PRESS BRAKES YODER MACHINERY SALES
1500 Holloway Rd, PO Box 100, Holland, OH 43528 USA Toll Free 1-800-MACHINE (622-4463) Phone 1-419-865-5555 • Fax 1-419-865-5557 www.yodermachinery.com ryan@yodermachinery.com
THE BASICS OF TODAY'S PRESS BRAKE MARKET
The past 20 years has seen a breakthrough in metal cutting technology including lasers and water jets. However, the same advance
has not occurred in the metal bending process where the press brake still reigns. The generation of force, construction, and technology involved with today’s press brakes has experienced significant upgrading during this same time period. This article will provide a summary glimpse into the basics of today’s press brake market. A press brake is defined as a machine tool for bending metal sheet and plate material through force between an upper and lower die. This can be accomplished in an upward or downward force & motion of the machine’s working ram. The type of press brake can be determined by the power source for the bending force, this includes mechanical, hydraulic, pneumatic, and servo electric brakes. The trend over time has been towards hydraulic machines and away from mechanical machines. This change can be attributed to safety of hydraulic brakes over mechanical brakes (the motion of the ram can be easily stopped at any time in response to a safety device), and also and the cost benefit of producing and maintaining hydraulic brakes. The majority of press brakes are rated by force capacity, in tons, and overall bending length capacity (i.e. 400 tons x 14'). Pneumatic and servo electric brakes are most common at low tonnage, less than 25 tons, and are hailed for their speed of bending. Hydraulic and mechanical brakes can range from 5 to 5,000 ton bending force capacity. To determine tonnage required to bend a metal sheet or plate, there is an engineered table available. This table outlines the bending force required for a job using factors including length of bend, die type, die width, and type of material. Often a press brake can be used to punch holes through sheet metal, in this case the same parameters apply and an engineered sheet needs to be consulted to determine a machines capabilities. Another type of brake that is common in basic bending is the apron brake and the box and pan brake. These brakes use a swinging bottom ram to fold metal to a degree angle of choice. While an apron brake has a solid clamping bar to make a bend the length of the workpiece, a box & pan brake uses different length, removable die blocks to determine and adjust the length of a bend. Both machines use built-in dies and adjustable stroke control to determine the final bend profile. These brakes can be manual, mechanical, or hydraulic and are rated by capacity, maximum length of bend x maximum thickness of material (i.e. 8' x ¼"). There are a number of options available for today’s new and used press brakes. The most common is a back gauge. The back gauge is used to position the material in the press brake in order to accurately bend at the correct location. This accessory can be factory installed or an aftermarket addition. Furthermore, the back gauge can be computer controlled with the press brake for up to 8 axis variation. A press brake with a back gauge uses the following labels for axis motions: Y axis – brake ram up and down; X axis – back gauge front to back; Z axis – back gauge left to right; R axis – back gauge up and down. Other options for press brakes can include additional stroke, more throat capacity, bend crowning compensation, hydraulic top & bottom die clamps, extended bed and ram horns, and more. So, when you are looking to bend an item off your laser, water jet, or shear, take it over to the press brake to get the job done.
About the Author: Ryan Yoder is the Vice President of Yoder Machinery Sales, 3rd generation, since 1957. 5000+ machines in stock, including 150+ press brakes and over 1100 press brakes sold! Ryan, VP, here for 15 years! 12
October 2016
***LOCATOR SPECIALTY***