Abstract: A muffler for a vehicle, may include a housing which defines a space therein, first and second baffles which partition the space inside the housing into first, second and third chambers, an inlet pipe which extends through the first baffle and the second baffle to be connected to the third chamber through the first chamber and the second chamber, an intermediate pipe which connects between the first and third chambers through the first baffle and the second baffle and has a plurality of holes in a portion thereof which may be placed in the second chamber, and an outlet pipe which sequentially extends through the first baffle and the second baffle from an first open end inside the first chamber, sequentially extends through the second baffle and the first baffle, sequentially extends through the first baffle and the second baffle, and then extends to the outside of the housing.

Abstract: Method for determining a starting time of a regeneration process of a particle filter which is connected into the exhaust train of an internal combustion engine, in particular of a diesel engine, wherein the data of an air mass flow rate meter, of an exhaust gas temperature sensor and of a differential pressure sensor are fed to a control unit and the control unit starts the regeneration on the basis of the data by means of the comparison with characteristic diagrams.

Abstract: A method pertaining to an SCR system which includes a dosing unit (250) to supply reducing agent to an exhaust duct (240) for exhaust cleaning, and a container for reducing agent: the steps of determining (s320) a cooling requirement of the dosing unit (250) and choosing (s340) a limit level for reducing agent in the container (205) on the basis of the cooling requirement. A computer program product containing program code (P) implements a method according to the invention. A device of an SCR system includes a dosing unit (250) to supply reducing agent to an exhaust duct (240) for exhaust cleaning. A motor vehicle (100) is equipped with the device.

Abstract: An exhaust gas purification system capable of preventing clogging of a reducing agent injection valve due to solidified urea aqueous solution to prevent a decrease in the exhaust gas purification efficiency of an internal-combustion engine. The exhaust gas purification system includes a diesel particulate filter, a reducing agent injection valve and an SCR catalyst in this order from the exhaust upstream side. A condition satisfaction determination section determines whether or not urea aqueous solution is likely to be solidified when detecting that an ignition switch is turned off, and an internal-combustion engine stop prevention section prevents the internal-combustion engine from being stopped, based on a determination by the condition satisfaction determination section.

Abstract: An air-fuel ratio control apparatus for an internal combustion engine according to an embodiment of the invention (the present control apparatus) sets a target air-fuel ratio to a target rich air-fuel ratio when it is determined on the basis of the output value Voxs of a downstream air-fuel ratio sensor 67 that the oxygen adsorption amount of a catalyst 43 tends to be excessive, and sets the target air-fuel ratio to a target lean air-fuel ratio when it is determined on the basis of the output value Voxs that the oxygen adsorption amount of the catalyst 43 tends to be insufficient. Further, the present control apparatus determines whether or not an operation state in which a large amount of nitrogen oxide flows into the catalyst 43 is reached on the basis of “whether a predetermined condition is fulfilled”, and makes the target rich air-fuel ratio obtained when the predetermined condition is fulfilled less than the target rich air-fuel ratio obtained when the predetermined condition is not fulfilled.

Abstract: The invention relates to a method for operating an internal combustion engine. According to the method, an exhaust gas produced by the internal combustion engine is conducted across a 3-way catalytic converter arranged in the exhaust duct. A lambda probe detects a value characteristic of an exhaust-gas lambda number upstream of the 3-way catalytic converter, and transmits said value to an engine control unit with an integrated PI or PID regulator. By means of the PI or PID regulator of the engine control unit, through the specification of a setpoint value, a substantially stoichiometric exhaust-gas lambda number is set, and the exhaust-gas lambda number is, with predefined periodic setpoint value variation, deflected alternately in the direction of a lean lambda number and a rich lambda number (lambda modulation).

Abstract: An exhaust gas purifying apparatus for an internal combustion engine is provided with: a first catalyst (234) which is disposed in an exhaust passage of the internal combustion engine (200); a second catalyst (235) which is disposed in the exhaust passage on a downstream side of the first catalyst; a reducing agent supplying device (233) which is disposed on an upstream side of the first catalyst and which is configured to supply a reducing agent into the exhaust passage; and a reducing agent supply controlling device (100) which is configured to control the reducing agent supplying device such that an air-fuel ratio on the upstream side of the first catalyst becomes momentarily rich.

Abstract: An object is to reduce the increase in the fuel consumption or the increase in emissions caused by processing for raising the temperature of an NOx catalyst in an exhaust gas purification apparatus for an internal combustion engine having the NOx catalyst arranged in an exhaust passage of the internal combustion engine. To achieve the above object, an exhaust gas purification apparatus for an internal combustion engine according to the present invention executes processing for raising the temperature of the NOx catalyst on condition that a temperature change ratio with a predetermined amount of assumed temperature rise of the NOx catalyst is equal to or higher than a reference value. According to the present invention, it is possible to activate the NOx quickly while keeping the unwanted increase in the fuel consumption and emissions caused by the temperature raising processing small.

Abstract: Systems, methods and apparatus are disclosed for thermal management of an SCR catalyst in an exhaust aftertreatment system of an internal combustion engine that includes an exhaust throttle but lacks a particulate filter. The thermal management can include interpreting, initiating, and/or completing a thermal management event for the SCR catalyst for removal of contaminants such as hydrocarbons and urea deposits. The thermal management event includes at least one of closing the exhaust throttle and increasing the thermal output of the engine to expose the SCR catalyst to a sufficiently high temperature over a time period that desorbs a sufficient amount of the hydrocarbons and/or removes a sufficient amount of the urea deposits to restore SCR catalyst performance.

Abstract: An exhaust gas treatment device (1), which contains at least one exhaust gas treatment insert (2) in a tubular housing (4), especially for an exhaust system of an internal combustion engine. A circumferential geometry of the at least one insert (2) is measured in at least one axial section of the particular insert (2). The at least one insert (2) is inserted axially into the housing (4). The measured circumferential geometry of the at least one insert (2) is taken into account during the deformation of the housing (4).

Abstract: A honeycomb filter 100 includes honeycomb segments 4, plugging portions 5, and joining layers 7, area of outflow end surface 12 of honeycomb segment is larger than area of inflow end surface 11, and shape of cross section of honeycomb segment vertical to axial direction X has a similarity in axial direction X. Moreover, thickness of joining layer decreases in at least a part of joining layer in direction from inflow end surface side toward outflow end surface side, and length L2 of joining layer in axial direction X is smaller than 95% of length L1 of honeycomb segment in axial direction X. Furthermore, a region of honeycomb segments 4, 5 mm or more from outflow end surface 12 in axial direction X, is not provided with joining layers 7 which join side surfaces of honeycomb segments 4 to each other.

Abstract: An internal combustion engine has at least one combustion chamber and an exhaust gas system arranged on an exhaust gas outlet port. The exhaust gas system includes at least one secondary air injection device for injecting secondary air into the exhaust system between the combustion chamber and an exhaust emission control system arranged in the exhaust gas system. During operation of the internal combustion engine, a residual gas content in the combustion chamber can be changed. The secondary air injection site on the exhaust gas system is arranged so far from the combustion chamber that injected secondary air flows back into the exhaust gas outlet port due to back-flowing exhaust gas in the exhaust gas system but does not flow back into the combustion chamber. This makes it possible to comply with SULEV emission limits even for engines having many combustion chambers and/or exhaust gas turbochargers.

Abstract: A temperature of a heated component is determined for control and monitoring. The heater driver, upon receipt of a turn-on signal, generates a current within a component of an electronic catalyst or exhaust after-treatment component, wherein the current through the component generates an appropriate loss to generate heat for facilitation of an exhaust after-treatment process. The heater driver regulates the energy to the heated component based on the electrical resistance of that component as a function of temperature and a predetermined reference value for that temperature.

Abstract: An exhaust sensor (10) includes a cylindrical sensor body (11) arranged outside of an exhaust pipe (5) of an engine (1), a gas inlet (12) formed at one end of sensor body (11), and a gas outlet (13) formed at the other end of sensor body (11). The gas inlet (12) communicates with the exhaust pipe (5) through an introduction pipe (16), while the gas outlet (13) communicates, through a return pipe (17), with the exhaust pipe (5) on the downstream side of a communication portion (16a) of the introduction pipe (16) in terms of flow of the exhaust gas, and the exhaust gas is introduced into the sensor body (11) through the gas inlet (12) and then discharged from the sensor body (11) through the gas outlet (13) by a pressure difference between the communication portions (16a), (17a) of the introduction pipe (16) and of the return pipe (17).

Abstract: A structure of a dual exhaust system for a cylinder deactivation (CDA) engine, may include two inlet pipes, two outlet pipes, each of which protrudes and extends from an inside of a corresponding main muffler to an outside of the corresponding main muffler, wherein each of the two outlet pipes releases the exhaust gas passing through the corresponding main muffler to an outside of the vehicle therethrough, a connecting pipe disposed in a vehicle width direction and connecting between the two main mufflers, and a valve mounted on one outlet pipe of the two outlet pipes to open and close the one outlet pipe, wherein when the valve may be closed, the exhaust gas passing through one of the main mufflers may be introduced into the other main muffler of the two outlet pipes through the connecting pipe and then may be emitted to the outside of the vehicle.

Abstract: A structure of an exhaust system for a CDA engine may include three baffles coupled in a main muffler in a lateral direction, and dividing an interior of the main muffler into a first space, a second space, a third space, and a fourth space, a first connecting pipe disposed outside the main muffler, connecting the second space and the third space and having a passage in which exhaust gas flows, a second connecting pipe disposed outside the main muffler, connecting the second space and the third space, and having a passage in which the exhaust gas flows, a first valve coupled to the passage of the first connecting pipe, and a second valve coupled to the passage of the second connecting pipe.

Abstract: A structure of an exhaust system for a cylinder deactivation (CDA) engine may include first, second and third baffles which are coupled in a main muffler, and divide an interior of the main muffler into first, second, third and fourth spaces respectively, a connecting pipe which connects the second space and the third space of the main muffler, and has a passage in which the exhaust gas flows, a first valve coupled to the passage of the connecting pipe to open and close the passage of the connecting pipe, and a second valve openably and closably coupled to the second baffle disposed between the second space and the third space, wherein the first baffle coupled between the first space and the second space, and the third baffle coupled between the third space and the fourth space, have a plurality of holes so that the exhaust gas flows therethrough.

Abstract: A spherical annular seal member 35 for use in an exhaust pipe joint has a spherical annular base member 33 which is defined by a cylindrical inner surface 29 forming a through hole 28, a partially convex spherical sliding surface 39, and annular end faces 31 and 32 on large- and small-diameter sides of the partially convex spherical sliding surface 39.

Abstract: This invention provides a coolant composition for an internal combustion engine that can improve the energy efficiency of an internal combustion engine and a method for operating an internal combustion engine using such coolant composition. The coolant composition for an internal combustion engine of the invention has kinematic viscosity of 8.5 to 3,000 mm2/sec at 25° C. and 0.3 to 1.3 mm2/sec at 100° C. The method for operating an internal combustion engine of the invention is carried out with the use of such composition.

Abstract: A modular cooling unit particularly useful for an automotive vehicle is configured with a heat exchanger having a tunnel port extending at least part way through the core of the heat exchanger. The case of a cooling fan motor is mounted within the tunnel port, so as to minimize the overall length of the cooling unit.

Abstract: A thermal management system is provided for a vehicle having an electric traction motor. The system includes a coolant system configured to convey coolant through a first thermal load, a refrigerant circuit including a condenser and a compressor configured to compress a refrigerant, a control system and a sensor. The refrigerant circuit is configured to cool at least one second thermal load. The sensor is configured to send signals to the control system that are indicative of a temperature of the first thermal load. The control system is configured to control an outlet pressure of the compressor based on the signals.

Abstract: A variable cylinder engine is provided. The engine includes an engine body having a plurality of cylinders, a cooling mechanism for cooling the engine body, and a controller for controlling the cooling mechanism and changing a number of active cylinders according to an operating state of the engine. The controller reduces the number of active cylinders in a reduced-cylinder operating range set within a partial engine load range, and in a first reduced-cylinder range set within a high load part of the reduced-cylinder operating range, the controller improves a cooling performance of the cooling mechanism compared with that in a second reduced-cylinder range set within a low load part of the reduced-cylinder operating range.

Abstract: A device for a vehicle or a production machine, having: a first hydraulic pump, which hydraulically drives a load; an internal combustion engine, which mechanically drives the first hydraulic pump; a second hydraulic pump, which is hydraulically coupled to the first hydraulic pump; an apparatus, which drives the second hydraulic pump while utilizing the energy in the exhaust gas stream of the internal combustion engine; the load on the output side being directly connected to a tank.

Abstract: An electric motor control apparatus includes a phase correction portion that generates and outputs an amount of phase correction with which to correct a phase of a signal from a position sensor detecting a position of a magnetic pole of an electric motor. The phase correction portion generates and outputs an energization stop signal in a case where a rotation speed of the electric motor is within a predetermined range and stores an amount of phase correction generated therein according to a comparison between a signal from the position sensor or a first phase and an induced voltage of the electric motor to output the amount of phase correction.

Abstract: A rotary engine includes a compressor having a first rotor, a first hinged vane, an air intake port and an air outlet and an expander having two-way check valve, a second rotor, a second hinged vane, a one-way check valve, a compressed air tank and a compressed air valve interposing between the compressor and the expander, where the first and second rotors have a first end contacting a housing and the other end spaced apart from the inner surfaces of the housing, where the first and second hinged vanes have one end hinged to the housing and the other end contacting outer surfaces of the rotating rotor for operation, and a combustion chamber formed as an airtight space by a depressed surface of the housing of the expander and a surface of the hinged vane.

Abstract: Some embodiments relate to a power generation system that includes an alternator and an engine that drives the alternator to generate power. The power generation system further includes a housing where the alternator and the engine are within the housing. The housing may provide improved sound attenuation when the power generation system is operating. The housing includes a first corner rail such that a bracket is connected to one end of the first corner rail and at least one side panel. The bracket is connected along an edge of the first corner rail. The first corner rail includes a channel that extends from the end of the first corner rail along a length of the first corner rail. The power generation system includes a first fastener that extends into the channel to connect the bracket to the first corner rail.

Abstract: A drive apparatus for a vehicle auxiliary device is provided that basically includes first and second drive sources, an auxiliary device, first, second and third rollers, first, second and third idler rollers and a roller pair selection mechanism. The first, second and third rollers are linked to rotary shafts of the first and second drive sources and the auxiliary device. The first, second and third idler rollers are disposed at gap positions formed between the first, second and third rollers. The roller pair selection mechanisms select a power-transmitting roller pair from among the first, second and third rollers by selectively moving the first, second and third idler rollers in roller contact directions, thereby interposing the first, second and third idler rollers therebetween.

Abstract: A bird strike prevention device for covering an air intake of a jet engine of an airplane includes a plurality of stays arranged to form a conical shape as a whole; and a joining portion configured to connect the plurality of stays to each other on an apex side of the conical shape. The plurality of stays is mounted on the jet engine near an outer edge of the air intake at a base of the conical shape. An axis of the conical shape coincides with a rotation axis of the jet engine. The number of the stays included in the plurality of stays is determined based on a minimum size of target birds to be prevented from striking the jet engine.

Abstract: An intermediate structure of an aircraft configured to mechanically attach an engine core and an engine fan module to each other and to the aircraft. The intermediate structure may have a ring-shaped portion and/or an elongated mount beam extending substantially perpendicularly from the ring-shaped portion. The ring-shaped portion may have a forward edge and an aft edge opposite of the forward edge, and may include a first attachment portion for attaching to a flange of the engine core, a second attachment portion for attaching to a flange of the engine fan module, and a mounting portion configured for mounting directly to a pylon or airframe of an aircraft. The engine core and/or the engine fan module may independently mechanically attach to and detach from the intermediate structure. The intermediate structure may have a gearbox mounted thereto for interfacing with rotary components of the engine core and the engine fan module.

Abstract: A method of metering fuel with a fuel valve. The method includes arranging a spool within to a sleeve along an axis, wherein the spool includes four seal lands. The sleeve includes a fuel inlet aperture, a fuel outlet aperture, and a shutoff port. A first cavity and a second cavity are defined between the spool, the sleeve, and subsets of the seal lands. The fuel inlet port and the fuel outlet port abut one such cavity. Sliding the spool along the axis results in the fuel outlet aperture extending longitudinally beyond the second seal land in the upstream direction.

Abstract: When starting a dual fuel turbine engine on liquid fuel, a flow of air assist into a combined pilot gaseous fuel and air assist tube is supplied. The velocity of the flow of air assist is increased as it is expelled through an outlet of the tube. The flow of air assist is directed into a first end of a pilot injector barrel. Additional air is drawn into the first end of the pilot injector barrel from an enclosure containing both the first end of the pilot injector barrel and the tube outlet. Liquid pilot fuel is supplied at a second end of the pilot injector barrel, and this fuel is atomized by the flow of the air assist and additional air. The atomized pilot liquid fuel may then be combusted.

Abstract: Methods and devices are described for performing engine diagnostics during skip fire operation of an engine while a vehicle is being driven. Knowledge of the firing sequence is used to determine appropriate times to conduct selected diagnostics and/or to help better interpret sensor inputs or diagnostic results. In one aspect, selected diagnostics are executed when a single cylinder is fired a plurality of times in isolation relative to a sensor used in the diagnosis. In another aspect, selected diagnostics are conducted while the engine is operated using a firing sequence that insures that no cylinders in a first cylinder bank are fired for a plurality of engine cycles while cylinders in a second bank are at least sometimes fired. The described tests can be conducted opportunistically, when conditions are appropriate, or specific firing sequences can be commanded to achieve the desired isolation or skipping of one or more selected cylinders.

Abstract: A method for controlling the movement of a component that moves towards a position defined by a limit stop in an internal combustion engine; the control method comprises the steps of detecting, by means of at least one acoustic microphone, the intensity of the microphonic signal generated by the impact of the component against the limit stop; and determining the impact instant and/or the impact speed of the component against the limit stop by analyzing the intensity of the microphonic signal generated by the impact.

Abstract: A method for operating a boost pressure control in an engine system having a supercharged internal combustion engine, including the following: performing a boost pressure control based on a setpoint controller variable and an actual controller variable, ascertaining a setpoint controller variable from a provided setpoint boost pressure with a first and a second model, ascertaining an intermediate variable from a provided actual boost pressure with the first model, correcting the intermediate variable with a provided dynamic variable, which represents a dynamic change in the state of the engine system using a higher dynamics than the actual boost pressure, and ascertaining the actual controller variable from the corrected intermediate variable with the second model.

Abstract: A method of controlling an exhaust gas temperature at a particulate filter inlet is disclosed. The particulate filter is located in an exhaust system of an internal combustion engine. The method of controlling exhaust gas temperature at the particulate filter inlet includes a late injection, whose quantity is estimated as function of an exhaust gas volumetric flowrate.

Abstract: A system and method for regeneration of an aftertreatment component are described. The disclosed method can employ any one or combination of operating modes that obtain a target condition of the exhaust gas to support or initiate regeneration of the aftertreatment device.

Abstract: A start control device of a compression self-ignition engine is provided. The device includes: a determining module for determining whether a piston of a compression-stroke-in-stop cylinder that is stopped on a compression stroke according to an automatic stop is within a specific range set on a bottom dead center side of a predetermined reference stop position; an injection control module for controlling each fuel injection valve to inject fuel into the compression-stroke-in-stop cylinder first after the piston of the compression-stroke-in-stop cylinder is determined to be stopped within the specific range and the engine restart condition is satisfied; and an in-cylinder pressure estimating module for estimating an in-cylinder pressure of the compression-stroke-in-stop cylinder at a first top dead center on the compression stroke in the restart, where the piston of the compression-stroke-in-stop cylinder reaches after the restart starts.

Abstract: Methods and systems for disabling a fuel shut-off state of a vehicle. One method includes counting, by a controller, a number of transitions of an engine included in the vehicle between a fuel shut-off state and a fuel state, determining, by the controller, whether the number exceeds a predetermined threshold, and issuing a disable command, by the controller, to the engine included in the vehicle. The disable command causes the engine to exit a current fuel shut-off state. Another system includes a controller configured to determine whether acceleration is requested while an engine included in the vehicle is in a fuel shut-off state. When acceleration is requested while the vehicle is in a fuel shut-off state, the controller is configured to issue a disable command to the engine prior to issuing an acceleration command. The disable command causes the engine to exit the fuel shut-off state.

Abstract: A method for recognizing irregular combustion in an internal combustion engine includes supplying fuel directly to a combustion chamber of a cylinder of the internal combustion engine using an injector. The injector is connected to a fuel supply line that includes a pressure sensor configured to measure pressure in the fuel supply line. The pressure in the fuel supply line is measured during the supply of fuel into the combustion chamber. It is then ascertaining whether irregular combustion is occurring based on the measured pressure in the fuel supply line.

Abstract: A fuel injection timing management system for a dual fuel engine is configured to determine a first diesel injection timing corresponding to a first mode of operation of the engine system and a second diesel injection timing corresponding to a second mode of operation. The system may further determine a direction of change in a mode of operation of the engine system, and selectively perform a change in the diesel injection timing from the first diesel injection timing to the second diesel injection timing at a first rate of transition or a second rate of transition, based on the direction of change in a mode of operation of the engine system.

Abstract: A method for preventing misdiagnosis of an oil level sensor may include determining whether a driving status of a vehicle satisfies a first diagnosis condition, a second diagnosis condition or both. When the first diagnosis condition is satisfied, the method may include measuring oil levels, calculating a first average of the measured oil levels, and comparing the calculated first average of the measured oil levels with a predetermined reference oil level. When the second diagnosis condition is satisfied, the method may include measuring oil levels, calculating a second average of the measured oil levels, and comparing the calculated second average of the measured oil levels with the predetermined reference oil level. The method may also include warning an excess of oil when the first, the second or both first and second averages of the measured oil levels are higher than the predetermined reference oil level.

Abstract: An internal combustion engine is provided. The internal combustion engine includes a cylinder block having a cooling jacket and a cylinder head having two cooling jackets. In one example, the internal combustion engine may be operated so as to reduce engine friction and emissions during cold engine starts.

Abstract: A piston and method of construction are provided. The piston has a piston body with an insert forming at least a portion of an upper combustion surface. The piston body is constructed from a first material having a first thermal conductivity and the insert is constructed from a second material having a second thermal conductivity. The first thermal conductivity is less than the second thermal conductivity. The piston body has an upper crown and a pair of pin bosses depending from the upper crown with the pin bosses presenting pin bores aligned with one another along a pin bore axis. The upper crown includes a recess in which the insert is fixed.

Abstract: In a reciprocating engine piston, added equipment to renew the piston pin's oil film once per crankshaft rotation. The equipment is located between the connecting rod's small end and the underside of the piston crown. There is a plunger carrier with a plunger, and a saddle with a plunger bore. The saddle closely straddles the plunger carrier, maintaining the alignment of the arcuate plunger with the arcuate plunger bore, for a plunger stroke without friction. The small end's natural oscillation during crankshaft rotation powers the plunger's working cycle. There is an oil-filling stroke and a delivery stroke. The delivery is to the saddle's top, which is just below the piston crown. The oil pressure pushes upward on the piston crown, lifting the piston slightly and the piston pin bosses off the piston pin. In the small gap thus created, new oil can enter, recreating the oil film.

Abstract: A turbine engine cooling arrangement includes a core passage for receiving a core flow for combustion, a first airflow source including a first passage adjacent the core passage for conveying a first airflow, and a second airflow source including a second passage adjacent the first passage for conveying a second airflow. A heat exchanger is thermally connected with the first passage and the second passage for transferring heat between the first airflow and the second airflow.

Abstract: A cascade assembly is provided for installation in an aircraft nacelle. The cascade assembly comprises a first cascade portion fixed to a non-movable portion of the nacelle. The first cascade portion comprises a bracket. A second cascade portion is fixed to a translating sleeve portion of the nacelle. The second cascade portion comprises a catch. The bracket is configured to receive the catch in response to the translating sleeve portion being in a deployed position.

Abstract: A hybrid aerodynamic thrust system as a prime mover for aircraft or other high-speed vehicles. An arrangement of dual thrust resources to alternately accommodate low and high airspeed regimes. Electromotive force is used in lieu of hot section power turbines to achieve engine air compression or alternately perform thrust work at low velocities.

Abstract: An engine propulsion system is configured to utilize bursts of pressurized media in order to transmit mechanical energy. The engine propulsion system includes at least one cannon, wherein each cannon is configured to displace the pressurized media and further includes a casing configured to accommodate a rotational firing pin. The rotational firing pin is configured to transmit the mechanical energy.

Abstract: Methods and systems are provided for draining water separated from diesel fuel into an EGR system. In response to the water volume in the fuel system and EGR flow at pre-determined levels, water may be introduced into the EGR system. EGR flow may also be controlled in response to introducing water into the EGR system and engine operating conditions.

Abstract: An abnormality detection device for an exhaust gas recirculation apparatus is provided that can perform abnormality detection with respect to an EGR valve while suppressing the influence of a size relationship between an intake pressure and an exhaust pressure. An ECU (Electronic Control Unit) executes processing for extracting a pulse from an intake pipe pressure value. The ECU executes arithmetic processing for performing Fast Fourier Transform (FFT) with respect to an output waveform of an intake pressure sensor obtained by sampling processing, and also executes extraction processing that extracts a “frequency component corresponding to a period of an exhaust pulse”. The ECU executes processing that determines, in steps, whether or not the size of the extracted pulse (amplitude size) exceeds a threshold value. If the amplitude size exceeds the threshold value, the ECU executes processing that determines that a totally closed abnormality is occurring in the EGR valve.