Honda Giken Kogyo Kabushiki Kaisha

Fumitomo Takano

Hitoshi Saito

Nobuo Kobayashi

Makoto Suzuki

Gen Tsujii

Kenji Miyanaga

Hidenori Koga

Yoshinari Tsukada

Atsushi Ueyama

Toshiaki Nagasawa

Toshihiro Murakawa

Kazuo Isogai

Hiroki Hashimoto

Yuko Suzuki

Gen Tujii

Tetsuya Ozawa

A control apparatus for a welding robot has a welding gun which is provided at a front end of a robot arm to be driven by plural kinds of servomotors. An amplifier circuit board is provided so as to mount thereon appropriate inverters by selecting out of those corresponding to respective kinds of servomotors and an inverter for the welding gun. A servo software corresponding to each of the inverters is called out of a memory device by discriminating the kind of each of the inverters. In a method of teaching the welding robot in which the welding gun is opened and closed by a servomotor, plural kinds of opening and closing patterns of the welding gun are set in advance. An appropriate opening and closing pattern is selected out of the plural kinds of opening and closing patterns in accordance with the motion of the robot arm, and the selected pattern is made the teaching data relating to the opening and closing of the welding gun.

Control apparatus for welding robot and method of teaching welding robot

Before a deterioration of a secondary current sensor is detected, a controller effects a feedback control process based on a secondary current from the secondary winding of a welding transformer which is energized by an inverter, for thereby controlling a welding current with a high degree of accuracy, e.g., an accuracy level of .+-.1%. At the same time, it is monitored whether a detected value of a primary current from the primary winding of the welding transformer, which is detected by a primary current sensor, exceeds a predetermined allowable range with respect to a reference value of the primary current. If the detected value of the primary current exceeds the predetermined allowable range, then it is decided that the secondary current sensor is deteriorated. When the secondary current sensor is deteriorated, the controller switches from the feedback control process based on the secondary current to a feedback control process based on the primary current to control the welding current with a certain degree of accuracy, e.g., an accuracy level of .+-.3%, without interrupting the welding process.

Method of controlling welding current and inverter-controlled DC

An apparatus for inspecting an electric component in an inverter circuit has a DC power supply for supplying a direct current to a given position in an inverter circuit, a voltage detector for detecting a voltage at a given position in the inverter circuit, a current detector for detecting a current flowing at a given position in the inverter circuit, a switching circuit for changing positions at which the direct current is supplied from the DC power supply, positions at which the voltage is detected by the voltage detector, and positions at which the current is detected by the current detector, and a controller for outputting a switching signal to the switching circuit. The switching circuit is controlled by the controller to charge an electrolytic capacitor in an inverter circuit with a current from the DC power supply. The electrolytic capacitor is determined as to its quality by determining whether the calculated electrolytic capacitance of the electrolytic capacitor falls within a preset range or not. Each of the transistors of the inverter circuit is determined as to its quality by determining whether an V.sub.CE -I.sub.C curve thereof falls in a preset range or not. The electrolytic capacitor, the transistors, and also diodes connected across the transistors can be determined as to whether they are acceptable or not while they are being connected in the inverter circuit.

Apparatus and method for inspecting an electrolytic capacitor in an

A method and apparatus for inspecting a transistor in an inverter circuit includes turning on only the transistor of the inverter circuit. A predetermined collector current is supplied to the transistor until a transistor junction temperature reaches a predetermined temperature. The transistor is acceptable if a difference between a transistor collector-to-emitter voltage when the predetermined collector current is supplied and a transistor collector-to-emitter voltage when the junction temperature reaches the predetermined temperature falls within a preset range. Switching elements of the inverter circuit are controlled to supply a current through a resistor to charge an electrolytic capacitor of the inverter circuit. A voltage across the electrolytic capacitor during charging and a time period is measured from the beginning of charging until a time when a voltage across the electrolytic capacitor attains a predetermined voltage. An electrostatic capacitance of the electrolytic capacitor is determined based on the measured time period and a resistance value of the resistor. The electrolytic capacitor is discharged and a discharging voltage and current are measured. An equivalent series resistance of the electrolytic capacitor is determined based upon the voltage of the electrolytic capacitor at the beginning of discharge, the electrolytic capacitance and the measured discharge voltage and current.

Inspecting transistors in an inverter circuit

Apparatus for inspecting electric component for inverter circuit

A direct current resistance welding machine and a method of controlling the direct current resistance welding machine wherein primary current of a welding transformer is detected when a plurality of switching devices of an inverter are controlled based on corresponding pulses having a predetermined frequency and each having a time width corresponding to the value of a required secondary current. Rise and fall times of the detected primary current are detected. An upper limit frequency Of the primary current is computed based on the time width of each pulse and on the rise and fall times. Thus, the primary current of the welding transformer is controlled by controlling the switching devices based on pulses having a frequency falling within the computed upper limit frequency.

Direct current resistance welding machine and method of controlling the

A DC resistance welding apparatus includes a pair of welding electrodes for sandwiching workpieces to be welded therebetween and a circuit connected to the welding electrodes for supplying a welding current to said welding electrodes. The circuit includes a plurality of parallel-connected rectifying circuits each having a welding transformer and rectifying circuit. The circuit allows a large welding current to be supplied to workpieces, and makes the DC resistance welding apparatus small in size and light in weight.

Switching control system for controlling an inverter of a spot

A DC resistance welding apparatus includes a pair of welding electrodes for sandwiching workpieces to be welded therebetween and a circuit connected to the welding electrodes for supplying a welding current to said welding electrodes. The circuit includes a plurality of parallel-connected rectifying circuits each having a welding transformer and rectifying circuit. The circuit monitors the power signal produced by inverters in the power supply to determine the proper energization time by producing a pulse signal corresponding to the waveform of the power signal. The rise and fall of the pulse signal is then detected and differentiated. The differential signal is used as a basis to control the energization time of the welding gun.

DC resistance welding apparatus

A direct-current resistance welding apparatus includes pneumatic actuators for pressurizing welding guns, respectively, to grip respective workpieces, an inverter composed of a plurality of parallel-connected switching device units each comprising a pair of series-connected switching devices, and a plurality of welding transformers connected to the welding guns, respectively, and also connected between the switching device units. A timer circuit applies an energization signal to energize the switching device units. The pneumatic actuators are actuated by a control circuit to pressurize the welding guns and successively energize the switching device units according to s sequence read from a sequence memory circuit.

Direct-current resistance welding apparatus and method of controlling

A welding transformer for use in a resistance welding machine has primary and secondary coils. The primary coil includes a plurality of spaced juxtaposed coil units mounted on a base board. Each of the coil units includes a plurality of juxtaposed coil unit elements with insulating members interposed therebetween. Each of the coil unit elements includes a plurality of turns of a conductive member, and a plurality of conductors mounted on the base board and electrically interconnecting the coil unit elements. A pair of cores is combined with the coil units.

Welding transformer and method of manufacturing same

A DC resistance welding apparatus includes a pair of welding electrodes for sandwiching workpieces to be welded therebetween and a circuit connected to the welding electrodes for supplying a welding current to said welding electrodes. The circuit comprises includes a plurality of parallel-connected rectifying circuits each comprising having a welding transformer and rectifying circuit. The circuit allows a large welding current to be supplied to workpieces, and makes the DC resistance welding apparatus small in size and light in weight.

A resistance welding apparatus mounted on a robot arm includes a transformer having primary and secondary windings. Two gun arms supporting respective welding electrodes in confronting relation to each other are relatively movable toward and away from each other. Conductors extending from the secondary winding are electrically connected to one of the welding electrodes through one of the gun arms, and the transformer is supported on said one gun arm. Rectifiers are used which have terminals engaging said one gun arm and opposite terminals engaging the conductors. The rectifiers and the conductors are securely joined to the one gun arm.

Resistance welding apparatus with gun-arm mounted transformer

A welding gun assembly includes a welding gun with a pair of electrodes for welding workpieces together therebetween. The welding gun assembly includes an array of transformers extending in one direction and having respective secondary coils. The welding gun assembly also has a plurality of terminal plates connected to the secondary coils, and a plurality of center tap terminal plates connected to intermediate portions of the secondary coils. A first conductor plate extends along the transformer array and interconnects the terminal plates, the first conductor plate being connected to one of the electrodes of the welding gun. A second conductor plate extends along the transformer array and interconnects the center tap terminal plates, the second conductor plate being connected to the other electrodes of the welding gun.

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Sayama, Japan

Fumitomo Takano