Kabushiki Kaisha Komatsu Seisakusho

Komatsu Corporation

Ryoichi Maruyama

Tsutomu Ishino

Hideki Yamada

Takayoshi Nishijima

Hideaki Aida

Keiji Hatayama

Hideyuki Konishi

Hiroshi Nakagami

Takashi Noda

Shingo Ota

Teruyoshi Kikuchi

Hiroyuki Mitsuya

Mamoru Hatano

Yuichi Nagahiro

Hideyuke Konishi

Keita Muto

Hisao Asada

Akinobu Takada

An apparatus for controlling the brake of a vehicle, which easily brings the vehicle to a halt, or starts it, only by the action of the accelerator without operating the brake pedal. Brakes (,) are applied when the vehicle speed detected by a speed detector (,) becomes a predetermined threshold value or less. The operation of the brakes (,) is turned off when a load detected by a load detector (,) becomes larger than a load operated by a load computer (,).

Apparatus for controlling brake of vehicle

A control system designed such that if a heavy load is imposed on a vehicle during running and a hydraulic relief state in which an oil pressure in a hydraulic circuit for a hydrostatic transmission unit exceeds a relief pressure is detected, the angle of a discharge controlling swash plate for a pump is reduced to a specified value (e.g., 50% of the maximum angle) or less, whereby the stall of the vehicle and the overheat of machine parts are prevented.

System for controlling a hydrostatic-mechanical transmission when an oil

A response control system for a hydrostatic-mechanical transmission. In this system, it is determined in digging/moving operation whether an actual speed ratio which is the ratio of the revolution speed of the output shaft to the revolution speed of the power source is equal to a specified value or less, and if so, a target speed ratio which is a target value for the ratio of the revolution speed of the output shaft to the revolution speed of the power source is set, limiting the amount of change in the target speed ratio per unit time. Based on the target speed ratio thus set, the angle of at least either of discharge controlling swash plates is controlled, thereby reducing vehicle acceleration at the primary stage of digging. In order to slow down the response to a change in load during digging operation, a constant indicating the response to a change in engine revolution is set small in proximity to a target engine revolution speed. With this arrangement, the response of the transmission to a change in load during digging operation can be retarded.

Response control system for hydrostatic-mechanical transmissions

A target engine revolution speed is calculated based on the throttle position of an engine such that the amount of change in the target engine revolution speed with respect to time is limited. According to the target engine revolution speed thus calculated, a target motor speed ratio, which is a target value for the ratio of the revolution speed of a motor in a hydrostatic transmission unit to the revolution speed of the engine, is set. With this target motor speed ratio, the angle of at least either of discharge controlling swash plates is adjusted.

System for controlling a hydrostatic-mechanical transmission at the time

A turning speed control system for use in a track-laying vehicle comprising: a steering motor for driving crawler belts provided at both sides of the vehicle such that a relative travel difference is caused between the crawler belts, thereby turning the vehicle to the right or left; a steering instructing device which can be displaced from a neutral position by operation and which instructs, according to the direction and distance of its displacement, a turning direction and a turning radius for the vehicle, the turning radius decreasing as the displacement distance increases; a displacement detector for detecting the displacement of the steering instructing device; and a control unit for performing a control such that when making the turning radius of the vehicle small by increasing the revolution speed of the steering motor according to the displacement of the steering instructing device detected by the displacement detector such that the crawler belts are driven with a relative travel difference therebetween, if the displacement distance of the steering instructing device exceeds a maximum steering motor revolution speed displacement value at which the steering motor reaches its maximum revolution speed, the vehicle speed at which the vehicle moves forwards or backwards is reduced as the displacement of the steering instructing device proceeds, while the maximum revolution speed of the steering motor being maintained, until the steering instructing device reaches a position corresponding to its maximum displacement value.

Turning speed control system for use in a track-laying vehicle

A control mechanism for a hydrostatic-mechanical power transmission system having a mechanical transmission unit driven through an input shaft connectable to a power source, and a hydrostatic transmission unit that is connectable to the input shaft and includes a pump and a motor each having a displacement setting swash plate. The control mechanism further includes a differential unit for connecting an output shaft to the mechanical transmission unit and the hydrostatic transmission unit to drive. At least either of the displacement setting swash plates is variable in angle. The control mechanism also includes a throttle position detector for detecting the position of a throttle in relation to the power source; a target motor speed ratio setting device for setting, based on the position of the throttle detected by the throttle position detector, a target motor speed ratio that is a target value for the ratio of the revolution speed of the motor in the hydrostatic transmission unit to the revolution speed of the power source; and a swash plate angle controller for controlling at least either of the angles of the displacement setting swash plates by feed-forward control in which the target motor speed ratio set by the target motor speed ratio setting device is used in such a way that the ratio of a displacement volume of the pump to a displacement volume of the motor is made to follow the target motor speed ratio.

Control mechanism for hydrostatic-mechanical power transmission system

A steering system for use in a track-laying vehicle comprising: a steering motor that is forwardly and reversely rotatable and designed to drive crawler belts provided at both sides of the vehicle such that a relative travel difference is caused between the crawler belts, thereby turning the vehicle rightwards or leftwards; a forward/reverse drive state detector for detecting whether the vehicle is in its forward drive state or reverse drive state; a lateral turn instructing device for instructing right turn or left turn of the vehicle; and a steering motor forward/reverse rotation control unit for determining the forward or reverse rotation of the steering motor in accordance with the forward or reverse drive state of the vehicle detected by the forward/reverse drive state detector, such that the vehicle turns to the right or left in response to a right turn instruction or left turn instruction released from the lateral turn instructing device.

Steering system for use in a track-laying vehicle

Upon detection of execution of operation for stopping a vehicle during its running state and of a drop in an actual speed ratio below a predetermined value, the actual speed ratio being the actual ratio of the revolution speed of an output shaft to the revolution speed of a power source, a feedback amount is determined, setting the integral component of the difference between a target motor speed ratio and an actual motor speed ratio to zero. Based on the feedback amount thus determined, an operation amount for controlling the angle of a swash plate is computed. With this amount, the angle of the swash plate is controlled.

Creep preventing control system for hydrostatic-mechanical transmissions

A control system in which a judgment is made such that (i) a vehicle is in a forward drive control state, on condition that the forward/reverse drive lever is placed in the forward drive position and the actual speed ratio exceeds a specified small value in a forward drive direction, (ii) the vehicle is in a reverse drive control state on condition that the lever is placed in the reverse drive position and the actual speed ratio exceeds a specified small value in a reverse drive direction, (iii) the vehicle is in an engine brake control state, on condition that the lever is placed in the neutral position and the actual speed ratio exceeds the specified small value in the forward or reverse drive direction, (iv) the vehicle is in an FR shift control state, on condition that the lever is placed in the forward or reverse drive position and the actual speed ratio exceeds the specified small value in the reverse or forward drive direction, and (v) the vehicle is in a neutral control state, on condition that the lever is placed in the neutral position and the actual speed ratio does not exceed the specified small values in the forward and reverse drive directions.

Forward/reverse drive and stop control system for hydrostatic

The maximum value of target motor speed ratio is calculated from the allowable revolution speed of a motor, and based on the maximum value, an allowable value of target speed ratio is set. Target speed ratio is then limited to the allowable value or less. This enables it to prevent overrun occurring e.g., when the vehicle rolls down a hill.

Overrun protecting control system for hydrostatic-mechanical

A speed change gear control system, wherein gear shift control for shifting the transmission from an arbitrary speed range into a higher speed range which provides higher absolute speed than the arbitrary speed range is performed, provided that the actual speed ratio e of the transmission satisfies .vertline.E.sub.1 .vertline.&lt;.vertline.e.vertline.&lt;.vertline.E.sub.0 .vertline. where E.sub.0 is a speed ratio for a shifting point at which the transmission is shifted from the arbitrary speed range into the higher speed range; and E.sub.1 is a specified speed ratio, or provided that .vertline.e.vertline.+(.DELTA.e/.DELTA.t).times.T.sub.1 &gt;.vertline.E.sub.0 .vertline.-.DELTA.E.sub.1 where .DELTA.e is an increase in the speed ratio e over a period of time .DELTA.t; T.sub.1 is the filling time required for supplying hydraulic oil to a clutch which shifts the transmission from the arbitrary speed range to the higher speed range; and .DELTA.E.sub.1 is a specified small speed ratio.

Speed change gear control system for hydrostatic-mechanical transmissions

A turning control system for use in a track-laying vehicle comprising: a steering motor for driving crawler belts provided at both sides of the vehicle such that a relative travel difference is caused between the crawler belts, thereby turning the vehicle rightwards or leftwards; a steering instructing device which can be displaced from a neutral position by operation and which instructs, in accordance with its displacement direction and displacement distance, a turning direction and a turning radius for the vehicle, the turning radius decreasing as the displacement distance increases; a displacement detector for detecting the displacement of the steering instructing device; a vehicle speed detector for detecting the vehicle speed at which the vehicle moves forwards or backwards; and a steering motor revolution speed control unit for controlling the revolution speed of the steering motor such that the revolution speed of the steering motor becomes proportional to the vehicle speed detected by the vehicle speed detector at least in the region of low vehicle speeds, when the steering instructing device is displaced and kept in a certain position and therefore there is no change in the displacement of the steering instructing device detected by the displacement detector.

Turning control system for use in a track-laying vehicle

A turning system for use in a track-laying vehicle comprising: a power source; a steering motor driven by the rotation of the power source, for driving crawler belts provided at both sides of the vehicle such that a relative travel difference is caused between the crawler belts, thereby turning the vehicle rightwards or leftwards; a power source revolution speed detector for detecting the actual revolution speed of tile power source; and a steering motor control unit for performing a control such that, a target revolution speed set for the steering motor is decreased when the actual revolution speed of the power source detected by the power source revolution speed detector decreases below a target revolution speed set for the power source by a specified revolution speed or more.

Turning system for use in a track-laying vehicle

A steering control system for use in a track-laying vehicle comprising: a power source; a steering motor driven by the rotation of the power source, for driving crawler belts provided at both sides of the vehicle such that a relative travel difference is caused between the crawler belts, thereby turning the vehicle rightwards or leftwards; a steering instructing device which can be displaced from a neutral position by operation and which instructs, according to the direction and distance of its displacement, a turning direction and a turning radius for the vehicle, the turning radius decreasing as the displacement distance increases; a displacement detector for detecting the displacement of the steering instructing device; and a steering motor revolution speed control unit for obtaining a target steering motor revolution speed which is made proportional to the revolution speed of the power source based on the displacement of the steering instructing device detected by the displacement detector and controlling the revolution speed of the steering motor with the target steering motor revolution speed.

Growing community of inventors

Komatsu, Japan

Ryoichi Maruyama