Products
ON-CENTER DETENT (OCD)
The Bishop OCD System offers dramatically improved on-center steering stiffness for medium and high speed freeway driving, while unaffecting parking effort and steering gear friction. It is adaptable to most rotary valve formats.

  

VARIABLE RATIO (VR)
Bishop’s Variable Ratio steering racks provide remarkable improvements in:

Primary Safety
more relaxing to drive at high speeds ensuring less fatigue and greater safety;
improved control during radical avoidance maneuvers and skid recover;
increased driver confidence in lateral placement of vehicle.

Driver Comfort
reduced need to change position of hands on steering wheel;
reduced turns lock-to-lock ensures easier parking.

Bishop VR has a significantly large ratio curve flexibility, which can achieve fast ratio changes and double ratio changes.

  







VARIATRONIC
Bishop VARIATRONIC is a speed-sensitive power steering solution, which offers complete flexibility in boost characteristic as a function of vehicle speed, with a minimum of additional componentry compared with a standard rotary valve.

  
Y-RACK
Bishop’s Y-Rack design reduces rack roll, thus improving steering stiffness (precision), provides even tooth load distribution and superior rack tooth strength.

    
Process
PRECISION WARM FORMING CELL
This innovative technology, the Bishop Precision Y-Forging Die and Warm Forming Cell - is the core technology behind the joint venture between Bishop Steering Technology and Mercedes-Benz Steering. The facility, BMB Steering Innovation located in Schoenebeck (in the State of Saxony Anhalt, Germany) manufactures warm forged steering racks for the global automotive market.

The Precision Y-Forging Die and Warm Forming Cell produces variable and constant ratio steering racks at a cycle time of 12 seconds. The racks produced in this process are net shape, free of flash and hence, require no finish machining of the teeth or the rack faces (Y-faces) that contact the rack pad. As-forged tooth mesh quality achieved is DIN Class 9 or better. Racks produced by this process have achieved a cost advantage of more than 25% over a competing cold formed rack technology.

  


EQUIPMENT USED IN THE WARM FORMING CELL

Washing Machine

 Die Monitoring System
Induction Heater Die Spray Unit
Robots Die Changeover Carriage
Robot Controllers Transfer Station
Press Rack Cool Quench Machine
Y-Forge Die Conveyor
Rack Bar during Forging Robot Safety Enclosure


 

Y-FORGING DIE
The Bishop Y-Forging Die is the heart of the Warm Forming Cell and precision warm forms a constant or variable ratio Y-form steering gear rack from a cylindrical bar.

The Y-Forging Die produces a stress relieved near net shape product of consistent quality with precision gear teeth. However, it avoids the distortion produced by the high residual stresses associated with cold forging and the lower harness caused by decarburization in hot forging. It is operated with an 800-1,250 tonne screw press and a 150-250kW 3-10Hz induction heater - depending on the rack size.

In variable ratio Y-form steering racks the tooth geometry changes from “On Centre” to “Lock” and for this reason the tooth form cannot be produced by conventional means (ie broaching or creep feed grinding). The Bishop Y-Forging Die produces precision warm formed steering gear racks with true involute variable ratio teeth in a one step process at low cost.