1. Welcome to KALLER International Distributors Meeting June 14-16, Workshop 7 • Delayed return units

2. Controllable Gas Springs KF
Delayed return units
Lockable piston rod
Controllable Gas Springs KF
Flex FormTM
Lockable piston rod
Advantages for the user:
All the benefits of a standard gas spring (e.g. even force distribution via link system, remote gas charging & discharging, high force ratings, long service lifetime)
No hydraulics to fill and bleed with thick hydraulic hoses to fit and maintain.
Adjustable Initial Forces from 1500 to 7500 daN.
Adjustable (KF2-A) stroke lengths from 10 to 160 mm (+7/-8 mm).

3. Flex FormTM Flex Form TM Press Lockable piston rod
Self Contained Option
Flexible Orientation
Controllable return speed
PED approved
High force hydraulic system
Delayed return option
Customized return force
Low contact force
No pressure increase

4. Flex FormTM No pressure increase Stroke Force Press Flex Form Cylinder
Flex Form Force (blank holder force)
Shows a working system (CC and HCP) in our press room. Note the movement of the hose, therefore hose clamps is recommended in dies. See also press diagram and the other movement curves in relation to each other.

5. Flex FormTM Hydraulic Fluid 7-100 bar Nitrogen System components
Cylinder Flex Form CFF
1- 6 pcs
Force Generator FFG
Hydraulic Fluid
7-100 bar
Nitrogen

6. Flex FormTM FFG CFF System components Flex Form Force Generator
Cylinder
Flex Form
FFG Flex Form Force Generator
One size
Control up to six flex form cylinders
Flow up to 300 l/min
Pressure range bar
Max working temp. 93 °C
CFF Cylinder Flex Form
Stroke lengths mm
Four sizes Force
CFF – 2 ton
CFF – 4.8 ton
CFF – 8.8 ton
CFF – 12.5 ton

7. Flex FormTM Force Generator FFG Thermal Relay Accumulator
Force generator pressure valve
Safety Pressure Relief Valve
Oil Bleed Plug
Pressure Relief Overflow Hose
Digital Pressure Gauge (24VDC)
Return valve (24VDC)
Return force control unit
Foot
Mount
This shows one version of a complete FlexCam system including Power Unit HCP and Compact Cam CC for piercing operation.

8. Flex FormTM Cylinder Flex Form CFF Height Rod Diameter
Cylinder Diameter
Oil bleeder valve
Bleeder Plug
Base Width
Base Height
To the force generator
This shows one version of a complete FlexCam system including Power Unit HCP and Compact Cam CC for piercing operation.

9. Flex FormTM Hydraulic Fluid 7-100 bar Nitrogen Function
Cylinder Flex Form CFF
1- 6 pcs
Force Generator FFG
Force generator pressure valve
pressure range bar
Hydraulic Fluid
7-100 bar
Nitrogen
Thermal Relay
Return valve (24VDC)
Digital pressure gauge (24VDC)
Accumulator
Return force control unit
pressure bar

10. Flex FormTM Requirements
To obtain a complete system the following data is required:
Number of pressure points
(maximum six CFF to one FFG)
• Needed tonnage for the system
• Production rate parts/minute
• Max high before stroked (L max)
• Used stroke length
• Max press velocity during stroke length (m/s)
• Needed return force

11. Flex FormTM Possible solutions & benefits High Force Hydraulic System
up to 12 ton with a single cylinder
Low Contact and Return Force System provides a soft hit and very low reverse force to decrease press wear.
Constant Force
System has no pressure rise which provides constant force through entire stroke for better control of part quality.
Flexible Orientation
Flex Form system can be used in upper or lower applications.
Delayed Return Option
Cylinders can be delayed
Applied stroke length optionally
Self Contained Option
The system can be provided
fully filled, bled, and ready to
be installed.

12. Delayed return units KF2 or TU CFF Energy Heat Energy Generates Heat
Work cycle for standard gas springs
Work cycle for delayed return systems
KF2 or
CFF
Force TU
Energy
Heat
Force
Energy
Stroke
Energy = Force x Stroke
Heat generation:
It is important to note that energy is given to a gas spring from the press each time it is stroked.
For a standard gas spring, this energy is given back to the press as the gas springs do work on the return stroke.
For KF2 gas springs this is different, since the energy given to the gas spring on the downstroke of the press is locked into the gas spring.
When the KF2 spring is released, the piston road is pushed up and the weight of tool it supports is lifted. However, the amount of energy the KF2 spring uses to do this is considerable less than when it was stroked.
This difference in energy received and given by the KF2 spring results in heat build up in the KF2 spring itself.

13. Delayed return units System choice
Dissipate 0.1 to 0.5 kW heat (depending of the spring size)
Dissipate 2.3 kW heat
Limited number of springs
High force / area
Not to high stroke length
Large number of springs
High stroke length & press velocity
No place for hose connections
Heat removal:
Heat energy is conducted from the KF2 spring to the tool and radiated from its external surfaces.
If the number of strokes a KF2 performs per minute reaches a predetermined maximum limit without additional cooling, then the KF2 will overheat, it’s seal will be damaged and this will lead to gas leakage.
To prevent overheating there are two engineered solutions to help cool down the KF2 gas spring: Liquid cooling and Gas cooling.

14. Flex FormTM Summary Flex Form TM Press Lockable piston rod
High force hydraulic system
Delayed return option
Customized return force
Low contact force
No pressure increase
Self Contained Option
Flexible Orientation
Controllable return speed
PED approved
Available!