Abstract: A secondary battery system of connecting secondary batteries includes first output-unit switches, second output-unit switches, series-connection switches, a positive-side discharging output unit connected to second terminals of the first output-unit switches, a negative-side discharging output unit connected to second terminals of the second output-unit switches, a positive-side charging input unit connected between a positive terminal of one of the secondary batteries at one end of the secondary batteries and a first terminal of one of the first output-unit switches associated with the one of the secondary batteries at the one end of the secondary batteries, a negative-side charging input unit connected between a negative terminal of one of the secondary batteries at the other end of the secondary batteries and a first terminal of one of the second output-unit switches associated with the one of the secondary batteries at the other end of the secondary batteries, and a control unit.

Abstract: A secondary battery system of connecting secondary batteries includes first output-unit switches, second output-unit switches, series-connection switches, a positive-side discharging output unit connected to second terminals of the first output-unit switches, a negative-side discharging output unit connected to second terminals of the second output-unit switches, a positive-side charging input unit connected between a positive terminal of one of the secondary batteries at one end of the secondary batteries and a first terminal of one of the first output-unit switches associated with the one of the secondary batteries at the one end of the secondary batteries, a negative-side charging input unit connected between a negative terminal of one of the secondary batteries at the other end of the secondary batteries and a first terminal of one of the second output-unit switches associated with the one of the secondary batteries at the other end of the secondary batteries, and a control unit.

Abstract: A hydraulic control device for a forklift includes a hydraulic pump, a single electric motor for driving the hydraulic pump, an outflow control mechanism provided between a lift cylinder and the hydraulic pump, a flow control valve provided between the outflow control mechanism and a draining portion, and a controller. When a lowering operation of a fork and either forward or rearward mast tilting operations of a mast are performed at the same time, the controller controls the electric motor based on a target speed of the hydraulic pump. The flow control valve controls the flow rate of hydraulic fluid from the lift cylinder to the hydraulic pump and the flow rate from the lift cylinder to the draining portion in accordance with the difference between the actual rotation speed of the hydraulic pump and the target rotation speed of the hydraulic pump.

Abstract: A hydraulic control device for a forklift includes a hydraulic pump, a single electric motor for driving the hydraulic pump, an outflow control mechanism provided between a lift cylinder and the hydraulic pump, a flow control valve provided between the outflow control mechanism and a draining portion, and a controller. When a lowering operation of a fork and either forward or rearward mast tilting operations of a mast are performed at the same time, the controller controls the electric motor based on a target speed of the hydraulic pump. The flow control valve controls the flow rate of hydraulic fluid from the lift cylinder to the hydraulic pump and the flow rate from the lift cylinder to the draining portion in accordance with the difference between the actual rotation speed of the hydraulic pump and the target rotation speed of the hydraulic pump.

Abstract: A charging circuit is provided that charges a battery for supplying power to a motor drive system that includes a three-phase motor and a three-phase inverter for controlling the three-phase motor. The three-phase inverter includes first to third sets of switching elements. Each set corresponds to one of the three phases. The charging circuit includes a single-phase output transformer, a rectifier circuit, a line, and a controller. The single-phase output transformer includes a secondary side output section having a first terminal and a second terminal. The rectifier circuit is connected in parallel with the three-phase inverter and the battery. The rectifier circuit is also connected to the first terminal of the secondary side output section. The line connects a connecting point between the first set of the switching elements in the three-phase inverter with the second terminal of the secondary side output section. The controller performs on-off control of the first to third sets of the switching elements.

Abstract: A load weight measuring device for a multi-stage mast forklift truck has a mast assembly, an oil passage, a flow regulator valve, a pressure sensor, a detecting device, a memory, a selector, and a calculator. The mast assembly has a lift bracket for receiving a load weight, a multi-stage mast unit having masts, and a multi-stage lift cylinder unit having lift cylinders each having an oil chamber for raising the lift bracket along the masts. Hydraulic oil flows in the oil passage. The pressure sensor detects a pressure of hydraulic oil and outputs a pressure signal. The detecting device detects a state which stage of the lift cylinder raises the lift bracket and outputs a detection signal. The memory stores predetermined parameters from which the selector selects the parameter based on the detection signal. The calculator calculates the load weight based on the selected parameter and the pressure signal.

Abstract: A travel control apparatus for a forklift is disclosed. The forklift is provided with a loading device that performs load handling operations by raising and lowering a load, and a drive motor which generates a drive force for travel and is capable of generating a braking force. The apparatus is provided with a sensor for detecting the speed of the motor, a seat switch, a height switch, a load sensor, and a control section. The control section causes the drive motor to generate a braking force when the seat switch detects that the driver has left the seat in the case where the motor speed sensor detects a traveling state, and also changes the strength of the braking in accordance with the height of the loading device and the weight of the load.

Abstract: A shock-detecting apparatus for an industrial vehicle has a shock-detecting sensor that is fixed to the industrial vehicle for detecting a shock and generating an output signal, a shock value computer for computing a shock value based on the output signal which is received sequentially, a judging device for judging whether or not the shock value is greater than a threshold value, a warning generator for generating a warning signal when the judging device judges that the shock value is greater than the threshold value and a threshold value setting device for setting the threshold value. The threshold value setting device includes a display for displaying a peak value in a predetermined period which allows a user to read the peak value, wherein the peak value is determined by the computed shock value during the predetermined period and a threshold value input unit for inputting the threshold value manually.

Abstract: A power converter includes a switching device composed of parallel-connected semiconductor chips evenly divided into two groups. The power converter includes a positive conductor, a capacitor and an output electrode. The positive conductor includes first and second terminal portions. The output electrode includes an end portion joined to a base portion having first and second connecting portions. The output electrode is formed so as to reduce or cancel a difference existing between an inductance L1 of a current path from a positive terminal of the capacitor to the first terminal portion and an inductance L2 of a current path from the positive terminal to the second terminal portion, by providing a difference between an inductance L3 of a current path from the first connecting portion to the end portion and an inductance L4 of a current path from the second connecting portion to the end portion.

Abstract: A power converter includes a base plate having thereon a switching device, and positive and negative conductors respectively including main portions disposed parallel to the base plate. One of the main portions is placed over the other of the main portions. The main portions are disposed adjacent to and parallel to each other. The main portions are insulated from each other. The power converter includes a capacitor having positive and negative terminals electrically connected to the respective main portions of the positive and negative conductors. Each of the positive and negative conductors includes a side portion extending from the main portion toward the base plate, and a terminal portion extending from the side portion and joined to the base plate. The side portion is formed with a cutout extending from the end adjacent to the base plate to the opposite end connected to the main portion.

Abstract: A power converter apparatus that includes a substrate, plate-like positive and negative interconnection members, capacitors, and a cover is disclosed. Pairs of groups of switching elements are mounted on the substrate. The cover is arranged over the substrate to encompass the switching elements, the positive interconnection member, the negative interconnection member, and the capacitor. The positive interconnection member and the negative interconnection member each have a terminal portion that is joined to a circuit pattern on the substrate by ultrasonic bonding.

Abstract: A power converter apparatus that includes a substrate, plate-like positive and negative interconnection members, and capacitors is disclosed. Pairs of groups of switching elements are mounted on the substrate. Each of the positive interconnection member and the negative interconnection member has a terminal portion. The terminal portion has a joint portion that is electrically joined to a circuit pattern on the substrate. The switching elements are arranged in the same number on both sides of the joint portion of at least the positive interconnection member of the positive and negative interconnection members.

Abstract: A power converter apparatus includes a substrate 22 on which switching elements Q, Q1 to Q6 are mounted, positive and negative terminal interconnection members 27, 28 mounted on the substrate, and a capacitor 17 having a positive terminal 17a connected to the main body of the positive terminal interconnection member 27 and a negative terminal 17b connected to the main body of the negative terminal interconnection member 28. The interconnection members each have a plate-like main body 27a, 28a that is located above and parallel to the substrate 22. The main bodies of the interconnection members are stacked to be close to each other while being electrically insulated from each other. Each of the positive terminal interconnection member and the negative terminal interconnection member further includes a plate-like extension 27b, 28b that extends from the corresponding main body toward the substrate, and a terminal portion 27c, 28c that extends from the extension and is joined to the substrate.

Abstract: A charging circuit is provided that charges a battery for supplying power to a motor drive system that includes a three-phase motor and a three-phase inverter for controlling the three-phase motor. The three-phase inverter includes first to third sets of switching elements. Each set corresponds to one of the three phases. The charging circuit includes a single-phase output transformer, a rectifier circuit, a line, and a controller. The single-phase output transformer includes a secondary side output section having a first terminal and a second terminal. The rectifier circuit is connected in parallel with the three-phase inverter and the battery. The rectifier circuit is also connected to the first terminal of the secondary side output section. The line connects a connecting point between the first set of the switching elements in the three-phase inverter with the second terminal of the secondary side output section. The controller performs on-off control of the first to third sets of the switching elements.

Abstract: A shock-detecting apparatus for an industrial vehicle has a shock-detecting sensor that is fixed to the industrial vehicle for detecting a shock and generating an output signal, a shock value computer for computing a shock value based on the output signal which is received sequentially, a judging device for judging whether or not the shock value is greater than a threshold value, a warning generator for generating a warning signal when the judging device judges that the shock value is greater than the threshold value and a threshold value setting device for setting the threshold value. The threshold value setting device includes a display for displaying a peak value in a predetermined period which allows a user to read the peak value, wherein the peak value is determined by the computed shock value during the predetermined period and a threshold value input unit for inputting the threshold value manually.

Abstract: A power converter includes a switching device composed of parallel-connected semiconductor chips evenly divided into two groups. The power converter includes a positive conductor, a capacitor and an output electrode. The positive conductor includes first and second terminal portions. The output electrode includes an end portion joined to a base portion having first and second connecting portions. The output electrode is formed so as to reduce or cancel a difference existing between an inductance L1 of a current path from a positive terminal of the capacitor to the first terminal portion and an inductance L2 of a current path from the positive terminal to the second terminal portion, by providing a difference between an inductance L3 of a current path from the first connecting portion to the end portion and an inductance L4 of a current path from the second connecting portion to the end portion.

Abstract: A load weight measuring device for a multi-stage mast forklift truck has a mast assembly, an oil passage, a flow regulator valve, a pressure sensor, a detecting device, a memory, a selector, and a calculator. The mast assembly has a lift bracket for receiving a load weight, a multi-stage mast unit having masts, and a multi-stage lift cylinder unit having lift cylinders each having an oil chamber for raising the lift bracket along the masts. Hydraulic oil flows in the oil passage. The pressure sensor detects a pressure of hydraulic oil and outputs a pressure signal. The detecting device detects a state which stage of the lift cylinder raises the lift bracket and outputs a detection signal. The memory stores predetermined parameters from which the selector selects the parameter based on the detection signal. The calculator calculates the load weight based on the selected parameter and the pressure signal.

Abstract: A semiconductor unit includes a semiconductor chip, a ceramic substrate having a circuit pattern on which the semiconductor chip is mounted, and a temperature sensor for detecting a temperature. The semiconductor unit further includes a pressing member for retaining the temperature sensor by pressing against the ceramic substrate.

Abstract: A power converter apparatus that includes a substrate, plate-like positive and negative interconnection members, capacitors, and a cover is disclosed. Pairs of groups of switching elements are mounted on the substrate. The cover is arranged over the substrate to encompass the switching elements, the positive interconnection member, the negative interconnection member, and the capacitor. The positive interconnection member and the negative interconnection member each have a terminal portion that is joined to a circuit pattern on the substrate by ultrasonic bonding.

Abstract: A power converter apparatus that includes a substrate, plate-like positive and negative interconnection members, and capacitors is disclosed. Pairs of groups of switching elements are mounted on the substrate. Each of the positive interconnection member and the negative interconnection member has a terminal portion. The terminal portion has a joint portion that is electrically joined to a circuit pattern on the substrate. The switching elements are arranged in the same number on both sides of the joint portion of at least the positive interconnection member of the positive and negative interconnection members.