ago. At that point, we assigned the work to a subcontractor.

In order to improve productivity, we have tried to automate the cutting of the burrs with the help of the cutting pliers. But we spent a lot of time loosening the screws to change or adjust the position of the clamp at every mold change, because the units were designed as a versatile unit for all products.

In mass production, the machines are used long after the mold is put in place, so there was no problem. However, as many of our products are manufactured in small quantities, machine downtime increases with mold installation time.

Therefore, we have developed dedicated gripper units for each product, so that we can exchange an entire unit when changing the mold. At the same time, we adopted the SpanClamps quarter-turn that tighten units faster than screws.

How did you find the quarter turns to tighten your clamp units?

When we were consulted by Anemo Engineering, a fast-moving solutions company for the industry, they introduced us to the SpanClamps range.
We found the range of products "quarter turn" in the catalog. There were different types of quick fixes.
Among them, we have selected the one that best suits our intended use.

Using a SpanClamp Quarter-Turn

We especially wanted "to be able to tighten the parts in a single operation ". Quarter turns are the best suited because they can be reached in a quarter turn of the button. In addition, we felt safe with a clamping force of 90 N sufficient to hold the units.
Secondly, we attach great importance to the height of the fasteners. It was necessary for an operator to hold the clamp unit in his hands during the exchange operation, so that weight gain was important. As a result, we had to minimize the thickness of the unit plates and looked for low-profile mountings that could be mounted on the thin plate.
Another important point was the visible clamping and un-clamping states of the unit. We can instantly recognize if the position of the button allows to fix quickly or not. Our operator can check visually and even if he forgets to lock the unit, other people can check remotely.

How do you rate the ease of use of the quarter turn ?

The downtime of the machines has been greatly reduced by instant switching of the gripper units.
6 of the 11 general purpose machines use quarter turns and we achieve a high utilization rate of the machine. (The other 5 machines concern products with different shapes of strawberries.)
In addition, we are satisfied with the "visualization" of our operation. For example, "the button in a vertical direction indicates blocked / the button in a horizontal direction indicates not attached" in our factory. Not only the operator but also the third person can check at a glance whether the unit is tight or not. Easily recognizable blocked / unrestrained states have increased safety in our factory. The ability to forget to lock the device can not be eliminated as long as the exchange is done by a human. It is therefore essential that we try to minimize the risks by adopting a simple means of verification.