The present invention provides an intake device and a fuel delivery pipe for a multiple-cylinder engine including a transpiration gas passage or an intake air pressure collecting passage capable of reducing the number of components and improving assembly operability. The intake device and the fuel delivery pipe for a multiple-cylinder engine include: a throttle body including a plurality of bores, each of which communicates with an inside of each cylinder of the engine, and provided with throttle valves for adjusting intake volumes inside the bores in an openable and closable manner; injectors provided in the throttle body and injecting a fuel to the bores; a delivery pipe for supplying the fuel to the injectors; and an intake pipe communication passage connected to an inside of the bores and communicating with the inside of the bores, and the intake pipe communication passage is formed integrally with the delivery pipe.

A system includes an electronic fuel injection system of an engine, the electronic fuel injection system including an electronic governor control unit for controlling various functions of the engine.

A dual compressor turbocharger includes two compressors. One compressor supplies fuel pressure, and one compressor supplies air pressure. The dual compressor turbocharger includes a turbine driven by exhaust of an engine and a shaft coupled to the turbine. The first compressor is mounted on the shaft and includes a first inlet coupled to an air supply and a first outlet coupled to an air intake of the engine. The second compressor is mounted on the shaft and includes a second inlet coupled to a fuel supply and a second outlet coupled to a fuel supply rail of the engine.

A physical quantity measuring device is configured to measure a physical quantity of a fluid. The physical quantity measuring device includes: at least two humidity detection parts configured to output a humidity signal corresponding to a humidity of the fluid; and an abnormality determination part configured to determine that an abnormality has occurred in the humidity detection parts in response to that a difference between the humidity signals obtained from the two humidity detection parts exceeds an abnormality determination threshold.

The present invention relates to a method and a control unit for avoiding condensation of humidity in an intake system of an internal combustion engine after engine switch off. Condensed liquid in the intake system of the stopped engine can lead to icing, corrosion and a hydrostatic lock at the next engine start. To prevent such an engine damage, it is necessary to determine if and in which amount condensed liquid occurs in the cooled intake system and to initiate appropriate actions to eliminate the liquid therefrom. The present invention predicts the occurrence of condensation in the intake system of the cooled engine and initiates corrective measures at engine switch off and during the cooling down period.

A method for checking the function of a pressure sensor in the air intake tract or gas outlet tract of an internal combustion engine and to an engine control unit for carrying out the method and based on measuring dynamic pressure oscillations of the intake air or the exhaust gas by the relevant pressure sensor and, on the basis of the pressure oscillation signal obtained, respectively determining with the aid of a discrete Fourier transformation for a number of selected signal frequencies in each case a value of a specific operating characteristic of the internal combustion engine and deviation values of the values determined for the different signal frequencies from one another. Depending on whether deviation values determined fall below or exceed a predetermined limit value, the satisfactory function of the pressure sensor is confirmed, or a malfunction of the pressure sensor is diagnosed.

Each time clogging of a filter (5) of an air cleaner is determined on the basis of intake negative pressure of an engine (2), and the air filter (5) is cleaned, an accumulated value of operating time of the engine (2) from previous cleaning until clogging is determined is taken as a cleaning interval (S), and sequentially measured. A plurality of stages are previously set by classifying a minimum value and a maximum value of the cleaning interval (S), and the measured cleaning interval (S) is added to the stage to which the measured cleaning interval (S) is to belong, among the stages. A histogram in which an axis of abscissas is taken as the stage, an axis of ordinates is taken as frequency of the cleaning interval (S) is constructed, and an approximate straight line (L2) illustrated by a solid line is obtained by approximating a characteristic line (L1) of the histogram illustrated by a dotted line to a straight line. A characteristic of the histogram is changed as the deterioration of the air filter (5) progresses, and when a slope of the approximate straight line (L2) based on the characteristic gradually decreases from right-upward slop illustrated by a thin line, exceeds (ΔY/ΔX=0) equivalent to the horizontal, deterioration of the air filter is determined.

A physical quantity measurement device includes a housing forming a measurement flow path in which a sensor support supports a physical quantity sensor. The measurement flow path includes a sensor path in which the physical quantity sensor is disposed, an upstream curved path between the sensor path and an inlet, and a downstream curved path between the sensor path and an outlet. The housing includes a measurement narrowed portion that gradually narrows the measurement flow path in a direction from the inlet toward the physical quantity sensor. An upstream end of the sensor support is provided upstream of the measurement narrowed portion in an arrangement cross section along an imaginary straight line passing through the physical quantity sensor and extending in an arrangement direction in which the upstream curved path and the downstream curved path are arranged.

A physical quantity measurement device includes a housing forming a measurement flow path including a measurement inlet and a measurement outlet. The measurement flow path includes a sensor path in which a physical quantity sensor is disposed, an upstream curved path curved to extend from the sensor path toward the measurement inlet, and a downstream curved path curved to extend from the sensor path toward the measurement outlet. An inner surface of the housing includes an upstream outer curved surface that defines an outer outline of a curved part of the upstream curved path, and a downstream outer curved surface that defines an outer outline of a curve part of the downstream curved path. A degree of recess of the downstream outer curved surface is larger than a degree of recess of the upstream outer curved surface.

Methods and systems are provided for assessing a state of a vent hose that fluidically couples a crankcase of an engine to an engine air intake system. In one example, a method may include sealing the crankcase from the vent hose, initiating cranking of the engine, monitoring a series of pressure pulsations during a monitoring window duration via a pressure sensor positioned between a crankcase oil separator and the vent hose, and indicating a presence of degradation associated with the vent hose based on the series of pressure pulsations and the monitoring window duration. In this way, diagnosis of a state of the vent hose may be reliably assessed without crankcase pressures confounding pressure measurements as recorded via the pressure sensor.