What Is a Laser Protection Device?

A Laser Protection Device for bending machines improves operator safety during metal forming. Laser Protection Device : Precision and Performance includes a transmitter, receiver, mounting brackets, and a controller. The system creates a clear safety zone using laser-based detection.

How the Laser Protection Device Works

Laser Protection:Simple and Programmable System

When paired with photoelectric curtains, the device works in a programmable mode. This makes it suitable for large and fully automatic bending machines. Operators can manage multiple input signals and adjust each signal’s logic settings with ease.

Laser Protection:Continuous Safety Barrier

The system forms a continuous laser shield in front of the tooling area. This shield helps protect the operator’s fingers, hands, and arms during bending operations. It keeps the machine safe without affecting production efficiency.

Laser Protection:Compatible With Many Bending Applications

The photoelectric curtain supports various bending tasks, including flat-plate bending, box folding, and Z-shaped bending. This flexibility makes it suitable for different workpiece styles.

User-Friendly Control Panel

All functions are grouped on one control panel. Users can switch modes quickly. The device includes a power stabilization module, reverse-polarity protection, and overload protection. Because of these modules, the device works with many types of bending machines.

Stable Alignment and Long Service Life

The visible light source uses automatic alignment technology. It keeps the laser aligned even during strong machine vibrations.
The self-diagnostic chips inside the photoelectric curtain adjust sensitivity and brightness automatically. They respond to light attenuation and ensure reliable long-term operation. The system is designed for a service life of 100,000 hours.

Laser Signal Technology

Laser Protection:Accurate Detection System

The device emits pulsed laser beams. The receiver uses three photodiodes to detect these beams. The microcontroller reads the signals and generates the correct control commands.

Laser Protection:Protection Against Interference

To reduce interference from sunlight and other light sources, the laser emits band-shaped signals at 635 nm. The photodiode receiver also filters this band, ensuring clean signal detection.

Smart Programming Modes

Both the transmitter and receiver use high-frequency pulses. They work only when synchronized. After synchronization, the microcontroller reads the status of the three indicator lights (E1, E2, E3).

When all three lights (E1, E2, E3) are blocked, the system switches to Shield Mode.
In Shield Mode, the system sends a PNP-NC shutdown signal directly to the machine controller.

When E1 and E2 light up and E3 stays blocked, the system enters Active Mode.

2.Why do many industries need laser protection?

Safety   incidents  frequently  occur  during sheet metal bending operations, as many press brakes  lack  safety  protection  devices.

Existing  laser  photoelectric  protection  systems in the market often use relays, resulting in slow signal  reception  and  delayed  equipment  resp-onse-leading to low safety protection coefficients. 

To address these issues, our company has developed a light curtain protection system. By eliminating relays and adopting a microcontroller, this  innovation  enhances  response  speed, improves safety factors, and ensures safe  pro- duction operations.

3.Laser protection components：

It Contains a Light Emitter, a Receiver, an Installat- ion   Base,  a   Bracket,  a  Scale  Adjustment,  a   Bracket Adjustment, an up and Down Adjustment and a Left and Right Adjustment.

4. Product Advantages:

▶Level 4 circuit safety design, the circuit is CE certified.

▶Each  detection  beam  corresponds  to  an  independent dual-channel control output.

▶The light source has a small divergence angle to avoid

reflection interference.

▶Beam position setting is suitable for the characteristics

of the bending machine, and the protective beam is set in

the  front  and  middle  of  the   die  tip  of  the   bending machine.

▶The  protection  range  reaches  20  meters,  suitable  for

the needs of various bending machines.

▶The mounting bracket can be adjusted in five degrees of freedom to facilitate the adjustment of beam position.  

▶It   can    provide   the    operator   with    comprehensive protection  very  close  to  the  workpiece,  allowing   high speed closure and improving production efficiency.

▶Provide improved functional design to meet the safety protection needs of bending machine processing differ- ent shapes of parts.

▶The independent control system is also suitable for the bending machine which has no programming capability.  

 ▶Strong   environmental    adaptability,    electromagnetic interference resistance up to the fourth level requireme- nts, working temperature up to 50 degrees.

5.Working Modalities

5.1 Normal Mode:

All detection lasers are in the detection state. After the disappearance of the uplink signal and before the effective transmission signal, any beam is blocked and the  control  output   is   disconnected  to   prevent  the formation of a start or stop stroke.

5.2 Fold Box Mode:

The laser in the front protection area of the sensor is shielded, and the laser in the middle protection area

plays a protective role.

5.3 Inhibition Mode:

The detection function of the sensor is shielded, the laser safety protection device does not play a protective role,  and  the  suppression  mode  is  continuous  mode unless the working mode is manually adjusted.

6. Wiring Diagram

Lighter: Aviation plug foot position 

①101 DC24V+②102 DC24V-Receiver: Aviation connector, foot position ①V+ ②V- ③slow down 1 ④slow down 2⑤OV ⑥light curtain ⑦NPN light curtain

▶The device has a wide range of applications, can be used for ordinary hydraulic bending machine, can also be used for CNC hydraulic bending machine.

▶Its features: can provide a variety of working modes for the bending machine, such as: normal mode, box folding mode, suppression mode, etc.;

▶And the foot pedal signal and external relay signal of the bending machine can be monitored.

7.. TECHNICAL PARAMETERS

8.  Description  of  Indicator Lights and Switches

E1, E2 and E3 are the indicator lights of the receiving   points.   When   the   three   receiving points receive the light beam normally, E1, E2 and E3 indicator lights are on. If any receiving point  is  blocked,  the  corresponding  indicator light of the receiving point is off.

8.1 Normal Mode:

The system operates in two modes: Light-Through and Light-Covered. During normal operation, the Light- Covered indicator stays on. When any one or all three receiving  points  are  blocked,  the  indicator  illuminates. This mode is activated during folding operations, where all three beams (E1, E2, E3) become active. During rapid lowering, if any beam gets obstructed, the safety output will be disconnected.

8.2 Shielding Mode:

When  the  key  switch  is  set  to  shield  mode,  it

activates the bending machine’s protective system and

turns  off  the  indicator   lights.  In  this  state,  shielding

remains ineffective while the machine operates normally.

This mode is used during mold replacement operations or  when  bending  irregular-shaped  components.  The

laser  in  the  indicator  light  is  extinguished,  completely suppressing  light  beams  at  all  three  receiving  points. When the safety output signal remains active, the laser protection   system   does   not   activate.   The   bending machine will  close the  mold  at  safe  speed  under  this mode. Our company assumes no legal liability for any accidents occurring under this function. The E1, E2, and E3 indicator lights correspond to receiving points: when normally  illuminated,  these  lights  indicate  successful beam   reception.   Shielding   any   receiving   point   will extinguish the corresponding indicator light.

8.3 Progress Mode:

The  working  mode  converts  the  signal  S1  of  the bending   machine   protection   device,  which can be provided by the controller or adopted by the bending machine slow down signal.

8.4 Fold Box Mode:

When the key switch is set to box bending mode, the bending machine’s protection system automatically activates shielding for the first receiving point, enabling safe  bending  of   box-shaped  workpieces.  During  box bending operations in this mode, the second and third beams remain fully operational while the first receiving point is deactivated. During the rapid lowering process, any obstruction of either the second or third beam will trigger a safety output disconnection.

8.5 Normal Indicator Light:

The system operates in two modes: normal illumin-

ation and light-blocking. During normal operation, the

light-blocking  indicator  illuminates when the  receiving

point is blocked. When performing folding operations in  normal  mode,  the   entire  light  beam  remains  active.

During  rapid  descent,  the  light-blocking  mechanism activates to safely disconnect the output.

8.6 Shielding Indicator:

When  the  key  switch  is  set  to  shield  mode,  the bending  machine’s  protective  device activates and the indicator  light  turns  off.  In  this  state,  the  shielding function  becomes  ineffective,  allowing  the  machine to operate  normally.  This  mode  should  be  used  when replacing   molds   or   performing   special-shaped   part operations. During these procedures, the laser emitter’s light  is  completely  extinguished,  suppressing  all  laser beams while maintaining safety output signals. The laser protection system will not activate under this condition. Even  if  the  machine  closes  the   mold  at  safe  speed,

potential   safety   hazards   may   still   exist.   Caution   is advised  when  using  this  function.  Should  any  safety incidents  occur  under  this  mode,  __the  company shall not be held liable for any legal consequences.

 8.7 Slow Down Indicator:

When the  slow  down  indicator  is  S1,  the  bending machine protection device enters the signal continuous output state.

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