With its new line of 7-Series 3-wheel electric lift trucks, Toyota Material Handling U.S.A. introduces the next generation of AC technology. The new AC power system consists of both drive and lift AC motors, resulting in a line of lift trucks with up to 45% more power than their predecessors, and cost savings per year due to improved efficiency, operator labor costs, and reduced maintenance requirements.
Toyota's New AC Power System
This cost-effective material handling solution can improve productivity and energy efficiency while significantly reducing overall operational costs for standard maintenance.
With the development of its AC power technology, Toyota has produced a lift truck that operates all functions with AC power, including mast control, drive, and steering.
Among the technology's benefits, AC motors have greater power capacity and operate with quicker acceleration, faster top speeds, and higher output than an equivalent-sized DC motor. In addition, Toyota's 7-Series 3-wheel electric lift trucks are configured with three motors instead of four: two AC motors in front to control the drive functions, and a third AC motor that controls both steering and hydraulic functions. The result is a more powerful, yet more compact lift truck.
By applying some of the same technology that has evolved for Toyota electric and hybrid automobiles, Toyota was able to design and build an AC motor that uses a MOSFET controller (Metal Oxide Semiconductor Field Effect Transistors), managing power regulation by adjusting the electrical frequency directed to the motor. This works to provide a compact system of energy management with built-in diagnostic capabilities.
Transistorized AC drive and hydraulic controls are a standard feature on the new line of 7-Series 3-wheel electric lift trucks. This state-of-the-art, user-friendly technology is fully programmable from the operator's digital display keypad, controlling all mast and auxiliary functions including attachments.
A common concern with electric lift trucks is the dramatic fade in power as the battery charge depletes. Toyota counters this performance challenge with its "power keep" function: the intelligent controller continually monitors performance and compensates for loss of power as the battery depletes, yielding longer run times and more consistent power between battery charges.
Toyota's AC power system incorporates energy recovery through three forms of regeneration: when the accelerator pedal is released (coasting), when the brake pedal is depressed, and when the directional lever is shifted from forward to reverse, or vice versa, to extend run time.
A "momentary hold and controlled descent" motor feature allows the operator to maintain control on a grade or incline when the accelerator is released, by regulating the rolling speed. This also allows the operator to start the truck on a ramp or other slanted surface without rolling backward.
Active Mast Control
Toyota's Active Mast Control (AMC) is designed to make load carrying and movement safer and more stable. It is a system of sensors, limit-switches, actuators, and a controller that detects and responds to changes in the operating status of the truck to enhance longitudinal stability when handling loads of varying sizes and weights at high lift heights.
Sensors monitor the height and weight of the load, as well as the forward tilt angle. When the controller detects that the forward tilt is approaching a potentially dangerous situation, the tilting angle is reduced to help prevent the load from falling off the forks or tipping the entire lift truck forward.
Similarly, the AMC system will automatically reduce the back tilt speed to reduce the potential of losing a load due to the mast "slamming" backward too quickly. The controller will detect how high the forks are raised and the hydraulic valve will slow the rear tilting of the mast as needed, depending on the height and weight of the load.
This technology also includes an automatic fork-leveling feature, which is especially useful when inserting forks into a pallet or placing a pallet on a rack. With the press of a button, the forks are leveled automatically, parallel to the floor, reducing the margin for human error that exists when forks are leveled manually according to the visual assessment of the operator. This function can significantly improve productivity and safety and reduce product damage, especially when placing loads at higher heights.
