Toyota Pallet Truck Service Manual Systems Overview Theory of Operation B- is supplied from TS2 to SW2, JP2-3, SW8, JP8-3, grab rail assembly JP4-5, Traction Motor Encoder JP6-4, and Traction Motor Temperature Sensor JP7-2 Travel Request, Forks-First When the directional/speed controls are rotated in the reverse direction (forks-first) from neutral: Travel Request, Tractor-First Same as for tractor-first travel, except the travel signal requests motion in the opposite direction and the truck travels in the opposite direction The directional/speed control descriptions assume that the battery is fully charged and connected, and the key switch is ON.
The control handle must be in the correct position to close brake (deadman) switch SW2. When SW2 is closed, main contactor (M1) is energized. Emergency Reverse (Model 8HBW30 and 8HBE30/40) N OTE : When the control handle is released and the brake (deadman) switch opened, main contactor (M1) will remain energized for several seconds before de-energizing. If the emergency reverse button (belly button) hall effect switch is closed with the control handle lowered in travel mode (SW2 closed), the control system will activate an immediate, rapid acceleration in the reverse (forks-first) direction:
When the directional/speed controls are rotated in the forward direction (tractor-first) from neutral:
The emergency reverse travel instruction is transmitted thru the CAN bus to the TPA A forward travel signal is detected in the hall effect sensors, converted into a travel request in the VM, and transmitted thru the CAN bus to the TPA Travel and speed inputs to the TPA are ignored The TPA provides maximum torque inputs to the TM immediately after the emergency reverse button is activated The VM verifies that the emergency reverse button is not activated before supplying the travel command to the TPA Travel in reverse (forks-first) direction will continue until the emergency reverse button is released The VM verifies that the arm angle is positioned correctly to activate SW2, indicating that the brake is released and contactor M1 is activated When the emergency reverse mode is activated, the TPA ceases to respond to the normal travel command from the directional/speed control.
To reset the truck for normal travel, return the directional/speed control to its neutral position and cycle the brake ON/OFF. The TPA monitors the rabbit switch (if supplied) to permit full speed travel The TPA receives a forward travel command from the VM thru the CAN bus and determines the correct sequence to energize traction motor leads (U, V, W) to move the truck in the correct direction. The TPA also determines the required amount of AC voltage to be sent thru the motor leads based on the requested RPM and the required frequency N OTE : For Model 8HBE30/40 with Jog Pick option:
the actuation of the emergency reverse switch will disengage the Jog Pick mechanism (if engaged) and return the brake to normal operating mode. Strip Curtain Bypass (Model 8HBE30/40 only) The TPA also receives feedback from the Traction Motor Encoder and the Traction Motor Temperature Sensor to adjust the voltage to the motor When the truck is traveling tractor-first, and the horn button on the grab rail is pressed, the 00700-CL398-07, Issued: 9 August 2007 3-9