Abstract: The present invention regards a tire braking characteristic test apparatus which can reflect the dynamic characteristics of a vehicle at the time of braking in order to evaluate the braking characteristics of tires. The test apparatus can also perform a test where a vehicle condition is changed in a manner which influences the braking characteristics of the tires.

Abstract: With respect to a method of controlling a pump flow rate of a hydraulic pump, a method having a small flow rate command value is selected between a pressure feedback control for controlling the pump flow rate based on a set pressure (a cutoff pressure) and a pump pressure, and, an ordinary control for controlling the pump flow rate based on operation information, and in a case that the pressure feedback control is selected, a flow rate increasing control for increasing the flow rate command value after the case with the passage of time is performed.

Abstract: The present invention is to provide a tire braking characteristic test apparatus capable of reflecting dynamic characteristic of a vehicle at the time of braking in order to evaluate braking characteristic of tires and also performing a test with easily changing a vehicle condition influencing the braking characteristic of the tires.

Abstract: A tire HIL simulator is provided which is capable of, in a testing apparatus where a vehicle model is incorporated into a tire testing apparatus, reproducing the behavior of a tire which corresponds to the three-dimensional behavior of a vehicle, even if a three-dimensional vehicle model is used. As a device for resolving this, this tire HIL simulator includes a tire testing apparatus 2 and a controller 3 connected mutually. The tire testing apparatus 2 conducts a running test on a tire 4a using a mimic road surface body 4, and includes a side force measuring device 37 for measuring a tire side force and each actuator which gives a contact load, a side-slip angle and a camber angle, respectively.

Abstract: A tire HIL simulator is provided which is capable of, in a testing apparatus where a vehicle model is incorporated into a tire testing apparatus, reproducing the behavior of a tire which corresponds to the three-dimensional behavior of a vehicle, even if a three-dimensional vehicle model is used. As a device for resolving this, this tire HIL simulator includes a tire testing apparatus 2 and a controller 3 connected mutually. The tire testing apparatus 2 conducts a running test on a tire 4a using a mimic road surface body 4, and includes a side force measuring device 37 for measuring a tire side force and each actuator which gives a contact load, a side-slip angle and a camber angle, respectively.

Abstract: With respect to a method of controlling a pump flow rate of a hydraulic pump, a method having a small flow rate command value is selected between a pressure feedback control for controlling the pump flow rate based on a set pressure (a cutoff pressure) and a pump pressure, and, an ordinary control for controlling the pump flow rate based on operation information, and in a case that the pressure feedback control is selected, a flow rate increasing control for increasing the flow rate command value after the case with the passage of time is performed.

Abstract: A hydraulic control system of the present invention comprising control valves for controlling the direction and flow rate of pressure oil discharged from a hydraulic pump, hydraulic actuators which the pressure oil is fed to and controlled by the control valves, the hydraulic actuators including hydraulic cylinders and a hydraulic motor, and a first return passage provided as a passage for returning return oil present at the head side of one of the hydraulic cylinders to the tank, the first return passage being in communication with the tank, and a second return passage for returning return oil from each of the other hydraulic actuators including the hydraulic motor except for the hydraulic cylinders to the tank, the second return passage having a back pressure check valve and a replenishing passage, the replenishing passage being configured so as to provide a back pressure developed by the back pressure check valve to the low pressure side of each of the other hydraulic actuators to prevent cavitations.

Abstract: A control device for a working machine according to the present invention comprises a capacity variable pump for supplying working oil, a controller for controlling the discharge amount of the pump, a control valve for controlling the working oil discharged from the pump, a hydraulic actuator operated by the working oil from the control valve, an operating lever for operating the hydraulic actuator, and a relief valve to be operated when the pressure of the working oil is a relief pressure or more. The controller has a dynamic emulation model of a hydraulic driving device, and is constituted to estimate the pressure oil flow rate passing through the relief valve from the emulation model according to the operation amount of the operating lever, and to control the pump flow rate of the pump so that the relief flow rate estimation value gets close to zero. According to this, relief loss can be precisely reduced without generating a response delay or pressure loss, and the power can be saved.

Abstract: A hydraulic control system of the present invention comprising control valves for controlling the direction and flow rate of pressure oil discharged from a hydraulic pump, hydraulic actuators which the pressure oil is fed to and controlled by the control valves, the hydraulic actuators including hydraulic cylinders and a hydraulic motor, and a first return passage provided as a passage for returning return oil present at the head side of one of the hydraulic cylinders to the tank, the first return passage being in communication with the tank, and a second return passage for returning return oil from each of the other hydraulic actuators including the hydraulic motor except for the hydraulic cylinders to the tank, the second return passage having a back pressure check valve and a replenishing passage, the replenishing passage being configured so as to provide a back pressure developed by the back pressure check valve to the low pressure side of each of the other hydraulic actuators to prevent cavitations.

Abstract: The present invention relates to a control system and method for a hydraulic working machine characterized by having a construction wherein a flow discharge control valve is disposed in a discharge-side pipe line of a main flow control valve, the amount of operation of an operating lever is converted to a pilot pressure by a remote controlled valve, the pilot pressure is then input to a controller and is calculated into a pressure change speed as operation speed, in a pressure change speed calculator, further, the operation speed is calculated into an electromagnetic valve current in an electromagnetic valve current calculator, then the electromagnetic proportional valve current is output to an electromagnetic proportional valve from a command unit, and the degree of opening of the discharge flow control valve is controlled with a secondary pressure in the electromagnetic proportional valve.

Abstract: A control device for a working machine according to the present invention comprises a capacity variable pump for supplying working oil, a controller for controlling the discharge amount of the pump, a control valve for controlling the working oil discharged from the pump, a hydraulic actuator operated by the working oil from the control valve, an operating lever for operating the hydraulic actuator, and a relief valve to be operated when the pressure of the working oil is a relief pressure or more. The controller has a dynamic emulation model of a hydraulic driving device, and is constituted to estimate the pressure oil flow rate passing through the relief valve from the emulation model according to the operation amount of the operating lever, and to control the pump flow rate of the pump so that the relief flow rate estimation value gets close to zero. According to this, relief loss can be precisely reduced without generating a response delay or pressure loss, and the power can be saved.

Abstract: A drive apparatus comprises an engine, a hydraulic pump, an electric motor concurrently serving as a generator, a battery, a first control device that charges the battery with the electric power generated by the electric motor concurrently serving as a generator and drives the electric motor concurrently serving as a generator using the electric power of the battery, and a controller. When the input of the hydraulic pump is smaller than the output of the engine, the engine is operated the set number of revolutions and the number of high idle revolutions. And, when the input of the hydraulic pump is larger than the output of the engine, the input of the hydraulic pump is reduced and the electric motor is operated in the electric motor action, whereby the engine output can be supplemented and the engine can be operated in the set number of revolutions.

Abstract: A winding-down side pilot port of a control valve is of a 2-port construction comprising a normal winding-down side port having a large pressure receiving area and a free fall side port having a small pressure receiving area, wherein in the free fall operation carried out by setting a motor to a small capacity, a pilot pressure of a winding-down side remote control valve is supplied to the free fall side port through a mode switching valve. Thereby, a stroke of the control valve can be suppressed so that a speed of a motor does not exceed an allowable speed.

Abstract: The present invention relates to a control system and method for a hydraulic working machine characterized by having a construction wherein a flow discharge control valve is disposed in a discharge-side pipe line of a main flow control valve, the amount of operation of an operating lever is converted to a pilot pressure by a remote controlled valve, the pilot pressure is then input to a controller and is calculated into a pressure change speed as operation speed, in a pressure change speed calculator, further, the operation speed is calculated into an electromagnetic valve current in an electromagnetic valve current calculator, then the electromagnetic proportional valve current is output to an electromagnetic proportional valve from a command unit, and the degree of opening of the discharge flow control valve is controlled with a secondary pressure in the electromagnetic proportional valve.

Abstract: According to the present invention, when a winch drum is in the wind-down rotation, operating a control valve is operated to the wind-down side in a state in which capacity of a hydraulic motor is set to small capacity by a free fall valve to thereby rotate the hydraulic motor to the wind-down side at high speeds, and at the same time, motor holding pressure is controlled according to an operating amount of the free fall valve by a holding pressure control valve to thereby regulate rotational speed of the hydraulic motor and stop the latter.

Abstract: A system for judging to permit actuating a safety device for protecting an occupant seated on the passenger seat of a vehicle. The system is capable of detecting a rearward facing child seat. The system is able to judge in many situations as to whether it is necessary to permit actuating the safety device. The safety device has an air bag storing portion holding an air bag therein. The storing portion is located in front of the front passenger seat. On rapid deceleration of the vehicle, the safety device is set into actuation to inflate the air bag. The system uses plural distance sensors to detect the distances to an upper portion and a lower portion, respectively, of an object existing in the space between the air bag storing portion and the passenger seat. According to the output signals from the distance sensors, the system judges as to whether it is necessary to permit actuating the safety device.

Abstract: The crash sensor of the present invention comprises a magnet, a sensing mass made of a ferromagnetic material and attractable by the magnet, a sleeve made of a paramagnetic material and restricting the movement of the sensing mass in one direction, a pair of strips that make a closed circuit by contact with the sensing mass having moved in one direction and a body fitted with the magnet and housing the sensing mass, the sleeve and the contacts; the crash sensor further comprising a magnetic shield made of a ferromagnetic material and covering the magnet and the body. The magnetic shield forms a closed-type magnetic field by covering the magnet and the body and forms an appropriate magnetic loop in the vicinity of the sensing mass, so that the crash sensor also acts as a magnetic shield to protect itself from being influenced by outside ferromagnetic bodies and makes effective use of the magnetic force of the magnet.