Diesel Kiki Co., Ltd.

Hiroyuki Sugiura

Nobuyuki Nakajima

Shinji Sutoh

Teruo Nakamura

Takeo Iijima

Toshio Kojima

Hara Toshizo

Ryota Hasegawa

A variable capacity compressor for use in a heat-exchange circuit. A pressure responsive valve is provided in a communication passageway extending between a low pressure chamber and a pressure controlled chamber. The pressure responsive valve is operative in response to pressure within the low pressure chamber for opening and closing the communication passageway to control pressure within the pressure controlled chamber, thereby varying the capacity of the compressor in such a manner as to reduce the capacity when the pressure within the low pressure chamber decreases to a level lower than a predetermined value. An electrically operated control device is operative in response to pressure or temperature of refrigerant gas in an evaporator of the heat-exchange circuit for maintaining the capacity large independently of operation of the pressure responsive valve, even if the pressure within the low pressure chamber decreases to a level lower than the predetermined value.

Variable capacity compressor

An air conditioning system includes a refrigerating circuit, and a variable capacity compressor forming part of the refrigerating circuit and having a high pressure zone and a device for varying the delivery quantity thereof in response to pressure in the high pressure zone. A high pressure communication passage communicates the high pressure zone with the refrigerating circuit. A pressure control valve is associated with the high pressure zone and the high pressure communication passage, and is operable in response to the pressure in the high pressure zone to reduce the opening degree of the high pressure communication passage when the pressure in the high pressure zone is lower than a predetermined value.

Air conditioning system with variable capacity compressor

An air conditioner including a cooling medium compressor, a condenser, an expansion valve and an evaporator, these being connected one another by a cooling medium capillary tube to circulate a cooling medium, whereby an oil returning mechanism of an evaporator for the air conditioner is characterized in that there is provided an oil reservoir for reserving a lubricating oil after oil separation at a lower part of the evaporator, the oil reservoir and an outlet tube for guiding the cooling medium passed through the evaporator to the cooling medium compressor being connected by an oil returning tube, the oil returning tube being provided with a controlling valve, when a pressure differential between the oil returning tube and the outlet tube is a predetermined level or more, the controlling valve being closed to enhance a normal flow of the cooling medium from the evaporator to the cooling medium compressor, when the pressure differential is a predetermined level or less, the lubricating oil staying in the oil reservoir being fed to the cooling medium compressor via the oil returning tube and outlet tube.

Oil returning mechanism of evaporator for air conditioner

In the freezing cycle of an air conditioner for an automotive vehicle, first and second evaporators are connected to the inlet of a compressor. The first evaporator cools air to be blown into the passenger compartment of the vehicle, and the second evaporator, provided in the intake system of the vehicle engine, cools air to be taken into the engine. A pressure control valve is provided at the outlet of the second evaporator for controlling the boiling pressure of the refrigerant therein, or alternatively, the compresser may be of variable displacement type, to thereby prevent the compressor from consuming increased power during high speed operation of the engine.

Air conditioner for automotive vehicles capable of cooling intake air

An automotive air conditioning apparatus is provided which, in raising the temperature inside a vehicle cabin from a low level to a preset higher level in a maximum cooling mode or in lowering the cabin temperature from a high level to a preset lower level in a maximum heating mode, suitably controls in an initial stage of the procedure the revolution speed of a blower but does not drive an air mix door at all to keep it at an existing opening degree. When the revolution speed of the blower reaches a predetermined lowest speed, the air mix door begins to be driven to vary its opening degree progressively and suitably while, at the same time, a first reference temperature level for deactivating a compressor associated with a cooler is shifted to a second reference temperature level.

Vehicle temperature control apparatus

A discharge air temperature control device which is provided in an air conditioning system for automotive vehicles, the device comprising a lever assembly for adjusting the angular position of an air-mix damper, a driving circuit for driving the compressor of the air conditioning system, and a switching device for opening or closing the driving circuit in response to an air flow temperature signal supplied from a temperature sensor, characterized in that means is provided which is responsive to a change in the angular position of the lever assembly to vary a reference temperature value with reference to which the switching device opens or closes the driving circuit. The frequency of actuation of the compressor can thus be reduced to thereby save energy to be consumed by the air conditioning system. Further provided is means for selectively changing the above-mentioned reference temperature value into two levels which vary at different rates of variation relative to a change in the angular position of the lever assembly. Provision of this reference temperature changing means permits interruption of the operation of the compressor driving circuit when dehumidifying operation is not required, thus further saving energy to be consumed by the air conditioning system.

Discharge air temperature control device having reference temperature

A float operated switch (21) is actuated when the level of refrigerant fluid in a reservoir (11) is below a predetermined value to produce an electrical signal. The signal is delayed by 10 to 30 seconds and applied to a switch circuit (54) to disengage an electromagnetic clutch (63) and thereby de-energize a compressor (64). The clutch (63) is also disengaged by the action of a thermal switch (61) when the temperature in a space which is being air conditioned drops below a predetermined value. The operation of the float operated switch (21) is inhibited when the sensed temperature is below the predetermined value and also when a motor which drives the compressor (64) is not operating to prevent erroneous de-energization of the compressor (64).

Air conditioning apparatus comprising refrigerant shortage sensor

A thermopneumatic actuator of the invention is used to control an automobile heater and/or air conditioner to maintain a desired temperature in the automobile passenger compartment through a mechanical output member of the actuator. The output member is connected to and moved by a diaphragm which is positioned by vacuum introduced from the automobile intake manifold and works against a diaphragm spring. A valve is controlled by a bimetal spring exposed to air from the passenger compartment to modulate the vacuum applied to the diaphragm. A feedback spring connected between the diaphragm and the valve works against the bimetal spring. An aspirator comprising a venturi tube causes air flow from the passenger compartment around the bimetal spring.

Thermopneumatic actuator

An output member of the present actuator is connected to control a temperature door in an air conditioning duct leading into an automobile passenger compartment and thereby the temperature in the compartment. The output member is connected to and moved by a diaphragm which is positioned by opposing forces of a diaphragm spring and modulated intake manifold vacuum. A valve is controlled by first and second bimetal springs which act in parallel against a feedback spring connected between the valve and the diaphragm. The first bimetal spring is responsive to air temperature in the compartment. The second bimetal spring is responsive to air temperature in the duct and compensates for variations in the operation of the air conditioning system caused by variations in load and the like.

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Konan, Japan

Hiroyuki Sugiura