JP6232346B2 - engine - Google Patents

Description

  The present invention relates to engine technology.

  Conventionally, an engine equipped with a supercharger has been publicly known. An engine provided with a supercharger sensor that detects the rotation speed of the supercharger is also known. For example, Patent Document 1 discloses an engine that detects a surging state of a supercharger using a detected supercharger rotation speed.

  However, the engine disclosed in Patent Document 1 does not suggest a configuration for detecting an abnormality of the turbocharger other than the surging state. In addition, it is difficult to detect an abnormality in the supercharger using only the supercharger rotation speed detected by the supercharger rotation speed sensor.

JP 2009-127453 A

  The problem to be solved by the present invention is to provide an engine capable of detecting abnormality of a supercharger using a supercharger rotation speed sensor.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  That is, in claim 1, a supercharger, a supercharger rotation speed detection means for detecting the rotation speed of the supercharger, an exhaust gas temperature detection means for detecting an exhaust gas temperature, and the supercharger Control means for detecting an abnormality, and the control means calculates the reference supercharger rotational speed by a supercharger rotational speed map that is a correlation between the engine rotational speed, the load, and the reference supercharger rotational speed. The reference exhaust gas temperature is calculated from an exhaust gas temperature map which is a correlation between the engine speed, the load and the reference exhaust gas temperature, and the supercharger rotation speed detected by the supercharger rotation speed detection means Abnormality of the supercharger is detected based on the magnitude relationship with the reference supercharger rotational speed and the magnitude relationship between the exhaust gas temperature detected by the exhaust gas temperature detection means and the reference exhaust gas temperature. Is.

  According to a second aspect of the present invention, in the engine according to the first aspect, the control means is configured such that the supercharger rotational speed is greater than the reference supercharger rotational speed and the exhaust gas temperature is equal to or lower than the reference exhaust gas temperature. In some cases, the supercharger rotational speed is equal to the reference supercharger rotational speed and the exhaust gas temperature is smaller or larger than the reference exhaust gas temperature, or the supercharger rotational speed is the reference supercharger. When the exhaust gas temperature is smaller than the rotation speed and the exhaust gas temperature is equal to or higher than the reference exhaust gas temperature, an abnormality of the supercharger is detected.

  According to a third aspect of the present invention, the engine according to the first or second aspect is provided with an atmospheric pressure sensor that detects an atmospheric pressure, and the control means is a correlation between the engine speed, the load, and a fuel injection amount. A fuel injection amount map, wherein the supercharger rotational speed is greater than the reference supercharger rotational speed, the exhaust gas temperature is equal to or lower than the reference exhaust gas temperature, and the atmospheric pressure is lower than a predetermined atmospheric pressure; Alternatively, when the supercharger rotational speed is equal to the reference supercharger rotational speed, the exhaust gas temperature is lower than the reference exhaust gas temperature, and the atmospheric pressure is lower than the predetermined atmospheric pressure, the fuel injection amount The map is corrected.

  According to the engine of the present invention, the abnormality of the supercharger can be detected using the supercharger rotation speed sensor.

The block diagram which shows the structure of an engine. The graph which shows a supercharger rotation speed map. The graph which shows an exhaust-gas temperature map. The flowchart which shows the flow of supercharger abnormality detection control. The table figure which shows the determination pattern of supercharger abnormality detection control.

The configuration of the engine 100 will be described with reference to FIG.
In addition, in FIG. 1, the structure of the engine 100 is typically represented with the block diagram. Moreover, the broken line of FIG. 1 represents the electric signal line.

  The engine 100 is an embodiment according to the engine of the present invention. The engine 100 includes an air supply path 10, an exhaust path 20, an engine body 30, a high-pressure supercharger 60, a low-pressure supercharger 70, and an engine control unit (hereinafter referred to as ECU) 50 as control means. I have.

  The engine 100 of the present embodiment is a direct injection 6-cylinder diesel engine equipped with a two-stage supercharger. The engine of the present invention is configured as a direct injection 6-cylinder diesel engine, but is not limited thereto. The engine of the present invention may be a direct injection type four-cylinder engine, a V-type engine, or a sub-chamber engine.

  The air supply path 10 is a path for supplying air to the engine body 30. The air supply manifold 11, the intercoolers 12 and 13, the high pressure compressor 61, the low pressure compressor 71, the air cleaner 14, Is connected.

  The air supply manifold 11, the intercoolers 12 and 13, the high pressure compressor 61, the low pressure compressor 71 and the air cleaner 14 are directed from the outside toward the engine body 30. The air supply manifolds 11 are arranged in this order and are connected by an air supply pipe.

  The air supply manifold 11 is a manifold for introducing air into the cylinders 31 of the engine body 30. The intercooler 12 is a heat exchanger that cools air whose temperature has been increased by compression of the high-pressure compressor 61 and the low-pressure compressor 71. The intercooler 13 is a heat exchanger that cools air whose temperature has been increased by compression of the low-pressure compressor 71.

  The high-pressure compressor 61 is a component of the high-pressure supercharger 60 and will be described in detail later. The low-pressure compressor 71 is a component of the low-pressure supercharger 70 and will be described in detail later. The air cleaner 14 separates dust contained in the air supply with a filter medium such as a nonwoven fabric.

  The exhaust path 20 is a path for discharging air (exhaust gas) from the engine body 30 and is configured by connecting an exhaust manifold 21, a high-pressure turbine 62, and a low-pressure turbine 72 to an exhaust pipe. The exhaust manifold 21, the high pressure turbine 62, and the low pressure turbine 72 are arranged in the order of the exhaust manifold 21, the high pressure turbine 62, and the low pressure turbine 72 from the engine body 30 to the outside, and are connected by an exhaust pipe.

  The exhaust manifold 21 is a manifold that collects a plurality of exhaust pipes from the cylinders 31 of the engine body 30 into one. The high pressure turbine 62 is a component of the high pressure supercharger 60 and will be described in detail later. The low-pressure turbine 72 is a component of the low-pressure supercharger 70 and will be described in detail later.

  An exhaust gas temperature sensor 56 is provided on the most upstream side of the exhaust path 20 (upstream of the high-pressure turbine 62). The exhaust gas temperature sensor 56 detects the exhaust gas temperature Te, which is the temperature of the exhaust gas. The exhaust gas temperature sensor 56 is connected to the ECU 50.

  The engine body 30 includes a cylinder block (not shown), a cylinder head (not shown), and a fuel injection device 35. A plurality (six) of cylinders 31, 31... Are formed in the cylinder block. The fuel injection device 35 is a device that injects fuel accumulated in the common rail into each cylinder by an injector. The fuel injection device 35 is connected to the ECU 50.

  The high-pressure supercharger 60 is a device that raises the pressure of air taken in by the engine 100 to atmospheric pressure or higher, and is provided on the upstream side (as viewed from the exhaust path 20) of the two-stage supercharger. The high pressure supercharger 60 includes a high pressure compressor 61 and a high pressure turbine 62.

  The high-pressure turbine 62 is rotated at high speed using the internal energy of the exhaust gas discharged from the exhaust pipe. The high-pressure compressor 61 is driven by the high-pressure turbine 62 and sends compressed air from the supply pipe to the engine 100.

  The high-pressure supercharger 60 is provided with a supercharger rotational speed sensor 55 that detects the supercharger rotational speed Nt. The supercharger rotation speed sensor 55 is connected to the ECU 50.

  The low-pressure supercharger 70 is a device that raises the pressure of air taken in by the engine 100 to atmospheric pressure or higher, and is provided on the downstream side (as viewed from the exhaust path 20) of the two-stage supercharger. The low pressure supercharger 70 includes a low pressure compressor 71 and a low pressure turbine 72.

  The low-pressure turbine 72 is rotated at high speed using the internal energy of the exhaust gas discharged from the exhaust pipe. The low-pressure compressor 71 is driven by the low-pressure turbine 72 and sends compressed air from the supply pipe to the engine 100.

  The bypass path 40 connects the upstream side and the downstream side of the high-pressure turbine 62. The bypass path 40 is provided with a bypass valve 22 (a waste gate valve) as a turbocharger speed increasing / decreasing means. The bypass valve 22 limits the flow rate of exhaust gas that passes through the bypass path 40.

  In other words, the bypass valve 22 increases or decreases the supercharger rotational speed Nt of the high-pressure supercharger 60 by limiting the flow rate of the exhaust gas passing through the bypass path 40 as supercharger rotational speed increase / decrease means. It is.

  The ECU 50 comprehensively controls the operation of the engine 100. The ECU 50 is connected to an engine speed sensor 51, a load sensor 52, an atmospheric pressure sensor 53, a supercharger speed sensor 55, an exhaust gas temperature sensor 56, and a fuel injection device 35.

  The engine speed sensor 51 detects the engine speed Ne of the engine 100. The load sensor 52 detects the load Ac of the engine 100 (accelerator opening in this embodiment). The atmospheric pressure sensor 53 detects the atmospheric pressure P around the engine 100.

  The ECU 50 has a function of detecting an abnormality of the high-pressure supercharger 60 by a supercharger abnormality detection control S100 described later. Further, the ECU 50 stores a supercharger rotation speed map Fnt, an exhaust gas temperature map Fte, and a fuel injection amount map Fq, which will be described later.

The supercharger rotation speed map Fnt will be described with reference to FIG.
In FIG. 2, the supercharger speed map Fnt is represented by a three-dimensional graph of the engine speed Ne, the load Ac, and the reference supercharger speed Ntm.

  The supercharger rotational speed map Fnt represents the correlation among the engine rotational speed Ne, the load Ac, and the reference supercharger rotational speed Ntm. The supercharger rotation speed map Fnt is stored in the ECU 50 in advance.

  The supercharger rotational speed map Fnt represents the reference supercharger rotational speed Ntm as an appropriate rotational speed at the engine rotational speed Ne and the load Ac. That is, the reference supercharger speed Ntm is calculated from the engine speed Ne, the load Ac, and the supercharger speed map Fnt.

The exhaust gas temperature map Fte will be described with reference to FIG.
In FIG. 3, the exhaust gas temperature map Fte is represented by a three-dimensional graph of the engine speed Ne, the load Ac, and the reference exhaust gas temperature Tem.

  The exhaust gas temperature map Fte represents the correlation among the engine speed Ne, the load Ac, and the reference exhaust gas temperature Tem. It is assumed that the exhaust gas temperature map Fte is stored in the ECU 50 in advance.

  The exhaust gas temperature map Fte represents a reference exhaust gas temperature Tem as an appropriate exhaust gas temperature at the engine speed Ne and the load Ac. That is, the reference exhaust gas temperature Tem is calculated from the engine speed Ne, the load Ac, and the exhaust gas temperature map Fte.

The flow of the supercharger abnormality detection control S100 will be described with reference to FIG.
In addition, in FIG. 4, the flow of supercharger abnormality detection control S100 is represented by the flowchart.

  The supercharger abnormality detection control S100 is performed by the ECU 50 based on the magnitude relationship between the supercharger rotation speed Nt and the reference supercharger rotation speed Ntm and the magnitude relationship between the exhaust gas temperature Te and the reference exhaust gas temperature Tem. In this control, an abnormality of the high-pressure supercharger 60 is detected.

  In step S110, the ECU 50 acquires the supercharger rotation speed Nt by the supercharger rotation speed sensor 55.

  In step S120, the ECU 50 acquires the engine rotational speed Ne by the engine rotational speed sensor 51, acquires the load Ac by the load sensor 52, and performs a reference excess from the engine rotational speed Ne, the load Ac, and the supercharger rotational speed map Fnt. The feeder rotation speed Ntm is calculated.

  In step S <b> 130, the ECU 50 acquires the exhaust gas temperature Te by the exhaust gas temperature sensor 56.

  In step S140, the ECU 50 acquires the engine rotational speed Ne by the engine rotational speed sensor 51, acquires the load Ac by the load sensor 52, and the reference exhaust gas temperature from the engine rotational speed Ne, the load Ac, and the exhaust gas temperature map Fte. Tem is calculated.

  In step S150, the ECU 50 determines that the supercharger rotational speed Nt is smaller than the reference supercharger rotational speed Ntm and the exhaust gas temperature Te is equal to or higher than the reference exhaust gas temperature Tem, or the supercharger rotational speed Nt is equal to the reference supercharger rotational speed Nt. It is confirmed whether the exhaust gas temperature Te is equal to the feeder rotation speed Ntm and the exhaust gas temperature Te is higher than the reference exhaust gas temperature Tem (first condition).

  If the first condition is satisfied, the ECU 50 proceeds to step S210. On the other hand, the ECU 50 proceeds to step S160 when the first condition is not satisfied.

  In step S160, the ECU 50 determines that the supercharger rotation speed Nt is greater than the reference supercharger rotation speed Ntm and the exhaust gas temperature Te is equal to or lower than the reference exhaust gas temperature Tem, or the supercharger rotation speed Nt is equal to the reference supercharger rotation speed Nt. It is confirmed whether the exhaust gas temperature Te is equal to the feeder rotational speed Ntm and the exhaust gas temperature Te is lower than the reference exhaust gas temperature Tem (second condition).

  If the second condition is satisfied, the ECU 50 proceeds to step S180. On the other hand, when the second condition is not satisfied, the ECU 50 proceeds to step S170.

  In step S170, the ECU 50 detects normality of the high pressure supercharger 60.

  In step S180, the ECU 50 acquires the atmospheric pressure P by the atmospheric pressure sensor 53.

  In step S190, the ECU 50 confirms whether the atmospheric pressure P is equal to or higher than a predetermined atmospheric pressure Pt. When the atmospheric pressure P is equal to or higher than the predetermined atmospheric pressure Pt, the ECU 50 proceeds to step S210. On the other hand, when the atmospheric pressure P is lower than the predetermined atmospheric pressure Pt, the ECU 50 proceeds to step S200. The predetermined atmospheric pressure Pt is an atmospheric pressure when the engine 100 is located on a flat ground, and is stored in the ECU 50 in advance.

  In step S200, the ECU 50 determines that the engine 100 is located at a high altitude, and corrects the fuel injection amount map Fq (not shown) (high altitude correction). In the present embodiment, detailed description of correction of the fuel injection amount map Fq is omitted.

  In step S210, the ECU 50 detects an abnormality of the high-pressure supercharger 60 and shifts to the failure diagnosis mode. In the present embodiment, detailed description of the failure diagnosis mode is omitted.

  The supercharger rotation speed Nt and the reference supercharger rotation speed Ntm are equal, the exhaust gas temperature Te and the reference exhaust gas temperature Tem are equal, or the atmospheric pressure P is equal to the predetermined atmospheric pressure Pt. The absolute value of the supercharger rotation speed Nt and the reference supercharger rotation speed Ntm may be within a predetermined range.

The detection pattern of the supercharger abnormality detection control S100 will be described with reference to FIG.
In addition, in FIG. 5, the detection pattern of supercharger abnormality detection control S100 is represented by the table.

  In the supercharger abnormality detection control S100, the high pressure overload is determined based on the magnitude relationship between the turbocharger rotation speed Nt and the reference supercharger rotation speed Ntm and the magnitude relationship between the exhaust gas temperature Te and the reference exhaust gas temperature Tem. The normality or abnormality of the feeder 60 is detected.

  In the supercharger abnormality detection control S100, when the supercharger rotational speed Nt is larger than the reference supercharger rotational speed Ntm and the exhaust gas temperature Te is larger than the reference exhaust gas temperature Tem, the supercharger rotational speed Nt is the reference supercharger. When the engine speed Ntm is equal and the exhaust gas temperature Te is equal to the reference exhaust gas temperature Tem, or when the turbocharger speed Nt is smaller than the reference turbocharger speed Ntm and the exhaust gas temperature Te is the reference exhaust gas temperature Tem If it is smaller, normality of the high-pressure supercharger 60 is detected.

  In the supercharger abnormality detection control S100, when the supercharger speed Nt is smaller than the reference supercharger speed Ntm and the exhaust gas temperature Te is equal to or higher than the reference exhaust gas temperature Tem, or the supercharger speed Nt is When the reference turbocharger speed Ntm is equal and the exhaust gas temperature Te is higher than the reference exhaust gas temperature Tem (when the first condition is satisfied), an abnormality of the high-pressure supercharger 60 is detected and a failure diagnosis mode is established. Migrate to

  In the supercharger abnormality detection control S100, when the supercharger speed Nt is larger than the reference supercharger speed Ntm and the exhaust gas temperature Te is equal to or lower than the reference exhaust gas temperature Tem, or the supercharger speed Nt is If the reference turbocharger speed Ntm is equal and the exhaust gas temperature Te is lower than the reference exhaust gas temperature Tem (when the second condition is satisfied), it is confirmed whether the atmospheric pressure P is lower than the predetermined atmospheric pressure Pt. .

  In the supercharger abnormality detection control S100, when the atmospheric pressure P is equal to the predetermined atmospheric pressure Pt, it is determined that the high-pressure supercharger 60 is abnormal, and the process proceeds to the failure diagnosis mode. On the other hand, when the atmospheric pressure P is smaller than the predetermined atmospheric pressure Pt, the high altitude correction of the fuel injection amount map Fq is performed.

The effect of engine 100 will be described.
According to the engine 100, using the supercharger speed sensor 55, the magnitude relationship between the supercharger speed Nt and the reference supercharger speed Ntm, and the magnitude between the exhaust gas temperature Te and the reference exhaust gas temperature Tem. Based on the relationship, the abnormality of the high-pressure supercharger 60 can be detected.

DESCRIPTION OF SYMBOLS 10 Supply path 11 Supply manifold 12 Intercooler 13 Intercooler 14 Air cleaner 20 Exhaust path 21 Exhaust manifold 22 Bypass valve 30 Engine main body 31 Cylinder 35 Fuel injection device 40 Bypass path 50 ECU (control means)
53 Atmospheric pressure sensor (atmospheric pressure detection means)
55 Supercharger rotation speed sensor (supercharger rotation speed detection means)
56 Exhaust gas temperature sensor (exhaust gas temperature detection means)
60 High-pressure turbocharger (supercharger)
61 High-pressure compressor 62 High-pressure turbine 70 Low-pressure turbocharger 71 Low-pressure compressor 72 Low-pressure turbine

Claims (3)

A turbocharger,
Supercharger rotation speed detection means for detecting the rotation speed of the supercharger;
Exhaust gas temperature detecting means for detecting the exhaust gas temperature;
Control means for detecting abnormality of the supercharger;
With
The control means includes
Calculating the reference supercharger speed by a supercharger speed map which is a correlation between the engine speed, the load and the reference supercharger speed,
Calculating the reference exhaust gas temperature by an exhaust gas temperature map which is a correlation between the engine speed, the load and the reference exhaust gas temperature;
The magnitude relationship between the supercharger rotation speed detected by the supercharger rotation speed detection means and the reference supercharger rotation speed, the exhaust gas temperature detected by the exhaust gas temperature detection means, and the reference exhaust gas temperature And detecting an abnormality of the turbocharger based on the magnitude relationship with
engine. The engine according to claim 1,
The control means includes
When the supercharger speed is greater than the reference supercharger speed and the exhaust gas temperature is equal to or lower than the reference exhaust gas temperature, the supercharger speed is equal to the reference supercharger speed and the When the exhaust gas temperature is smaller or larger than the reference exhaust gas temperature, or when the turbocharger rotation speed is smaller than the reference turbocharger rotation speed and the exhaust gas temperature is equal to or higher than the reference exhaust gas temperature Detecting an abnormality of the supercharger,
engine. The engine according to claim 1 or 2,
Equipped with an atmospheric pressure sensor that detects atmospheric pressure,
The control means includes
A fuel injection amount map that is a correlation between the engine speed, the load, and the fuel injection amount;
When the supercharger rotation speed is larger than the reference supercharger rotation speed and the exhaust gas temperature is equal to or lower than the reference exhaust gas temperature and the atmospheric pressure is lower than a predetermined atmospheric pressure, or the supercharger rotation When the number is equal to the reference supercharger rotation speed, the exhaust gas temperature is lower than the reference exhaust gas temperature, and the atmospheric pressure is lower than the predetermined atmospheric pressure, the fuel injection amount map is corrected.
engine.

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