A vehicle weight measurement device includes a diaphragm which covers an opening area of a groove portion of a mounting part to form an oil chamber of a predetermined space together with the groove portion; a pressure sensor which detects a change in pressure of measurement fluid in the oil chamber; a first piston which presses the diaphragm; a second piston which presses the first piston; and a bearing unit interposed between the second piston and a spring bush which receives one end of a spring of a suspension device and is relatively rotatable. The bearing unit includes a thrust needle bearing which swingably supports a load in a longitudinal direction of the suspension device, and a slide bush which does not receive a load in the longitudinal direction and receives a load in a radial direction while causing constant damping to swinging.

A vehicle load metering device has a displacement sensing module, a signal processing/transmission module, and a signal receiving/processing module. The displacement sensing module has multiple displacement sensors respectively mounted on flexible supporting devices of a vehicle suspension system. Each displacement sensor is connected to two supporting boards of the corresponding flexible supporting device to meter amount of displacement between the two supporting boards. The signal processing/transmission module transmits the signals that are detected by the displacement sensors to the signal receiving/processing module. The present invention provides a vehicle load metering device that may assemble on the vehicle conveniently and detect the load of the vehicle accurately.

A vehicle load metering device has a displacement sensing module, a signal processing/transmission module, and a signal receiving/processing module. The displacement sensing module has multiple displacement sensors respectively mounted on flexible supporting devices of a vehicle suspension system. Each displacement sensor is connected to two supporting boards of the corresponding flexible supporting device to meter amount of displacement between the two supporting boards. The signal processing/transmission module transmits the signals that are detected by the displacement sensors to the signal receiving/processing module. The present invention provides a vehicle load metering device that may assemble on the vehicle conveniently and detect the load of the vehicle accurately.

A work vehicle, a method of determining a weight of a payload supported by a work tool mounted to an upper structure of a work vehicle, and a method of calibrating a weight of a payload supported by a work tool mounted to an upper structure of a work vehicle are provided. The work vehicle includes an undercarriage having a plurality of ground engaging members supporting the work vehicle, an upper structure rotatable relative to the undercarriage about a vertical axis, a rotation sensor configured to determine a rotation angle of the upper structure relative to the undercarriage, a work tool mounted to the upper structure and configured to support a payload, and a controller configured to determine a weight of the payload based at least partially on the rotation angle of the upper structure relative to the undercarriage.

A work vehicle, a method of determining a weight of a payload supported by a work tool mounted to an upper structure of a work vehicle, and a method of calibrating a weight of a payload supported by a work tool mounted to an upper structure of a work vehicle are provided. The work vehicle includes an undercarriage having a plurality of ground engaging members supporting the work vehicle, an upper structure rotatable relative to the undercarriage about a vertical axis, a rotation sensor configured to determine a rotation angle of the upper structure relative to the undercarriage, a work tool mounted to the upper structure and configured to support a payload, and a controller configured to determine a weight of the payload based at least partially on the rotation angle of the upper structure relative to the undercarriage.

A method for the weight-dependent control of the internal pressure of a supporting body loaded by a weight load or payload, wherein the internal pressure is produced by means of an electric-motor-driven compressor, and the weight load or payload which is present and which acts on a supporting body in the form of a mass m.sub.Load under the effect of acceleration due to gravity g is determined in that a reduction and a subsequent increase in the internal pressure take place, wherein the increase in the internal pressure causes the position of an application point of the weight load or payload to change by a position difference Z, wherein:

during the increasing of the internal pressure by means of the compressor, the motor current I.sub.Load of the drive motor of the compressor is measured with a constant motor voltage U and integrated over the time of the increase in pressure, and the electrical work W.sub.Load which is necessary for the change in position is determined therefrom,

wherein the electrical work W.sub.Load the electrical work W.sub.Load is compared with a characteristic value of the electrical work W.sub.0 from a characteristic diagram, wherein the change in position Z, the difference in mass m and the difference in payload F.sub.Z are determined from the difference W between W.sub.Load and W.sub.0 and the mass m.sub.Load and the weight load or payload which is actually present as a result is determined therefrom.

A method for the weight-dependent control of the internal pressure of a supporting body loaded by a weight load or payload, wherein the internal pressure is produced by means of an electric-motor-driven compressor, and the weight load or payload which is present and which acts on a supporting body in the form of a mass m.sub.Load under the effect of acceleration due to gravity g is determined in that a reduction and a subsequent increase in the internal pressure take place, wherein the increase in the internal pressure causes the position of an application point of the weight load or payload to change by a position difference Z, wherein:

during the increasing of the internal pressure by means of the compressor, the motor current I.sub.Load of the drive motor of the compressor is measured with a constant motor voltage U and integrated over the time of the increase in pressure, and the electrical work W.sub.Load which is necessary for the change in position is determined therefrom,

wherein the electrical work W.sub.Load the electrical work W.sub.Load is compared with a characteristic value of the electrical work W.sub.0 from a characteristic diagram, wherein the change in position Z, the difference in mass m and the difference in payload F.sub.Z are determined from the difference W between W.sub.Load and W.sub.0 and the mass m.sub.Load and the weight load or payload which is actually present as a result is determined therefrom.

Based on information sensed by a work phase sensing unit, a work phase by a work implement is distinguished. Correction of boom pressure is switched when distinction of excavation in the work phase is switched.

Based on information sensed by a work phase sensing unit, a work phase by a work implement is distinguished. Correction of boom pressure is switched when distinction of excavation in the work phase is switched.

Hydraulic valve circuitry adapted for automatic weight-responsive control of load-clamping members of a load-lifting system having a free lift mast. The load-lifting system generally includes one or more fluid power actuator for applying a gripping force to a load, at least one elongate, longitudinally-extensible fluid power lifting device having a free lift range of motion and at least one main lift range of motion, and manually operated load-clamping and load-lifting selector valves. The hydraulic valve circuitry provides, independently, weight-responsive control of the load-clamping members when lifting a load, full-time automatic weight-responsive force control of the load-clamping members without concurrent manual actuation of load-clamping or load-lifting selector valves, and equalization of sensed load weight so that the sensed load weight is substantially independent of the longitudinally-extensible position of the lifting device.