A work machine includes a boom, a work tool configured to drive with respect to the boom, an actuator configured to drive the work tool, a sub-link attached to the boom, and a control section. The sub-link is configured to transmit driving force of the actuator to the work tool. The control section is configured to control the actuator based on a posture of the sub-link with respect to the boom. A method of controlling a work machine includes controlling an actuator based on a posture of a sub-link with respect to a boom, the sub-link being configured to transmit driving force of the actuator to a work tool configured to drive with respect to the boom.

In an unloaded state of the bucket (3), a control device (30) calculates an unloaded moment (M.sub.0) around a hinge pin G from the pressure of the lift arm cylinder that is detected by pressure sensors (15a, 15b), the angle of a lift arm that is detected by a lift arm angle sensor 14, and dimension data extracted from a vehicle body information database (35). In a loaded state of the bucket, the control device calculates a loaded moment (M.sub.1) around the hinge pin G from the pressure of the lift arm cylinder, the angle of the lift arm, and the dimension data extracted from the vehicle body information database. The control device calculates the load (W) on the bucket by dividing the difference between the unloaded moment and the loaded moment by the horizontal distance (L.sub.w) between the hinge pin and the gravity center position of the bucket.

A control system for a material handling vehicle has a boom arm connected to a vehicle frame for rotation about the vehicle frame. An actuator is connected to the vehicle frame and the boom arm to cause the boom arm to rotate about the vehicle frame, and an attachment is connected to the boom arm for rotation with respect to the boom arm. The control system includes a controller that is configured to calculate a pre-determined acceleration limit of the attachment, and a sensor that senses acceleration of the attachment and communicate the sensed acceleration to the controller. The controller is configured to compare the pre-determined acceleration limit of the attachment to the sensed acceleration of the attachment and is configured to adjust a control valve to limit flow to the actuator in response to the sensed acceleration of the attachment being above the pre-determined acceleration upper limit.

A filter attachment body is attached to a vehicle body of a work vehicle provided with a pump. The filter attachment body includes a bracket attached to the vehicle body, a filter device attached to the bracket, and a plurality of elastic members interposed between the bracket and the filter device. The bracket has an attachment plate to which the filter device is attached. The attachment plate is disposed substantially perpendicular to an up-down direction. The filter device has a filter case connected to the pump, and a filter body attached to the filter case. A geometric center of the filter body overlaps a figure drawn by linking the elastic members with straight lines when viewed from a top view of the attachment plate. At least a portion of at least one of the elastic members is located outside of the filter body when viewed from the top view.

A work equipment control device of a work vehicle includes state determination unit and an automatic dump determination unit. The state determination unit determines a work state of the work vehicle based on a traction force of the work vehicle and a posture of work equipment. An automatic dump determination unit determines an automatic dump availability mode indicating the availability in performing automatic dump control for automatically driving a bucket to a predetermined dump angle, in accordance with the work state.

A work machine includes a main body, a boom to drive with respect to the main body, a work tool connecting to the boom, the work tool to drive with respect to the boom, an actuator connecting to the main body and the work tool, the actuator to drive the work tool, and a sub-link to transmit drive of the actuator to the work tool. A method for calibrating the work machine includes outputting a detection value to detect an angle of the sub-link with respect to the boom in a predetermined posture of the boom and a work tool posture, converting the detection value as a measurement angle of the sub-link with respect to the boom based on a conversion value, and calibrating the conversion value based on a relationship between the measurement angle and an actual angle in the work tool posture which is specified.

A work machine includes an engine, a travel drive system, a work implement, an apparatus drive system with a hydraulic pump, an accelerator operating member, a work implement operating member, and a controller. The controller controls the apparatus drive system in accordance with an operating amount of the work implement operating member. The controller determines a target tractive force of the travel drive system based on an operating amount of the accelerator operating member. The controller determines an allowable acceleration of the work machine. The controller determines an upper limit of tractive force of the travel drive system based on the allowable acceleration. The controller corrects the target tractive force so as to be equal to or less than the upper limit when the target tractive force is greater than the upper limit. The controller controls the travel drive system based on the corrected target tractive force.

A method for monitoring a machine operating at a worksite, is provided. The machine includes an implement for performing one or more implement operations and is configured to be propelled by a set of ground engaging members between a first location and second location. A first input indicative of start of a travelling operation of the machine after completion of a first implement operation at the first location, is received. One or more transmission parameters associated with the machine are determined, when the machine moves from first location to second location. A second input indicative of end of the travelling operation at start of a second implement operation at the second location is received. A number of revolutions completed by ground engaging members between the first location and the second location is determined based on the transmission parameters. The number of revolutions is displayed on input/output device associated with machine.

A method of controlling a drive device of a construction machine with a split transmission, which is at least coupled, at an input side, to a drive force source and, on the output side, with a drive range change transmission so as to set at least two shiftable drive ranges. The method includes a detection step (S1) for detecting drive dynamic requests for operation of the construction machine and a determination step (S2) for determining whether a drive dynamic request with an increased drive dynamic is present. If a drive dynamic request with increased drive dynamics is determined, then a shifting step (S4) is executed for shifting the drive range change transmission from a second, of the at least two drive ranges, to a first of the at least two drive ranges, to achieve increased driving dynamics of the construction machine.

Provided is a loading vehicle in which a control characteristic of traction force can be easily and finely set and changed while a configuration of a hydraulic circuit is simple. An HST traveling driven wheel loader includes an electronically controlled HST pump and HST motor, including a solenoid proportional pressure reducing valve to control displacement volume of the HST pump based on a control signal output from a controller. The controller stores characteristic tables indicating a correlation between discharge pressure of a loading hydraulic pump or an operation state of an engine and a maximum discharge pressure of the HST pump, and when the vehicle speed corresponds to work requiring traction force, outputs a control signal to the solenoid proportional pressure reducing valve so as to obtain the maximum discharge pressure Pm of the HST pump that corresponds to one of the characteristic tables.