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 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 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: 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 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: 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: 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: 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: A spool, including a substantially cylindrical flange portion and a substantially cylindrical front end portion which is thinner than the flange portion and whose center axis is substantially coincident with the center axis of the flange portion, is provided in a manner capable of slidingly moving in a cavity formed in a casing. The flange portion is inserted in a first cavity which has a center axis substantially coincident with the center axis of the casing and which has an inner diameter that is substantially the same as the diameter of the flange portion in length. The front end portion is inserted in a second cavity which is formed with its center axis being substantially coincident with the center axis of the casing, and which has an inner diameter greater than the diameter of the front end portion and less than the inner diameter of the first cavity in length.

Abstract: A spool, including a substantially cylindrical flange portion and a substantially cylindrical front end portion which is thinner than the flange portion and whose center axis is substantially coincident with the center axis of the flange portion, is provided in a manner capable of slidingly moving in a cavity formed in a casing. The flange portion is inserted in a first cavity which has a center axis substantially coincident with the center axis of the casing and which has an inner diameter that is substantially the same as the diameter of the flange portion in length. The front end portion is inserted in a second cavity which is formed with its center axis being substantially coincident with the center axis of the casing, and which has an inner diameter greater than the diameter of the front end portion and less than the inner diameter of the first cavity in length.

Abstract: An electric motor vehicle having a drive system comprises a controller including an inverter device. The inverter comprises first and second series of semiconductor switches which is arranged in parallel with a power source. When a key switch provided between the power source and the first series of the semiconductor switches is open in a stop mode of the vehicle, a signal is given to a control terminal of only the second series of the semiconductor switches to prevent a short circuit of a main battery.

Abstract: An electric motor vehicle comprises as a drive system a battery, a motor, and a controller for controlling the rotation of the motor. The electric motor vehicle disposes an accelerator for controlling speed of the motor, a key switch for turning on or off the motor and the controller, a circuit for judging an opening/closing state of the accelerator when the key switch is turned on, and a circuit for preventing the rotation of the motor when the key switch is turned on with the accelerator open.

Abstract: An electric motor vehicle includes a motor case having first and second hollow section, with the first hollow section having a smaller diameter than that of the second hollow section, forming a step between the first and second hollow sections; a stator provided in the second hollow section and having an end engaged with the step; a motor cover having a cylindrical projection in sliding relationship to the second hollow section and sufficiently long to press the stator against the step and provide a space between the motor case and the motor cover for a minimum thickness of the stator; and a filler made of a liquid packing provided in the space between the motor case and the motor cover for sealing the motor against winds and rains.

Abstract: A method for disassembling and assembling a mold enables a return pin to be safely attached or detached against an elastic force of the return spring. The fitting length between the return pin and the sliding hole formed in the movable mold plate is so determined that a fitting state of a predetermined length remains between the return pin and the sliding hole when the elastic force of the return spring is released to a practically safe level, and the return pin has, at the end, a threaded hole for fitting an operation male screw to be used for disassembling and assembling of the mold. While the male screw is screwed into the threaded hole through the sliding hole from the fixed side, the male screw is fed to move the return pin in the sliding hole, until the elastic force of the return spring is released to a practically safe level.