Abstract: A valve device (100) includes an operation shaft (50) operable to be moved along a rotation axis A1 of an operation pin (40) to be switched between a coupled state in which the operation shaft (50) is coupled to the operation pin (40) and rotates together with the operation pin (40), and an uncoupled state in which the operation shaft (50) is not coupled to the operation pin (40) and supports the operation pin (40) such that the operation pin (40) is rotatable. The operation pin (40) is operable to be rotated about the rotation axis A1 such that a spool (20) is moved when the operation shaft (50) is rotated about the rotation axis A1 in the coupled state.

Abstract: A relief valve relieves hydraulic fluid from a first port to a second port, and includes a housing and an adjustment member capable of advancing and retracting; a seat member with a relief passage connecting to the two ports; a relief valve body that is unseated from or seated on the seat member to open or close the relief passage, and that receives pressure of the first port in a direction of opening the relief passage; a first biasing member that biases the relief valve body against the pressure of the first port, with a force adjusted by the adjustment member; a check valve body that opens or closes a check passage connecting to the two ports, and that receives pressure of the second port in a direction of opening the check passage; and a second biasing member that biases the check valve body.

Abstract: A valve device that changes the direction of flow of a hydraulic fluid supplied to and discharged from a cylinder mechanism to actuate the cylinder mechanism, the valve device including: a control valve including a main spool axially movable between different positions; a lock valve including a plunger and a pressure chamber; and a selector valve including a selector spool operable in conjunction with the main spool to axially move between different positions, the selector spool being located adjacent to the main spool and having an axis crossing an axis of the main spool.

Abstract: A solenoid flow control valve includes: an inlet passage that allows an inlet port to communicate with a pilot pressure chamber; an outlet passage that allows the pilot pressure chamber to communicate with an outlet port; a fixed restrictor provided on the outlet passage; a pilot spool that closes the inlet passage when a solenoid is in a non-excitation state, whereas when solenoid is in an excitation state, opens inlet passage at an opening degree corresponding to an input current value to generate a pilot pressure corresponding to the input current value in pilot pressure chamber, the pilot spool opening a bypass passage when input current value is less and closes bypass passage when input current value is greater than or equal to the predetermined value; and a main spool that controls a flow rate from inlet to outlet port in accordance with the pilot pressure chamber's pilot pressure.

Abstract: A valve device includes: a pilot chamber cover to which pilot pressure is introduced, the pilot chamber cover including a through hole extending in a direction intersecting with an axial direction of the spool; an operating pin configured to swing with movement of the spool in the axial direction; a rotating shaft configured to turn with swinging of the operating pin; a coupling plug coupled to the rotating shaft, a part of the coupling plug inserted into the through hole, the coupling plug being configured to switch between a coupled state where rotational force of the rotating shaft is transmitted to the coupling plug and a canceled state where the transmission of the rotational force of the rotating shaft to the coupling plug is canceled; an operating lever coupled to the coupling plug; and a sealing member between an inner peripheral surface of the through hole and the coupling plug.

Abstract: A valve device that changes the direction of flow of a hydraulic fluid supplied to and discharged from a cylinder mechanism to actuate the cylinder mechanism, the valve device including: a control valve including a main spool axially movable between different positions; a lock valve including a plunger and a pressure chamber; and a selector valve including a selector spool operable in conjunction with the main spool to axially move between different positions, the selector spool being located adjacent to the main spool and having an axis crossing an axis of the main spool.

Abstract: A solenoid flow control valve includes: an inlet passage that allows an inlet port to communicate with a pilot pressure chamber; an outlet passage that allows the pilot pressure chamber to communicate with an outlet port; a fixed restrictor provided on the outlet passage; a pilot spool that closes the inlet passage when a solenoid is in a non-excitation state, whereas when solenoid is in an excitation state, opens inlet passage at an opening degree corresponding to an input current value to generate a pilot pressure corresponding to the input current value in pilot pressure chamber, the pilot spool opening a bypass passage when input current value is less and closes bypass passage when input current value is greater than or equal to the predetermined value; and a main spool that controls a flow rate from inlet to outlet port in accordance with the pilot pressure chamber's pilot pressure.

Abstract: A valve device includes main valve element and pilot valve element. The main valve element divides valve element space of housing into first pressure chamber and second pressure chamber. The pilot valve element is provided in the second pressure chamber. In one example, first pilot passage including first restrictor extends from primary passage to the second pressure chamber, and second pilot passage including second restrictor is formed at the main valve element. The main valve element and the pilot valve element are coupled to each other by pin, and gap is formed between the pin and one of the main valve element and the pilot valve element. The pilot valve element opens and closes the second pilot passage by biasing member and drive mechanism. The main valve element is driven so as to open the secondary passage by differential pressure between the first pressure chamber and the second pressure chamber.

Abstract: Provided is a configuration in which: a spool driven by an electromagnetic proportional solenoid is urged by a spool-returning spring configured to exert urging force in an opposite direction to a driving direction of the electromagnetic proportional solenoid; a mechanical stopper is disposed at the stroke end of the spool; current dither causes a control current to micro-vibrate, the control current driving the electromagnetic proportional solenoid; and the mechanical stopper includes a stopper-urging spring configured to allow the spool to vibrate owing to the current dither even when the spool is in contact with the mechanical stopper. A proportional solenoid control valve with this configuration is capable of reducing hysteresis at the stroke end of the spool by means of the current dither, and controlling the spool in a stable manner over the entire control range including the stroke end of the spool.

Abstract: A sintered ferrite magnet having a ferrite phase with a hexagonal structure as the main phase, wherein the composition of the metal elements composing the main phase is represented by the following general formula (1): RxCamA1?x?m(Fe12?yMy)z: ??(1), x, m, y and z in formula (1) satisfying all of the conditions represented by the following formulas (2)-(6): 0.2?x?0.5: ??(2) 0.13?m?0.41: ??(3) 0.7x?m?0.15: ??(4) 0.18?yz?0.31: ??(5) 9.6?12z?11.8: ??(6), and wherein the density of the sintered ferrite magnet is at least 5.05 g/cm3, and the crystal grains of the sintered ferrite magnet satisfy all of the conditions represented by the following formulas (7) and (8), where L ?m is the average for the maximum value and S ?m is the average for the minimum value among the diameters passing through the center of gravity of each grains in the crystal cross-section parallel to the c-axis direction of hexagonal structures. L?0.95: ??(7) 1.8?L/S?2.5: ??(8).

Abstract: An image forming apparatus, wherein the packing density at a closest point where the first peripheral surface and the second peripheral surface are the closest to each other is within a range from 0.3 to 0.4; wherein a maximum magnetic flux density of a principal magnetic pole for generating the magnetic field for development is located in an upstream side from the closest point with respect to the specified direction and at a point where the packing density is equal to or greater than 0.2; and wherein a magnetic flux density of the principal magnetic pole at a point where the packing density is 0.2 in a downstream side from the closest point with respect to the specified direction is equal to or less than ½ of a magnetic flux density of the principal magnetic pole at a point where the packing density is 0.2 in the upstream side.

Abstract: Provided is a configuration in which: a spool driven by an electromagnetic proportional solenoid is urged by a spool-returning spring configured to exert urging force in an opposite direction to a driving direction of the electromagnetic proportional solenoid; a mechanical stopper is disposed at the stroke end of the spool; current dither causes a control current to micro-vibrate, the control current driving the electromagnetic proportional solenoid; and the mechanical stopper includes a stopper-urging spring configured to allow the spool to vibrate owing to the current dither even when the spool is in contact with the mechanical stopper. A proportional solenoid control valve with this configuration is capable of reducing hysteresis at the stroke end of the spool by means of the current dither, and controlling the spool in a stable manner over the entire control range including the stroke end of the spool.

Abstract: An image forming apparatus for forming a toner image on a print medium with a developer composed of toner and carriers, wherein when the first distance is longer than the second distance, an average gap between the first peripheral surface and a member that faces to the first peripheral surface in an area with a length of the first distance extending upstream from the closest point with respect to the specified direction is smaller than an average gap between the first peripheral surface and a member that faces to the first peripheral surface in an area with a length of the first distance extending downstream from the closest point with respect to the specified direction.

Abstract: A two-component developing device using a developer containing toner and magnetic carrier particles. The developing device comprises a housing, a developing roller, a magnetic field generator mounted inside the developing roller, and a developer restricting member, and further comprises a developer guide member providing a developer guide path for guiding the developer to the developer amount restricting clearance, providing a developer circulation path for circulating the developer to an upstream end of the guide member, and providing a communication path for bringing the developer guide path into communication with the developer circulation path, an upstream end of the guide member being positioned above the position of a peak of magnetic flux density of the magnetic pole of the magnetic field generator which is closest to a low-magnetic force area downstream of the low-magnetic force area or positioned upstream of such a position and downstream of the low-magnetic force area.

Abstract: A pressure compensated electromagnetic proportional directional flow control valve of the present invention integrally includes: an electromagnetic proportional directional flow control valve configured to be driven by a solenoid; and a pressure compensated valve configured to carry out pressure compensation of a flow rate controlled by the electromagnetic proportional directional flow control valve. A pressure compensation spool moves so as to balance forces of a spring, a first pressure chamber, and a second pressure chamber. With this, the pressure compensation for maintaining a constant pressure difference between an upstream side and a downstream side of a first variable aperture can be carried out, and a surplus liquid of a liquid flowing from a liquid-pressure supply port to a derivation port can flow out from a branch port to outside.

Abstract: A hybrid developing carrier, comprising a resin layer formed on an outermost surface, wherein the surface of said resin layer is provided with sites formed of an inorganic compound having basic points or acidic points and sites where the resin forming the resin layer is exposed, a hybrid developing device equipped with the hybrid developing carrier, and an image-forming apparatus equipped with the hybrid developing device.

Abstract: A holding control valve of the present invention is configured such that: a spool is configured to perform strokes by a piston configured to operate by introduction of pilot pressure and have a larger diameter than the spool; the piston is divided into a pilot piston configured to receive the pilot pressure and a relief operation piston disposed adjacent to the spool to receive pressure of relief oil discharged when a relief valve operates; and the relief oil is introduced to between the pilot piston and the relief operation piston.

Abstract: An image forming apparatus, wherein the packing density at a closest point where the first peripheral surface and the second peripheral surface are the closest to each other is within a range from 0.3 to 0.4; wherein a maximum magnetic flux density of a principal magnetic pole for generating the magnetic field for development is located in an upstream side from the closest point with respect to the specified direction and at a point where the packing density is equal to or greater than 0.2; and wherein a magnetic flux density of the principal magnetic pole at a point where the packing density is 0.2 in a downstream side from the closest point with respect to the specified direction is equal to or less than ½ of a magnetic flux density of the principal magnetic pole at a point where the packing density is 0.2 in the upstream side.

Abstract: An image forming apparatus for forming a toner image on a print medium with a developer composed of toner and carriers, wherein when the first distance is longer than the second distance, an average gap between the first peripheral surface and a member that faces to the first peripheral surface in an area with a length of the first distance extending upstream from the closest point with respect to the specified direction is smaller than an average gap between the first peripheral surface and a member that faces to the first peripheral surface in an area with a length of the first distance extending downstream from the closest point with respect to the specified direction.

Abstract: A two-component developing device using a developer containing toner and magnetic carrier particles. The developing device comprises a housing, a developing roller, a magnetic field generator mounted inside the developing roller, and a developer restricting member, and further comprises a developer guide member providing a developer guide path for guiding the developer to the developer amount restricting clearance, providing a developer circulation path for circulating the developer to an upstream end of the guide member, and providing a communication path for bringing the developer guide path into communication with the developer circulation path, an upstream end of the guide member being positioned above the position of a peak of magnetic flux density of the magnetic pole of the magnetic field generator which is closest to a low-magnetic force area downstream of the low-magnetic force area or positioned upstream of such a position and downstream of the low-magnetic force area.