Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Honda Giken Kogyo Kabushiki Kaisha

Nifco Inc.

Mitsubishi Denki K.k.

Tateki Mitani

Shigeki Kanamaru

Hiroshi Yoshioka

Satoshi Nishikawa

Eiji Yagyu

Masakazu Takabayashi

Kiichi Yoshiara

Mikio Bessho

Susumu Nagano

Yutaro Hamatani

Kazushi Ishii

Toshio Iwata

Tsuyoshi Kato

Atsushi Ueda

Akira Demizu

Yasuyoshi Hatazawa

Yasuo Tada

Sadayuki Matsumoto

Kenichi Sawada

Seiki Kodama

Toshihide Kimisawa

Takanobu Takeuchi

Motomi Ichihashi

Michihiro Hayashi

Etsuo Nishimura

Yasuhisa Shimakura

Yuji Hase

Seiji Tsutsui

Minoru Takata

Yusaku Sakai

Yutarou Hamatani

Tetsushi Noda

An objective of the present invention is to provide an optical fiber sensor which has a simple configuration to enable sensitively measuring a refractive index of a measurement medium in a wide range of refractive indexes. An optical fiber sensor according to the present invention includes; an optical fiber having a core in which a short-period gratings are formed and a cladding, the optical fiber being made so that transmission loss occurs due to cladding-propagation-mode leakage at its cladding portion where the short-period gratings are formed; a light source from which light having a wavelength range of the cladding propagation mode is emitted; and a light receiving unit for receiving transmission or reflection light having passed through the cladding at the position where the short-period gratings are formed. The optical fiber sensor detects, based on the total receiving light intensity that the light receiving unit receives, the refractive index of the measurement medium contacting the cladding, in which the optical fiber is multi-mode one, and the short-period gratings have plural kinds of periods.

Optical fiber sensor

An optical fiber sensor includes: an optical fiber; a light source portion; and a light receiving portion. The optical fiber includes: a core that includes a grating that generates a clad mode upon receipt of light; a clad that covers the core; and a fiber jacket that covers the clad, wherein a part of the fiber jacket corresponding to an area where the grating is formed is removed so that the clad is contactable with the fuel. The light source portion includes a light cutting element that emits light, whose wavelength is within a wavelength band of the cladding mode toward the optical fiber. The light receiving portion that detects intensity of the light transmitted through the grating. The optical fiber, the light receiving portion and the light source portion are arranged linearly.

Optical fiber sensor and fuel supply apparatus having the same

An optical fiber sensor measuring refractive index of a medium with high sensitivity in a wide range. The optical fiber sensor includes an optical fiber causing a transmission loss due to leakage in the clad propagation mode from a portion of a core and a clad where a Bragg grating is provided, a light source permitting light in a wavelength band in the clad propagation mode to enter the optical fiber, and a light-receiving section receiving the transmitted or reflected light transmitted through the core and the clad at the portion where the Bragg grating is provided. The refractive index of the medium to be measured in contact with the clad is measured according to total intensity of the light received by the light-receiving section. The Bragg grating is inclined at a predetermined angle of inclination to the vertical line vertical to the length direction of the optical fiber.

The detection device provides with an optical fiber composed of a core, a clad and a fiber jacket. A grating is applied to the core, and the fiber jacket located at the portion to which the grating is applied is removed so that the clad is in contact with a fuel fed to an injector of a vehicle. The detection device also provides with a light source for incidence of a light in a range of clad mode wavelength to the optical fiber, and a light-sensitive part for detecting an intensity of the light transmitting through the region to which the grating is applied. The optical fiber, light source and light-sensitive part are held in a conduit disposed in a fuel tank or between a fuel pump and the injector of the vehicle.

On-vehicle fuel property detection device

An optical fiber sensor that can detect a liquid level or detect a property of liquid with high reliability even under a frequently vibrational environment. The optical fiber sensor includes an optical fiber that includes a core having an area where a grating is formed and a clad, the optical fiber being disposed so that at least a part of the area with the grating is immersed in liquid, a light source for making light incident to the optical fiber so that a cladding mode light having a wavelength band is generated by the grating, and a light receiving unit for detecting the intensity of light which is incident from the light source to the optical fiber and transmitted through the grating.

A leak detecting system for a transpiration purge system including a fuel tankand a canisterincludes a jet pump, which leads the atmosphere into the fuel tankusing a return flow of excess fuel of fuel pumped to an internal combustion engine, internal pressure measuring means, and fuel volume detecting means. After intaking air via pressurizing means for a predetermined time, the leak detecting system judges that a leak is present when a holding pressure measurement value in a state in which the transpiration purge system is closed is lower than a decompression calculation value calculated from a pressurization measurement value, an air volume, and a leak hole diameter.

Transpired fuel gas leak detecting device

A leak detecting system detects fuel gas leakage of a fuel tank. The detecting system includes a fuel pump, a jet pump, and a bent valve, which are disposed in the fuel tank. A fuel flow path system includes a relief line connected to the fuel pump for relieving an excess fuel, a relief flow path switching valve disposed in the relief line, and a sub-line for connecting the switching valve and the vent valve. An air flow path system includes a first air flow line to connect the vent valve to a canister, a second air flow line for connecting the first air flow line to the jet pump, and an air flow switching valve for switching communication between the first and second air flow lines. An inner pressure sensor is provided to the fuel tank for detecting an inner pressure of the fuel tank.

Fuel evaporation gas leakage detecting system and method of detecting fuel evaporation gas leakage

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.

Fuel vapor leak detecting apparatus, and fuel supplying apparatus to be applied to the same

An apparatus for detecting fuel-vapor gas leaks that includes a jet pump () that introduces outside air into and pressurizes a vapor purge system including a fuel tank () by gasoline flow from a fuel pump (); an internal pressure sensor () for measuring vapor purge system internal pressure, an open/close controllable reference orifice () 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 () for a predetermined time period, with the reference orifice () 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 () pressurization over the predetermined time period while idling with the vapor purge system completely shut-off, with a time series in the initial curve.

Apparatus for detecting fuel-vapor gas leaks, and vent valve apparatus applied to this apparatus

A fuel supply system includes a bracket fitted around an opening portion of a fuel tank and having a discharge pipe disposed, and a fuel pump for sucking a fuel from the fuel tank and discharging the fuel through the discharge pipe, the fuel pump being mounted on the bracket. The fuel pump includes a pump portion for sucking and discharging the fuel from the fuel tank, a motor portion for rotating a rotor accommodated within the pump portion, through which the fuel discharged from the pump portion is passed internally, a cover out portion for accommodating a discharge filter for filtering the fuel passed through the motor portion, and a debris storage case for storing the debris in the fuel that is captured by the discharge filter, the case being disposed near the discharge filter.

Fuel supply system

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.

Fuel pump module and vehicle residual fuel detector

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.

Fuel pump module and vehicle fuel tank internal pressure sensor

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. Consequently, an atmospheric pressure is detected by the booster pressure sensor.

Brake booster device

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.

Pressure sensor

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.

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Tokyo, Japan

Tateki Mitani