Abstract: In order to provide an electric power steering apparatus which can be made compact as well as reduced in cost and can be improved in reliability, a control circuit and a drive circuit are provided on a deformable flexible circuit substrate. The circuit substrate is provided on the housing of a reduction gear mechanism while being deformed so as to cover a portion of the outer surface of the housing along the shape of the outer surface.

Abstract: A four-wheel steering apparatus comprises a front wheel steering angle sensor for detecting the steering angles given to the front wheels, a vehicle speed sensor for detecting vehicle speeds, a rear wheel output shaft for giving steering angles to the rear wheels by being displaced it in the axial direction, a centering spring having the resiliency enabling the rear wheel output shaft to be returned to the neutral position, an electric motor for causing the rear wheel output shaft to be displaced in the axial direction against the resiliency of the centering spring, and a controller for controlling the energizing of the electric motor on the basis of the signals from the front wheel steering sensor and vehicle speed sensor, the controller adjusting the output torque of the electric motor on the basis of the signals from the front wheel steering sensor and vehicle speed sensor to control the rear wheel output shaft to be displaced for a desired amount by open loop control.

Abstract: A heat exchanger includes a pair of header pipes, tubes disposed between the header pipes, and radiation fins provided along the tubes. Each of the header pipes has a plurality of connection holes for the tubes. Each of the header pipes is formed by bending a longitudinal flat plate in the form of a pipe and connecting the side edge portions of the bent plate to each other. The side edge portions of the bent longitudinal plate have connecting portions which are connected to each other with a junction area larger than the cross-sectional area defined by the thickness and length of each header pipe at a position other than the side edge portions. The connection holes are processed before the longitudinal flat plate is bent, and therefore, can be easily and precisely formed at desired positions. The manufacture of the heat exchanger can be simplified and the cost for the manufacture can be reduced.

Abstract: A heat exchanger includes a pair of header pipes and tubes disposed between the header pipes. Each tube is connected to the header pipes at its end portions. Each of the header pipes comprises a tubular member and a connecting plate. The tubular member defines an opening which is formed at a position in the circumferential direction of the tubular member and extends in the longitudinal direction of the tubular member. The connecting plate is installed in the defined opening of the tubular member and has a plurality of holes for inserting the end portions of the tubes therein to connect the tubes to each header pipe. The connecting plate is formed as a simple shape, and the plurality of holes are easily and precisely processed. Therefore, the tubes can be easily and efficiently connected to the header pipes and the header pipes can be inexpensively manufactured.

Abstract: A heat exchanger includes a serpentine tube, a plurality of fins provided on the sides of the tube, and unions into which the respective end portions of the tube are inserted and to which the end portions are brazed. An expanded portion is formed on the tip of each inserted end portion of the tube, and a corresponding engaging portion is provided in each union. The expanded portion is engaged with the engaging portion of the union. Since the end portion of the tube is temporarily fixed to the union by the engagement of the expanded portion with the engaging portion, it is possible to simultaneously braze the tube to the union, and the tube to the fins, in a furnace. The manufacturing process of the heat exchanger can be simplified, the efficiency of the brazing process is increased, and the quality of the brazed portion is consistently high.

Abstract: A heat exchanger includes a pair of headers, a plurality of flattened oval heat exchange tubes, and a plurality of fins positioned between the headers over the length of the heat exchange tubes. The tubes are connected to the headers through a plurality of elongated holes in the header that have tapered lips. The lip taper forms an annular depression around the tube upon insertion that provides a good structural integrity. The connector holes are formed in each of the headers by a pressing method that eliminates header warping and produces dimensionally accurate hole shapes.

Abstract: A condenser for a refrigerant circuit including a compressor, a condenser, an expansion valve and an evaporator which are sequentially disposed is disclosed. The condenser includes a plurality of tubes having opposite first and second open ends, and a plurality of fins disposed between the plurality of tubes. First and second header pipes are fixedly disposed at the opposite ends respectively, and the open ends of the tubes are disposed in fluid communication with the interior of the header pipes. The first header pipe has an inlet which links the condenser to an external element of the circuit. The second header pipe includes a wall partitioning an interior of the second header pipe into first and second isolated cavities which are linked by a pipe member. An outlet union joint is linked to the second cavity. In operation, the refrigerant condenses to a mist as it passes through the condenser into the first cavity.

Abstract: A heat exchanger for a refrigerant fluid circuit is disclosed which includes a plurality of tubes which have opposite first and second open ends. A plurality of fin units are disposed between the plurality of tubes. The first and second header pipes have at least one open end and are fixedly disposed at the first and second opposite open ends of the tubes, respectively. The open ends of the tubes are disposed in fluid communication with the interior of the header pipes, and the heat exchanger is linked in fluid communication to external elements of the circuit through the first and second header pipes. The first and second header pipes are respectively formed by bending rectangular plate members into a tubular shape, and the rectangular plate members have a plurality of slits and joint portions such that when the plate is bent into the tubular shape slots are formed for the insertion of the ends of the tubes.

Abstract: A heat exchanger for use in an automobile air conditioning system including inlet and outlet union elements is disclosed. The heat exchanger comprises a plurality of flat tubes for conducting refrigerant and a plurality of corrugated fins fixedly sandwiched between the flat tubes. The flat tubes and the corrugated fins jointly form a heat exchange region. First and second header pipes are fixedly and hermetically connected to the flat tubes and communicate with the interior of the tubes. The header pipes are also provided with inlet and outlet union elements for connecting the heat exchanger to other external elements of the air conditioning system. Each of inlet and outlet union elements includes a rectangular parallelpiped block having a cavity formed therein. Each of the blocks is generally located at a coner of the heat exchanger defined by the top and bottom ends of the header pipes and the heat exchanger region.