Hitachi, Ltd.

Hitachi Car Engineering Co., Ltd.

Hidefumi Adachi

Toshio Manaka

Taisetsu Tanimichi

Yoshikatsu Hashimoto

Yuichi Kuramochi

Mitsunori Nishimura

Tatsuya Yoshida

Eiichiro Kondo

Kentarou Ueno

Yasufumi Konishi

Kimihiro Yamai

Eiichirou Kondou

After cruise control is restored by an accelerating operation, the driver set speed is changed according to the displacement of the accelerator pedal. It becomes possible to reduce the driver set speed due to release of the accelerator pedal, that is, the vehicle can be decelerated by the engine. Even if the cruise control is restored, the cruise control is not conducted and the vehicle can be decelerated by the engine if the driver wants to decelerate the vehicle by the release of the accelerator pedal.

Adaptive cruise control system

A cruise control capable of maintaining the speed of a vehicle at a set cruise speed is selected when the headway distance to a preceding vehicle is equal to or greater than a set distance. Headway distance control, maintaining the headway distance to the preceding vehicle at a required value, is selected when the headway distance is smaller than a set distance. Fleet driving, in which the vehicle runs at the same set speed as that of the preceding vehicle, is enabled by increasing the vehicle speed upper limit existing under the headway distance control above a set cruise speed.

Automatic vehicle speed control apparatus

To provide a headway control system, in which a congestion following processing can be started by the same operation as in ordinary driving. An arrangement is provided that lets a following control unitto start a control to follow a preceding vehicle on condition that a characteristic value, which is produced in a host vehicle when a driver starts moving the host vehicle, is detected in congested traffic. Acceleration or a vehicle speed may be used as the characteristic value. Another possible arrangement is to start the following control on condition that a variation in an engine of the host vehicle, which is generated in the host vehicle when the driver operates to start moving the host vehicle, is detected in congested traffic. For example, the following control may be started under condition that at least either one of the following is detected: an increase in an engine speed, an increase in an intake pressure, an increase in an injection pulse width, an increase in an engine oil pressure, and an increase in the number of ignition pulses.

Headway control system

A vehicle cruise control apparatus is provided for controlling a vehicle to run at a set speed desired by a driver. The apparatus stores a state in which the driver inputs a set speed (for example, the number of times the driver inputs the set speeds and a period at which the driver inputs the set speeds), and calculates a target acceleration/deceleration from the input state and a vehicle speed deviation (calculated by subtracting the actual vehicle speed from the set speed).

Method and apparatus for controlling vehicle cruise

A throttle valve is rotatably mounted to a throttle body through a throttle shaft. An internal bore shape of the throttle body is of a straight bore type having a shape in which the center of rotation of the throttle valve is placed on the central line of the throttle body. Spherically-shaped internal profile portions are provided in an idle control region lying in the neighborhood of a fully-closed angle of the throttle valve. Further, spherically-shaped internal profile portions are provided as regions following the spherically-shaped internal profile portions referred to above. Moreover, regions each formed by a spherical shape and a composite surface profile of a cylindrical surface substantially parallel to the flow of intake air or regions each formed by a conical surface profile are provided as regions following the spherically-shaped profiles. Incidentally, the center of each spherical profile is offset on the central line of the bore in upward and downward directions. As a result, a clearance defined between each spherical profile and the throttle valve increases as the degree of opening of the throttle valve increases. When the present invention is used in an electronically-controlled type throttle valve control device, the engine speed is set so as to be changed 20 rpm when the throttle valve is opened 0.1&deg; in a low degree-of-opening region of the throttle valve. Therefore, idle control exercised by an ISC valve is unnecessary.

Throttle valve control device for an internal combustion engine

Disclosed is a throttle valve control device for internal combustion engines which has good measuring accuracy and improved controllability of an air flow rate. A throttle valve is rotatably attached to a throttle body through a throttle shaft. The throttle body has an inner surface of straight bore type that the center of rotation of the throttle valve is positioned on a line connecting the centers of an upstream opening and a downstream opening of the throttle body. The throttle body has a spherical inner surface X2 in an idle speed control area .theta.2 near the fully closed angle of the throttle valve. The throttle body also has, in an area .theta. subsequent to the spherical inner surface X2, an inner surface X3 having a composite form made up of a spherical surface and a cylindrical surface substantially parallel to a flow of intake air.

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Mito, Japan

Hidefumi Adachi