Drill Bit Breakage Detection Sensor [DFM Series]

Drill Bit Breakage Detection Sensor DFM Series

Air-driven needle for detection of tool breakage

Mounted on machine tools such as automatic machines and special-purpose machines to detect breakage of drills, taps, and reamers. It prevents defective workpieces caused by tool breakage.
One of the main feature is that this sensor is highly coolant-resistant unlike motor-controlled sensors.


IP67 protective structure, outstanding durability against coolant

The world’s first air-driven system!
Without the use of a control motor, this sensor demonstrates outstanding durability even in adverse environments inside the machine tool where it is exposed to chips and coolant.
Users will achieve significant reduction in maintenance costs caused by breakdowns.

Achieves affordable tool breakage/damage detection.

Eliminates the need for expensive control motors and control units.
The mounting diameter is M22, and it is also interchangeable with conventional parts.

High reliability + Low cost: Fewer false detection achieved by touch sensor method

Since the detection is made by the needle’s direct contact with the tool, coolant splatter or mist is less likely to interfere when comparing with expensive non-contact sensors (e.g., laser sensors), thus ensuring high reliability.

Main Specifications

Product name DFM3
Purpose of use detection of tool breakage/damage detection.
Contact Shape  φ1.5 needle
Protective structure IP67
Contact Force  0.1N
Cable Length3m Oil resistant φ4 / 5 cores Minimum bending R7
Accessories Sensor mounting nuts (×2), Air hose clamp (×1) , Needle adjustment pushing rod (×1)
(Over travel signal) Output mode Please check the product Catalog and Manual.
(Over travel signal) Contact rating Please check the product Catalog and Manual.
Operating temperature range 0 - 60℃ (Ice-free)
Working air pressure 0.4 - 0.5MPa(dry air)
Air tube diameter: φ4 × 2.5
Output specification Open collector
(type: C-DF-01N output: NPN)
(type: C-DF-01P output: PNP)
Power supply voltage DC+24V
Drive method Pneumatic drive type (single-action push-out air cylinder type)
Signals 3 signals
Direction of needle rotation Clockwise / counterclockwise
Stroke (rotation angle) 100°
Minimum tool diameter φ0.5mm (For small diameter drill bits φ1mm or less, refer to catalog p12-3)
Needle Specifications Length: 100mm(from center of rotation)
Thickness: φ1.5 Material: Quenched SUS420 HRC50
Net weight Approx. 250g
Type C-DF-01N / C-DF-01P
Current consumption 10mA
LED display Origin: Green, Judgment: Red, Stroke end: Yellow
Output rating DC24V 150mA (MAX)
Insulation resistance 100MΩ with DC250V megger
Withstand voltage AC500V, 50/60HZ for 1 minute between each pin and case
Protective circuits Reversed power connection protection, Surge protection

Names of Components and Internal Structure


How it Operates:

The driver turns the home signal ON at the home position (LED lit green) and the end signal ON at the stroke end position after operation (LED lit yellow). If the cutting tool is damaged (or not present), the needle rotates to the stroke end position, the evaluation signal is turned off, and the LED red turns off.

If the cutting tool is in good condition, the needle stops after contacting the tool and does not reach the stroke end, so the evaluation signal remains ON and the LED remains lit.

To determine whether or not the cutting tool is broken, please transmit the evaluation signal ON/OFF (LED red light ON or OFF) at the point when the stroke end signal is ON (LED yellow light ON) to an external device.
*The stroke end signal is turned ON at every stroke regardless of the condition of the cutting tool (good or damaged).