Air brake system and trailer hitch for Komatsu wheeled loader
Development of an air brake system and trailer hitch for the Komatsu WA270-8 wheeled loader which pulls various trailers, screening and cleaning systems to the site of operation on public roads.
Customer
Schlüter Baumaschinen GmbH headquartered in Erwitte, is the leading exclusive dealer of Komatsu and Sennebogen construction machines. In addition to sales, rental and customer service, the company’s range of services includes the individual production of special accessories.
Customer requirement
The objective was to develop an air brake system for the wheeled loader and to replace the existing towing device on the cast steel rear weight with a trailer hitch suitable for road use. One of the challenges was to develop a towing device that transfers the high trailer and supporting loads via the rear weight into the rear machine frame of the wheeled loader.
Solution
As a replacement for the towing device, Tietjen has developed an adapter plate that accepts various trailer hitch types. This adapter plate is made of a steel that is suitable for machine parts that are subject to high stress. This allows trailer and supporting loads to be transferred from the trailer hitch to the rear frame of the machine via the adapter plate. Furthermore, the adapter plate is constructed with various struts to ensure that the maximum permissible bending stresses of the adapter plate are not exceeded.
The special design of this new adapter plate now eliminates the need to dismantle the entire rear weight for its installation. By removing only two fastening bolts each in two successive work steps, the rear weight remains permanently connected to the machine rear frame and the adapter plate is mounted in the same two work steps. This results in a considerably easier and more reliable assembly during the assembly process. With four fastening bolts, the adapter plate is attached to the rear frame of the machine together with the counterweight.
Advantage for the customer
In addition to the simplified installation of the adapter plate, it allows for mounting various trailer hitch types with different pin shapes as well as hitches by different manufacturers. There is the option of integrating a tow-bar for height-adjustable hitches as well. All necessary threaded holes are implemented in the adapter plate to accommodate holders for air coupling heads as well as light and ABS/EBS plug sockets.
For the air brake system, ZF (Wabco) supplied the main components such as compressor, unloader valves, trailer control valves and air reservoirs. The compressor console, various holders and steel pipelines were developed by Tietjen’s design engineers using the latest design software, and adapted to the available space in the vehicle. These parts were manufactured with the aid of our company CNC machines.
Advantage for the customer: The newly developed air brake system can be purchased as a kit with pre-mounted assemblies and colour-coded connectors. All installation steps are documented in an assembly manual including detailed descriptions and figures.
Taken as a whole, the proximity of Dipl. Ing. Tietjen GmbH to the production site of the Komatsu wheeled loader in Hanover is an advantage. Schlüter has new machines transported directly from there to Tietjen for the development or assembly of the air brake systems, trailer hitches or cleaning systems. After successful assembly and TÜV approval, the modified machines are then transported to the respective Schlüter sales location. This approach saves costs and delivery times.
Customer feedback
"Tietjen works professionally and reliably in close cooperation with the customer services of Schlüter Baumaschinen GmbH. All questions regarding the generation of compressed air for construction machinery are answered quickly and competently. We have been working together in a spirit of trust for years."
Jörn Beyer, Office Manager for Project Planning and Sales Support,
Schlüter Baumaschinen GmbH
The Komatsu WA270-8 wheeled loader was equipped with an air brake system and an adapter plate that accepts various trailer hitch types.