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JP-7856040-B2 - Control device for internal combustion engines

JP7856040B2JP 7856040 B2JP7856040 B2JP 7856040B2JP-7856040-B2

Inventors

  • 野々村 仁志

Assignees

  • 株式会社豊田自動織機

Dates

Publication Date
20260511
Application Date
20230414

Claims (3)

  1. A control device for a compression-ignition type internal combustion engine, A fuel injection amount calculation means for calculating a reference fuel injection amount to achieve the required air-fuel ratio, Each injection amount calculation means allocates the reference fuel injection amount to a main injection amount injected in the main injection and a post-injection amount which is the injection amount of a post-injection injected at a retarded angle compared to the main injection, based on the operating state of the internal combustion engine. An injection timing calculation means calculates the main injection timing, which is the injection timing of the main injection, and the post-injection timing, which is the injection timing of the post-injection, based on the required torque. A post-burning period determination means for determining whether the end time of the post-injection combustion is at a set crank angle, A control device for an internal combustion engine, comprising: correction means for correcting the post-injection timing and the main injection amount when the combustion termination timing is not the set crank angle.
  2. The correction means is When the combustion termination time is advanced compared to the set crank angle, the post-injection timing is corrected to retard the angle and the main injection amount is increased. The control device for an internal combustion engine according to claim 1, wherein when the combustion termination time is retarded compared to the set crank angle, the post-injection timing is advanced and the main injection amount is reduced.
  3. The exhaust passage of the aforementioned internal combustion engine is equipped with an exhaust gas purification catalyst. The control device for an internal combustion engine according to claim 1 or claim 2, wherein the required air-fuel ratio is the air-fuel ratio set when the exhaust gas purification catalyst is warmed up.

Description

This disclosure relates to a control device for an internal combustion engine. Japanese Patent Publication No. 2011-32949 (Patent Document 1) describes a method for increasing exhaust temperature in a compression-ignition internal combustion engine by performing a secondary injection following the main injection of fuel. This Patent Document 1 describes controlling the in-cylinder temperature at the secondary injection timing (secondary injection timing) within a predetermined temperature range, where the secondary injection fuel combustion temperature is the lower limit and the temperature at which the torque generated by the combustion of the secondary injection fuel falls below an acceptable value is the upper limit. This ensures sufficient combustion of the fuel injected by the secondary injection while suppressing the torque generated by the combustion of the fuel injected by the secondary injection to an acceptable value. This is said to increase the exhaust temperature and prevent the torque fluctuation of the internal combustion engine from exceeding an acceptable level. Japanese Patent Publication No. 2011-32949 This diagram schematically shows the overall configuration of the internal combustion engine according to this embodiment.This diagram illustrates an example of fuel injection and combustion in the warm-up mode.This figure shows an example of a functional block configured in the ECU in this embodiment.This flowchart shows an example of the fuel injection control process performed in the ECU during warm-up mode.This flowchart shows an example of the processing in the post-combustion end time calculation routine. The embodiments of this disclosure will be described in detail below with reference to the drawings. Parts identical or corresponding to those shown in the drawings are denoted by the same reference numerals, and their descriptions will not be repeated. Figure 1 is a schematic diagram showing the overall configuration of the internal combustion engine according to this embodiment. Referring to Figure 1, the engine (internal combustion engine) 1 is a compression-ignition type internal combustion engine (diesel engine) equipped with an exhaust gas purification device 70. The engine 1 is used, for example, as a power source for a vehicle. The engine 1 is an internal combustion engine that injects fuel from a fuel injector 14 into the combustion chamber formed in the cylinder 12 of the engine body 10, and performs compression auto-ignition. In this embodiment, the engine 1 has four cylinders. The intake passage 20 of the engine 1 is provided with an air cleaner 22, an intercooler 24, and an intake throttle valve (diesel throttle valve) 26. Fresh air (air) from which foreign matter has been removed by the air cleaner 22 is supercharged (compressed) by the compressor 32 of the turbocharger 30, cooled by the intercooler 24, supplied to the intake manifold 28, and then supplied to each combustion chamber from the intake port. Fuel is stored in the fuel tank 40. The fuel in the fuel tank 40 is supplied to the high-pressure fuel pump 42 by the feed pump 41. The high-pressure fuel discharged from the high-pressure fuel pump 42 is then pumped through the fuel passage 43 to the common rail 44. The high-pressure fuel stored in the common rail 44 is then injected from the injector 14 into the combustion chamber (cylinder). The exhaust gas discharged from the combustion chamber is collected in the exhaust manifold 50 and released into the outside air via the exhaust passage 52. A portion of the exhaust gas is also recirculated to the intake manifold 28 via the EGR (Exhaust Gas Recirculation) passage 60. The EGR passage 60 is equipped with an EGR cooler 62 and an EGR valve 64. The exhaust passage 52 is equipped with a turbocharger 30 turbine 34. Downstream of the turbine 34, an exhaust gas purification device 70 is provided, comprising an oxidation catalyst 71, a DPF (Diesel Particulate Filter) 72, a selective reduction catalyst (hereinafter also referred to as an SCR (Selective Catalytic Reduction) catalyst) 73, and an oxidation catalyst 74. The oxidation catalyst 71 oxidizes and purifies CO (carbon monoxide), HC (hydrocarbons), and SOF (Soluble Organic Fraction) contained in the exhaust gas. Furthermore, when the oxidation catalyst 71 burns and removes particulate matter (PM) collected in the DPF 72, it burns (oxidizes) the supplied HC, thereby increasing the exhaust gas temperature. A sculptural crystal (SCR) catalyst 73 is located in the exhaust passage 52 downstream of the DPF 72. The SCR catalyst 73, for example, is made by supporting copper (Cu) ion-exchange zeolite as a catalyst on a ceramic carrier, and exhibits a high NOx purification rate by using ammonia (NH3) as a reducing agent. The ammonia used as a reducing agent is generated by hydrolysis and thermal decomposition of urea water supplied to the exhaust passage 52 upstream of the SCR catalyst 73. A urea addition valve (urea water injec