For precise speed control in rolling mills the main drives of the roll stands and the coilers need to be equipped with an encoder. In addition, it is often necessary to provide increased protection for personnel during special operating modes, such as: For this application Johannes Hübner Giessen has been working with Motor OEMs for many decades to provide complete solution ie. Electrical and mechanical components.
Home Case Studies Rolling Mill / Rolling Mills / Screw Downs: Replacing Mechanical Cam Limit Switches at the Screw Downs (Rolling Mill) Increases Precision and Lowers Costs
Rolling Mills / Screw Downs: Replacing Mechanical Cam Limit Switches at the Screw Downs (Rolling Mill) Increases Precision and Lowers Costs
Pilger mill in tube rolling mills - hot and cold pipe detection
- Simple programming & presetting
- Additional real-time position data (4 – 20 mA)
- Direct attachment without distribution gears
Before: Distribution gears and mechanical position switch
Challenges
- The customer wanted a 1:1 replacement of the existing mechanical solution. There were several reasons behind this:
- Higher precision required
- Spare parts no longer available
- Reduce costs by stocking less spare parts
- Additional current output for real-time position data
After: Directly attached electronic position switch ERC 40 with an additional current output for up-to-date position monitoring.
Solution
- Setting the switching points was difficult with the obsolete
mechanical solution. This is much simpler with the ERC 40.
It enables the customer to move the screw downs to the desired
position for a switching point – and then transmit the information
to the software by drag & drop. - As the data is stored in the ERC 40 and can be stored on the
PC the customer is able to simply copy previously set switching
points as required to further devices. Storing the reference position
and preset configuration makes it possible to reference the
ERC 40 along with the application, for instance after changing
rolls. Eliminating the need for distribution gears combined with
the higher precision of the ERC 40 has significantly increased the
accuracy of the whole system. The current output (4 – 20 mA)
of the ERC 40 also supplies additional real-time position data.
Products and Accessories
Case Study Number
- TP3
Challenge
- The increasing flexibility of production lines requires a high adaptability of sensors. Continually changing object geometries, different temperatures and very high radiation or surrounding temperatures are no rarity.
- In a pilger mill those rough conditions can be found, among others in the production of seemless steel pipes. The raw steel blocks, each weighing a few tons are heated up first in a round oven at a temperature of 1300 °C.
- After descaling of the surface, the steel block is prepunched in a hole press with a strength from a converted 2000 t. In the next sloping rolling mill the growing pipe rotates between two rollers that are positioned at an angle to each other. The punching is widened to the size of the mandrel diameter.
Previous solution / Competitor product
- N/A
Solution
- The sensor that was installed at this application is the HMD OKA 2038.38 G with tube OL 19.
- The signal of the infrared sensors controls the movement of centering device and abutment. The point of view is restricted by the tube and prevents disturbances by steam in the cooling phase.
- An optimum adaptation to the operating conditions is given due to the adjustable response temperature. The HMD with self-learning response temperature (Auto-Teach function) is suited to continually changing conditions.
- The compact sensor with a stainless steel housing can withstand surrounding temperatures of up to 75° C. The use of a cooling jacket raises this up to 200° C.
- Alternatively sensors with fibre optic cables are available which permit an application at ambient temperatures up to 600° C without cooling.
Customer Benefits
- Maintenance-free
- High temperature stability
- Recognition of hot objects at big distances
- Self adjustment with Auto-Teach or step switch for the response temperature
Product Part number
- OKA 2038.38 G
Brand
- Proxitron
Accessories
- Piros swivel stand HM2
- Tube OL 19
- Pilot light unit (for alignment) DAK 308 + OL 26
- Different cable lengths (e.g. 15 m)
Customer Testimonial
compared to previous solution or competition
