Denso Corporation

Mitsuo Hara

Hisashi Iida

Hiroaki Takeishi

Takashi Senda

Daisuke Nakanishi

Yoshiyuki Okamoto

Koichi Ban

Hideki Suzuki

Michio Nishikawa

Takanobu Kawano

Mitsunobu Uchida

Takeo Matsumoto

An ECU controls waste heat quantity of an engine according to a required heat quantity in response to a heat-utilize requirement. The ECU controls a valve opening period of an intake valve based on an engine driving condition and an ignition timing based on a most efficient timing at which fuel economy is highest. The ECU determines whether there is an ignition advance margin relative to the most efficient timing. When there is no margin, an actual compression ration of the engine is decreased by advancing or retarding a valve close timing of the intake valve and the ignition timing is advanced relative to the most efficient timing in order to increase the waste heat quantity.

Waste heat controller

During engine warm-up, a flow regulating unit in a cooling system operates in a fuel efficiency priority mode. In this mode, a head-side cooling water flow rate (Qhd) is regulated to be equal to or smaller than a first upper limit; a block-side cooling water flow rate (Qbk) is regulated to be equal to or smaller than a second upper limit; and cooling water flowing out of a block-side passage and a head-side passage flows mainly into a bypass passage. When a heating request to heat blown air is made during engine warm-up, the regulating unit operates in a heating priority mode. In this mode, Qhd is regulated to be equal to or smaller than a third upper limit; Qbk is regulated to be equal to or smaller than a fourth upper limit; and at least cooling water flowing out of the head-side passage flows into a heat exchanger.

Cooling system for internal combustion engine

An apparatus is provided for application to a waste heat reuse system that recovers and reuses engine waste heat, and for controlling the amount of waste heat based on a requested heat amount of a heat utilization request. In the apparatus, an overlap angle between a valve-opening period of an intake valve and that of an exhaust valve of the engine is controlled based on an engine driving condition. Ignition timing of the engine is controlled to fall on maximum-efficient timing that minimizes fuel consumption in a current engine driving condition. When a requested heat amount cannot be satisfied, overlap-increase control is performed to increase an overlap angle, and ignition advance control is performed to advance ignition timing with reference to a maximum-efficient timing that corresponds to the increased overlap angle. Waste heat amount of the engine is controlled with the overlap-increase control and the ignition advance control.

Apparatus for controlling the amount of waste heat of an engine

The waste heat control apparatus is used in a heat recovery system for recovering and reusing waste heat of an engine. The waste heat control apparatus includes a plurality of waste heat amount adjusting sections activated to increase an amount of the waste heat of the engine, and a control section which performs waste heat control in accordance with a heat utilization demand to increase the amount of the waste heat of the engine by activating at least one of the plurality of waste heat amount adjusting sections.

Waste heat control apparatus

A first oxygen sensor is mounted on an exhaust pipe. An ECU determines an electric power to be fed to a sensor heater, by a heater control quantity calculating block, in accordance with a difference between an actual impedance and a target impedance calculated by a running condition determining block and a specific gas sensitivity priority determining block. As a result, the detection sensitivity of the oxygen sensor to a rich component or a lean component is improved according to the running condition. This improved output is detected by an output detecting block and reflected on the air/fuel ratio control so that an air/fuel ratio is controlled thereby.

Exhaust gas purifying system for internal combustion engines

A throttle valve for an engine is disabled to be driven by an actuator by limiting a target throttle angle upper limit of a target throttle angle, when a failure is detected by an electronic control unit. Then, the target throttle angle is returned to a value used at a normal time at a restoration timing of a restoration of the system to a normal state or while the opening speed of a throttle valve at a restoration is being restrained. Thus, an abrupt opening operation of the throttle valve in response to the depression carried out by the driver on an accelerator pedal. Further, the throttle valve is driven in a limp-home operation mode by controlling the reduced number of operating cylinders of the engine. The reduced number of operating cylinders is increased or the operations of all cylinders are halted, when the engine speed rises above a predetermined value.

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Ichinomiya, Japan

Mitsuo Hara