Oil-Resistant Connector XS5□R Fluororesin Cable

• Uses a fluororesin cable that demonstrates strong durability to cutting oils.
• Structure designed to achieve greater oil resistance
• Newly developed lock structure compatible with M12 round type connectors
• Simply insert the connector and turn it by approximately 1/8th. The connector is now engaged and blocks cutting oils from coming in.
• There is a distinct click sensation when locking is complete.
• Protective structure IP67G (JIS C 0920 Annex 1)

We took the first step toward developing the E2ER that remains oil-resistant for 4 years after learning the real needs of operators in the auto industry, etc., engaged in machining of metal parts. In metal machining, a sudden equipment failure due to cutting oil triggers an emergency shutdown of the entire facility, not only adding the cost of replacing the equipment, but also lowering the utilization ratio of production processes that in turn causes schedule delays and lost opportunities. These sudden failures are attributed to proximity sensors used primarily in machining systems at the highest frequency. Improving the oil resistance of proximity sensors has long been a challenge for our customers and for us, too.
When we began developing oil-resistant components that provide value to the customers, we set our goal of at least doubling their oil resistance, or specifically half-reducing the sudden stoppages that are caused by failed proximity sensors. Based on the after-service data showing that conventional products are failing after approx. 1 to 2 years on average, we set remaining oil-resistant for 4 years as our final target and began development under this objective.
To develop and mass-produce components that remain oil-resistant for 4 years, we worked on three key areas: (1) evaluation technology, (2) development of structure/method to achieve the 4‑year design, and (3) design of process quality. Achievements in these three areas finally led to the product.

We will not complete the development if we spend 4 years evaluating the oil resistance that actually remains 4 years. So, establishment of accelerated testing procedures became an important theme. Put it simply, we had to correlate the data of when and how failures were occurring in the market with the in-house accelerated testing procedures and come up with Omron's proprietary accelerated testing procedures.
With help from our own Material Department and cutting oil manufacturers, we analyzed the mechanisms of how materials would deteriorate, and from numerous types of cutting oils, we selected a specific cutting oil (A1) that attacks materials very aggressively. By using this cutting oil undiluted (*) and also in a temperature environment of 55°C where deterioration progresses eight times faster than at normal temperature, we successfully replaced 4 years in the actual use environment with just 2,000 hours (a little less than 3 months) in our verification environment.

*Normally the oil is diluted 20 to 30 times.

As we were treading into an unknown territory to achieve 4 years of oil resistance, the first step we took was to logically evaluate all components to select suitable materials and structural sealing technologies.
When we analyzed the failures experienced by conventional products in the market, we learned that failures were caused by deterioration, caused by cutting oils, of the cable itself or parts that were sealing the cable and the main body.
In contrast, the remaining materials and structures were found very durable.
In developing a new cable, we learned that PVC (polyvinyl chloride) and PUR (thermoplastic polyurethane) normally used for oil-resistant cables of proximity sensors failed before one year was up at the low end, and did not last more than 2 to 3 years even if the material composition was tweaked. In other words, it was clear we could not achieve 4 years of oil resistance using PVC or PUR or modified versions thereof.
So, we abandoned the conventional method and took on a challenge of making a cable using fluororesin.
Fluororesin comes in different grades, one of which is PTFE (polytetrafluoroethylene), for example. PTFE has adequate oil resistance, but it is very hard and not suitable as a material for cables that must be bent.
So, to strike a good balance between oil resistance and flexibility, we made several dozen prototypes using fluororesin and finally succeeded in customizing a fluororesin cable that would remain oil-resistant for 4 years and was flexible enough to be used as a cable.
The fluororesin cable is expensive to make, so our next challenge is to reduce its cost.

No matter how superior it is, a design cannot be put in mass-production unless it is realizable through processes.
After the aforementioned parts, etc., are assembled together, epoxy resin offering very high oil resistance is filled to seal the inside in the final injection molding step.
To increase the reliability of this filling/sealing, we worked on designing in-process controls to suppress variation of parts assembly accuracy. In addition to the facility-side controls to improve accuracy, use of cameras to inspect the assembly accuracy in-process is one key difference from the conventional practice.
Given the high level of required assembly accuracy, we resorted to mechanical judgment instead of visual judgment using the naked eye.
When these accurately assembled parts are filled with resin in the molding step, highly reliable sealing is achieved. This is the technology behind our mass-producible cable that remains oil-resistant for 4 years.