Abstract: A method and a device intended to purify pollutants from an exhaust gas flow of an internal combustion engine operated with sulphur containing fuel, in particular of a ship internal combustion engine operated with heavy fuel oil, are provided. Exhaust gas flow is in contact with a solid adsorption agent of the adsorber in a first step and binding in particular acid pollutants, which comprise sulphur dioxide and sulphur trioxide. The exhaust gas flow is then guided by a second stage of the adsorber realising fine purification of the exhaust gas flow. The adsorption agent of the second stage is used in the first stage as an adsorption agent.

Abstract: A catalyst temperature estimation device that estimates a temperature of a catalyst provided in an exhaust passage of an internal combustion engine includes a storage device and processing circuitry. The storage device stores mapping data that specifies a mapping that uses multiple input variables to output an estimation value of the temperature of the catalyst. The multiple input variables include at least one variable of an ambient temperature variable or an excess amount variable. The multiple input variables further include a fluid energy variable, which is a state variable related to energy of fluid flowing into the catalyst, and a previous cycle value of the estimation value of the temperature of the catalyst. The processing circuitry is configured to execute an acquisition process, a temperature calculation process, and an operation process. The mapping data includes data that is learned through machine learning.

Abstract: A reductant generator includes a housing defining a chamber, an inlet to direct engine exhaust gas into the chamber, a moveable member that receives driving input from an engine and which is configured to compress engine exhaust gases within the chamber, and a supply to provide a fluid into the chamber to be transformed into reductant. The generator also includes an outlet from which the reductant is directed into an exhaust system.

Abstract: A method for operating an internal combustion engine of a motor vehicle, which has an exhaust gas system that exhaust gas from at least one combustion chamber of the internal combustion chamber can flow through and includes at least one nitrogen oxide storage catalyst, at least one particulate filter, and at least one selective catalytic reduction (SCR) catalyst.

Abstract: There is provided a motorcycle which includes an engine including an exhaust port; an exhaust pipe connected to the exhaust port of the engine; and a catalyst disposed within the exhaust pipe. The exhaust pipe includes a catalyst case accommodating the catalyst, and a pipe connecting the exhaust port of the engine and the catalyst case. The catalyst is disposed in front of the engine. An occupied area of the catalyst in a direction orthogonal to a flow direction of exhaust gas is larger than an opening area of the pipe in a direction orthogonal to a flow direction of exhaust gas. A central axis of the catalyst is inclined with respect to a vehicle width direction in a vehicle front view. And the central axis of the catalyst and a center line of the engine in the vehicle width direction intersect at a position overlapping with the catalyst in the vehicle front view.

Abstract: The present invention relates to a catalyst comprising a carrier substrate of the length L, a passive nitrogen oxide adsorber and means to control the temperature of the carrier substrate, as well as a process for cleaning of an exhaust gas emitted from a lean burn engine.

Abstract: The present disclosure is directed to a system for treating an exhaust gas stream from an engine, which includes a diesel oxidation catalyst (DOC) located downstream of the engine and adapted for oxidation of hydrocarbons and carbon monoxide, an injector adapted for the addition of a reductant to the exhaust gas stream located downstream of the DOC, a catalyzed soot filter (CSF) located downstream of the injector, and a selective catalytic reduction component adapted for the oxidation of nitrogen oxides located downstream of the CSF. The CSF is adapted for oxidizing hydrocarbons and includes a selective oxidation catalyst composition on a filter with high selectivity ratio for hydrocarbon oxidation: ammonia oxidation (e.g., at least 0.6).

Abstract: An exhaust gas purification including: a base of wall flow structure having inlet side cells wherein an end on the exhaust gas inflow side is open and outlet side cells wherein an end on the exhaust gas outflow side is open, and a porous partition wall that partitions the side cells; and first and second catalyst layers disposed in the interior of the porous partition wall so as to be in contact with the side cells, wherein either of the catalyst layers contains an oxidation catalyst but does not contain a reduction catalyst, and the other contains the reduction catalyst but does not contain the oxidation catalyst; and a ratio of the lengths of the catalyst layers differs between a surface of the porous partition wall on the side in contact with the inlet side cells and a surface on the side in contact with the outlet side cells.

Abstract: Methods of combining catalytic plates into an assembly of a non-monolithic structure, such as a catalyst substrate or filter assembly, of an exhaust aftertreatment system. A plurality of plates may be disposed within a housing in an arrangement that may define a catalytically active volume of a substrate. Each of the plurality of plates may be single-curved or multiple-curved and/or may be represented by three-dimensional nestable structures. The arrangement of plates may be configured such that the flow is axial, radial, or represented by a hybrid, multi-segment intake path. The plurality of plates may be arranged such that they are configured to receive targeted amounts of coating agent, which may differ among the plates.

Abstract: A catalytic composite is formed of a catalytic layered assembly including a porous catalytic fluoropolymer film and one or more felt batts connected with the porous catalytic fluoropolymer film. At least one felt batt is positioned adjacent the upstream side of the porous catalytic fluoropolymer film to form the catalytic composite. The fluoropolymer film is perforated to allow for enhanced airflow therethrough while retaining the capability of catalyzing the reduction or removal of chemical species in fluid flowing through the catalytic composite.

Abstract: A mixer for mixing an exhaust gas flow with a fluid injected into an exhaust gas line comprises means for generating a swirl effecting a rotating flow and means for a radial displacement in the exhaust gas flow admixed with the fluid and flowing axially through the mixer. In this respect, the swirl generation means and the radial displacement means are arranged and designed such that, viewed over the cross-section of the mixer perpendicular to the axial exhaust gas flow, at least two separate swirl regions result which are built up via tangentially acting vane-like swirl elements and at least one respective radial displacement region results which is arranged between two separate swirl regions.

Abstract: In a control apparatus, a calculation calculates an additional heating amount for an exhaust gas from an internal combustion engine in accordance with an activity of an exhaust purification catalyst in response to the internal combustion engine being required to be started after start of heating of the exhaust purification catalyst by an electric heating device. A drive control unit controls, in accordance with the additional heating amount for the exhaust gas, an amount of heat of the exhaust gas from the internal combustion engine.

Abstract: A storage device stores mapping data and association data. The mapping data defines a mapping that outputs an estimated value of the temperature of a catalyst using a warm-up operation amount variable and the previous value of the estimated value as an input. The association data associates the integrated value of an intake air amount of an internal combustion engine from the startup of the engine and the temperature of the catalyst. The execution device repeatedly calculates the estimated value based on the output of the mapping. When the correspondence relationship between the integrated value and the estimated value is different from the correspondence relationship between the integrated value and the temperature of the catalyst in the association data, the warm-up process is determined to have an anomaly.

Abstract: A method for operating a nitrogen oxide sensor of a vehicle having a first nitrogen oxide sensor, a second nitrogen oxide sensor and a catalytic converter, one of the first and second nitrogen oxide sensors being arranged upstream of the catalytic converter with respect to the exhaust gas flow direction, and the other of the first and second nitrogen oxide sensors being arranged downstream of the catalytic converter, includes: determining a first characteristic value of the first nitrogen oxide sensor; determining a second characteristic value of the second nitrogen oxide sensor; determining a ratio of the first characteristic value to the second characteristic value; and adapting a sensor measured value of the second nitrogen oxide sensor in accordance with the ratio of the first characteristic value to the second characteristic value.

Abstract: A catalyst deterioration detection device is provided to detect deterioration of a catalyst provided in an exhaust passage of an internal combustion engine. The catalyst deterioration detection device includes a storage device and processing circuitry. The storage device stores map data specifying a mapping that uses time series data of an excess amount variable in a first predetermined period and time series data of a downstream detection variable in a second predetermined period as inputs to output a deterioration level variable. The processing circuitry executes an acquisition process that acquires data, a deterioration level variable calculation process that calculates a deterioration level variable of the catalyst based on an output of the mapping using the data acquired by the acquisition process as an input. The map data includes data that is learned through machine learning.

Abstract: An integrated flow rate control valve assembly is provided between an engine and a radiator. The integrated flow rate control valve assembly includes a housing in which a plurality of valve rooms separated by partition walls are formed and a plurality of rotary valves provided in the plurality of valve rooms, respectively, and an engine cooling system including the same, and according to the present disclosure, a sealing between cooling water lines is fundamentally solved, thereby enabling cooling water leakage prevention and structural robustness.

Abstract: A thermostat for an engine cooling system, which is arranged between an engine and a radiator may include a housing having a coolant inlet through which coolant flows in from the engine and an outlet leading the coolant to the radiator; and a main valve provided in the housing and coupled to one side of wax to open or close the outlet as the volume of the wax is changed. In particular, the main valve is formed with a coolant hole.

Abstract: A water pump of an engine cooling system includes a thermal valve that divides an outlet space of a pump housing of an outlet port, through which the engine coolant pumped into the internal space of a pump housing is discharged, into a front end discharge region and a rear end discharge region. The thermal valve also forms a dual flow path through which the engine coolant is discharged to the front end discharge region and the rear end discharge region according to the increase of the coolant temperature. The cooling of a cylinder block and a cylinder head of an engine are thus separately adjusted.

Abstract: A dual volute turbocharger for use with an internal combustion engine includes a valve for controlling exhaust gas flow to a turbine housing interior of the dual volute turbocharger. The dual volute turbocharger also includes a first volute and a second volute each adapted for fluid communication with the internal combustion engine. The dual volute turbocharger further includes a wall separating the first and second volutes and a valve seat. The valve seat and the wall collectively define a valve cavity. The valve is movable between a closed position and an open position. The valve and the wall of the turbine housing collectively define a first cross-sectional flow area. The valve and the valve seat collectively define a second cross-sectional flow area. A method of controlling the valve of the dual volute turbocharger is also disclosed.

Abstract: A valve assembly for controlling exhaust gas flow to a turbine housing interior of a dual volute turbocharger includes a first valve member, a valve shaft, and a second valve member. The first valve member is disposed about and extends along an axis between a first end and a second end and is movable between a first, a second, and a third position for controlling exhaust gas flow to the turbine housing interior. The first valve member defines a valve interior between the first and second ends. The valve shaft is partially disposed in the valve interior and is coupled to the first end of the first valve member. The second valve member has a base coupled to and disposed about the valve shaft and a projection extending from the base and about the shaft into the valve interior. The second valve member is movable between closed and open positions.

Abstract: A system includes a dual volute turbocharger and a controller. The dual volute turbocharger includes a turbine housing. The turbine housing includes a wall, a valve seat, and an interior surface defining a turbine housing interior, a first volute, a second volute, and a turbine housing outlet. The dual volute turbocharger also includes at least one valve member engageable with at least one of the valve seat and the wall of the turbine housing. The at least one valve member and the wall of the turbine housing collectively define a first cross-sectional flow area. The at least one valve member and the valve seat of the turbine housing collectively define a second cross-sectional flow area. The controller is adapted to control the at least one valve member to have an area ratio constant operating range according to a brake-specific fuel consumption of the internal combustion engine.

Abstract: A waste heat recovery (WHR) system and method for regulating exhaust gas recirculation (EGR) cooling is described. More particularly, a Rankine cycle WHR system and method is described, including an arrangement to improve the precision of EGR cooling for engine efficiency improvement and thermal management.

Abstract: A piston internal combustion engine with generator has two cylinders and cylinder heads and pistons with connecting rods and two crankshafts which are connected by gears with a ratio of 1:?1 (with opposite direction of rotation). The first crankshaft with the gear is mounted parallel to the second crankshaft with the second gear in one engine case such, that the gears engage. The first crankshaft is coupled to the first generator rotor and the second crankshaft is coupled to the second generator rotor or the flywheel. The moment of inertia of the first crankshaft assembly with the first gear and the first generator rotor is equal to the moment of inertia of the second crankshaft assembly with the second gear and the second generator rotor or flywheel. The cylinders with the pistons and are positioned perpendicularly to the plane of symmetry between the crankshafts, with the axes of the pair of cylinders lying in a plane with the both pistons being at the top dead center simultaneously.

Abstract: Systems and methods are provided for a turbocharger system for use with a process gas capture system. In one example, the turbocharger system comprises: a heat exchanger positioned to receive inlet gas from a gas generating system via a first inlet; a low pressure compressor driven by a low pressure turbine and coupled to a first outlet of the heat exchanger; a mid-pressure compressor driven by a mid-pressure turbine and coupled in series with the low pressure compressor, the mid-pressure compressor configured to receive low pressure compressed gas from the low pressure compressor; and a high pressure compressor driven by a high pressure turbine and coupled in series with the mid-pressure compressor, the high pressure compressor configured to receive mid-pressure compressed gas from the mid-pressure compressor and output high pressure compressed gas to the process gas capture system and a second inlet of the heat exchanger.

Abstract: A gas turbine engine includes a fan, a compressor section, and a turbine section configured to drive the compressor section and the fan. A buffer system is configured to communicate a buffer supply air to a portion of the gas turbine engine. The buffer system includes a first bleed air supply having a first pressure, a second bleed air supply having a second pressure that is greater than the first pressure, and an ejector that selectively augments the first bleed air supply to prepare the buffer supply air for communication to the portion of the gas turbine engine. A method and a buffer system are also disclosed.

Abstract: An oceanic offshore system and method for generating electric power which comprises a structure positioned at an offshore location. A power generating module is mounted on the structure, the power generating module including a turbine, an electric power generator coupled to the turbine, and a generating source of power fluid for the turbine resulting from the combustion of a fossil fuel. There is a capture system connected to the generating source for transferring carbon dioxide combustion gases to a subsea location for sequestration of CO2.

Abstract: A gas turbine engine generates noise during use, and one particularly important flight condition for noise generation is take-off. A gas turbine engine has high efficiency together with low noise, in particular from the turbine that drives the fan. The contribution of the turbine noise emanating from the rear of the engine to the Effective Perceived Noise Level (EPNL) is in the range of from 7 EPNdB and 30 EPNdB lower at a take-off lateral reference point than at an approach reference point.

Abstract: A heat shield panel for a combustor of a gas turbine engine including a panel body having a first surface and a second surface. The second surface being configured to be oriented toward a combustor liner of the combustor. The heat shield further includes a plurality of first pin fins projecting from the second surface of the panel body. Each of the plurality of first pin fins has a rounded top opposite the second surface. The heat shield further includes a plurality of second pin fins projecting from the second surface of the panel body. Each of the plurality of second pin fins has a flat top opposite the second surface. The plurality of second pin fins are intermittently spaced amongst the plurality of first pin fins. The plurality of second pin fins are organized in a uniform distribution across the second surface of the heat shield panel.

Abstract: The proposed solution concerns in particular an engine assembly with a casing part extending along a central axis, at least one cover part which at least partially covers an outside of the casing part, and for this, in relation to the central axis, extends along a circumferential direction which points along a circular path around the central axis, and at least one connecting element via which the at least one cover part is fixed relative to the casing part and which compensates for different thermal expansions of the casing part and the at least one cover part.

Abstract: A gas turbine engine with an accessory gearbox. The accessory gearbox is rotatably coupled to the engine drive shaft. The gearbox has a gear shaft rotatable about a gear shaft axis. The gear shaft has a first end drivingly engaged to a first accessory and a second end drivingly engaged to a second accessory.

Abstract: An accessory system for a gas turbine engine having a driveshaft with an axis of rotation is provided. The accessory system includes a towershaft coupled to the driveshaft and driven by the driveshaft along a towershaft axis of rotation. The accessory system also includes a shaft including a first shaft bevel gear coupled to a towershaft bevel gear. The shaft is rotatable by the towershaft along a shaft axis of rotation and defines an air-oil separator. The shaft axis of rotation is transverse to the towershaft axis of rotation. The accessory system includes a first accessory drive shaft having a first accessory bevel gear driven by the shaft. The accessory system also includes a second accessory drive shaft having a second accessory bevel gear driven by the shaft.

Abstract: A gas turbine engine includes a frame member extending generally along an axial direction and defining a plurality of slots spaced along a circumferential direction; and a gearbox including a ring gear, a plurality of planet gears, and a sun gear, the plurality of planet gears each positioned at least partially in a respective slot of the plurality of slots defined by the frame member such that the frame member extends through the gearbox.

Abstract: A sun gear for a mechanical reduction gear of a turbine engine, in particular for aircraft, the sun gear having a general annular shape about an axis and comprising at the outer periphery thereof, a meshing gearing with planet gears of the reduction gear, and at the inner periphery thereof, splines for coupling with an input shaft of the reduction gear, characterised in that the sun gear has a staged profile in axial cross-section, and preferably comprises an annular recess opening radially inwards and configured to receive at least one oil jet.

Abstract: A planetary gear train speed reduction gear planetary carrier (130) assembly and an elastically deformable annular member (160), for a turbine engine, in particular for an aircraft. The planetary carrier (130) has a general annular shape about an axis X. The annular member (160) extends about the axis X, and is fixed to the planetary carrier and configured to be fixed to a stator element (162) of the turbine engine ensuring a flexible connection between the planetary carrier and the stator element. The planetary carrier carries a series of protruding teeth (180) extending substantially radially outwards with respect to the axis X. Each of these teeth has first opposite side faces (180a, 180b) extending into planes passing through the axis X capable of engaging by abutment in the circumferential direction with the stator element. A vibration absorption system is inserted between the first faces and the stator element.

Abstract: Provided is a turbo fan engine (TF) provided with a power transmission device that switches main shafts (MSs) connected to a starter generator (SG) so as to perform power transmission, between at startup and after the startup. The TF includes a first MS and a second MS. The power transmission device includes a first shaft, an intermediate shaft, and a second shaft that are coaxially disposed, and a clutch. The first shaft is connected to the first MS through bevel gears, the intermediate shaft is disposed outside of the first shaft and is connected to the SG through bevel gears, and the second shaft is disposed outside of the intermediate shaft and is connected to the second MS through bevel gears.

Abstract: According to some embodiments, the present disclosure may relate to a system including a gaseous fuel consuming engine operating at an air to fuel ratio (AFR) and including a throttle valve controlling a speed of engine, and an engine controller coupled to the engine. The engine controller may be configured to obtain the speed of the engine and obtain the AFR of the engine. The engine controller may also be configured to, based on a transient event affecting the engine, coordinate modification of both the throttle valve to change the speed of the engine and trim valve to change the AFR of the engine to maintain at least one of the speed and the AFR of the engine within a threshold deviance.

Abstract: Methods and systems are provided for estimating ethanol content in fuel and an age of the fuel in a vehicle engine. In one example, a method may include estimating fuel ethanol content and/or fuel age based on fuel temperature, a speed of sound in fuel, and an attenuation co-efficient of an ultrasonic signal in fuel. One or more engine operating parameters may be adjusted based on the estimated fuel ethanol content and fuel age.

Abstract: A state detection system for an internal combustion engine is provided. Rotation waveform variables include information on a difference between cylinders in the rotational speed of a crankshaft during periods in which the respective cylinders generate combustion torque. An obtainment process obtains a value of the rotation waveform variables and a value of a road surface state variable based on an output of a sensor that detects a state of the road surface. A selection process selects, from a plurality of types of mapping data stored in the storage device, the mapping data that is associated with the road surface state variable as the detection mapping. A determination process determines whether the engine is in a predetermined operating state based on an output value of the selected detection mapping that takes the rotation waveform variables as inputs.

Abstract: A PM amount estimation device is applied to a filter that collects PM in the exhaust gas discharged to an exhaust passage of an internal combustion engine. A storage device stores mapping data which is data defining a mapping that outputs the PM amount collected by the filter. The mapping has at least one of an intake air temperature variable and a wall surface variable, and a flow rate variable as inputs. The intake air temperature variable relates to the temperature of air drawn into the engine. The wall surface variable relates to a cylinder wall surface temperature of the engine. The flow rate variable indicates the flow rate of the fluid entering the filter. The execution device calculates the PM amount based on the output of the mapping having the acquired data as an input.

Abstract: A method for operating a motor vehicle having an engine and an electric machine, a transmission, a battery, and an exhaust treatment system having a particulate filter. The battery discharges during a charge-depleting mode of the electrical machine and charges when the electrical machine operates as a generator such that the battery charge state moves between lower and upper limits. If a filter regeneration requirement is detected, the filter is regenerated by raising the temperature of the exhaust gas. When the need for filter regeneration is detected, the battery is discharged to below the lower limit, in the charge-depleting mode of the electrical machine, prior to the regeneration. Subsequently, to regenerate the filter, the engine is operated to raise the exhaust gas temperature by increasing the torque provided by the engine, and the electric machine operates as a generator to charge the battery and/or operate an auxiliary electrical load.

Abstract: A method is presented for facilitating oxygen vacancy generation in a resistive random access memory (RRAM) device. The method includes forming a RRAM stack having a first electrode and at least one sacrificial layer, encapsulating the RRAM stack with a dielectric layer, constructing a via resulting in removal of the at least one sacrificial layer of the RRAM stack, the via extending to a high-k dielectric layer of the RRAM stack, and forming a second electrode in the via such that the second electrode extends laterally into cavities defined by the removal of the at least one sacrificial layer.

Abstract: Systems and methods for operating a vehicle that includes an engine that may be automatically stopped and started are described. In one example, an engine may be automatically stopped in response to a brake booster vacuum threshold level that is adjusted responsive to vehicle speed so that opportunities to automatically stop an engine may be increased, thereby conserving fuel.

Abstract: A system or method for determining virtual data of a system, relative to a measurement point having a sensor located nearby, is determined by a controller. The system calculates modeled data at the measurement point, filters the modeled data to determine filtered data, and calculates a differential between the modeled data and the filtered data to determine a compensation term. The system also determines raw-sensed data from the sensor at the measurement point, and combines that raw-sensed data with the compensation data to calculate the virtual data at the measurement point. In some configurations, the modeled data is determined from a physics-based model. Furthermore, filtering the modeled data may include using a low-pass filter, and a time constant for the low-pass filter may be calculated based on operating conditions of the system.

Abstract: With respect to a vehicle mass air-flow sensor that includes a temperature sensor for measuring a temperature of a sensor element of the mass air-flow sensor, a method for controlling a heating element for heating the sensor element of a mass air-flow sensor includes identifying a dew formation on the sensor element by evaluating a temperature profile that is recorded during an operation of the vehicle using the temperature sensor, and generating a switch-on signal for switching on the heating element in response to the identification of the dew formation.

Abstract: A misfire detection device for an internal combustion engine is provided. A mapping takes time series data of instantaneous speed parameters as inputs. Each instantaneous speed parameter corresponds to one of a plurality of successive second intervals in a first interval. The instantaneous speed parameters correspond to the rotational speed of the crankshaft. The first interval is a rotational angular interval of the crankshaft in which compression top dead center occurs. The second interval is smaller than an interval between compression top dead center positions. The mapping outputs a probability that a misfire has occurred in at least one cylinder that reaches compression top dead center in the first interval. The mapping data defining the mapping has been learned by machine learning.

Abstract: An ECU includes a cooling water temperature sensor, an intake air temperature sensor, a storage unit, a determination unit, and a calibration unit. In an after-run control performed after the internal combustion engine stops, the determination unit compares a cooling water temperature Tw detected by the cooling water temperature sensor with a first threshold value T1 and determines that the environment is not the cold environment in which an EGR differential pressure sensor is likely to be frozen, if the cooling water temperature Tw is equal to or higher than the first threshold value T1, or if the cooling water temperature Tw is less than the first threshold value T1 but is equal to or higher than a second threshold value T2 which is lower than the first threshold value T1 and an intake air temperature Ta from the intake air temperature sensor is equal to or higher than a third threshold value T3, and determines that the environment is the cold environment otherwise.

Abstract: An internal combustion engine according to one or more embodiments of the present disclosure may include an engine cylinder having a cylinder head and cylinder sidewalls and a piston that reciprocates within the engine cylinder. The piston, the cylinder head, and the cylinder sidewalls may at least partially define a combustion chamber. The internal combustion engine may also include a fuel injector that is positioned to inject fuel directly into the combustion chamber. The internal combustion engine may further include an engine control module that is in electronic communication with the fuel injector. The engine control module may determine if the internal combustion engine is operating at conditions corresponding to a super knock condition may occur and commands the fuel injector to operate under a split injection mode in which fuel is injected into the combustion chamber in a plurality of injection pulses.

Abstract: A combustion control system for a dual fuel engine includes a combustion control unit structured to receive phasing data for combustion of a main charge of gaseous fuel ignited by way of pilot shots of a liquid fuel, output a pilot fueling command based on the phasing data, and output a valve timing command. The combustion control unit is further structured to vary a phasing of combustion of a main charge of a gaseous fuel ignited by pilot shots of a liquid fuel based on an adjustment to at least one of a pilot shot delivery parameter or a valve timing parameter such as intake valve closing timing from a first engine cycle to a second engine cycle. Control of the intake valve timing can be based on a main pilot shot timing error.

Abstract: A cooling apparatus includes a coolant passage provided in a device to be cooled. The coolant passage is configured in such a manner that coolant passes through the coolant passage. The coolant passage includes a wall surface, first ribs, and second ribs. The first ribs and the second ribs are provided on at least a part of the wall surface. The first ribs protrude from the wall surface toward inside of the coolant passage and extend in a first direction. The second ribs protrude from the wall surface toward the inside of the coolant passage and extend in a second direction crossing the first direction. The first ribs and the second ribs are disposed alternately when viewed in at least one direction.

Abstract: A piston for an internal combustion engine includes a piston head portion, a pair of piston skirt portions, and a pair of side-wall portions. Each of the side-wall portions includes a pin boss portion having a piston pin hole, and is located between the pair of piston skirt portions. There are set a first axis corresponding to a center longitudinal axis of the piston, a second axis corresponding to an axis of the piston pin holes, and a reference plane corresponding to a plane that passes through the first axis and is orthogonal to the second axis.