Takenaka Hiroshi

Bio: Takenaka Hiroshi is an academic researcher from Hitachi. The author has contributed to research in topics: Heat exchanger & Refrigerant. The author has an hindex of 4, co-authored 12 publications receiving 94 citations.

Active noise control apparatus for three-dimensional space

Abstract: An active noise control system for a three-dimensional space, including noise detecting means, sound generating means, noise control effect detecting means and a control device consisting of a phase of a wave signal fed from the noise detecting means wherein a plurality of noise control effect detecting means and sound generating means are disposed at a distance shorter than a wavelength of the noise to be controlled, and input signals of the respective sound generating means and output signals of the respective noise control effect detecting means are fed through filters, separately, to control the sound for active noise control. In case of an air conditioner, the noise control effect detecting means are disposed at positions where an air stream flowing through the air conditioner is not obstructed thereby.

Outdoor machine for air conditioner

Abstract: PROBLEM TO BE SOLVED: To make compact and silent an outdoor machine for an air conditioner which uses the air blowing-out surface of an axial fan installed to the upper section of an enclosure as its upper surface by providing a corner guide to at least one of the void sections in the corner sections formed of the front-face plate, roof plate, and one side-face plate which is adjacent to the front-face plate SOLUTION: A top-flow type outdoor machine 1 is provided with air supplying openings on its side-face sides and a heat exchanger 8 on its back side The machine 1 is also provided with a compressor 9, an accumulator 10, an axial fan, a bell mouth 12, etc, and a heat-exchanged wind exhausted front the fan 11 is discharged upward after passing through an exhaust pipe 7 and a guard net 16 In the machine 1, a corner guide 18a is provided to the void of each corner section formed of the front-face plate 2, side-face plate, roof plate 6, and bell mouth of the machine 1 Therefore, the outdoor machine 1 can be operated silently, because the heat-exchanged wind sucked from the heat exchanger 8 is prevented front staying in the voids of the corner sections and, at the same time, the efficiency deterioration of the fan 11 caused by uneven flows in the circumferential direction can be suppressed

Heat exchanger and air conditioner

Abstract: PROBLEM TO BE SOLVED: To improve strength of a heat exchanger while maintaining desired dripping performance by processing contacts of individual fins of superposed heat exchanger units as fins to become one or more points. SOLUTION: After part of a continued fin material corresponding to a fin end is cut, a convexo-concave shape is provided by pressing, and independent fins of the shape bent at upper and lower ends are obtained. Fin lower part end 101L of upper stage of the fin 101 and upper part end 101U of lower stage are crossed at least at one point in the fin shape, and the fins are brought into close contact with each other while preventing engagement of the fins. Then, a heat transfer tube 2 is inserted, several fin blocks are formed, and pipes are bent so that the fins are brought into contact with each other, all the fins are aligned in the same direction in the direction of bending, inserted, and aligned to the tube 2. When the tube 2 is bent, upper and lower fins are brought into contact with each other at two points. Thus, dripping properties and heat exchanger strength can be largely improved.

Air conditioner and its control method

Abstract: PROBLEM TO BE SOLVED: To provide a highly reliable air conditioner suppressing viscosity deterioration of refrigerating machine oil in starting of a refrigerant compressor SOLUTION: A refrigerating cycle is composed by sequentially connecting the refrigerant compressor, an outdoor heat exchanger 3, an outdoor expander 4, a receiver 5, a supercooling circuit 17, an indoor expander and an indoor heat exchanger A bypass refrigerant circuit 19 is branched from a main refrigerant circuit at an outlet of the receiver 5, it is passed through a refrigerant flow regulating device 16 and the supercooling circuit 17, and it is joined with the main refrigerant circuit between the indoor heat exchanger and the refrigerant compressor An opening of the refrigerant flow regulating device 16 right after starting of the refrigerant compressor is set at an opening wherein a degree of superheat of a refrigerant of the refrigerant circuit in a joining part of the main refrigerant circuit and the bypass refrigerant circuit is a predetermined degree of superheat A control part is provided for changing the opening so that dryness of the refrigerant of the bypass refrigerant circuit 19 in the joining part is ≤1 when a temperature of the refrigerant delivered from the refrigerant compressor becomes a predetermined temperature, and then changing the opening in an opening direction COPYRIGHT: (C)2004,JPO

Ceiling cassette type air conditioner

Abstract: PURPOSE:To reduce a working burden of a worker for installing an indoor device of an air conditioner to be hung in a room, make a convenience in working operation and safety in operation by a method wherein the indoor device of the air conditioner is provided with some temporary fixing fittings at its main body. CONSTITUTION:In the case that an air conditioner is to be hung, supporting bolts 6 are not directly inserted into recessed holes 9 for the supporting bolts in a main body fixing plate 2, but a temporary fixing fitting 4 arranged at the main body of the air conditioner is inserted in advance into a longitudinal temporary fixing hole 5 of a main body fixing plate, and the main body of the air conditioner is displaced to align the supporting bolts 6 with their normal positions and then the bolts are fastened with nuts. In this case, it is not necessary for the worker to support the air conditioner with both hands and one hand of the worker can be freely moved or used, thereby it becomes possible to simplify the fastening operation of the main body side four supporting bolts to the main body fixing plate with nuts. In this way, it is possible to reduce a burden of a worker at a high location where the worker hardly operates such as a tri-pod foot work and the like.

Active noise control system using phased-array sensors

Abstract: An active noise control system is provided with a plurality of error sensor arrays (50, 77) which provide signals on lines (64-74, 90-100) to beam forming and beam steering logic (76) which cause the arrays (50, 77) to exhibit acoustic response profiles (104, 106), respectively. The profiles (104, 106) intersect in a predefined region (116) to be quieted. The logic (76) provides signals on lines (118), one for each region to be quieted, to active noise control (ANC) logic (20) which also receives inputs from feedforward sensing microphones (10) and provides output signals to acoustic speakers (24) which generate anti-noise (26) to cancel the noise in the quiet region (116). The quiet region (116) may be selectively positioned to any region in the room by steering the beams (104, 108). Alternatively, the system may have a plurality of distributed sensors which, when taken together, have an overall maximum (main lobe) acoustic response at a predetermined selectable quiet region.

Vehicle internal noise reduction system

Abstract: In an automobile vehicle, fuel injection pulse outputted from an electronic control unit of an engine is transformed into a voltage value as a primary source. The voltage values is transformed by the convolution sum process and synthesized into a sound to cancel the engine noise. The synthesized sound is outputted through the speaker in the passenger compartment. On the other hand, the reduced noise sound is detected as an error signal by the microphone. The error signal is inputted to an LMS circuit where the filter coefficient is updated in accordance with both inputted error signal and the primary source. Since the fuel injection pulse before the combustion stroke is used, the noise sound can be precisely and immediately reduced even in the transient conditions of the vehicle operation.

Active noise control device

Abstract: An active noise control device detects composite vibration of a vibration transmitting route to which both vibration of a rotating body caused by generation or transmission of drive force of a vehicle and vibration of a wheel generated by contact between the wheel and a road surface are transmitted. A first reference signal for defining a reference waveform of a canceling sound for canceling vibration noise in a vehicle interior is generated based on the composite vibration. The component of the canceling sound for canceling vibration noise of the rotating body is removed from the first reference signal to generate a second reference signal for defining a reference waveform of the canceling sound for canceling vibration noise of the wheel. The canceling sound is outputted based on the second reference signal.

Indoor unit of air-conditioning apparatus and air-conditioning apparatus

Abstract: An indoor unit (100) includes a casing (1) having a suction port (2) formed on an upper portion and a blow-out port (3) on a lower side of a front surface portion, an axial-flow or mixed-flow fan (20) provided on the downstream side of the suction port (2) in the casing (1), and a heat exchanger (50) provided in the casing (1) at a position on the downstream side of the fan (20) and on the upstream side of the blow-out port (3). The heat exchanger (50) includes a plurality of fins (56) arranged side by side with predetermined gaps therebetween and a plurality of heat-transfer tubes (57) penetrating through the plurality of fins (56). The heat exchanger is configured in such a manner that the air-flow resistance of an area facing the outer peripheral side of the fan (20) is larger than the air-flow resistance of an area facing a center portion of the fan (20).

Quiet fan incorporating active noise control (ANC)

Abstract: An active noise control (ANC) system may be implemented to both sides of a fan, such that both directions of the noise emitting are treated to reduce the overall noise. The impact on airflow is minimal, and the technique is very effective in a broad range of low frequencies. Passive sound-absorbing materials may be included for attenuation of high frequencies. The resulting quiet fan produces a low level of noise compared to any other device based on fan, which produces the same capacity of airflow. The quiet fan may be incorporated in any mechanical system which requires airflow induction such as: computers, air conditioners, machines, and more.