Mechanical Detection Switches
Contact-type micro-switches that verify ejector plate return through physical lever or plunger actuation — simple, reliable detection for standard molds.
Mechanical Detection Switches Products
Mechanical Detection Switches — Type A
Rated 100K-500K operations | NO/NC dry contact | IP40
Mechanical Detection Switches — Type B
Rated 100K-500K operations | NO/NC dry contact | IP40
Mechanical Detection Switches — Type C
Rated 100K-500K operations | NO/NC dry contact | IP40
Mechanical Detection Switches — Type D
Rated 100K-500K operations | NO/NC dry contact | IP40
Mechanical Detection Switches — Type E
Rated 100K-500K operations | NO/NC dry contact | IP40
Mechanical Detection Switches — Type F
Rated 100K-500K operations | NO/NC dry contact | IP40
How Mechanical Detection Triggers Work
Mechanical detection switches use a physical actuator (lever arm or spring-loaded plunger) that contacts the ejector plate or a cam surface on the plate. When the plate returns to its home position, the actuator is depressed, closing (or opening) an electrical contact that sends a signal to the injection molding machine controller.
Two trigger types:
- Lever type: A pivoting arm contacts the plate edge. Longer detection range (5-10 mm) but requires precise alignment. Best for molds with consistent plate travel.
- Plunger type: A spring-loaded pin contacts the plate face. Shorter detection range (2-5 mm) but more tolerant of misalignment. Better for molds with slight plate wander.
Both types output a dry-contact signal (normally open or normally closed) that interfaces directly with machine safety interlocks.
Troubleshooting False Triggers
| Problem | Cause | Fix |
|---|---|---|
| Switch triggers but plate hasn't returned | Trigger point set too far from home position | Adjust actuator position closer to plate home |
| Plate returned but no trigger signal | Oil film on contact surfaces insulating the circuit | Clean contacts with electrical contact cleaner |
| Intermittent signal | Lever arm vibrating at trigger boundary | Add dead-band: adjust trigger 0.5 mm past edge |
Troubleshooting: If you're experiencing issues, refer to How to Troubleshoot False Triggers in Mechanical Plate Return Switches.
About Mechanical Detection Switches
Mechanical detection switches verify ejector plate return through physical contact. A lever or plunger actuator contacts the ejector plate surface, closing an electrical circuit that signals the machine controller. Simple, low-cost, and requiring no external power supply — but limited by contact wear life (100K-500K operations) and susceptibility to oil contamination.
Application Scenarios
Budget and Low-Volume Molds
Low-volume molds need plate return verification at minimum cost.
Why it fits: Mechanical switches cost $15-30 vs $80-120 for proximity sensors. Adequate for molds running < 100K cycles/year.
Frequently Asked Questions
How does a mechanical plate return detection switch trigger?+
What is the typical contact life of a mechanical detection switch?+
How do I adjust the trigger point on a mechanical switch?+
Engineering Resources
Need Custom Mechanical Detection Switches?
Precision mechanical detection switches manufactured to JIS and DIN standards. Custom dimensions available. MOQ 1 piece.