Abstract: A method for welding a steel pipe in a steel pipe structure and a joint is provided. The welding method includes: a measurement step of measuring a manufacturing error of the steel pipe, a calculation step of calculating the positions of the steel pipe and the joint where the manufacturing error measured in the measurement step is absorbed, and a welding step of welding the steel pipe and the joint at the positions of the steel pipe and the joint, the positions being calculated in the calculation step.

Abstract: To achieve higher efficiency at a low-load region and to enable power saving throughout a year. The refrigeration cycle apparatus 1 includes a compressor 4 that has a flow in/out port 4d through which a refrigerant is capable of flowing out and flowing in, in fluid communication with a compression room 4c; pipes 21, 22 disposed at a suction side of the compressor 4; a pipe 25 connected to the flow in/out port 4d of the compressor 4; a pipe 27 that has one end connected to the pipe 25 and an opposite end connected to the pipe 21; and a second solenoid valve 13 for opening and closing a fluid passage of the pipe 27.

Abstract: A heat exchanger includes: a gas-side port connected to piping for a gaseous refrigerant; a liquid-side port connected to piping for a liquid refrigerant; a refrigerant path that links the gas-side port to the liquid-side port; at least four heat exchange part regions that perform heat exchange between air and the refrigerant flowing through the refrigerant path; and a branching and merging part that branches and merges the refrigerant path to connect the heat exchange part regions in series between the gas-side port and the liquid-side port through the refrigerant path. The heat exchange part regions are connected to each other through the branching and merging part so as to allow the number of refrigerant paths provided in the heat exchange part region near the gas-side port to be greater than the number of refrigerant paths provided in the heat exchange part region near the liquid-side port.

Abstract: A refrigerant flow path switch arranged between an outdoor device and each of multiple indoor devices controls a refrigerant flow and is provided with a housing; a refrigerant flow path switching circuit having multiple refrigerant flow path switching circuits, wherein each refrigerant flow path switching circuit includes a high/low pressure gas pipe, a low pressure gas pipe, a high/low pressure electric valve provided at the high/low pressure gas pipe, and a low pressure electric valve provided at the low pressure gas pipe. A liquid pipe assembly is arranged in the housing and has multiple liquid pipes connected to the multiple indoor devices. A first divider plate is provided between adjacent ones of the refrigerant flow path switching circuits and divides an internal space of the housing such that a space divided by the first divider plate is in a substantially cubic shape, which is filled with a foaming agent.

Abstract: Provided is a air conditioner including high-and-low-pressure gas pipe expansion valves each of which is provided to a corresponding one of the cooling-heating switching units and adjusts feeding of high-temperature and high-pressure gas refrigerant to the corresponding indoor unit; and a refrigeration cycle controller which adjusts a valve opening degree of the high-and-low-pressure gas pipe expansion valve of the cooling-heating switching unit connected to one of the indoor units which is not in heating operation, in accordance with a determination result on excess or deficiency of refrigerant in a refrigeration cycle.

Abstract: A hot gas bypass circuit that connects a discharge side of the compressor and a portion between the heat source side heat exchanger and the expansion valve, an on-off valve that opens and closes a channel of the hot gas bypass circuit, and a control device performing control to select one of hot gas bypass defrosting and reverse cycle defrosting according to a frosting amount on the heat source side heat exchanger and perform defrosting. The control device controls to open the on-off valve of the hot gas bypass circuit such that a part of a refrigerant discharged from the compressor is supplied to the heat source side heat exchanger via the hot gas bypass circuit and, the control device switches switch the four-way valve such that the refrigerant discharged from the compressor is supplied to the heat source side heat exchanger after passing through the four-way valve.

Abstract: To achieve higher efficiency at a low-load region and to enable power saving throughout a year. The refrigeration cycle apparatus 1 includes a compressor 4 that has a flow in/out port 4d through which a refrigerant is capable of flowing out and flowing in, in fluid communication with a compression room 4c; pipes 21, 22 disposed at a suction side of the compressor 4; a pipe 25 connected to the flow in/out port 4d of the compressor 4; a pipe 27 that has one end connected to the pipe 25 and an opposite end connected to the pipe 21; and a second solenoid valve 13 for opening and closing a fluid passage of the pipe 27.

Abstract: The air conditioner has a configuration such that, in an air-warming operation: the average refrigerant exit temperature, which is obtained by averaging the temperature of the refrigerant exits of indoor heat exchangers 7 in a plurality of indoor units 10, as detected by heat-exchanger-refrigerant-exit temperature probes 34 in the indoor units 10, is determined; the temperature difference between the average refrigerant exit temperature and the refrigerant exit temperatures of the indoor heat exchangers 7 of each of the indoor units 10 is determined; and the degree to which indoor expansion valves 9 of the indoor units 10 are open is controlled such that the determined temperature difference falls within a predetermined temperature difference range.

Abstract: A method for welding a steel pipe in a steel pipe structure and a joint is provided. The welding method includes: a measurement step of measuring a manufacturing error of the steel pipe, a calculation step of calculating the positions of the steel pipe and the joint where the manufacturing error measured in the measurement step is absorbed, and a welding step of welding the steel pipe and the joint at the positions of the steel pipe and the joint, the positions being calculated in the calculation step.

Abstract: A refrigerant flow path switch arranged between an outdoor device and each of multiple indoor devices controls a refrigerant flow and is provided with a housing; a refrigerant flow path switching circuit having multiple refrigerant flow path switching circuits, wherein each refrigerant flow path switching circuit includes a high/low pressure gas pipe, a low pressure gas pipe, a high/low pressure electric valve provided at the high/low pressure gas pipe, and a low pressure electric valve provided at the low pressure gas pipe. A liquid pipe assembly is arranged in the housing and has multiple liquid pipes connected to the multiple indoor devices. A first divider plate is provided between adjacent ones of the refrigerant flow path switching circuits and divides an internal space of the housing such that a space divided by the first divider plate is in a substantially cubic shape, which is filled with a foaming agent.

Abstract: The air conditioner has: an outdoor heat exchanger that exchanges heat between the air and a refrigerant flowing in the interior of this heat exchanger; an outdoor fan that blows air into the outdoor heat exchanger; an outdoor fan motor that rotationally drives the outdoor fan; an outdoor fan inverter that supplies a desired current to the outdoor fan motor; a current detector that detects the current flowing in the outdoor fan motor; and a control unit that controls the outdoor fan inverter such that the rotational frequency of the outdoor fan motor reaches a target rotational frequency. The control unit starts a defrosting operation of the outdoor heat exchanger on the basis of a detection value from the current detector during the heating operation.

Abstract: A heat exchanger includes: a gas-side port connected to piping for a gaseous refrigerant; a liquid-side port connected to piping for a liquid refrigerant; a refrigerant path that links the gas-side port to the liquid-side port; at least four heat exchange part regions that perform heat exchange between air and the refrigerant flowing through the refrigerant path; and a branching and merging part that branches and merges the refrigerant path to connect the heat exchange part regions in series between the gas-side port and the liquid-side port through the refrigerant path.

Abstract: Provided is a air conditioner including high-and-low-pressure gas pipe expansion valves each of which is provided to a corresponding one of the cooling-heating switching units and adjusts feeding of high-temperature and high-pressure gas refrigerant to the corresponding indoor unit; and a refrigeration cycle controller which adjusts a valve opening degree of the high-and-low-pressure gas pipe expansion valve of the cooling-heating switching unit connected to one of the indoor units which is not in heating operation, in accordance with a determination result on excess or deficiency of refrigerant in a refrigeration cycle.

Abstract: An operation control apparatus of air-conditioning apparatus having an outdoor unit and an indoor unit includes a controller programmed to execute energy conservation control of the air conditioning apparatus. The controller includes at least one required temperature calculation part calculating a required evaporation temperature or a required condensation temperature based on either a current amount of heat exchanged in a usage-side heat exchanger of the indoor unit and a greater amount of heat exchanged in the usage-side heat exchanger than the current amount, or an operating state amount that yields the current amount of heat exchanged in the usage-side heat exchanger and an operating state amount that yields the greater amount of heat exchanged in the usage-side heat exchanger than the current amount.

Abstract: The air conditioner has a configuration such that, in an air-warming operation: the average refrigerant exit temperature, which is obtained by averaging the temperature of the refrigerant exits of indoor heat exchangers 7 in a plurality of indoor units 10, as detected by heat-exchanger-refrigerant-exit temperature probes 34 in the indoor units 10, is determined; the temperature difference between the average refrigerant exit temperature and the refrigerant exit temperatures of the indoor heat exchangers 7 of each of the indoor units 10 is determined; and the degree to which indoor expansion valves 9 of the indoor units 10 are open is controlled such that the determined temperature difference falls within a predetermined temperature difference range.

Abstract: Provided is an air conditioner which comprises multiple outdoor units, the air conditioner being configured so that, with the use of a low cost configuration, required refrigeration machine oil is supplied to all the outdoor units through refrigerant piping and so that the air conditioner has increased reliability. An air conditioner is provided with multiple indoor units and with four outdoor units which are connected to the multiple indoor units through refrigerant piping. A line of first refrigerant piping leading from the multiple indoor units is branched into two lines of second refrigerant piping, each of the two lines of second refrigerant piping is branched into two lines of third refrigerant piping, and the four lines of third refrigerant piping are respectively connected to the four outdoor units.

Abstract: A hot gas bypass circuit that connects a discharge side of the compressor and a portion between the heat source side heat exchanger and the expansion valve, an on-off valve that opens and closes a channel of the hot gas bypass circuit, and a control device performing control to select one of hot gas bypass defrosting and reverse cycle defrosting according to a frosting amount on the heat source side heat exchanger and perform defrosting. The control device controls to open the on-off valve of the hot gas bypass circuit such that a part of a refrigerant discharged from the compressor is supplied to the heat source side heat exchanger via the hot gas bypass circuit and, the control device switches switch the four-way valve such that the refrigerant discharged from the compressor is supplied to the heat source side heat exchanger after passing through the four-way valve.

Abstract: The air conditioner has: an outdoor heat exchanger that exchanges heat between the air and a refrigerant flowing in the interior of this heat exchanger; an outdoor fan that blows air into the outdoor heat exchanger; an outdoor fan motor that rotationally drives the outdoor fan; an outdoor fan inverter that supplies a desired current to the outdoor fan motor; a current detector that detects the current flowing in the outdoor fan motor; and a control unit that controls the outdoor fan inverter such that the rotational frequency of the outdoor fan motor reaches a target rotational frequency. The control unit starts a defrosting operation of the outdoor heat exchanger on the basis of a detection value from the current detector during the heating operation.

Abstract: A braking device for the motorcycle is configured to permit actuation control in an interlocking manner of a rear-wheel brake caliper and a front-wheel brake caliper based on an operation of a brake pedal. The braking device includes a hydraulic pressure detector for detecting rear-wheel brake hydraulic pressure caused by the operation of the brake pedal; a determining portion that determines whether or not a detected value by the hydraulic pressure detector is a predetermined value or more; and a hydraulic pressure controller that, when it is determined by the determining portion that the detected value is the predetermined value or more, changes a rising rate of the rear-wheel brake hydraulic pressure to a value lower than a rising rate during a period until the time when the rear-wheel brake hydraulic pressure reaches the predetermined value to control the rear-wheel brake hydraulic pressure, and also controls front-wheel brake hydraulic pressure.

Abstract: An electric valve is provided in a supply pipe. A flow rate control unit controls the degree of opening of the electric valve such that the flow rate in the supply pipe lies within a predetermined range, on the basis of a pressure difference between pressure of refrigerant supplied to the supply pipe and the pressure of refrigerant on the suction side of a compressor. An outdoor air temperature sensor detects outdoor air temperature; and a low-pressure side pressure sensor detects refrigerant pressure on the suction side of the compressor. The pressure difference is a difference between a saturation pressure corresponding to the outdoor air temperature detected by the outdoor air temperature sensor and refrigerant pressure detected by the low-pressure side pressure sensor.