Technology for the World KURAKI

CNC Notching Machine KURAKI’s Notching Technology

Notching Processes Ideal for High-Mix, Small-Lot Production

Notching machines are mainly used for press working of stator cores and rotor cores, which are the cores of electromagnetic steel sheets used in laminated steel plates for electric motors and generators. Slot grooves are punched out at high speeds while indexing each slot in the blank base material, enabling processing with a minimum number of dies, thereby reducing die costs. In the case of small-lot slotting with a base metal which has outer diameter of 300 mm or more, one-punch processing using a full die results in high die costs, making notching advantageous in terms of cost.

The image shows an example of KNCP series processing.

CNC controlled high-speed punching!

AC servo motors are used for punching and indexing. The NC controller, by FANUC, a highly reliable manufacturer, is applied and the optimum time constant setting function (patented) of the dedicated software achieves a punching stroke count of 1000 spm. The CNC indexing mechanism enables high-precision processing with a punching accuracy of ±0.05 mm.

Pitch correction function realizes even higher precision indexing

In the machining of EV motors and other components that require high-precision indexing, pitch errors between slots caused by workpiece rigidity and other factors can be corrected for each slot, enabling even higher-precision indexing. (Option)

Various Automation Systems to Improve Machining Efficiency

The KNCP series offers equipment and systemization to meet detailed customer specifications, processes, and layouts.Combined with an automatic transfer device for base materials and various options, stator and rotor punching can be efficiently produced at the same time. In addition, a full range of safety devices necessary for unmanned automatic operation are available, such as prevention of malfunctions during setup work and display of various alarm messages.

System Configuration Example

A linear transfer system is used between stations, which offers excellent cost performance in terms of transfer speed, setup efficiency, and space saving. We can propose a system that meets each customer’s requirements.


(1) Blank supply station (2 stacks)
(2) Orientation station
(3) Notching machine (Status lot processing)
(4) Stator stack station (2 stack)
(5) Notching machine (Lotus lot processing)
(6) Rotor stack station (2 stack)


(1) Blank supply station (4 stack)
(2) Orientation station
(3) Notching machine (Status lot processing)
(4) Stator stack station (4 stack)
(5) Intermediate station
(6) Rotor stack station (4 stack)