Pneuparts

Our customer's demand

Our customer wants to make their installation safer, without complicating operation or requiring electronics. Important wishes are:

The solution must be completely pneumatic
No complex sensors or electronics
Operation must remain simple for the operator

The situation at the customer

Our customer is a specialist in metalworking who, among other things, bends metal sheets for special seals. A highly accurate bending radius is crucial here: only with the right radius do the parts fit together seamlessly for a perfect seal.

Currently, the plates are secured with pneumatic cylinders and operated by a 5/2 foot valve with spring return. This clamping causes metal parts to bend over a roller, creating the desired radius.

For the safety of the operators, it is necessary to change the current way of working. This is because there is a risk of pinching in the current set-up, as the operator's hands may still be in the clamping zone when the pneumatic cylinders close.

Our challenge

Our specialist Frans has come up with a solution with a two-step operation.

The product is placed in the mold and clamped by operating the foot pedal. Allowing the cylinders to move at low pressure and low speed minimizes the risk of injury to hands or fingers, even if they should accidentally enter the clamping zone.

When the product is stable in the mold, the cylinders stay in place, allowing hands to safely keep out of the machine while the final clamping force is built up.

To activate the full clamping force, a two-hand operation is required. This means that both push buttons must be pressed simultaneously so that both hands can stay out of the danger zone while building up the maximum force.

After the product is securely clamped, metal plates can be manually bent over the mold for the desired radius.

When this process is complete and the foot pedal is pressed again, the clamping cylinders move back to the starting position in a controlled manner, so that the product can be safely removed. Always check that the cylinder is completely returned before removing the product.

What pneumatics do we need to realize this solution?

To ensure safe and accurate clamping of the product in phase 1 , we used the following components:

3/2 Foot valve: for operating the first clamping phase
Pneuparts polyurethane PU hose: High-quality, flexible air hoses for the pneumatic system
Push-in couplings For leak-free and quick assembly of the pneumatic system.
Plugs: For sealing unused ports in the valve terminal.

Pneuparts pressure regulator

Important for setting the low pressure during the approach stroke, so that injury is avoided

5/2 flip/flop valve

for controlling and maintaining the cylinder position (memory function)

Throttling silencer

To adjust the cylinder speed, while keeping noise levels to a minimum when venting

For phase 2 of the clamping process, a two-hand pneumatic control is used. For this we have selected the following valves and articles:

3/2-way hand valves with black push buttons: The physical control buttons for the operator
Pneumatically operated 3/2 valve: For controlling the cylinders based on the safety signal
OF valve (divergence) valve: For linking the various control functions

Two-hand safety valve (3/2 way)

The central safety block that checks that both buttons are operated simultaneously

Screw-in dampers made of sintered bronze

For controlled and low-noise venting of the system

Step-by-step guide

In this manual we explain how we converted the current foot-operated clamp into a safety system.

Phase 1:

1. Plug in Port 4 of the 5/2 foot valve. It is now a 3/2 valve.
2. Connect the main air to the pressure regulator. Connect the regulator output to port 1 (P) of the flip-flop valve.
3. Set the pressure reducer to 1.5 to 2 bar.
4. Pull a hose from the foot valve outlet to the flip-flop valve control port.
5. Screw the smudge detectors into ports 3 and 5 of the flip-flop valve.

Phase 2:

6. Thread couplings into ports 1 and 2 of both 3/2 hand valves.
7. Connect the main compressed air (full pressure) to port 1 of both hand valves.
8. Connect port 2 of both hand valves to the two inputs (port 1) of the hand safety valve.
9. Connect the outlet (port 2) of the safety valve to the control port (12/P1) of the pneumatically operated 3/2 valve.

Phase 3:

10. Connect the main compressed air to port 1 of the pneumatically actuated 3/2 valve.
11. Place the OF valve between the valves and the cylinder.

Input A: Connect to the output of the pneumatically operated 3/2 valve (High Pressure).
Input B: Connect to the tubing of the flip-flop valve (port 2).

12. Connect the output of the OF valve (port 2) to the "outgoing" port of the cylinder.
13. Place a tee between the flip-flop valve (port 4) and the "inserting" port of the cylinder.
14. Pull a hose from this tee to the control port (14/P2) of the pneumatically operated 3/2 valve.