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: 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: 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: 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: 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 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: 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 case that internally includes a filter element including a filtration member having a substantially cylindrical shape that filters the liquid and an inner tube having a substantially cylindrical shape provided inside the filtration member. The inner tube includes a partition plate that covers a hollow portion of a side surface. A heater provided on a bottom surface of the filter case includes a substantially rod-shaped heating unit. The heating unit is inserted into a space surrounded by the side surface and the partition plate of the inner tube via a first hole formed at a position overlapping with the hollow portion of the inner tube in the first plate that covers a lower end of the filtration member.

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 first plate of a filter element includes a first tubular portion having a substantially cylindrical shape that protrudes toward a lid member with the filter element inserted into a filter case. The first tubular portion includes first projections protruding outward in a radial direction. The lid member includes a second tubular portion inserted into a hollow portion of the first tubular portion. With the lid member attached to the first plate, the first projections are inserted into notches formed in ribs provided along an outer circumferential surface of the first tubular portion.

Abstract: A leakage of liquid inside a differential pressure detection device is reliably preventable. A diaphragm portion that detects a differential pressure as a pressure difference between a high pressure side and a low pressure side includes an annular member, a strain gauge provided in a hollow portion of the annular member, and a first plate and a second plate provided such that the annular member and the strain gauge are sandwiched. The first plate and the second plate each abut on a first annular packing. A first groove and a second groove (the first annular packing) overlap with the annular member when viewed from a first direction along an axis of the first hole.

Abstract: A protruding portion is formed on an inner tube inserted into a hollow portion of a filter medium so as to protrude upward from a flange portion. The flange portion having a substantially circular plate shape is disposed on a lower side of a second plate. A recessed portion into which the protruding portion is inserted is formed on a surface on a lower side of the second plate provided so as to cover an opening at a lower end of the filter medium.

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: A rod having a substantially-cylindrical shape with both ends being covered is provided to a lid body, which covers an upper end surface of a case having a bottomed substantially-cylindrical shape, the rod protruding in the case. A first hole is formed in a portion of a side surface of the rod, which is exposed to the inside of the case. Further, an air vent pit (passage) is formed in the lid body, and a second hole is formed in a portion of the side surface of the rod, which is exposed to the inside of the air vent pit. A moving member moves along the rod from a first position at which the moving member does not cover the first hole and a second position at which the moving member covers the first hole.

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 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 liquid surface height inside a tank is allowed to be confirmed while blow-back of a liquid is reduced. A strainer body having a substantially bottomed tubular shape has a substantially D shape when viewed in a longitudinal direction. A bottom surface of the strainer body has a shape in which a part of a conical shape is cut away, and a top of the substantially conical shape overlaps with a notched portion notched to form the substantially D shape. The bottom surface protrudes toward an opening of the strainer body. A rod is provided adjacent to the notched portion of the strainer body, and a float is provided on a lower end of the rod.

Abstract: A fine fiber production method and a fine fiber production apparatus are provided. The fine fiber production method includes: discharging a flowable polymer compound from a discharge port provided at an extruder; forming fibers having a fiber diameter of from 50 nm to 15 ?m by spraying, in a direction intersecting with a discharge direction of the flowable polymer compound, a pressurized gas from an air nozzle to the discharged flowable polymer compound, the air nozzle including a temperature control member and a spindle-shaped nozzle or a De Laval nozzle; and collecting the fibers using a collection member provided downstream in a gas spraying direction.