Abstract: A work machine pump control system includes: a pump horsepower control valve (22) which causes a first urging force determining a limited horsepower (F) of a hydraulic pump and a second urging force due to a delivery pressure of the hydraulic pump to act on a spool in opposition to each other and which controls the pump flow rate such that it does not exceed the limited horsepower (F); a target pump flow rate computation section (42) computing a target pump flow rate based on an operation pressure (px) and a load pressure (py); a target horsepower computation section (41) which computes a required horsepower (Freq) corresponding to an operation pressure (px) from a relationship related to the operation pressure (px) and which computes a target horsepower (Ftar) based on the required horsepower (Freq); and a pump horsepower control section (35) which controls the pump horsepower control valve (22) such that the target pump flow rate (Qtar) is delivered with the limited horsepower (F) determined by the pump hor

Abstract: Provided is a material having an excellent sound-absorbing performance which can be easily applied to the desired area at the operation site and which can effectively prevent sound leakage The material includes a 2-part reactive urethane resin composition prepared from a polyisocyanate component and a polyol-containing component, wherein the polyol-containing component comprises a polyol component (a), catalysts (b), a foam stabilizer (c), an amine compound having primary or secondary amino groups (d), and carbon dioxide (e). The 2-part reactive urethane resin composition, when cured, is an open-cell soft polyurethane foam, wherein the average sound absorption coefficient of said polyurethane foam is 30% or more, measured in accordance with JIS A 1405-2:2007 for 63 hertz to 5000 hertz.

Abstract: The present invention is to provide a composition which can easily form a polyurethane resin which exerts particularly excellent damping properties in an operating temperature range. A resin composition for damping materials, including a polyol-containing component (A) and a polyisocyanate (B) is provided. The polyol-containing component (A) contains a castor oil. When the composition is cured, the peak on its Tan ? curve is 0.7 or more and the temperature for the peak is in a range of ?10° C. to 100° C.

Abstract: A hydraulic excavator (1) includes a hydraulic pump (22) driven by an engine (20), an electromagnetic proportional valve (24) for hydraulic pump that adjusts pump torque of the hydraulic pump (22) in response to a pump torque target value (Tp), a hydraulic actuator operated by a delivery pressure of the hydraulic pump (22), a motor generator (30) connected to the engine (20), and a controller (26) configured to calculate the pump torque target value (Tp). The controller (26) acquires a pump torque adjustment amount (Qadj) based on a deviation (?AH) between a current integrating value (AH1) acquired by integrating a value of a current flowing into the motor generator (30) when the hydraulic actuator is driven and a current integrating reference value (AH0).

Abstract: An output command calculating section (40) of an HCU (36) restricts a battery discharge power from an electricity storage device (31) based upon a battery electricity storage rate (SOC) and a current square integrating rate (Risc) of the electricity storage device (31). Thereby, the HCU (36) transfers from a normal mode (NMODE) to a low speed mode (LSMODE) to lower a movement speed of a hydraulic actuator. A monitor display amount calculating section (50) of the HCU (36) calculates a maximum speed reduction rate (DRs) based upon a battery discharge power limit value (Plim0) and an engine output upper limit value (Pemax) from the output command calculating section (40). A monitor device (39) displays a reduction rate of the movement speed of the hydraulic actuator in the low speed mode (LSMODE) based on the maximum speed reduction rate (DRs).

Abstract: A work machine includes directional control valves 43 and 44 each controlling a direction and a flow rate of a pressurized fluid supplied to each a boom cylinder 32 and a bucket cylinder 36; operation amount sensors 51a, 52a, and 52b detecting operation amounts of operation devices 51 and 52; a variable flow control valve 45 that can restrict the flow rate of the pressurized fluid in a meter-in passage of the directional control valve 44 related to the bucket cylinder 36; and a controller 60 controlling the variable flow control valve on the basis of the detection results by the operation amounts from the operation amount sensors, and the controller changes over an action mode to any one of a normal mode for restricting the flow rate of the pressurized fluid by the variable flow control valve and a responsiveness priority mode for not restricting the flow rate of the pressurized fluid by the variable flow control valve in response to the detection results of the operation amounts of the plurality of operation

Abstract: A hydraulic excavator is equipped with: an arm cylinder driven by a hydraulic working fluid from a hydraulic pump; a meter-out passage through which the hydraulic working fluid discharged from the arm cylinder flows; a control valve controlling the hydraulic fluid flow rate of the meter-out passage; a pressure sensor detecting a load acting on the arm cylinder; a pressure sensor detecting an operation amount of an operation device operating the arm cylinder; and a controller. The controller alternatively selects a normal operation mode in which the opening area of the control valve is controlled based on an actuator load and the operation amount, and a substitution operation mode in which the opening area of the control valve is controlled based on the operation amount. When the substitution operation mode is selected, a delivery flow rate of the hydraulic pump is further increased as compared with the normal operation mode.

Abstract: It becomes possible to prevent deterioration of an electric storage device due to overdischarge of the electric storage device and engine stalling due to insufficient assist or disabled assist when a charge amount of the electric storage device falls, ensure that work is continuously conducted, suppress an operator from feeling discomfort in operation, and ensure favorable operability. A pump target output power computing section (21) computes present pump demanded power on the basis of work related information, limits the present pump demanded power in response to a degree of reduction of a state of charge of an electric storage device (12a) when the state of charge is lower than a preset threshold, and computes the limited present pump demanded power as present pump target output power.

Abstract: A work machine pump control system includes: a pump horsepower control valve (22) which causes a first urging force determining a limited horsepower (F) of a hydraulic pump and a second urging force due to a delivery pressure of the hydraulic pump to act on a spool in opposition to each other and which controls the pump flow rate such that it does not exceed the limited horsepower (F); a target pump flow rate computation section (42) computing a target pump flow rate based on an operation pressure (px) and a load pressure (py); a target horsepower computation section (41) which computes a required horsepower (Freq) corresponding to an operation pressure (px) from a relationship related to the operation pressure (px) and which computes a target horsepower (Ftar) based on the required horsepower (Freq); and a pump horsepower control section (35) which controls the pump horsepower control valve (22) such that the target pump flow rate (Qtar) is delivered with the limited horsepower (F) determined by the pump hor

Abstract: The Construction machinery includes at least two actuators, a main pump that generates hydraulic energy for driving the actuators, control valves disposed between the main pump and the actuators, a hydraulic pump motor driven by the generator motor that generates energy to be added to the hydraulic energy, and a controller that reduces hydraulic energy generated by the main pump when the hydraulic pump motor driven by the generator-motor generates energy. The construction machinery further comprises changeover valves that selectively change a location at which the energy from the hydraulic pump motor driven by the generator-motor is to be added according to the actuators. The controller changes a reduction rate of the hydraulic energy generated by the main pump depending on a specific actuator to which the energy is to be added.

Abstract: A construction machine capable of achieving favorable operability in a combined operation is provided. A hybrid excavator includes: a boom cylinder 10 driven by hydraulic fluid from a hydraulic pump 16b; a swing hydraulic motor 5 driven by hydraulic fluid from the hydraulic pump 16b; a swing electric motor 6 connected mechanically with the swing hydraulic motor 5; an inverter 19 that controls operation of the swing electric motor 6; and a controller 21 that outputs to the inverter 19 a torque command value for controlling electric driving torque or electricity generating torque of the swing electric motor 6.

Abstract: An outer side wall includes a bent sealing portion bent so as to be raised toward the inside of a cabin. When a window glass is closed, the bent sealing portion is elastically deformed so as to stretch along the outer surface of the window glass. The outer surface of the bent sealing portion is provided with a soft portion made of a softer material than the outer side wall.

Abstract: Disclosed is a technique of narrowing a trim strip and improving ease of assembly. A boundary portion between upper and outer plate portions in the cross-section of a core is curved to have a large curvature. An outer portion of a glass run body is provided with an upper elastic protrusion engaging with an upper engagement portion of the trim strip. A gap is formed between an upper part of the outer portion of the glass run body and an upper portion of the trim strip. The gap allows the trim strip to move excessively toward the inside of a cabin.

Abstract: A hybrid work machine that can suppress excessive limiting on pump absorption power even in a situation in which supply of electric power to an electric motor is limited is provided. The hybrid work machine includes: an engine 22; an assist generator motor 23 connected to the engine 22 in such a manner that a torque can be transmitted to the engine 22; an electric storage device 24 that supplies electric power to the assist generator motor 23; a monitoring device 28 that monitors the electric storage device 24 and that acquires electric storage device information; a hydraulic pump 41 driven by the engine 22 and the assist generator motor 23; and a pump regulator 43 that regulates a delivery flow rate of the hydraulic pump 41.

Abstract: The hydraulic fluid energy recovery apparatus includes a fluid communication line for holding a bottom-side hydraulic fluid chamber and a rod-side hydraulic fluid chamber of a hydraulic cylinder in fluid communication with each other, a fluid communication valve connected to the fluid communication line for adjusting the pressure and/or flow rate of a hydraulic fluid passing through the fluid communication line in a manner that allows for adjustment of a degree of opening of the fluid communication valve, first pressure detecting means for detecting a signal indicative of pressure at the bottom-side hydraulic fluid chamber of the hydraulic cylinder, an amount-of-operation detecting means for detecting an amount of operation of the operating means, and a control device for capturing the signal of pressure at the bottom-side hydraulic fluid chamber of the hydraulic cylinder detected by the first pressure detecting means.

Abstract: A hybrid work machine has an engine, an assist motor, a hydraulic pump which is driven by the total torque of the engine and the assist motor, and an electric storage device which accumulates electric power generated by the assist motor and supplies the electric power when the assist motor performs electric discharge. The continuous electric discharge from the electric storage device due to continuous operation at high load pressure can be suppressed without an operator experiencing an unusual operational characteristic. To this end, a pump flow rate correction control unit judges whether each hydraulic pump is in a high load operation state or not based on the output horsepower and/or the delivery pressure of each hydraulic pump and performs control such that the delivery flow rate gradually decreases when the hydraulic pump is in the high load operation state and this state continues beyond a predetermined time.

Abstract: A construction machine includes: a swing structure (50); a hydraulic pump (1); a hydraulic motor (3) for driving the swing structure (50) using hydraulic fluid from the hydraulic pump (1); an electric motor (14) for driving the swing structure (50) with or without the aid of the hydraulic motor (3); and a hydraulic actuator (16) driven by the hydraulic fluid from the hydraulic pump 1, the hydraulic actuator can be operated together with the swing structure (50). When the swing structure (50) is operated together with the hydraulic actuator (16), only the electric motor (14) is used to swing the swing structure (50).

Abstract: This invention provides a hybrid construction machine including a swing structure, a hydraulic pump, a hydraulic swing motor driving the swing structure using hydraulic fluid from the hydraulic pump, an electric swing motor driving the swing structure in conjunction with the hydraulic swing motor, a boom cylinder operated simultaneously with the swing structure at times and driven by the hydraulic fluid from the hydraulic pump, a first directional control valve controlling flow of the hydraulic fluid supplied from the hydraulic pump to the hydraulic swing motor, a second directional control valve controlling the flow of the hydraulic fluid returning from the hydraulic swing motor, and a controller and solenoid pressure reducing valves which prevent operation of the second directional control valve when the boom cylinder is operated simultaneously with the swing structure.

Abstract: The first engine speed or a work machine is higher than the minimum engine speed, and the second engine speed is higher than the first engine speed and lower than the maximum engine speed. The ratio of the change in the target engine speed to the change in the operation amount of the engine speed instructing device when the operation amount of the engine speed instructing device is changed from the operation amount for instructing the minimum speed to the operation amount for instructing the first engine speed is larger than the ratio of the change in the target engine speed to the change in the operation amount of the engine speed instructing device when the operation amount of the engine speed instructing device is changed from the operation amount for instructing the second engine speed to the operation amount for instructing the maximum speed.

Abstract: A hydraulic excavator is equipped with: an arm cylinder driven by a hydraulic working fluid from a hydraulic pump; a meter-out passage through which the hydraulic working fluid discharged from the arm cylinder flows; a control valve controlling the hydraulic fluid flow rate of the meter-out passage; a pressure sensor detecting a load acting on the arm cylinder; a pressure sensor detecting an operation amount of an operation device operating the arm cylinder; and a controller. The controller alternatively selects a normal operation mode in which the opening area of the control valve is controlled based on an actuator load and the operation amount, and a substitution operation mode in which the opening area of the control valve is controlled based on the operation amount. When the substitution operation mode is selected, a delivery flow rate of the hydraulic pump is further increased as compared with the normal operation mode.