Archive for July, 2009

31
Jul

Solid Model Press Assy

Solid Model Press Assy

A hydraulic press, like any complex machine, is an assembly of many components that must alll work together in order to function properly.  In modern engineering design the tool that best facilitates this coordination is solid modeling.

In a solid modeling CAD system, parts and assemblies are developed in 3D representations as opposed to the traditional 2 dimensional drafting of the past.  The solid modeler can manipulate the parts of an assembly to rotate and fit the various components together just as the physical parts would be.  This allows precise placement and the ability to develop complex assemblies that would be nearly impossible to do in a 2D drawing.

An additonal feature of solid modeling systems is the ability to share the design data with multiple design engineers at the same time.  In this way multiple features of the product design may be developed concurrently, saving time and eliminating potential errors or interferences between assemlies.

Category : Blog | Blog
27
Jul

by Michael Riehn

Custom Pad Forming Hydraulic Press with push button and lever

Custom Pad Forming Hydraulic Press with push button and hand lever

In an effort to meet the growing demands of today’s modern metal forming and fabricators, hydraulic press builders are continually adding flexibility and performance to their offerings. Hydraulic press builders can strengthen the “just-in-time” and “lean manufacturing” philosophies of many manufacturers by designing a press for a business’s specific application. Manufacturing companies can streamline their process to cut excess “bells and whistles” that they don’t need or use.

Technology in the hydraulic press industry is providing the ability to build machines specifically designed to meet the comprehensive needs of individual buyers. These needs range from dedicated cell production presses to sophisticated machines with unlimited capabilities. 

For press buyers who require simple machines with simple electrical and hydraulic circuits, capital equipment costs can be kept to a minimum while still ensuring that the end result will be a quality machine comprised of quality components. Machine tool purchasers that have a demand for machinery capable of performing more complex or demanding applications, can add proven features to reach the level of sophistication they require.

Cost control is possibly the greatest advantage to having a press built to a customer’s specific needs. Cost savings in new hydraulic presses can be gained by reducing the complexity and sophistication of the machine to meet their exact needs; which does not equate to a reduction in quality or integrity.

Keeping things simple helps companies lower the price of their machine. Customers that depend on being able to deliver various and differentiated products quickly can benefit from economical hydraulic presses that are dedicated units used in work cells.

“Custom” building a hydraulic press does not necessarily result in an elevated selling price, especially when dealing with manufacturers who specialize in machine customization. The progression of modern manufacturers has generated customers who want to avoid the cost of large, general-purpose presses; the sort of monument press that must be run continuously to be profitable.   Custom building a hydraulic press can complement a value engineering approach, putting only as much technology into a press as the customer requires. 

Currently, almost every hydraulic press builder can offer its customers a multitude of choices for each feature found on a machine. Whether it be: speed, force, footprint or the integration of auxiliary equipment, hydraulic press companies can offer a package that is specifically designed to suit their customers needs. A truly built to specification press will posses the customer’s desired bed size, tonnage and speed system all at an affordable cost.

Category : Blog | Hydraulic Press | Blog
24
Jul

Below is a list of important terms associated with hydraulic presses:

  1. Stroke - The amount of possible ram travel.  Stroke is the total distance the ram can travel, from full extension to full retraction.
  2. Shut Height - The distance between the bed and ram bolsters when the press is fully extended.  This is also known as ‘Closed Height.’
  3. Daylight - The distance between the bed and ram bolsters when the ram is fully retracted.  Naturally, this results in the following equation: Daylight = Stroke + Shut Height
  4. Bolster - Plate that serves as the working surface for the bed and ram.  The plate is typically bolted to the bed and ram substructures and can be machined with a variety of workholding features such as; t-slots, drilled & tapped holes, lift rails for quick die change systems, etc…
  5. Bed Height - The distance from the bottom of the hydraulic press structure to the working height, or top of the bed bolster.
  6. Stroke Control - The ram travel of the press may be controlled in a variety of ways. Most hydraulic presses are standard with Adjustable Retract Limit Switches to limit the retract distance of the ram (also know as the Up Limit Position). This can shorten cycle times by only utilizing the required stroke for part loading and unloading. Other adjustable limits may include: Slow Down Limit for deceleration from Fast Speed to Slow Speed; Bottom Stop Position and/or Bottom Stop Pressure, etc..
  7. Method of ReturnBy Pressure: The press may be designed to return on pressure.  This method utilizes a pressure sending device which is adjustable and is set to determine the desired maximum pressure to be achieved by the ram.  Once this pressure is achieved, the ram typically completes the cycle by returning to the pre-determined home, or up-limit position.  By Position: The press may be designed to return on position.  This method utilizes either a position sensing device or a limit or proximity switch that can be set to signal that the desired ram extension position has been achieved.  By both Pressure & Position: This method allows the operator to select the desired method of return.  For manual systems, a Pressure/Position keyswitch is provided for selecting the deisred return method.  For programmable systems, the return method is programmed into the HMI.
  8. Dwell - Hydraulic presses are capable of maintaining force on the work for extended periods of time.  This is typically accomplished by using pressure lock valves or variable volume piston pumps that are remotely controlled for precise holding pressures.  Dwell cycles are typically employed for applications which require a set or curing time for the material in question, such as molding & compacting applications.
  9. Heated Platens - Hydraulic presses can be equipped with heated platens which utilize electric rods, steam, hot oil, water, or other heating methods for achieving the desired working temperature.  These systems usually require thermal breaks between the heated platens and the hydraulic press structure.  Also, depending on the working temperature, the hydraulic action of the press is often configured in an up-acting manner, allowing the hydraulic components to be placed near the bottom of the press system and away from the rising heat.  Platens can be set to achieve and maintain a working temperature, or can be designed to increase and decrease temperature over time depending on the requirements of the part being manufactured.
  10. Bed Cushion - A bed cushion is a commonly required for draw tooling and is a system that applies resistance when pushed upon. This resistance can be dynamic or statically controlled throughout the stroke. Bed cushions have a “pusher pin plate” that is located just beneath the bed bolster. The bed bolster is provided with multiple through holes where “pusher pins” are inserted. These pins are used by the tooling to generate resistive force as the hydraulic press ram pushes down. The cushion can also be configured for multiple control zones for on-the-fly dynamic control.
Category : Blog | Hydraulic Press | Blog