Controller of internal combustion engine

Abstract

To provide a controller of an internal combustion engine capable of operating an internal combustion engine as continuously as possible while avoiding failure of engine parts and / or increase in rotation speed, when a fuel injection valve is in a fuel increase abnormality.SOLUTION: When at least one of average exhaust temperature values of a right bank and a left bank is higher than a first threshold value, a controller 80 stops fuel injection in the bank with the higher average exhaust temperature value. In the state, when the average exhaust temperature of the bank in which fuel injection is not stopped is higher than a second threshold value, fuel injection in that bank is also stopped, but when it is equal to or lower than the second threshold value, fuel injection in that bank is continued, allowing an engine to continue operating only on one bank side.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a control device for an internal combustion engine equipped with a fuel injection valve. [Background technology]

[0002] When the exhaust temperature of an internal combustion engine is considerably higher than the expected temperature, it can be considered that the fuel injection valve of the cylinder discharging the exhaust gas falls into an abnormal state (flow rate increase side abnormality) in which the fuel is excessively injected. Therefore, a device has been proposed that determines whether or not an abnormality has occurred in the fuel injection valve based on the detected exhaust temperature (see Patent Document 1).

[0003] Furthermore, a multi-bank engine (e.g., a V-type engine) is known that has one surge tank, a first bank (right bank) consisting of multiple cylinders each equipped with a fuel injection valve, and a second bank (left bank) consisting of multiple cylinders each equipped with a fuel injection valve. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-080399 A Summary of the Invention

[0005] In a multi-bank engine, when the average value of the exhaust gas temperature of each bank is higher than a threshold temperature, a device is being considered that stops fuel injection and ignition by the fuel injection valves of all cylinders belonging to the bank that emits exhaust gas whose average value is higher than the threshold temperature. In particular, when the fuel is hydrogen, abnormal combustion is likely to occur and even a small change in the excess air ratio leads to a large torque change, so there is a strong demand for a device that performs the above-mentioned procedure to prevent engine parts from being damaged or the rotation speed from increasing suddenly.

[0006] For example, if a fuel injection valve of a cylinder belonging to the first bank falls into a flow rate increase side abnormality, the average value of the exhaust temperature of the first bank becomes higher than the threshold temperature. At this time, if an abnormality occurs in the intake valve of the cylinder having the fuel injection valve with the flow rate increase side abnormality, the "intake gas containing excess fuel" of the cylinder flows into the surge tank during the compression stroke, and the gas is drawn from the surge tank into the cylinder belonging to the second bank. Therefore, the average value of the exhaust temperature of the second bank may also become higher than the threshold temperature. As a result, not only is fuel injection by the fuel injection valve of the cylinder belonging to the first bank stopped, but also fuel injection by the fuel injection valve of the cylinder belonging to the second bank is stopped. In this case, even though the second bank side is originally operable, both the first bank and the second bank (i.e., the entire engine) stop operating. This causes a problem that the vehicle cannot be driven to an evacuation mode.

[0007] The present invention has been made to solve the above problems. That is, one of the objects of the present invention is to provide a control device for an internal combustion engine that is capable of operating the internal combustion engine as continuously as possible while avoiding failure of engine parts and / or an increase in rotation speed when a fuel injector falls into a fuel increase side abnormality.

[0008] The control device for an internal combustion engine of the present invention (the device of the present invention) includes a first exhaust gas temperature sensor (70R) that detects a first exhaust gas temperature corresponding to the temperature of the exhaust gas discharged from a plurality of cylinders (21, 23, 25) belonging to a first bank, a second exhaust gas temperature sensor (70L) that detects a second exhaust gas temperature corresponding to the temperature of the exhaust gas discharged from a plurality of cylinders (22, 24, 26) belonging to a second bank, and a controller (80) that controls the fuel injection valves of each cylinder. The cylinders of the first and second banks take in air through a common surge tank (14).

[0009] The controller: when at least one of the average value of the first exhaust temperature and the average value of the second exhaust temperature is higher than a predetermined first threshold value, stopping the fuel injection from the fuel injection valves provided for the plurality of cylinders belonging to the first bank when the average value of the first exhaust temperature is higher than the average value of the second exhaust temperature, and stopping the fuel injection from the fuel injection valves provided for the plurality of cylinders belonging to the second bank when the average value of the second exhaust temperature is higher than the average value of the first exhaust temperature; when the average value of the second exhaust temperature is higher than a predetermined second threshold value in a case where the fuel injection from the fuel injection valves provided for the plurality of cylinders belonging to the first bank is stopped and the fuel injection from the fuel injection valves provided for the plurality of cylinders belonging to the second bank is continued, the fuel injection from the fuel injection valves provided for the plurality of cylinders belonging to the second bank is also stopped, When the fuel injection from the fuel injection valves provided for the plurality of cylinders belonging to the second bank is stopped and the fuel injection from the fuel injection valves provided for the plurality of cylinders belonging to the first bank is continued, if the average value of the first exhaust temperature is higher than the second threshold value, the fuel injection from the fuel injection valves provided for the plurality of cylinders belonging to the first bank is also stopped.

[0010] According to this, even if a fuel injector of a cylinder belonging to one bank falls into a flow rate increase side abnormality and, as a result, the average value of the exhaust temperature of not only the one bank but also the other bank becomes higher than the first threshold value, the operation of the one bank is stopped first. As a result, if the average value of the exhaust temperature of the other bank becomes lower than the second threshold value, the operation of the other bank is continued. Therefore, since the operation of the engine by at least the other bank is continued, the evacuation operation of the vehicle can be continued. Furthermore, if a fuel injector with a flow rate increase side abnormality exists in the other bank, the average value of the exhaust temperature of the other bank becomes higher than the second threshold value, and therefore the operation of the other bank is also stopped. Therefore, damage to engine parts and / or a sudden increase in the rotation speed can be avoided. [Brief description of the drawings]

[0011] [Figure 1] 1 is a schematic configuration diagram of a control device for an internal combustion engine according to an embodiment of the present invention; [Diagram 2] This is a routine executed by the CPU of the ECU shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] <Configuration> A control device for an internal combustion engine according to an embodiment of the present invention (hereinafter referred to as "the present embodiment device") is applied to a spark ignition type internal combustion engine 10 shown in Fig. 1. This internal combustion engine uses hydrogen (hydrogen gas) as fuel, but may be an internal combustion engine using other fuels.

[0013] The internal combustion engine 10 is a V-type six-cylinder engine and includes an air cleaner 11, an intake passage component 12, a throttle valve 13 rotatably supported on the intake passage component 12, a surge tank 14, an engine block 20 which constitutes the first to sixth cylinders (21-26), first to sixth intake manifolds (31-36) each having one end connected to the surge tank 14 and the other end connected to each of the first to sixth cylinders (21-26), first to sixth exhaust manifolds (41-46) each connected to the first to sixth cylinders (21-26), a right exhaust passage component 50R in which a right catalytic converter 51R is disposed, and a left exhaust passage component 50L in which a left catalytic converter 51L is disposed. The part of engine block 20 constituting the first, third, and fifth cylinders (21, 23, 25) is referred to as the right bank (first bank), and the part of engine block 20 constituting the second, fourth, and sixth cylinders (22, 24, 26) is referred to as the left bank (second bank).

[0014] The first, third, and fifth exhaust manifolds (41, 43, 45) are connected to a right exhaust passage component 50R at a junction SR. The second, fourth, and sixth exhaust manifolds (42, 44, 46) are connected to a left exhaust passage component 50L at a junction SL.

[0015] The present embodiment includes an actuator 13A for changing the opening of the throttle valve 13, fuel injection valves (61-66) provided in the first to sixth cylinders (21-26), a right exhaust temperature sensor (first exhaust temperature sensor) 70R provided between the collecting section SR of the right exhaust passage component 50R and the right catalytic converter 51R, a left exhaust temperature sensor (second exhaust temperature sensor) 70L provided between the collecting section SL of the left exhaust passage component 50L and the left catalytic converter 51L, other sensors 71, and a controller (i.e., an ECU, which is an electronic control device) 80 having a microcomputer including a CPU. The other sensors 71 include a crank angle sensor, an engine speed sensor, an accelerator pedal operation amount sensor, an air flow meter, and the like. The controller 80 is electrically connected to the above-mentioned components (13A, 61-66, 70R, 70L, and 71). The controller 80 determines the fuel injection amount Fin based on the accelerator pedal operation amount detected by the accelerator pedal operation amount sensor and the engine speed detected by the engine speed sensor, and injects fuel in the determined fuel injection amount Fin from each of the fuel injection valves (61-66) and generates sparks from a spark generating device (not shown) of each cylinder.

[0016] The right exhaust temperature sensor 70R detects the temperature TexR of the exhaust gas discharged from the first, third, and fifth cylinders (21, 23, 25) in the right bank (first bank). The left exhaust temperature sensor 70L detects the temperature TexL of the exhaust gas discharged from the second, fourth, and sixth cylinders (22, 24, 26) in the left bank (second bank).

[0017] (Activation) The CPU repeatedly executes the routine shown in FIG. 2 every time a predetermined time has elapsed. In the following, "step" is abbreviated as "S". At a predetermined timing, the CPU starts processing from S200 in FIG. 2, and determines whether or not there is a stopped bank in S205. A stopped bank is a bank (right bank or left bank) in which fuel injection from the fuel injection valves of all cylinders belonging to that bank and ignition of the cylinders are stopped. If there is a stopped bank, the CPU proceeds directly to S295.

[0018] If there is no stopped bank, the CPU proceeds from S205 to S210 and determines whether or not at least one of the following first and second conditions is satisfied. (First condition) The average value (left bank exhaust temperature average value) TexLav of the exhaust temperature TexL from the cylinders belonging to the left bank over a specified period of time (e.g., one engine revolution) is higher than a first threshold value (first abnormality determination temperature) TthB(Fin, NE) determined by the average fuel injection amount Fin and the average engine rotation speed NE during that specified period of time. (Second condition) The average value (right bank exhaust temperature average value) TexRav of the temperature TexR of the exhaust from the cylinders belonging to the right bank over a predetermined time period (for example, one engine revolution) is higher than the first threshold value TthB(Fin, NE).

[0019] If neither the first nor the second condition is satisfied, the CPU proceeds directly to S295. On the other hand, if at least one of the first and second conditions is satisfied, the CPU proceeds from S210 to S215, where it determines whether the left bank exhaust temperature average value TexLav is higher than the right bank exhaust temperature average value TexRav. The exhaust temperature average value of the bank to which the cylinder having the fuel injector with the flow rate increase abnormality belongs is higher than the exhaust temperature average values ​​of the other banks.

[0020] If the left bank exhaust temperature average value TexLav is higher than the right bank exhaust temperature average value TexRav, the CPU performs the processes from S220 to S235 described below, proceeds to S295, and temporarily ends this routine.

[0021] S220: The CPU stops fuel injection from the fuel injectors and ignition spark generation (ignition) from the spark plugs of all cylinders (the second, fourth, and sixth cylinders (22, 24, 26)) belonging to the left bank. That is, the CPU sets the left bank as the operation stop bank. S225: The CPU determines whether a predetermined time (for example, the time required for several revolutions of the engine) has elapsed since the execution of the process of S220, and repeats the determination of S225 until the predetermined time has elapsed. When the predetermined time has elapsed, the CPU proceeds to S230.

[0022] S230: The CPU judges whether the right bank exhaust temperature average value TexRav for a predetermined time (for example, one engine revolution) is higher than a second threshold value (second abnormality judgment temperature) TthC(Fin, NE) determined by the average fuel injection amount Fin and the average engine speed NE for the predetermined time (i.e., whether the third condition is satisfied). The second threshold value TthC(Fin, NE) may be the same as or different from the first threshold value TthB(Fin, NE). If the third condition is not satisfied, the CPU proceeds directly to S295 and ends this routine. As a result, the engine continues to operate only on the right bank. On the other hand, if the third condition is satisfied, the CPU proceeds to S235.

[0023] S235: The CPU stops fuel injection and ignition for all cylinders (the first, third and fifth cylinders (21, 23, 25)) belonging to the right bank. That is, the CPU also sets the right bank as an operation stop bank. As a result, the operation of the engine is stopped.

[0024] On the other hand, when the CPU proceeds to S210, if the right bank exhaust temperature average TexRav is equal to or higher than the left bank exhaust temperature average TexLav, the CPU performs the processes from S240 to S255 described below, proceeds to S295, and temporarily ends this routine.

[0025] S240: The CPU stops fuel injection and ignition for all cylinders (the first, third and fifth cylinders (21, 23, 25)) belonging to the right bank. That is, the CPU sets the right bank as the stopped bank. S245: The CPU determines whether a predetermined time (for example, the time required for several revolutions of the engine) has elapsed since the execution of the process of S240, and repeats the determination of S245 until the predetermined time has elapsed. When the predetermined time has elapsed, the CPU proceeds to S250.

[0026] S250: The CPU determines whether the left bank exhaust temperature average value TexLav is higher than the second threshold value TthC(Fin, NE) (i.e., whether the fourth condition is met). If the fourth condition is not met, the CPU proceeds directly to S295 and ends this routine. As a result, the engine continues to operate only on the left bank. On the other hand, if the fourth condition is met, the CPU proceeds to S255.

[0027] S255: The CPU stops fuel injection and ignition for all cylinders (the second, fourth, and sixth cylinders (22, 24, 26)) belonging to the left bank. That is, the CPU also sets the left bank as an operation stop bank. As a result, the operation of the engine is stopped.

[0028] As explained above, the present embodiment first stops the operation of the bank with the higher average exhaust temperature value, and in that state, if the average exhaust temperature value of the bank that continues to operate is equal to or lower than the second threshold value, the operation of that bank continues. Thus, the operation of the normal bank can be continued. In addition, the present embodiment also stops the operation of the bank that continues to operate if the average exhaust temperature value of that bank is higher than the second threshold value.

[0029] In addition, the CPU constantly determines whether or not the cylinder abnormality condition, "the amount of change per unit time dTex of the temperature of the exhaust gas discharged from the Nth cylinder is greater than the abnormal change threshold value dTexth," is satisfied, and if the cylinder abnormality condition is satisfied, the CPU may stop fuel injection from the fuel injection valve of the Nth cylinder and also stop ignition of the Nth cylinder. [Explanation of symbols]

[0030] 14...surge tank, 70R...right exhaust temperature sensor, 70L...left exhaust temperature sensor.

Claims

[Claim 1] a first bank and a second bank each having a plurality of cylinders; a surge tank common to the plurality of cylinders belonging to the first bank and the plurality of cylinders belonging to the second bank; A plurality of fuel injection valves provided for each of the plurality of cylinders; The present invention is applied to an internal combustion engine comprising: a first exhaust gas temperature sensor that is provided in a portion of an exhaust passage through which exhaust gas discharged from the plurality of cylinders belonging to the first bank passes after being collected, the first exhaust gas temperature sensor detecting a first exhaust gas temperature corresponding to a temperature of the exhaust gas discharged from the plurality of cylinders belonging to the first bank; a second exhaust gas temperature sensor that is provided in a portion of an exhaust passage through which exhaust gas discharged from the plurality of cylinders belonging to the second bank passes after being collected, and that detects a second exhaust gas temperature corresponding to a temperature of the exhaust gas discharged from the plurality of cylinders belonging to the second bank; a controller for controlling the plurality of fuel injection valves so that the plurality of fuel injection valves inject fuel; In a control device for an internal combustion engine, The controller: when at least one of the average value of the first exhaust temperature and the average value of the second exhaust temperature is higher than a predetermined first threshold value, stopping the fuel injection from the fuel injection valves provided for the plurality of cylinders belonging to the first bank when the average value of the first exhaust temperature is higher than the average value of the second exhaust temperature, and stopping the fuel injection from the fuel injection valves provided for the plurality of cylinders belonging to the second bank when the average value of the second exhaust temperature is higher than the average value of the first exhaust temperature; when the average value of the second exhaust temperature is higher than a predetermined second threshold value in a case where the fuel injection from the fuel injection valves provided for the plurality of cylinders belonging to the first bank is stopped and the fuel injection from the fuel injection valves provided for the plurality of cylinders belonging to the second bank is continued, the fuel injection from the fuel injection valves provided for the plurality of cylinders belonging to the second bank is also stopped, when the average value of the first exhaust temperature is higher than the second threshold value in a case where the fuel injection from the fuel injection valves provided for the plurality of cylinders belonging to the second bank is stopped and the fuel injection from the fuel injection valves provided for the plurality of cylinders belonging to the first bank is continued, the fuel injection from the fuel injection valves provided for the plurality of cylinders belonging to the first bank is also stopped. It was configured as follows: A control device for an internal combustion engine.

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