HITACHI CONSTRUCTION MACHINERY

“Made by Hitachi” is a global quality statement for the construction industry and proof that an Hitachi excavator has been manufactured at the “mother design factory” in Tsuchiura City, Japan. The Zaxis-3 excavator range is a typical example of this, with its environmentally friendly features and evolutionary performance. In an exclusive interview, the Zaxis-3 project designers, Kouji Tahara (KT) and Kazunori Nakamura (KN) reveal how they collaborated to create such a widely acclaimed product.

How did the basic performance of the Hitachi Zaxis-3 range evolve?

KT: Our goal for the new Zaxis range was to implement “a global machine”, i.e. one that is best for all the markets worldwide. Owners and operators wanted the basic performance to be improved and among the features requested were increased power and durability, smooth and fast operation, and improved fuel efficiency.

The Zaxis-3 series is the result of the progress that has been made in all of the basic performance standards. We also made sure that environmental concerns were taken into account and it was important that the Zaxis-3 would comply with the third generation of Japanese/US/EU emission control standards.

KN: Extensive surveys were carried out all over the world – before the development even started – to find out the standard of basic performance required. The chief designer travelled to more than 30 countries, mainly in Europe, North America and Asia, over a two-year period. He collected detailed information regarding the kind of work and job site conditions in which the excavators would be used.

He also evaluated the existing Zaxis range. By finding the common features and differences – depending on the location – we settled on the basic design of our global machine.

How did the Design & Development Department in the Tsuchiura factory prepare for this project?

KT: We wanted to maintain the uniformity of design in all classes of mid-range excavator, from the ZX70 to ZX350. So, we allowed the parts designers to communicate with the teams responsible for designing each class, across all classes.

As a result, an efficient system was established using common parts. This enabled more than 200 staff working on the development of mid-range excavators in the Tsuchiura factory to share information with each other. This also included requests from the field which affected the product design.

KN: The shared vision was: “Where quality meets ability”. This is also a slogan used for the promotion of Zaxis-3 excavators and ZW wheel loaders in the Japanese market.

The origin is based on the following slogan: “Our scrupulous attention to detail will lead to high quality”, which is applied to all product development. However, there wasn’t enough integration between the brand and product development, so we also combined these within the overall concept of “Made by Hitachi”.

Were all the basic elements created in the Tsuchiura factory?

KT: Yes, because we designated Tsuchiura Works as the “mother design factory” from the beginning of the Zaxis-3 development programme. Previously, any products with regional specifications were designed at their local factories. Dealers were also sometimes required to make modifications. Now, the complete specification is designed at Tsuchiura. The main parts – such as hydraulic pumps or engines – are sent from Japan to other parts of the world.

Were the hydraulic system and engine both completely redesigned with the latest technology for the Zaxis-3 series?

KN: We have developed core technology to maintain a good balance between increased workloads – using the efficient control of engine rpm, torque and hydraulic pressure – and reduced fuel consumption. The redesign of technologies made the tuning of hydraulic controls and engine optimisation more complicated.

However, we carried out a series of tests to determine “excavator best practice” and were able to find a match. Installing the new “E” mode allows a powerful, yet fuel-efficient machine. We also designed a new swing mechanism and upgraded the swing torque.

The advanced technology relating to efficient hydraulic pressure enables the arm to move faster. The knowledge which Hitachi accumulated during the development of the hydraulic excavator was analysed to find such features. As a result, the enhanced basic operations of the Zaxis-3 help to increase workload.

Is Hitachi continuing to build partnerships with engine makers such as Isuzu?

KN: We spent almost four years developing the best engine for the Zaxis-3 series. We made over 30 prototype engines and 25 units were installed into test machines.

Ten of these 25 units were tested in Europe, USA, China, Australia, Asia and Africa to ensure that the global machine could really be used all over the world. We have previously carried out overseas tests at various stages of development, but the number of machines involved on this occasion was incredible. Domestic tests also helped us to realise that a machine which satisfies our Japanese customers – who we consider to be the most demanding in the world – can also satisfy the global standard.

KT: As far as the engine goes, I think there is merit in building relationships with companies so that we can develop what we need as a result of their technical design knowledge and expertise. That leaves us to concentrate on the development of the hydraulic pressure and electronic controls.

The engine is one of the major parts, but it is still just a part. The birth of a good engine is not equal to the birth of a good excavator. The key to developing the hydraulic excavator was primarily due to the evolution of other technologies rather than just a better engine design.

What has been the reaction to the Zaxis-3 range around the world?

KT: The Dutch BouwMachines magazine conducted a survey to compare the performance of 20-tonne class excavators from the ten leading manufacturers in the world. The results awarded the Hitachi ZX210-3 first place in both the workload and fuel efficiency categories. This proves that the Zaxis-3 series is more advanced than all our competitors’ machines.

I believe that customers who haven’t tried the Zaxis-3 range should do so. The differences are clear – even after a brief test. It is especially easy to see the differences between Hitachi and its competitors. The Zaxis-3 series also received the 2006 Good Design Award. This judged function, quality, safety and environmental efficiency, as well as exterior design. In addition, the Zaxis-3 also received the product design award in the transportation category at the International Design Forum Hannover (iF) in 2007.

KN: At Tsuchiura, we collect the operating information of hydraulic excavators from all over the world and analyse this to assess the condition of the machines. The e-Service Owner’s Site narrows the distance between the Hitachi designers and customers. It allows us to carry out remote maintenance and share machine information with dealers, customers and the production team.

The relationship developed by listening to customers over many years – in addition to technical innovation – contributes to a high level of customer satisfaction. For example, customers in Europe requested that the Hitachi name should be made larger on the counterweight. This kind of request verifies that they are proud of Hitachi products.

Overseas customers often ask if a new Zaxis-3 is made in Japan. The main parts are sent from Japan, but the assembly process is completed in the closest factory to the market. This shortens the delivery period and cuts the cost of distribution.

So, while our products are not all assembled in Japan, they are developed in the “mother design factory” in Tsuchiura, where our quality control is thorough and guaranteed. If someone now asks this question, our answer is, “This is made by Hitachi.”