The challenge
Tine harrows are mainly used for mechanical weed control as an alternative to chemical herbicides in organic farming. One of the world’s leading manufacturers has developed a new generation of devices in which the individual harrows are hydraulically controlled for even better performance.
The entire system must be absolutely leak-proof due to the hydraulic cylinders used – even minimal leaks would lead to contamination of the soil with hydraulic oil. Nevertheless, costs must be kept under control so that the new technology can establish itself on the market.
The special nature of the task
The assembly consists of a 7075 aluminum housing with piston bores. These holes, with a drilled depth of 100 mm, must meet the highest standards in terms of absence of burr, accuracy (0.014 mm tolerance) and surface roughness (Ra 0.2) in order to ensure absolute leak-tightness and a long service life.
The Dakoko solution
Dakoko manufactures all metal components of the cylinder itself and sources the sealing elements from leading European manufacturers. A multi-stage drilling process, including drilling, reaming, grinding, rolling and polishing is used. The consistent use of special tools and internal cooling ensure that the surface quality is excellent, even at large drilled depths.
The housings then have to be chemically nickel-plated in order to achieve a higher surface hardness for a long service life. The manufacturer of the sealing elements requires a hardness of > 500 HV10 on the surface.
Moreover, Dakoko manufactures all of the turned parts for the pistons itself. These components are also subject to the highest requirements, with tolerances of 0.01mm. The piston rods are hard chrome plated externally and ground by Dakoko following chrome plating to ensure the highest surface quality and precision across the entire component.
Details that make the difference
In consultation and cooperation with the customer, an additional test bench was purchased on which Dakoko tests each assembled component before delivery and ensures 100% traceability thanks to the serial number on every component.
Benefits for the customer
- 100% quality through a very high level of vertical integration at Dakoko and 100% monitoring
- Attractive terms due to production in low-wage China, which significantly reduces assembly costs