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Wet multiple plate clutches consist of friction plates, on which a friction material is bonded, and mating plates that are plain metal plates. Since the frequency and the range of load in the field of forklift trucks vary widely and are more severe than those for passenger cars, the wet multiple plate clutches on forklift trucks are often damaged. Damaged clutches that were returned from the field typically had 3 types of symptoms: 1.Only the friction material was damaged, 2.Only the mating plates were deformed, 3.Both symptoms were observed. It was clear that the cause of these symptoms depended on the difference of the operating application and the strength criteria of each part. This showed that a design guide for wet multiple plate clutches considering the strength balance between the two parts according to the work application was required. The relevant flow chart of this design process was proposed.

A manned Mars mission will be undertaken in the near future. Then the need for ‘water’ will become critical. One of the solutions to the problem is making use of the resources on Mars. We take notice of CO2 reduction. The method is to generate H2O from CO2, which is major composition of Martian atmosphere. Nominally, the reaction of CO2 reduction is performed at atmospheric pressure on Earth. However, the nominal pressure of the Martian atmosphere is below 10 torr. Therefore, it is necessary to confirm whether the reaction of CO2 reduction can be performed with same efficiency as on Earth. This paper summarizes the results of a fundamental study of CO2 reduction system for a Mars mission.

Mud adhesion to the rear surfaces of trucks, vans and buses causes troublesome results such as aesthetic degradation, hindered rear view and laborious washing. To raise the product value of trucks and buses, it is important to develop effective measures for suppressing such mud adhesion. In this research the authors first clarified the mechanism of mud adhesion through flow visualization tests. Then, wind tunnel tests were performed to predict the effects of various countermeasures, and prospective ones were put under actual driving tests to verify their effects. The following measures were found effective in suppressing mud adhesion. (1) Aerodynamic improvement by attaching corner vanes to the upper and side edges of the rear surface. (2) Blocking road splash with a slanted plate under the truck and close to the base.

In order to design a well-balanced truck frame, optimization of not only the stiffness of the entire body and stress of each member, but also the internal force of each member is necessary, including the effect of a rear body mounted on the frame. This paper proposes a new parameter, “torsional stiffness share rate,” that directly correlates the contribution of member torsional stiffness to frame torsional stiffness with the internal force of the members as to torsion of the truck frame. The merits of the torsional stiffness share rate are shown in comparison with the strain energy share rate and the stiffness contribution rate. The results of experimental and FEM analyses of the torsional stiffness share rate are also presented.

In closed environments such as space stations, it is necessary to eliminate CO2 produced by the metabolisms of crew members, for their life support, and to regenerate the air by supplying O2 to make up for the deficiency. If humans are to be in space only a short time, it is in general advantageous to adsorb CO2 with lithium hydroxide, and to supply O2 from tanks. But when the stay in space is long, it is essential to establish a highly reliable and energy-efficient system to recover CO2 in high concentrations and regenerate O2 from this recovered CO2 Fig. 1 shows the system presently conceived, which is roughly divided into the following processes: A process that removes and concentrates CO2 from the air; a CO2 reduction process that separates carbon from CO2 and obtains water; and a water electrolysis process that decomposes water electrically and recovers O2.

Water is one of the most valuable items in the closed environment such as the space station. It will be used for human habitation and various experiments. However, it will be not supplied from the earth. Therefore, water reclamation is one of the most indispensable technologies in the space station. The water treatment processes used to be combinations of the membrane separation technologies of pre-filter (PF), ultra-filtration (UF) and reverse osmosis (RO) which has been developed for the salt-to-fresh distillation technology. One the other hand, more efficient hydrophobic membranes have been developed recentry. Using these new water treatment technology of hydrophobic membranes, the membrane distillation (MD), combined with the conventional water treatment process in now being investigated for water reclamation. The MD is expected to be most important process of the water reclamation system integrated into the space station in the future.

Some research and development studies concerning Mitsubishi DC2 diesel engines are described. The engines are of 90-deg V type newly designed, for trucks or buses of more than 14 tons (30,900 lb) gross weight, after exhaustive fundamental researches and many years' experience. The series covers 6-, 8-, and 12-cyl engines of the water-cooled, precombustion-chamber type with a 130-mm (5.12 in.) bore and a 125-mm (4.92 in.) stroke. The engines are capable of developing a maximum output of 200-400 ps (197.5 ∼ 395 hp) and combine high reliability with compact and light-weight construction. Naturally the use of common parts among these engines in series facilitates their parts' supply and maintenance. In addition to the naturally aspirated engines, turbocharged 8- and 12- cyl engines are available.