Denso Corporation

Toyota Jidosha Kabushiki Kaisha

Kabushiki Kaisha Toyoda Jidoshokki Seisakusho

Yasutane Hijikata

Yoshikatsu Sawada

Kazuhito Miyagawa

Takeshi Wakisaka

Kazuma Miyazaki

Masato Komura

Kimihiko Sato

Masahiro Kawaguchi

Masaki Ota

Ken Suitou

Kazuya Kimura

Taku Adaniya

Ryo Matsubara

Hiroyuki Nakaima

Yasukazu Aikawa

Kenji Tsubone

Takashi Tanaka

Hiromasa Tanaka

Takafumi Masuda

Takahiro Ishihara

Nobuhiro Miura

A compressor drive torque estimating device to be adapted for a system provided with a refrigeration cycle in which a refrigerant is circulated by a compressor driven by a drive source mounted in a vehicle, comprising heat load detecting means for detecting a heat load of the refrigeration cycle, a storage unit storing a plurality of estimated drive torque characteristics establishing correlation between a drive torque change characteristic of the compressor and an elapsed time from a time of start of operation of the compressor, an estimated drive torque characteristic selecting means for selecting the one of the plurality of estimated drive torque characteristics stored in the storage unit based on detected values detected by the heat load detecting means, and an estimated drive torque calculating means for calculating an estimated drive torque of the compressor based on the estimated drive torque characteristic selected by the estimated drive torque characteristic selecting means.

Compressor driving torque estimating apparatus

A compressor inlet pressure estimation apparatus for a refrigeration cycle system is disclosed. An electronic control unitanswers YES by judging that the command to start a compressoris issued when an air-conditioning switch is turned on in step S. After that, the electronic control unitanswers NO in the case where a timer count time Tc is shorter than a predetermined time Tin step S. At the same time, Tefin_C is set to 15&#xb0; C. in step S. The lower one of Tefin_C and Tefin determined in this way is determined as Tefin_d (step S). After that, Tefin_d is input to the first-order lag function to acquire Tefin_AD(N). Then, the control proceeds to step S, where the estimated value Ps_es(N) of the refrigerant inlet pressure of the compressoris determined using Tefin_AD(N) and Gr.

Compressor inlet pressure estimation apparatus for refrigeration cycle system

A refrigeration cycle apparatus includes a compressor, a condenser, a pressure-reducing mechanism, an evaporator, an orifice provided in a refrigerant flow path from the compressor to the pressure-reducing mechanism, a differential pressure sensor that detects the differential pressure before and after the orifice, a refrigerant flowrate calculating portion that calculates a refrigerant flowrate based on the differential pressure, and a torque estimating portion that estimates the torque required to drive the compressor based on the refrigerant flowrate calculated by the refrigerant flowrate calculating portion, the intake pressure of the compressor, and the discharge pressure of the compressor.

Refrigeration cycle apparatus

A refrigeration cycle system is disclosed. A compression unitfor compressing the refrigerant by the drive force of a vehicle engineis arranged in a housingof a compressor. The flow rate of the refrigerant discharged from the compression unitis detected by a flow rate sensorincluding a throttle portionand a pressure difference detection mechanism. The throttle portionreduces the flow rate of the refrigerant discharged from the compression unit. The pressure difference detection mechanismdetects the pressure difference between the upstream side and the downstream side of the throttle portionin the refrigerant flow thereby to detect the flow rate of the refrigerant discharged from the compression unit. An oil separatorfor separating the lubricating oil from the refrigerant discharged from the compression unitis interposed between the compression unitand the flow rate sensor

Refrigeration cycle system

A compressor inlet pressure estimation apparatus for a refrigeration cycle system is disclosed. An electronic control unituses Tefin_lag(N) as an actual corrected temperature Tefin_AD(N) during a period Tpincluded in the timing tto t. During a period Tpincluded in the timing tto t, Tefin_fwd(N) is used as the actual corrected temperature Tefin_AD(N). Thus, a highly accurate corrected temperature Tefin_AD(N) can be determined over the on period (tto t) of a compressor. In addition, Tefin_fwd(N) is used as the actual corrected temperature Tefin_AD(N) during the off period (tto) of the compressor. As a result, a highly accurate corrected temperature Tefin_AD(N) can be determined over the whole period including the on and off periods of the compressor. In this way, a highly accurate estimated value Ps_es(N) of the refrigerant inlet pressure of the compressorcan be determined.

A refrigerant cycle device includes a compressor driven by a vehicle engine for drawing and compressing gas refrigerant from an evaporator, a variable displacement mechanism which varies a discharge capacity of the compressor based on a control value from an exterior to approach a suction pressure of the compressor to a predetermined suction pressure, and a control unit for controlling the discharge capacity of the compressor. The control unit includes a determining part for determining an accelerating state of the vehicle engine, a detecting member which detects a thermal load of the evaporator, a setting part for setting a minimum control value in accordance with the thermal load, and a controlling part. The controlling part reduces the control value to the minimum control value and returns the reduced control value to a control value before the reducing, when the determining means determines an accelerating state of the vehicle engine.

Refrigerant cycle device and control system for vehicle

A compressor drive torque estimating device suppresses a discrepancy between an estimated drive torque, which is based on a torque estimating device of a compressor, and an actual drive torque of the compressor. The discrepancy is due to delay in switching between employment of the torque estimating device and the actual drive torque of the compressor in judging the compressor torque. Thus, even in a transitional state immediately after the start of compression, the idling speed of an engine driving the compressor is controlled based on an accurate estimate of the compressor torque, to improve the stability of the engine idle speed.

Torque estimating device of compressor

An air conditioning system for cooling or heating an air, and for feeding the heated or cooled air to predetermined portions is characterized by comprising: a first circulating circuit for circulating a first heating medium; a second circulating circuit for circulating a second heating medium; a control unit for controlling the heat for executing heat exchange between the first heating medium and the second heating medium to flow through either the heat exchanger or the first heat storing device. Moreover, an air temperature is controlled by heat of the second heating medium.

Air conditioning apparatus

When a hybrid compressor starts being driven by an electric motor, the electric current of a capacity control valve is applied at an initial control electric current SS that is greater than a control electric current S, which is from the state of a refrigerating circuit. This triggers a swash plate of the hybrid compressor to be rapidly inclined. Thereafter, the electric current of the displacement control valve is applied at the control electric current S. This structure enables the displacement of the hybrid compressor to rapidly recover when the hybrid compressor starts being driven by the electric motor.

Hybrid compressor and control device

A compressor for a vehicle air conditioner includes a pressure sensor and a torque computing unit for computing the compressor torque. The compressor also has a communication unit that allows data communication with other devices based on vehicle data communication protocols. The torque computing unit and the communication unit are integral with the compressor. Therefore, it is possible to calculate the driving torque quickly, and an engine electronic control unit can control an engine such that the torque required for the compressor can be quickly generated.

Compressor with integral control unit

In a vehicle air conditioner, a compressor is driven by a vehicle engine, and a displacement of the compressor is controlled based on a cooling load. When a post-evaporator air temperature (TE) is higher than a predetermined value (TEO+&#x3b2;), it is determined that the cooling load is large, and the compressor is forcibly controlled at maximum displacement that is larger than a control value controlled based on the cooling load. Accordingly, the post-evaporator air temperature (TE) can be rapidly reduced to be lower than the predetermined value (TEO+&#x3b2;), so that a driving time of the vehicle engine can be made shorter. As a result, fuel consumption efficiency of the vehicle engine can be effectively improved.

Vehicle air conditioner

An air conditioner for vehicle has a refrigeration cycle with a variable displacement type compressor. A fuel cut control is carried out in response to a vehicle deceleration. In the fuel cut control, the displacement is first increased so that an evaporator performs as a cold storage. Then, if an engine speed is decreased to a certain level, the displacement is decreased to decrease an engine load. The displacement is kept in the decreased level for a predetermined time period or until the end of the fuel cut control. Even when the displacement is decreased, the evaporator can cool air, since the evaporator performs as the cold storage. Further, the time period for keeping the displacement in the decreased level is limited. Therefore, it is possible to prevent an excessive temperature rise and to keep comfortable air conditioning.

Air conditioner for motor vehicles

A method of control for preventing warm air from being exhausted during a fuel cut when driving an air-conditioning system by a vehicle engine comprising, when it is judged that the fuel has been cut when the engine is decelerating and the engine speed has fallen to a first judgement value, causing the amount of discharge and torque of the refrigerant compressor to fall once to for example zero or a value close to zero, then causing them to gradually rise in a pattern of torque control of the refrigerant compressor and, when it is judged that the engine speed has fallen to a second judgement value, causing the fuel cut of the engine to end so as to secure the minimum necessary cooling capacity and extend the fuel cut time simultaneously.

Method of control of air-conditioning system driven by vehicle engine

A control valve is located in a variable displacement compressor that is installed in a refrigerant circuit. The control valve operates such that the pressure difference between first and second pressure monitoring points in the refrigerant circuit seeks a predetermined target value. The first pressure monitoring point is located in a discharge chamber of the compressor. The second pressure monitoring point is located in a flow pipe that extends from the discharge chamber. The static pressure of refrigerant in the discharge chamber is introduced into a control valve from the first pressure monitoring point. A pressure that includes the static pressure and the dynamic pressure of refrigerant in the flow pipe is introduced into the control valve from the second pressure monitoring point. As a result, the displacement of the compressor is reliably controlled without being affected by the thermal load of an evaporator.

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Nagoya, Japan

Yasutane Hijikata