Abstract: A fuel pump module is liquid-tightly mounted in an opening of a vehicle fuel tank. The fuel pump module includes a residual fuel detector provided near the fuel tank. The residual fuel detector includes a diaphragm having a first diaphragm for receiving fuel pressure Pg by a head and atmospheric pressure Po, and a diaphragm portion for receiving atmospheric pressure Po and internal pressure Pi. The residual fuel detector detects the amount of fuel remaining in the fuel tank on the basis of these kinds of pressure Po, Pg and Pi. At the same time, the residual fuel detector detects the in-tank pressure Pt of the fuel tank on the basis of Po and Pi.

Abstract: An apparatus for detecting fuel-vapor gas leaks that includes a jet pump (8) that introduces outside air into and pressurizes a vapor purge system including a fuel tank (1) by gasoline flow from a fuel pump (2); an internal pressure sensor (14) for measuring vapor purge system internal pressure, an open/close controllable reference orifice (21) that causes leakage through a reference leak hole; and a storage device for storing as an initial curve pressure changes during pressurization by the jet pump (8) for a predetermined time period, with the reference orifice (21) alone opened. The device can accurately detect leakage even while an internal combustion engine is running because it judges leak presence/absence by comparing a time series in a pressure curve obtained by jet pump (8) pressurization over the predetermined time period while idling with the vapor purge system completely shut-off, with a time series in the initial curve.

Abstract: A fuel pump module is formed in such a manner that a sensor unit having a semiconductor diaphragm is provided in a recess of a bracket having a flange portion holding a fuel pump through a high-pressure filter. The recess is closed by a sensor cap having a lead-in pipe to thereby form an tank internal-pressure sensor. While internal pressure of a fuel tank is led into the tank internal-pressure sensor through an internal pressure lead-in pipe, atmospheric pressure is led into the tank internal-pressure sensor through an external air intake hole provided in the lead-in pipe. Thus, internal pressure of the fuel tank is detected.

Abstract: A fuel vapor leak detecting apparatus, includes: a valve which is in a vapor purge system including a canister that is communicated with a fuel tank and an internal combustion engine, and which controllably closes the vapor purge system; a pressurizing section which introduces atmospheric air into the vapor purge system to pressurize the vapor purge system; and an internal-pressure measuring section which detects an internal pressure of the vapor purge system. The pressurizing section supplies the air for a predetermined time in a state where the vapor purge system is closed. When the internal pressure measured by the internal-pressure measuring section at the air supply is equal to or lower than a preset criterion pressure, it is judged that leak occurs.

Abstract: A fuel pump module is liquid-tightly mounted in an opening of a vehicle fuel tank. The fuel pump module includes a residual fuel detector provided near the fuel tank. The residual fuel detector includes a diaphragm having a first diaphragm for receiving fuel pressure Pg by a head and atmospheric pressure Po, and a diaphragm portion for receiving atmospheric pressure Po and internal pressure Pi. The residual fuel detector detects the amount of fuel remaining in the fuel tank on the basis of these kinds of pressure Po, Pg and Pi. At the same time, the residual fuel detector detects the in-tank pressure Pt of the fuel tank on the basis of Po and Pi.

Abstract: A fuel pump module is formed in such a manner that a sensor unit having a semiconductor diaphragm is provided in a recess of a bracket having a flange portion holding a fuel pump through a high-pressure filter. The recess is closed by a sensor cap having a lead-in pipe to thereby form an tank internal-pressure sensor. While internal pressure of a fuel tank is led into the tank internal-pressure sensor through an internal pressure lead-in pipe, atmospheric pressure is led into the tank internal-pressure sensor through an external air intake hole provided in the lead-in pipe. Thus, internal pressure of the fuel tank is detected.

Abstract: A brake booster having a body in which a booster pressure sensor for detecting the internal pressure of an atmospheric pressure chamber is provided, and in which the operating state of a brake pedal is detected by a pedal sensor. Further, when the brake pedal is not depressed, the internal pressure of the negative pressure chamber is detected by the booster pressure sensor. In contrast, when the brake pedal is depressed, an atmospheric pressure is detected by the same booster pressure sensor. Namely, when the brake pedal is not depressed, the negative pressure chamber and the atmospheric pressure chamber communicate with each other and are thus shut off from atmospheric air. Therefore, the internal pressure of the negative pressure chamber is detected by the booster pressure sensor which communicates with the atmospheric pressure chamber. Moreover, when the brake pedal is depressed, the atmospheric pressure chamber communicates with atmospheric air.

Abstract: A pressure sensor comprises two sensor, a casing and a filter. A first sensor is a suction air pressure sensor for measuring the pressure of the air sucked in an internal combustion engine and the like. A second sensor is an atmospheric pressure sensor for measuring the atmospheric pressure. The casing accommodates the suction air pressure sensor and the atmospheric pressure sensor. The filter prevents the infiltration of solid matter and liquid form outside of the puressure sensor, and is mounted on the air introducing part of the atmospheric pressure sensor in the casing.

Abstract: A pressure detection apparatus including a pressure detection diaphragm, pressure detection circuit for outputting a pressure detection signal proportional to a pressure applied to the pressure detection diaphragm and clamping circuit for clamping the pressure detection signal to a predefined maximum or minimum value when the detected pressure signal is larger than the maximum value or less than the minimum value. Signal clamping by the clamping circuit is cut-off or cancelled when the pressure applied to the pressure detection diaphragm causes an operational error. This operational error may be detected by forming part of the clamping circuit on a semiconductor diaphragm of the sensor. Also, a failure detection circuit may be used to detect sensor failure and then cancel signal clamping.

Abstract: In a pressure sensor, a metallic pressure introducing pipe is fit into the pressure receiving inlet formed in a metallic housing and fixed there by welding. The housing has a flange portion in its upper portion, and the flange portion is fixed to the outer wall of a tank which is an object to be measured so that the pressure sensor body is located inside the tank. A porous filter made of fluoroplastics is arranged adjacently to the atmospheric pressure introducing inlet. An adhesive tape which is removable is attached to the atmospheric pressure introducing inlet. The pressure sensor can realize stabilized maintenance and highly reliable airtightness for a sensor element, less limitation to sensor layout design in a small space and also can surely introduce air with no drop of water and dust into the sensor.

Abstract: A pressure sensor into which the internal pressure of a fuel tank is introduced through a nipple portion and the atmospheric pressure is introduced through an atmosphere introducing hole, and a pressure difference between the internal pressure and the atmospheric pressure is detected by a diaphragm, comprises a check valve provided in the nipple portion to prevent fuel from leaking out to the atmospheric side. A pressure buffer chamber in the nipple portion of the pressure sensor is provided in which a ball is installed. A bottom face of the pressure buffer chamber is formed to be concave, and a receiving seat for receiving the ball is provided on the bottom face. Therefore, no fuel leaks outside, even when the vehicle comes across an accident and overturns sideways under the condition that the diaphragm used as a sensor element is fractured in the measurement of internal pressure of the fuel tank.

Abstract: A pressure sensor is capable of detecting a certain pressure and an atmospheric pressure individually and independently in real time, with miniaturization and light weight. This is attained by providing a pressure sensor comprising a first pressure sensor; and an atmospheric pressure sensor. Each sensor includes a pressure-sensitive element and a circuit for amplifying an output signal from the pressure-sensitive element. The amplifying circuit for the first pressure sensor, and the pressure-sensitive element and the amplifying circuit for the atmospheric pressure sensor are provided on the same chip. The amplifying circuit compensates for nonuniformity in characteristics of the pressure-sensitive element due to temperatures.

Abstract: A pressure sensor comprising a passage for introducing a pressurized medium; a member surrounding the passage; first and second sealants disposed between the member and the passage for preventing the pressurized medium from leaking to the outside through a clearance between the member and the passage; and a pressure sensing element communicating with the passage; the first sealant being made of a first material which is difficult to be deformed by the pressurized medium; the second sealant being made of a second material having a sealing effect against temperature change; the first and second sealants being arranged in series between the passage and the member surrounding the passage.

Abstract: A pressure sensor comprising a hollow main body (11) defining a bore (14) extending therethrough and having a detection end and an output end. A pressure sensing assembly is disposed within said bore (14) to divide it into a detection cavity (17) and an output cavity (18) through which output signal lines from said pressure sensing assembly extend. A flexible diaphragm (19) is attached to the detection end of the bore to define a sealed detection cavity (17) in which a pressure transmitting liquid is filled. The pressure sensing assembly comprises support plate (24) welded to said main body (11) and supporting a pressure sensing element (26) within said detection cavity (17) through a mounting bed (4). The signal lines sealingly extend through said support plate (24) from said detection cavity (17) to said output cavity (18).

Abstract: A pressure deriving port of an internal combustion engine having an intake manifold in which at least one of an exhaust gas recirculating port and a blow-by gas discharge port and an opening of said pressure deriving port are formed, is opened on an upstream side of the exhaust gas recirculating port and/or blow-by gas discharge port and in a stepped-up portion of an inner wall of intake manifold.

Abstract: A glow plug control system which includes a controller connected to a battery through an ignition switch, an indicator lamp and a glow plug relay connected to the controller and a parallel combination of four glow plugs connected to the battery through normally open contacts of the relay. The controller includes a comparator having its two inputs connected across the parallel glow plugs, and a constant current circuit for supplying a constant current to the parallel combination of the glow plugs for sensing the resistance of the glow plugs. The controller senses the resistance of the glow plugs due to their temperature through the comparator and permits the battery to supply a current to the parallel combination of the glow plugs for a time determined in response to the sensed resistance.