• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.4
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• pp.13-19
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• 2008

In order to reduce the level of recoil force, new recoil technology must be employed. The present study discusses a soft-recoil system that can reduce dramatically the recoil force. The firing sequence of the soft recoil system is radically different from that of a conventional system. The gun is latched and preloaded in its out-of-battery position prior to firing. When unlatched, the gun is accelerated and forward momentum is imparted to the recoiling parts. This momentum is opposed by the ballistic force imparted by firing and the recoil force and stoke will be reduced. In the present study, the soft-recoil system with hydraulic dampers is simulated and its characteristics are investigated theoretically. The results of the simulation show that the soft-recoil system could dramatically reduce the recoil force and the recoil stroke compared to the conventional recoil systems. However, the soft-recoil system was not able to perform well when the firing fault modes like prefire, hang-fire, and misfire happen. Hence, we need to employ a control algorithm to prevent the damage of the recoil system due to these fault mode.

• Journal of Drive and Control
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• v.13 no.2
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• pp.10-18
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• 2016

A front-end loader (FEL) mounted on an agricultural tractor is one of the most commonly used implements to mechanize routine agricultural tasks. When the FEL is used with a loaded bucket, careful operation is required to maintain safety and avoid spillage when the tractor passes a bump because a change in the gravity center of the tractor due to varied loadings can affect the stability of the tractor. Use of a boom suspension system consisting of accumulators and orifice dampers can be instrumental in reducing pitching vibrations while increasing the handling performance of the FEL-mounted tractor. The objective of this research was to reduce bump shocks by adding an orifice and a flow control valve to the original hydraulic circuit composed solely of accumulators. A simulation study was performed using the SimulationX program to investigate the effects of an accumulator and an orifice-throttle damper on bump shocks. Results showed that the peak pressure on a boom cylinder and the vertical acceleration of a bucket were significantly affected by use of both an accumulator and an orifice damper. In a field test conducted with a 75-kW tractor, the peak pressure of the boom cylinder, and the root mean square (RMS) vertical acceleration of the bucket and seat were reduced by on average, 23.0, 42.2, and 44.9% respectively, as compared to those measured with the original accumulator system, showing that an improved design for the accumulator hydraulic circuit can reduce bump shocks. Further studies are needed to design a tractor suspension system that includes the effects of cabin suspension and tires as well as dynamic analysis.