Hitachi, Ltd.

Hitachi Construction Machinery Co., Ltd.

Hitachi Automotive Systems, Ltd.

Shiro Yamaoka

Hiromu Kakuya

Yoshihiro Sukegawa

Kengo Kumano

Minoru Oosuga

Atsushi Shimada

Noboru Tokuyasu

Toshiharu Nogi

Kinya Nakatsu

Hiroaki Hoshika

Takuya Shiraishi

Shinji Nakagawa

Yuusuke Kihara

Nobuyasu Kanekawa

Minoru Ohsuga

Masatoshi Hoshino

Seiji Ishida

Kazumasa Ide

Yusuke Kajita

Kunihiko Suzuki

Yusuke Kihara

Katsuaki Fukatsu

Shinya Satou

Kaori Kashio

Youichi Iihoshi

Eiichiro Ohata

Masamichi Yamada

Shinya Igarashi

Hidetoshi Satake

Jun Kubo

Kazuo Fujishima

Shinji Ishihara

Yoichi Iihoshi

Takanobu Ichihara

Takashi Okada

Hidefumi Iwaki

Daisuke Terada

Mitsuo Sonoda

Akira Nakayama

Takashi Kadohiro

Junji Yamamoto

Toshiki Otsuki

Naoyuki Tashiro

He Bao

Ryou Inaba

A hybrid work machine includes: an engine controller () that controls rotational speed of an engine () in accordance with a target rotational speed input from an EC dial (); an assist motor () that generates electricity using power of the engine (); a hydraulic pump () operated using power of the engine and/or of the assist motor; and a vehicle body controller () that estimates power (Pe) the engine is required to output when a request to generate electricity is sent to the assist motor and permits the assist motor to generate electricity only when the engine power requirement is not greater than an electricity generation threshold value (E). The electricity generation threshold value (E) is determined based on the power and characteristics of energy loss of the engine ().

Hybrid work machine

A construction machine including an internal combustion engine controlled based on a torque command, an electric motor mechanically connected to the internal combustion engine, and an electric energy storage device that supplies electric power to the electric motor, the construction machine performing work by driving a hydraulic pressure generator using the internal combustion engine and the electric motor, the construction machine including: a speed control device that controls a speed of the electric motor based on a speed command; and a torque limiter that limits the torque command relative to a torque target, wherein the torque command is limited by the torque limiter in such a manner that a rate of change with time of the torque command is limited to be equal to or less than a predetermined value.

Construction machine

A hydraulic working machine has an assist electric motor connected to an engine and a hydraulic pump. The emissions of air pollutants in the exhaust gas from the engine are minimized regardless of fluctuations in the load torque of the hydraulic pump. A specific revolution speed suitable for reducing the emissions of air pollutants is stored, and an engine is controlled using the specific revolution speed as a target revolution speed. The absorption torque of a hydraulic pump is subjected to high-pass filtering whereby a high-frequency component devoid of a trend component is obtained. Target assist torque is computed from the high-frequency component, and the assist electric motor is subjected to power running/generation control accordingly. A specific output torque range suitable for reducing the emissions of air pollutants is stored, and the target assist torque is corrected so that the trend component does not exceed the specific output torque range.

Hydraulic working machine

An object is to provide a control device and control method for a compressed self-ignition type internal combustion engine, which can reduce torque variation due to misfire when the air-fuel ratio varies during compressed self-ignition type combustion, and thereby effectively use the potential for reducing fuel consumption. As the combustion mode, a spark-ignition type combustion mode by use of an ignition plug and a compressed self-ignition type combustion mode which utilizes a pressure increase in a combustion chamber in association with upward movement of piston are selectively set depending on an operational state of the engine, and when the air-fuel ratio in the compressed self-ignition type combustion mode is rich, a regional upper limit of the compressed self-ignition type combustion region is changed toward the lower engine torque side, and when the air-fuel ratio is lean, the regional upper limit is changed toward the higher engine torque side.

Control device for compressed self-ignition type internal combustion engine

A control device for an engine, capable of accurately estimating the quantity of exhaust heat from the engine and performing engine control which improves the exhaust quality and fuel consumption of the engine in various operating conditions thereof, by using the accurate estimated value of the quantity of exhaust heat. A control device for an engine is provided with an exhaust flow rate sensor for directly sensing the flow rate of exhaust gas discharged from the engine, an exhaust temperature estimating device for sensing or estimating the temperature of the exhaust gas discharged from the engine, and an exhaust heat quantity estimating device for estimating, based on an output of the exhaust flow rate sensor and an output of the exhaust temperature estimating device, the quantity of heat of the exhaust gas discharged from the engine.

Control device for engine

In an in-cylinder injection type spark ignition internal combustion engine in which the intake air amount is controlled by use of an intake valve or an exhaust valve, which is provided with mainly a variable valve mechanism, instable combustion during a low-load operation is avoided without an increase in pumping loss (without a decrease in the thermal efficiency). In the in-cylinder injection type spark ignition internal combustion engine, during low-load operation, on the basis of the cooling water temperature of the engine the opening and closing timing of the intake valve is controlled in a retard angle manner and the opening and closing timing of the exhaust valve is controlled in an advance angle manner. Furthermore, the fuel injection timing is controlled in a retard angle manner on the basis of the retard angle amount of the intake valve opening and closing timing.

Control apparatus of spark ignition internal combustion engine

Disclosed herein is a control apparatus for a spark-ignition engine that is capable of avoiding knocking at the time of high-load operation. With this control apparatus, a residual-gas suction unit or the like is not used, an exhaust gas does not deteriorate due to injection in a compression stroke, and a thermal efficiency also does not decrease. An engine control apparatus (ECU)is used for the control of a direct-injection type spark-ignition engine. During the high-load operation of the spark-ignition engine, the ECUinjects fuel a plurality of times. In addition, the ECU performs first fuel injection toward internal EGR that exists in a combustion chamber of the spark-ignition engine.

Control apparatus for spark-ignition engine

An engine controller capable of reducing torque fluctuation and the like in change between spark ignition combustion and homogeneous charge compression ignition combustion is provided. Spark ignition burning mode or homogeneous charge compression ignition burning mode is selectively set as burning mode according to the operating state of an engine. In spark ignition burning mode, a spark plug is used. In homogeneous charge compression ignition burning mode, fuel is burned utilizing pressure rise in a combustion chamber in conjunction with the ascent of a piston. The burning mode is changed between these modes. In transition for change between the spark ignition burning mode and the homogeneous charge compression ignition burning mode, the following measure is taken: a period during which the lift amount and/or the valve opening period (IVevent) of an intake valve is made smaller than a set value for the homogeneous charge compression ignition burning mode is provided.

Apparatus and method for controlling engine

A first, a second, and a third combustion region are defined by the air-fuel ratio of the mixture gas feeding combustion. Upon switching of combustion regions from the first combustion region to the third combustion region and from the third combustion region to the first combustion region, namely, when the second combustion region is passed, the mass of NOx emission downstream of an exhaust purifying device and the torque variation are estimated online. Based on the estimated value of the mass of NOx emission and the estimated value of the torque variation, the mass of intake air introduced into the combustion chamber is adjusted in a manner different from when normal, such as by changing the amount of lift of the intake valve, for example, so as to reduce the mass of NOx emission downstream of the exhaust purifying device and the torque variation below predetermined values upon passing of the second combustion region. Thus, the increase in exhaust emissions and the deterioration of operability during the switching of combustion regions can be suppressed.

Engine controller

In an engine controller capable of carrying out spark ignition type combustion and compressed self-ignition type combustion, in order to suppress operation performance deterioration and exhaust performance deterioration at the time of switching a combustion mode from the compressed self-ignition type combustion to the spark ignition type combustion, intake pipe pressure downstream a throttle is quickly reduced by making the throttle opening degree smaller than a target throttle opening degree of the spark ignition type combustion immediately after switching for a certain period during the combustion mode is switched from the compressed self-ignition type combustion to the spark ignition type combustion. As a result, responsiveness of an intake amount at the time of switching the combustion mode from the compressed self-ignition type combustion to the spark ignition type combustion is enhanced, and combustion switching without exhaust deterioration and torque variation is realized.

There is provided a thermal type flow meter capable of accurately detecting a flow rate even when a fluid temperature varies rapidly or when the fluid temperature is high. A probe includes: a first main heating resistor; a second main heating resistor set at a temperature different from that of the first main heating resistor; and a sub-heating resistor for heating lead wires of the two main heating resistors. A CPU of a sensor control circuit finds a fluid temperature by using the two main heating resistors, and finds a fluid flow rate by using at least one of the two main heating resistors.

Thermal type flow meter

A control apparatus of an EGR control valve has an EGR control valve has an exhaust gas recirculation passage to circulate exhaust gas of an combustion engine from an exhaust gas passage to an intake air passage. A measurement unit measures a flow rate of EGR gas flowing in the exhaust gas recirculation passage, and a controller receives an input from the measurement unit and closes the EGR control valve if the EGR-gas flow rate is smaller than a predetermined threshold value when the EGR gas is flowing from the exhaust side to the intake side of the internal combustion engine.

Control apparatus of EGR control valve

A controller of an internal combustion engine capable of spark ignition combustion and compression ignition combustion which restrains the degradation of operation performance and exhaust performance at the time of combustion type switching. The controller includes control means for performing combined combustion which leads to ignition combustion by a pressure rise by spark ignition combustion through adjustment of an internal cylinder temperature and a combustion speed at the end of compression, wherein the combined combustion is performed in the process of combustion type switching between spark ignition combustion and compression ignition combustion based on a result of determination of whether or not combustion type switching is possible, thus implementing a smooth combustion type switching.

Controller of internal combustion engine of compression ignition combustion type

In a homogeneous charge compression-ignited internal-combustion engine, based on information regarding the operational state of the engine, a combustion mode switching discriminator selects a homogeneous charge compression-ignited combustion mode if engine operating conditions allow homogeneous charge compression-ignited combustion. If not, the combustion mode switching discriminator selects a spark-ignited combustion mode. Immediately after switching from spark-ignited combustion to homogeneous charge compression-ignited combustion, a combustion mode switching corrector outputs switching correction values for operating quantities for homogeneous charge compression-ignited combustion. The correction values are used to adjust the operating quantities for homogeneous charge compression-ignited combustion, and new operating quantities obtained from the adjustments are output as control quantities from a combustion mode selector.

Apparatus and method for controlling a homogeneous charge compression-ignited internal-combustion engine

An engine that re-circulates its exhaust gas suffers decreased accuracy in estimating an EGR rate real-time especially while the operating state of the engine is in a transitional state, which often results in torque fluctuations and deteriorated exhaust gas. A sensor for directly detecting an EGR flow rate is disposed in an EGR path. An EGR rate and in-cylinder oxygen concentration are calculated from the output value of that sensor. In addition, when this EGR rate calculation method is used, the calculation is properly switched between a steady operation state characterized by a low load and small rotational fluctuations and a transitional operating state including the acceleration and deceleration. This makes it possible to correctly estimate the EGR rate and the in-cylinder oxygen concentration under a wide range of engine operation conditions, and thereby to avoid the fluctuation of torque and the deterioration of exhaust gas.

Engine control system and control method thereof

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Hitachi, Japan

Shiro Yamaoka