A solenoid proportional relief valve includes: a joint in which the flow path is disposed; a coil wound to be energized; a needle supported movably along an axial direction of the coil; and a stator generating an attraction force on the needle by excitation of the coil, the needle being formed into a bottomed cylinder having a wall portion and a bottom portion and configured as a biasing member accommodation space accommodating a biasing member in a state where a resilient force is generated in an inner cylindrical portion, an inner surface of the bottom portion being configured as a force receiving section for the biasing member, and the valve body being formed integrally with an outer surface of the bottom portion.
F15B 13/043 - Dispositifs de distribution ou d'alimentation du fluide caractérisés par leur adaptation à la commande de servomoteurs pour utilisation avec un servomoteur unique actionnés par la pression du fluide avec clapets-pilotes commandés électriquement
A directional control valve includes: a housing having a cylindrical spool hole communicating with an inlet port letting a fluid from an external supply source at a predetermined pressure and an outlet port flowing the fluid to a working cylinder; a spool movable in the spool hole axially and changing an amount of flow of the fluid; a first solenoid driving section having a first needle coupled to or integral with a first end portion of the spool and driving the spool; and a second solenoid driving section having a second needle coupled to or integral with a second end portion of the spool and driving the spool, the directional control valve including a pressure equalization circuit equally applying a pressure to the end portions.
F16K 31/06 - Moyens de fonctionnementDispositifs de retour à la position de repos électriquesMoyens de fonctionnementDispositifs de retour à la position de repos magnétiques utilisant un aimant
F16K 11/07 - Soupapes ou clapets à voies multiples, p. ex. clapets mélangeursRaccords de tuyauteries comportant de tels clapets ou soupapesAménagement d'obturateurs et de voies d'écoulement spécialement conçu pour mélanger les fluides dont toutes les faces d'obturation se déplacent comme un tout comportant uniquement des tiroirs à éléments de fermeture glissant linéairement à glissières cylindriques
This power steering valve (1) includes a sleeve (40), a spool (60) held in such a way as to be able to rotate within the housing (40), to which an input shaft U of a steering wheel S is coupled, a gerotor (30) fixed to the sleeve (10) and configured to be driven by hydraulic fluid which flows out from the predetermined opening of the sleeve (40), and a drive shaft (80) meshing with an inner rotor (32) of the gerotor (30) and pivotally supported in a swingable manner by the sleeve (40) with use of a pin (81), wherein an overall length Ld of the drive shaft (80) is formed to have a dimension defined by (¼)·Ls≤Ld≤(½)·Ls relative to an overall length Ls of the sleeve (40), and the pin (81) is arranged at a position nearer the gerotor (30) in an axial direction than a middle position in the sleeve (40).
B62D 5/097 - Télémoteur actionné par le mouvement du volant de direction du type "gérotor"
B62D 5/06 - Direction assistée ou à relais de puissance à fluide, c.-à-d. au moyen d'un fluide sous pression produisant toute la force nécessaire, ou la plus grande partie de celle-ci, pour commander la direction du véhicule
Provided is a power steering valve (1) which is compact in comparison to conventional power steering valves. The power steering valve (1) is provided with: a circular cylindrical sleeve (40) having a predetermined opening, the circular cylindrical sleeve (40) being held within a housing (10) so as to be capable of pivoting; a circular cylindrical spool (60) having a predetermined axial groove, the circular cylindrical spool (60) being held within the sleeve (40) so as to be capable of pivoting, the circular cylindrical spool (60) having connected thereto an input shaft U for steering S; a gerotor (30) affixed to the housing (10) and driven by operating oil flowing from the predetermined opening in the sleeve (40); and a drive shaft (80) with which the inner rotor (32) of the geroter (30) meshes and which is supported by the sleeve (40) in a rockable manner by means of a pin (81). The drive shaft (80) is formed so that the overall length Ld thereof relative to the overall length Ls of the sleeve (40) is in the range of (1/4)∙Ls ≤ Ld ≤ (1/2)∙Ls, and the pin (81) is disposed in the sleeve (40) at a position axially closer to the gerotor (30) than a center position.
B62D 5/097 - Télémoteur actionné par le mouvement du volant de direction du type "gérotor"
B62D 5/09 - Direction assistée ou à relais de puissance à fluide, c.-à-d. au moyen d'un fluide sous pression produisant toute la force nécessaire, ou la plus grande partie de celle-ci, pour commander la direction du véhicule caractérisée par les moyens d'actionnement des valves
A hydraulic driving device of an industrial vehicle includes: a tank which stores hydraulic oil; a hydraulic pump which includes a suction port sucking the hydraulic oil and a discharge port discharging the hydraulic oil; a hydraulic cylinder which is driven by the hydraulic oil discharged from the discharge port of the hydraulic pump; a direction switching valve which is disposed among the hydraulic pump, the tank, and the hydraulic cylinder and switches a hydraulic oil flow direction in response to an operation state of operation means for driving the hydraulic cylinder; in which the direction switching valve includes a main spool which moves in response to the operation state of the operation means and a flow regulator which is disposed inside the main spool to control a flow rate of the hydraulic oil flowing from the hydraulic cylinder to the tank.
F15B 13/04 - Dispositifs de distribution ou d'alimentation du fluide caractérisés par leur adaptation à la commande de servomoteurs pour utilisation avec un servomoteur unique
F15B 11/10 - Systèmes de servomoteurs dépourvus d'asservissement avec un seul servomoteur dans lesquels la position du servomoteur est fonction de la pression
F15B 11/16 - Systèmes de servomoteurs dépourvus d'asservissement avec plusieurs servomoteurs
F15B 13/042 - Dispositifs de distribution ou d'alimentation du fluide caractérisés par leur adaptation à la commande de servomoteurs pour utilisation avec un servomoteur unique actionnés par la pression du fluide
F15B 13/06 - Dispositifs de distribution ou d'alimentation du fluide caractérisés par leur adaptation à la commande de servomoteurs pour utilisation avec plusieurs servomoteurs
F16K 11/07 - Soupapes ou clapets à voies multiples, p. ex. clapets mélangeursRaccords de tuyauteries comportant de tels clapets ou soupapesAménagement d'obturateurs et de voies d'écoulement spécialement conçu pour mélanger les fluides dont toutes les faces d'obturation se déplacent comme un tout comportant uniquement des tiroirs à éléments de fermeture glissant linéairement à glissières cylindriques
When an engine stall is likely to occur, the pressure of the back pressure chamber of a relief pressure valve is released to adjust the relief pressure of the relief pressure valve. This actuates a pressure compensating circuit to release the pressure in a control circuit to an oil tank. Thus, a rapid increase of the pressure due to a cargo handling operation is restricted, and an engine stall due to insufficient torque of the engine is avoided.
An industrial vehicle includes a hydraulic brake device, a hydraulic load handling device, a first hydraulic circuit, a second hydraulic circuit, a pressure compensating circuit, and a controller. The controller sets an electromagnetic valve to a first position during operation of the load handling device. The controller sets the electromagnetic valve to a second position and controls an electric motor to drive a hydraulic pump when determining that pressure needs to be accumulated in a hydraulic accumulator based on a detection result of a detector. When the electromagnetic valve is at the second position, hydraulic pressure generated by driving the hydraulic pump is applied to a pressure compensating valve and produces a force acting in a direction to disconnect the hydraulic pump and an oil tank from each other, so that hydraulic pressure is generated in a first oil passage to be accumulated in the hydraulic accumulator.
F15B 1/033 - Installations ou systèmes comprenant des accumulateurs comportant des dispositifs de remplissage des accumulateurs avec des moyens de commande électriques
F15B 11/17 - Systèmes de servomoteurs dépourvus d'asservissement avec plusieurs servomoteurs utilisant plusieurs pompes
F15B 13/06 - Dispositifs de distribution ou d'alimentation du fluide caractérisés par leur adaptation à la commande de servomoteurs pour utilisation avec plusieurs servomoteurs
A hydraulic mechanism is mounted on a forklift. The hydraulic mechanism has a control valve and a pressure compensation circuit for compensating pressure within the hydraulic mechanism. The pressure compensation circuit has a relief pressure valve and an unloading valve for releasing pressure within the pressure compensation circuit to a discharge oil passage. Upon instructed to perform cargo handling operation, the unloading valve is switched to an open state, and the relief pressure valve is thereby actuated, so that rapid increase of pressure within the circuit is avoided. Further, the unloading valve is switched to an open state, and the pressure within the hydraulic mechanism is thereby released to the discharge oil passage, so that the cargo handling operation by the tilt cylinder and the lift cylinder is restricted.
A hydraulic control device for a forklift includes a hydraulic pump, a single electric motor for driving the hydraulic pump, an outflow control mechanism provided between a lift cylinder and the hydraulic pump, a flow control valve provided between the outflow control mechanism and a draining portion, and a controller. When a lowering operation of a fork and either forward or rearward mast tilting operations of a mast are performed at the same time, the controller controls the electric motor based on a target speed of the hydraulic pump. The flow control valve controls the flow rate of hydraulic fluid from the lift cylinder to the hydraulic pump and the flow rate from the lift cylinder to the draining portion in accordance with the difference between the actual rotation speed of the hydraulic pump and the target rotation speed of the hydraulic pump.
F15B 11/044 - Systèmes comportant essentiellement des moyens particuliers pour commander la vitesse ou la puissance d'un organe de sortie pour commander la vitesse par des moyens de commande situés dans le circuit de retour
E02F 9/22 - Entraînements hydrauliques ou pneumatiques
F15B 11/042 - Systèmes comportant essentiellement des moyens particuliers pour commander la vitesse ou la puissance d'un organe de sortie pour commander la vitesse par des moyens de commande situés dans le circuit d'alimentation
This hydraulic control device for a forklift includes a hydraulic pump, a single electric motor for driving the hydraulic pump, an outflow control mechanism provided between a lift cylinder and the hydraulic pump, a flow rate control valve provided between the outflow control mechanism and a drain unit, and a control unit. When a lowering operation for a fork and either a forward or a rearward tilting operation for a mast are performed at the same time, the control unit controls the electric motor on the basis of a target speed of the hydraulic pump that is necessary for causing operation at an instructed speed that is in accordance with the operation amount of a raising/lowering instruction member or the operation amount of a tilting instruction member. The flow rate control valve controls the flow rate of hydraulic oil from the lift cylinder to the hydraulic pump and the flow rate from the lift cylinder to the drain unit in accordance with the difference between the actual speed of the hydraulic pump and the target speed of the hydraulic pump that is necessary for lowering at the instructed speed for the operation amount of the raising/lowering instruction member.
A flow divider includes a spool for distributing fluid from a supply flow path to priority and surplus flow paths. First and second surplus restrictions vary flow rate in accordance with the movement of the spool and restrict the flow rate to the surplus flow path respectively from first and second supply passages. The second surplus restriction is formed to restrict the flow rate in at least two steps. The spool includes a cross-sectional area changing portion located at a position corresponding to the second surplus restriction. Therefore, the circuit structure is prevented from becoming complicated and the fluid force acting as a spool urging force is suppressed.
F16K 11/07 - Soupapes ou clapets à voies multiples, p. ex. clapets mélangeursRaccords de tuyauteries comportant de tels clapets ou soupapesAménagement d'obturateurs et de voies d'écoulement spécialement conçu pour mélanger les fluides dont toutes les faces d'obturation se déplacent comme un tout comportant uniquement des tiroirs à éléments de fermeture glissant linéairement à glissières cylindriques
12.
Hydraulic pressure control apparatus and hydraulic circuit
A supply passage, a discharge passage, an actuator passage, and a spool bore are defined in a housing. The spool bore accommodates a spool and communicates with the supply passage, the discharge passage, and the actuator passage. Load pressure detection circuit sections of load pressure detection circuit are provided in correspondence with two switch. Each of the load pressure detection circuit sections detects load pressure when the actuator passage is connected to the supply passage. Each load pressure detection circuit section is defined by a through hole provided in the housing and connected to the spool bore. Check valves are each arranged in a corresponding one of the load pressure detection circuit sections. This simplifies the configuration of each load pressure detection circuit 21 and saves the space for arranging the load pressure detection circuit 21., resulting in a relatively compact housing.
F15B 13/04 - Dispositifs de distribution ou d'alimentation du fluide caractérisés par leur adaptation à la commande de servomoteurs pour utilisation avec un servomoteur unique
A valve seat 20 is arranged between the supply circuit 8 and a downstream circuit 18. A valve body 21 blocks a fluid flow between the supply circuit 8 and the downstream circuit 18 by contacting the valve seat 20. The valve body 21 connects the supply circuit 8 to the downstream circuit 18 for supplying the fluid to the downstream circuit 18 by separating from the valve seat 20. A through hole 24 extends through the valve body 21 and thus defines a part of the supply circuit 8. The through hole 24 is defined in such a manner that the fluid that has flowed from the through hole 24 proceeds between the valve seat 20 and the valve body 21 and is thus supplied to the downstream circuit 18. The valve body 21 is formed in such a manner that a pressure receiving area at an upstream side of the through hole 24 is smaller than a pressure receiving area at a downstream side of the through hole 24. This reduces a pressure loss caused by the fluid passing through a backflow prevention structure that permits forward fluid flow from the supply circuit 8 to the downstream circuit 18 but prohibits backflow of the fluid.
A hydraulic control apparatus (1) includes a switch valve (11) , a valve support chamber (35) , a flow control valve (12) movable therein, an on-off valve (13) movable within a communication path chamber (12a) located inside the flow control valve (12)', and a valve control device 14. The on-off valve (13) can open and shut off a communication path X between a cylinder line (32) and a switch valve line (33) . A restrictor formed between the flow control valve (12) and a wall defining the valve support chamber (35) connects the cylinder line (32) and the communication path chamber (12a) . The restrictor opening is changed in correspondence with movement of the flow control valve (12) . When the switch valve (11) is located at the drainage position, the valve control device (14) applies a pilot pressure lower than the pressure in the cylinder line (32) to a back pressure chamber (12d) of the flow control valve (12) , thereby moving the on-off valve (13) in a direction for opening the communication path X.
F15B 11/04 - Systèmes comportant essentiellement des moyens particuliers pour commander la vitesse ou la puissance d'un organe de sortie pour commander la vitesse
F15B 11/044 - Systèmes comportant essentiellement des moyens particuliers pour commander la vitesse ou la puissance d'un organe de sortie pour commander la vitesse par des moyens de commande situés dans le circuit de retour
F15B 11/05 - Systèmes comportant essentiellement des moyens particuliers pour commander la vitesse ou la puissance d'un organe de sortie pour commander la vitesse spécialement adaptés pour maintenir une vitesse constante, p. ex. à compensation de pression, sensibles à la charge
F15B 13/04 - Dispositifs de distribution ou d'alimentation du fluide caractérisés par leur adaptation à la commande de servomoteurs pour utilisation avec un servomoteur unique
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