Abstract: Damage of elastic members provided at both ends of a filtration section can be prevented. A cylindrical filtration section and the annular elastic members provided at both ends of the filtration section are provided. A plate-like reinforcing plate is provided inside the elastic member. The reinforcing plate has an annular shape when viewed along an axis of the filtration section. Alternatively, a plurality of the reinforcing plates are disposed along a circle centered on the axis of the filtration section when viewed along the axis.

Abstract: A first differential pressure that is a differential pressure as a pressure difference between a high pressure side and a low pressure side in a filtration device is detected at a first time as a time while the filtration device filters a liquid. A remaining life that indicates how long the filtration member is usable from the first time is obtained based on the first differential pressure and differential pressure characteristics.

Abstract: A backflow of liquid inside a filter device during an operation of an internal combustion engine is allowed to be obviated while air inside the filter device is purged so as not to generate bubbles in the liquid. An outflow portion that includes a cylindrical portion having a substantially bottomed cylindrical shape and a back pressure valve provided inside the cylindrical portion is provided so as to penetrate a bottom surface of a case. In addition, a lid body provided on the case and an upper plate of a filter element so as to cover an upper end of the case has a first hole that communicates between a space inside the case and a space outside the case. When the back pressure valve opens (a valve body does not abut on a first valve seat), a space inside the filter element communicates with the space outside the case via a second through-hole formed in a side surface of the cylindrical portion.

Abstract: Inside a tank body storing a liquid, a return filter is provided protruding downward from an upper surface of the tank body, and a substantially plate-like (plate-shaped) float is also provided that is inserted into the tank body and floats in accordance with change in a liquid surface of the liquid stored in the tank body. The float is provided with an opening larger than a diameter of a filter case, and in a plan view, the float is disposed between the tank body and the filter case.

Abstract: An inner case being substantially cylindrical and being covered at an upper end is provided to cover a heater being substantially rod-shaped. A float being substantially plate-shaped and having substantially the same inner diameter as an inner diameter of the inner case is provided movably in the vertical direction in the inner case, and in the float, a hole through which the heater is inserted is formed. Gas is enclosed in a space surrounded by the inner case and the float. The length in the vertical direction of the inner case is smaller than the length in the vertical direction of the heater. In addition, when the float is positioned at a lower end of the inner case, a gap exists between the float and a bottom surface of a filter case.

Abstract: An IC tag is attached to a filter element and a contact of the IC tag with liquid is avoidable. An IC tag is provided inside an upper plate provided so as to cover an upper end surface of a filter medium in a filter element. A lid body is provided on the case into which the filter element is inserted, and an antenna is provided on the lid body.

Abstract: A head made of metal is provided covering an opening of a filter case, and a filtration member having a tubular shape is provided in an internal space formed by the filter case and the head. A plate made of metal is provided near the opening of the filter case, and an IC tag is provided between the filtration member and the plate. The head is provided with an antenna unit including an antenna section including an antenna configured to communicate with the IC tag. The antenna unit includes a case having a rod shape and at least partially inserted into the head, the antenna section is provided adjacent to a first end corresponding to one end of the case, the case is provided in the head such that the antenna section is exposed when the head is viewed from a side of the filter case, and the plate is provided with an aperture from which the IC tag is exposed.

Abstract: A measurement portion and an antenna are allowed to be provided in a filter device by simply mounting one member. An antenna unit that includes an antenna configured to communicate with an IC tag is provided in a vicinity of a first end face as one end of a case. A sensor is provided inside the case and a back side of the case with respect to the antenna unit.

Abstract: Air bubbles are removable with the use of an air vent structure having a compact and simple configuration. An air vent hole is formed in an upper plate that covers an entire upper end surface of a filtration section having a substantially tubular shape formed by bending a thin plate in a pleat shape. A moving member is provided to be movable between a position of closing the air vent hole and a position of opening the air vent hole.

Abstract: A filter device that facilitates maintenance is provided. A case that internally includes a filter element includes a lid body. The lid body includes a flange portion having a substantially cylindrical shape fixed to the case and a cover having a substantially plate shape detachably provided to the flange portion. The flange portion has a first hole, and the cover has a second hole. The first hole and the second hole communicate between a space inside the case and a space outside the case.

Abstract: A tank has two substantially parallel side surfaces, a tank first side surface and a tank second side surface, and the return filter is provided in the tank via an insertion hole formed in the tank first side surface. The strainer has one end provided on an outflow portion provided on a bottom surface of a filter case and the other end provided on the tank second side surface.

Abstract: An outflow portion that causes a space inside a filter element to communicate with a space outside a filter case includes an upper surface and a bottom surface that are provided so as to be separated from each other. The back pressure valve includes the valve body having the substantially plate-like shape and the elastic member provided between the bottom surface and the valve body. The valve body is movable between a closed position in which the valve body is in contact with the upper surface, and an open position in which the valve body is not in contact with the upper surface. A recessed portion is provided in a surface, of the valve body, that comes into contact with the upper surface, and an outflow port is formed in a side surface or the upper surface of the outflow portion.

Abstract: An upper plate provided on upper ends of a filtration member and an inner tube includes a tubular portion along the inner tube, a rib formed so as to protrude inward in a radial direction from an inner circumference of the tubular portion, and a hole formed in the rib. A gripping member has a protrusion portion that protrudes downward from a body portion having a thick plate shape inserted into a hollow portion of the tubular portion. When the gripping member is mounted on the upper plate, the protrusion portion is inserted into the hole.

Abstract: A first differential pressure that is a differential pressure as a pressure difference between a high pressure side and a low pressure side in a filtration device is detected at a first time as a time while the filtration device filters a liquid. A remaining life that indicates how long the filtration member is usable from the first time is obtained based on the first differential pressure and differential pressure characteristics.

Abstract: A differential pressure measurement range is widened and differential pressure can be measured particularly during low differential pressure. A first spool facing a space in a high pressure side is lighter than a second spool facing a space in a low pressure side in a state where a magnet is provided. Urging force of a first elastic member that urges the first spool toward the space in the high pressure side is smaller than urging force of a second elastic member that urges the second spool toward the space in the high pressure side, and the first elastic member and the second elastic member are disposed in series.

Abstract: A filter device allows avoiding liquid and dust before filtration to flow out to a tank during replacement of a filter element. A case includes a first tubular portion and a second tubular portion positioned with a lower side of the first tubular portion. The second tubular portion has a diameter smaller than that of the first tubular portion. In a state where the filter element is provided inside the case, a tubular portion of the filter element abuts on the second tubular portion. A part abutting on the second tubular portion of the tubular portion is absent of a hole. A part without abutment on the second tubular portion of the tubular portion has a plurality of holes.

Abstract: When a liquid flows into a case along a tangential direction at an arbitrary point on a side surface of a filter case from an inflow pipe provided substantially around an outer periphery, at the side surface of the filter case, a swirling flow is produced in the liquid flowed and air contained in a fluid is collected in a center portion of the swirling flow to generate bubbles. The inflow pipe and a filter element are positioned not to overlap each other in a height direction, whereby the liquid flows into a hollow portion of a filter element from a case while swirling. The bubbles generated in the center portion of the swirling flow are released to a space above a liquid surface of the fluid retained in a tank through an air outlet portion formed in an upper end surface or the side surface of the filter case.

Abstract: An air vent hole includes a substantially columnar hole main body portion, a first hole portion formed on the upper side of the hole main body portion, and a second hole portion formed on the lower side of the hole main body portion. Each of the first hole portion and the second hole portion partly has, in a cross section of the hole portion substantially orthogonal to a first direction that is a longitudinal direction of the hole main body portion, a cross-sectional area smaller than a cross-sectional area of a cross section of the hole main body portion substantially orthogonal to the first direction. A float inserted into the air vent hole is movable between a position where the float occludes the first hole portion and a position where the float occludes the second hole portion. The float occludes the first hole portion under the weight of the float. However, the float is pushed up by air. Furthermore, the float is formed of a material having a smaller specific gravity than a liquid to be filtered.

Abstract: A phosphorus adsorbent includes a carrier that is a carbonized organic substance and iron supported on the carrier. A method of producing the phosphorus adsorbent includes immersing an organic substance in a chemical solution containing iron ions and carbonizing the organic substance after the immersion.

Abstract: An IC tag is attached to a filter element and a contact of the IC tag with liquid is avoidable. An IC tag is provided inside an upper plate provided so as to cover an upper end surface of a filter medium in a filter element. A lid body is provided on the case into which the filter element is inserted, and an antenna is provided on the lid body.