4 Sensing Methods to Verify Part Ejection in Metal Forming by Pepperl+Fuchs

MC Four Sensing Methods to Verify Part Ejection in Metal Forming 1 400x275

November 10, 2022

 

When punching, notching, or trimming metal strips, unwanted material must be cleared before the next press downstroke. If scrap or formed parts inadvertently remain, the press must be stopped before its motion reaches the critical angle, the “point-of-no-return” at which further movement risks damage to the press and die. A variety of precise and reliable sensors are available to protect the die. Keep reading to learn four sensing methods to verify part ejection in metal forming.

Monitor Stripper Plate

MC Four Sensing Methods to Verify Part Ejection in Metal Forming 2 400x275

During the press downstroke, spring-loaded stripper plates push down on the fed material, preventing it from being pulled upward as the punch tooling retracts. Monitoring the presence of the plate during the downstroke confirms there is no material remaining in the die. A missing stripper plate means that something is preventing the plate from bottoming out and the controller must stop the press.

A residual slug pulled through a die can cause major tooling damage

MC Four Sensing Methods to Verify Part Ejection in Metal Forming 3 400x275

In order to avoid such errors and machine downtime it is common to install inductive sensors such as the NMB6-F104M in the lower die to detect strippers. Placing a sensor at each corner ensures the die is fully protected, regardless of where an unwanted metal piece is located (here, one or more of the four corners will not bottom-out).

 

A pulled slug prevents the plate from bottoming-out

Part Detection on Ejection Chute

MC Four Sensing Methods to Verify Part Ejection in Metal Forming 4 400x275

Sometimes verifying that a part has been ejected is enough to make sure the die is clear. Monitoring the passage of a workpiece through a chute or its free fall into a bin with a thru-beam sensor, such as the MD17MV17 is all that is required. The ejected part is detected when it breaks the beam.

 

Thru-beam photoelectric sensors confirm the workpiece was ejected

Reliable Object Detection with a Wide Detection Area

MC Four Sensing Methods to Verify Part Ejection in Metal Forming 5 400x275

Slot grids sensors such as the RAL150 are also an ideal choice for confirming part ejection. Compared to a single-line thru-beam, they provide a wider detection area, which is helpful when the position and orientation of the ejected parts cannot be accurately controlled. An entire field for object detection and adjustable sensitivity levels enable reliable detection of both very small and larger objects.

 

Light grids and slot grid sensors provide a wider detection area

Camera Systems Instantly “Map” Dies

MC Four Sensing Methods to Verify Part Ejection in Metal Forming 6 830x445

Camera systems compare the die surface or tooling to a stored master image

The use of camera technology in industrial environments has evolved rapidly in recent years as camera performance has increased while their cost has decreased. Industrial camera systems such as the vision sensor VOS2000-F226R instantly “map” dies and scan them from a longer distance and make the detection of unwanted slugs and scraps possible. If the scan does not match the image the sensor expects, there is an unwanted part in the area.

If the forming tool has been severely damaged, the discrepancy between the dimensions of an original “pristine” tool and the damaged tool could be detected.

Camera-based sensors require sufficient illumination of the target area for optimal performance. The greater the distance between the upper and lower dies, the less shadowing and the easier to illuminate the picture.

 

For m ore information, click here 

Pepperl Fuchs Logo 300x150

 

 

 

Related Articles


Latest Articles

  • All You Need to Know: Disconnect Switches from ABB

    June 1, 2023 Disconnect switches are essential safety devices that play a critical role in electrical circuitry, both in industrial settings and in everyday life. These switches are designed to ensure the safe de-energization of electrical circuits during emergency stoppages, maintenance, or repairs. ABB, a leading global technology company, offers a wide range of high-quality… Read More…

  • Guillevin: Your Trusted Distributor of Breakers and Panels

    May 31, 2023 Guillevin is one of Canada’s largest distributors of electrical products in Canada. Founded in 1906 by François-Xavier Guillevin in Montreal, Quebec, they have enjoyed considerable expansion to become a leading distributor of electrical materials and products. Growth is something Guillevin is familiar with, and since their founding, they have opened numerous locations… Read More…


Featured Article

Humber Students Take Home Gold at Skills Ontario Competition in Mechatronics

Humber Students Take Home Gold at Skills Ontario Competition in Mechatronics
Paxton C. (left) and Dillon K. (right) win gold at 2023 Skills Ontario Competition in Mechatronics (Team of 2)

Skills Ontario recently held the 2023 Skills Ontario Competition in person at the Toronto Congress Centre. It was the first in-person event after three years of it being held virtually during the COVID pandemic.

Paxton C. and Dillon K. won gold and advanced to compete in Toronto against the best-of-the-best from the province in the Mechatronics Contest. 

Read More


Products