JP2021110285A - Control device of internal combustion engine - Google Patents

Abstract

To optimally switch a cylinder pause operation and a full-cylinder operation according to the loading weight of a vehicle and a road face gradient.SOLUTION: There is provided a control device of an internal combustion engine 1 which is mounted to a vehicle, and can pause a part of cylinders #1, 4 out of all the cylinders #1 to 4. The control device comprises a weight detector 42 for detecting the loading weight of the vehicle, and a control unit 100 for performing a cylinder pause operation when a requirement load is equal to a load threshold or smaller, and performing a full-cylinder operation when the requirement load is larger than the load threshold. When the detected loading weight is equal to the first weight threshold or smaller, the control unit performs the cylinder pause operation even if the requirement load is larger than the load threshold, and when the detected loading weight is larger than a second weight threshold which is larger than the first weight threshold, the control unit performs the full-cylinder operation even if the requirement load is equal to the load threshold or smaller.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a control device for an internal combustion engine, and more particularly to a control device applied to a multi-cylinder internal combustion engine mounted on a vehicle and capable of suspending some of all cylinders.

A multi-cylinder internal combustion engine capable of suspending some of all cylinders in order to improve the fuel efficiency and exhaust emissions of a vehicle is known (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2016-133008

Generally, switching between cylinder deactivation operation and all-cylinder operation is performed by comparing the load required for the internal combustion engine by the driver of the vehicle, that is, the required load with a predetermined load threshold value.

However, depending on the load weight of the vehicle, such switching may not always be optimal. The same applies to the slope of the road surface on which the vehicle travels.

Therefore, the present disclosure was conceived in view of such circumstances, and an object thereof is to provide a control device for an internal combustion engine capable of optimally switching between cylinder deactivation operation and all-cylinder operation according to the load weight of a vehicle and the slope of a road surface. There is.

According to one aspect of the present disclosure
It is an internal combustion engine control device that is installed in a vehicle and can suspend some of all cylinders.
A weight detector that detects the loaded weight of the vehicle and
When the required load of the internal combustion engine is equal to or less than a predetermined load threshold value, the internal combustion engine is deactivated, and when the required load of the internal combustion engine is larger than the load threshold value, the internal combustion engine is operated in all cylinders. The configured control unit and
With
The control unit is
When the loaded weight detected by the weight detector is equal to or less than a predetermined first weight threshold value, the internal combustion engine is deactivated by cylinder even when the required load of the internal combustion engine is larger than the load threshold value.
When the loaded weight detected by the weight detector is larger than the predetermined second weight threshold value larger than the first weight threshold value, even when the required load of the internal combustion engine is equal to or less than the load threshold value. Provided is a control device for an internal combustion engine, which comprises operating the internal combustion engine for all cylinders.

Preferably, the control unit is
A plurality of maps that define the relationship between the rotation speed of the internal combustion engine and the load threshold value, the first map used when the load weight is equal to or less than the first weight threshold value, and the first map in which the load weight is the first. A plurality of maps including a second map used when the weight is greater than one weight threshold value and equal to or less than the second weight threshold value, and a third map used when the loaded weight is larger than the second weight threshold value. In advance,
By switching the plurality of maps according to the load weight detected by the weight detector, cylinder deactivation operation and all cylinder operation are switched according to the load weight.

According to another aspect of the present disclosure.
It is an internal combustion engine control device that is installed in a vehicle and can suspend some of all cylinders.
A gradient detector that detects the gradient of the road surface on which the vehicle travels, and
When the load of the internal combustion engine is equal to or less than a predetermined load threshold value, the internal combustion engine is operated in cylinder deactivation, and when the load of the internal combustion engine is larger than the load threshold value, the internal combustion engine is operated in all cylinders. Control unit and
With
The control unit is
When the gradient detected by the gradient detector is equal to or less than a predetermined first gradient threshold value, the internal combustion engine is deactivated by cylinder even when the load of the internal combustion engine is larger than the load threshold value.
When the gradient detected by the gradient detector is larger than a predetermined second gradient threshold value larger than the first gradient threshold value, the internal combustion engine is also when the load of the internal combustion engine is equal to or less than the load threshold value. A control device for an internal combustion engine is provided, which is characterized by operating the engine in all cylinders.

Preferably, the control unit is
A plurality of maps that define the relationship between the rotation speed of the internal combustion engine and the load threshold value, the first map used when the gradient is equal to or less than the first gradient threshold value, and the first gradient whose gradient is the first gradient. A plurality of maps including a second map used when the gradient is larger than the threshold value and equal to or less than the second gradient threshold value and a third map used when the gradient is larger than the second gradient threshold value are stored in advance. death,
By switching the plurality of maps according to the gradient detected by the gradient detector, cylinder deactivation operation and all cylinder operation are switched according to the gradient.

According to the present disclosure, it is possible to optimally switch between cylinder deactivation operation and all-cylinder operation according to the load weight of the vehicle and the slope of the road surface.

It is the schematic of the internal combustion engine which concerns on embodiment. It is a figure which shows a base map and a problem. It is a figure which shows the ranking of a load weight and a gradient. It is a figure which shows three maps corresponding to each rank. It is a figure which shows the map switching method. It is a flowchart which shows the routine of control.

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be noted that the present disclosure is not limited to the following embodiments.

FIG. 1 is a schematic view of an internal combustion engine according to an embodiment of the present disclosure. The internal combustion engine (also referred to as an engine) 1 is a multi-cylinder compression ignition type internal combustion engine mounted on a vehicle (not shown), and specifically, an in-line 4-cylinder diesel engine. The vehicle is a large vehicle, specifically a truck. However, the type, type, application, etc. of the vehicle and the internal combustion engine are not particularly limited. For example, the vehicle may be a small vehicle such as a passenger car, and the engine may be a spark-ignition internal combustion engine (for example, a gasoline engine or a natural gas engine). There may be.

The engine 1 includes an engine main body 2 and an intake passage 3 and an exhaust passage 4 connected to the engine main body 2. The engine body 2 includes structural parts such as a cylinder head, a cylinder block, and a crankcase, and movable parts such as a piston, a crankshaft, an intake valve, and an exhaust valve housed therein. The intake and exhaust flows are indicated by white arrows and black arrows, respectively.

Each cylinder is provided with a fuel injection valve, that is, an injector 7, which injects fuel directly into the cylinder 9.

The intake passage 3 is mainly defined by an intake manifold 10 connected to the engine body 2 (particularly a cylinder head) and an intake pipe 11 connected to the upstream end of the intake manifold 10. The intake pipe 11 is provided with an air cleaner 12, an air flow meter 13, a turbocharger 14 compressor 14C, an intercooler 15, and an electronically controlled intake throttle valve 16 in this order from the upstream side. The air flow meter 13 is a sensor for detecting the intake air amount (intake flow rate) per unit time of the engine 1.

The exhaust passage 4 is mainly defined by an exhaust manifold 20 connected to the engine body 2 (particularly a cylinder head) and an exhaust pipe 21 arranged on the downstream side of the exhaust manifold 20. A turbine 14T of a turbocharger 14 is provided between the exhaust pipe 21 or the exhaust manifold 20 and the exhaust pipe 21. A plurality of catalysts are provided in the exhaust pipe 21 on the downstream side of the turbine 14T. In the present embodiment, the oxidation catalyst 22, the particulate filter 23, the selective reduction NOx catalyst 24, and the ammonia oxidation catalyst 26 are provided in this order from the upstream side. An addition valve 25 for adding urea water is provided on the upstream side of the NOx catalyst 24. Since the particulate filter 23 is a continuously regenerating filter with a catalyst, it is included in the catalyst here.

The engine 1 also includes an external EGR30. The external EGR device 30 is installed outside the engine body 2 in order to recirculate a part of the exhaust gas (EGR gas) in the exhaust passage 4 (particularly in the exhaust manifold 20) into the intake passage 3 (particularly in the intake manifold 10). The EGR passage 31 is provided, an EGR cooler 32 for cooling the EGR gas flowing through the EGR passage 31, and an EGR valve 33 for adjusting the flow rate of the EGR gas.

The engine 1 includes four cylinders # 1 to # 4. Two of them, specifically # 2 and 3, are considered to be constantly operating cylinders that are always operated when the engine is running. The remaining two cylinders, specifically # 1 and # 4, are considered to be pauseable cylinders that can be paused when the engine is running.

The combustion order of each cylinder is # 1, 3, 4, 2. Since the operating cylinder and the deactivated cylinder appear alternately during the cylinder deactivation operation, it is advantageous in terms of vibration suppression. It should be noted that which cylinder number is used for the constantly operating cylinder and the suspendable cylinder is arbitrary.

Here, cylinder deactivation means to stop the fuel injection of the deactivated cylinder and to stop the operation of at least one of the intake valve and the exhaust valve (collectively referred to as a valve) to maintain the valve closed state. In this embodiment, the operation of both the intake valve and the exhaust valve is stopped.

The engine 1 is provided with a valve stop device 50 configured to selectively stop the intake valves and exhaust valves of the stoptable cylinders # 1 and # 4. The valve deactivation device 50 includes a plurality of valve deactivation mechanisms 51 provided for the intake valve and the exhaust valve of each cylinder. The configuration of these valve suspension mechanisms 51 is the same. As for the configuration of the valve suspension mechanism 51, various ones including known ones can be adopted. For example, one that switches the presence or absence of driving force transmission from the camshaft to the valve by flood control, one equipped with an electromagnetic actuator that drives the valve, and the like can be adopted. When the valve suspension mechanism 51 is activated (on), the intake valve or exhaust valve of the corresponding cylinder is stopped in the closed state, and when the valve suspension mechanism 51 is activated (off), the intake valve or exhaust valve of the corresponding cylinder is activated. do.

The vehicle is provided with a control device for controlling the engine 1. The control device includes a control unit, a circuit element (circuitry), or an electronic control unit (referred to as an ECU (Electronic Control Unit)) 100 that forms a controller. The ECU 100 includes the above-mentioned air flow meter 13, a rotation speed sensor 40 for detecting the rotation speed of the engine (specifically, the number of revolutions per minute (rpm)), and the amount of depression of the accelerator pedal by the driver of the vehicle. The accelerator opening sensor 41 for detecting the accelerator opening proportional to the above is electrically connected.

The ECU 100 is configured to control the injector 7, the intake throttle valve 16, the addition valve 25, the EGR valve 33, and the valve suspension mechanism 51 based on the parameters related to the engine operating state detected by these sensors and the like.

The ECU 100 is based on the engine speed Ne and the accelerator opening Ac detected by the rotation speed sensor 40 and the accelerator opening sensor 41, respectively, and according to a predetermined map (may be a function; the same applies hereinafter), the engine required by the vehicle driver. The required torque Tr, which is the value of the torque, is calculated. The required torque Tr can also be calculated based only on the accelerator opening degree Ac. The ECU 100 calculates a fuel injection amount Q such that a torque equal to the required torque Tr is actually output from the engine, and injects a fuel equal to the fuel injection amount Q from the injector 7. For example, the ECU 100 calculates the fuel injection amount Q according to a predetermined map based on the detected engine speed Ne and the calculated required torque Tr.

The required torque Tr is a value that correlates with the load required for the engine by the driver of the vehicle, that is, the required load, in other words, is an index value representing the required load. Other such index values can be considered. For example, the accelerator opening degree Ac or the fuel injection amount Q may be used instead of the required torque Tr.

The ECU 100 basically switches between cylinder deactivation operation (or cylinder deactivation operation) and all cylinder deactivation operation (that is, cylinder deactivation control is executed) according to a base map stored in advance as shown in FIG. 2A. In the figure, the line a shows the maximum required torque Trmax for each engine speed Ne, and the line b shows the torque threshold Trs which is a load threshold value for each engine speed Ne. The low load side region where the required torque Tr is equal to or less than the torque threshold Trs is the cylinder deactivation region A, and the high load side region where the required torque Tr is larger than the torque threshold Trs is the all cylinder region B.

When the engine operating state defined by the engine speed Ne and the required torque Tr is in the cylinder deactivation region A, that is, when Tr ≤ Trs, the ECU 100 operates the constantly operating cylinders # 2 and 3 and the deactivated cylinder # 1. Executes cylinder deactivation operation to deactivate ， 4. At this time, in the suspendable cylinders # 1 and 4, the ECU 100 turns off the injector 7 to stop the fuel injection, and also stops the operation of the intake valve and the exhaust valve by the valve suspension mechanism 51 to close them. maintain.

On the other hand, when the engine operating state defined by the engine speed Ne and the required torque Tr is in the all cylinder region B, that is, when Tr> Trs, the ECU 100 has the constantly operating cylinders # 2 and 3 and the pauseable cylinders # 1,. Execute all-cylinder operation in which 4 is operated together. At this time, the ECU 100 turns on the injectors 7 of all cylinders at each injection timing to execute fuel injection, and opens and closes the intake valve and the exhaust valve of the suspendable cylinders # 1 and 4 by the valve suspension mechanism 51.

The switching between cylinder deactivation operation and all-cylinder operation is performed by comparing the required torque Tr with the torque threshold value Trs corresponding to the engine speed Ne.

However, depending on the load weight of the vehicle, such uniform switching may not always be optimal. The same applies to the slope of the road surface on which the vehicle travels. This problem will be described below.

As shown in FIG. 2B, when the load weight of the vehicle is light, such as when the vehicle is empty, the driver depresses the accelerator pedal to accelerate the vehicle, and the engine operating state is the cylinder deactivation region on the low load side. It is assumed that the shift from A (point c) to the high load side all cylinder region B (point d).

At this time, in many cases, it is empirically understood that the engine output and acceleration become excessive, the driver releases the accelerator pedal, weakens the acceleration, and the engine operating state returns to the cylinder deactivation region A (point e) again. ..

That is, when the load weight of the vehicle is light, there is a high possibility that even if the vehicle is once shifted from the cylinder deactivation region A to the all cylinder deactivation region B, it will return to the cylinder deactivation region A again. On the other hand, since the operation and suspension of the suspendable cylinders # 1 and 4 are switched when straddling each region, the durability and reliability of the valve arrest device 50 may decrease. When the engine operating state frequently straddles the cylinder deactivation region A and all cylinder regions B near the torque threshold value Trs, control hunting occurs, which is even more so.

Similar problems can occur when the road surface is steep, for example downhill. Here, the slope S of the road surface means the slope of the road surface along the vehicle traveling direction, and the gradient S is represented by S (%) = tan θ × 100, where θ is the inclination angle of the road surface along the vehicle traveling direction. .. The gradient S is positive when it is uphill and negative when it is downhill.

As shown in FIG. 2B, when the slope of the road surface is small, the driver depresses the accelerator pedal to accelerate the vehicle, and the engine operating state changes from the cylinder deactivation region A (point c) to the entire cylinder region B (point d). ).

At this time as well, it is empirically understood that in many cases, the engine output and acceleration become excessive, the driver releases the accelerator pedal, weakens the acceleration, and the engine operating state returns to the cylinder deactivation region A (point e) again. ing. Therefore, the operation and deactivation of the deactivated cylinders # 1 and 4 may be unnecessarily switched, and the durability and reliability of the valve deactivation device 50 may decrease.

Therefore, as will be described in detail later, in the present embodiment, the engine is used even when the required torque Tr is larger than the torque threshold Trs when the load weight is light and one or both of the road surface slopes are small. Is operated with cylinder deactivation. As a result, it is possible to eliminate the switching to all-cylinder operation, which is less necessary, and suppress the deterioration of the durability and reliability of the valve arrest device 50.

On the other hand, contrary to the above, when the load weight of the vehicle is heavy, for example, when the load is full, the driver loosens the accelerator pedal, weakens the acceleration of the vehicle, and the engine, as shown in FIG. 2 (C). It is assumed that the operating state shifts from the all cylinder region B (point f) on the high load side to the cylinder deactivation region A (point g) on the low load side.

At this time, in many cases, it is empirically that the engine output becomes insufficient after the acceleration is weakened, the driver depresses the accelerator pedal, the acceleration of the vehicle is strengthened, and the engine operating state returns to the whole cylinder region B (point h) again. It is grasped.

That is, when the loaded weight of the vehicle is heavy, there is a high possibility that even if the vehicle shifts to the cylinder deactivation region A once, it returns to the all cylinder region B again. On the other hand, since the operation and suspension of the suspendable cylinders # 1 and 4 are switched when straddling each region, the durability and reliability of the valve arrest device 50 may decrease. When the engine operating state frequently straddles the cylinder deactivation region A and all cylinder regions B near the torque threshold value Trs, control hunting occurs, which is even more so.

Similar problems can occur when the road surface is steep, for example on steep uphill slopes. As shown in FIG. 2C, when the road surface slope is large, the driver loosens the accelerator pedal, weakens the acceleration of the vehicle, and the engine operating state changes from the all cylinder area B (point f) to the cylinder deactivation area A (point g). ).

At this time as well, in many cases, the engine output is insufficient after the acceleration is weakened, the driver depresses the accelerator pedal, the acceleration of the vehicle is strengthened, and the engine operating state returns to the whole cylinder region B (point h) again. Is grasped. Therefore, the operation and deactivation of the deactivated cylinders # 1 and 4 may be unnecessarily switched, and the durability and reliability of the valve deactivation device 50 may decrease.

Therefore, as will be described in detail later, in the present embodiment, the engine is used even when the required torque Tr is equal to or less than the torque threshold Trs when the load weight is heavy and when one or both of the road surface slopes are large. To operate all cylinders. As a result, it is possible to eliminate the switching to the cylinder deactivation operation, which is less necessary, and suppress the deterioration of the durability and reliability of the valve deactivation device 50.

As described above, according to the present embodiment, it is possible to optimally switch between cylinder deactivation operation and all-cylinder operation according to the load weight of the vehicle and the slope of the road surface.

The control device of the present embodiment includes a weight detector that detects the load weight of the vehicle and a gradient detector that detects the gradient of the road surface on which the vehicle travels. It should be noted that the detection includes estimation.

Various configurations of the weight detector are possible. In the present embodiment, the weight detector is configured by the weight sensor 42 (see FIG. 1) that directly detects the weight of the load loaded on the loading platform of the vehicle, that is, the loaded weight W. The weight sensor 42 is mounted on the vehicle and electrically connected to the ECU 100. Alternatively, a position sensor that detects the height position of a specific part in the suspension unit of the suspension device or the loading platform is electrically connected to the ECU 100, and the load weight is loaded by the ECU 100 based on the height position detected by this position sensor. May be estimated. In this case, the position sensor and the ECU 100 constitute a weight detector. The lower the height position, the heavier the load weight.

Various configurations of the gradient detector are possible. In the present embodiment, the navigation system 43 (see FIG. 1) mounted on the vehicle detects the slope S of the road surface at the current position of the vehicle based on its own vehicle position information and map information. In addition to this, the slope S of the road surface in front of the vehicle may be detected. The navigation system 43 is electrically connected to the ECU 100 and sends the detected value of the gradient S to the ECU 100. The navigation system 43 constitutes a gradient detector. Alternatively or additionally, the gradient S may be estimated by photographing the road surface in front of the vehicle with a camera mounted on the front surface of the vehicle and analyzing the photographed image with the ECU 100. In this case, the camera and the ECU 100 are included in the components of the gradient detector. The gradient S may be detected by using the navigation system 43 and the camera together. In addition, the gradient S may be detected by using another sensor such as an acceleration sensor.

In the present embodiment, as shown in FIG. 3, the load weight W and the gradient S are generally classified into three stages of small, medium, and large. On the other hand, as shown in FIG. 4, the ECU 100 stores in advance three maps corresponding to each rank. The ECU 100 selects a map corresponding to the actual rank of the load weight W and the gradient S, and switches between cylinder deactivation operation and all cylinder operation according to the selected map.

As shown in FIG. 3A, the first weight threshold value W1 and the second weight threshold value W2 are preset for the loaded weight W and stored in the ECU 100. The first weight threshold value W1 is slightly larger than the minimum weight Wmin (specifically, zero) when the load is empty. The second weight threshold value W2 is larger than the first weight threshold value W1 and slightly smaller than the maximum weight Wmax when fully loaded.

When the load weight W is equal to or less than the first weight threshold value W1, the rank of the load weight W (hereinafter referred to as the weight rank) is small. When the load weight W is larger than the first weight threshold value W1 and equal to or less than the second weight threshold value W2, the weight rank is medium. When the load weight W is larger than the second weight threshold value W2, the weight rank is large.

Further, as shown in FIG. 3B, the first gradient threshold value S1 and the second gradient threshold value S2 are preset for the gradient S and stored in the ECU 100. The first gradient threshold value S1 is slightly larger than zero, which is the gradient on flat ground. The second gradient threshold value S2 is larger than the first gradient threshold value S1 and is substantially equal to the value of the gradient such that the boundary between the normal ascending gradient and the steep ascending gradient is formed.

When the gradient S is equal to or less than the first gradient threshold value S1, the gradient rank is small. When the gradient S is larger than the first gradient threshold value S1 and equal to or less than the second gradient threshold value S2, the gradient rank is medium. When the gradient S is greater than the second gradient threshold S2, the gradient rank is large. The small slope rank includes the case where the road surface is flat and the case where the road surface is a downward slope.

Next, the map will be described. The aforementioned base map shown in FIG. 2 (A) is used when the weight rank or gradient rank is medium, which is the same as the second map shown in FIG. 4 (B). Hereinafter, the second map shown in FIG. 4B is referred to as a medium rank map.

On the other hand, the first map shown in FIG. 4A is used when the weight rank or the gradient rank is small, and this is referred to as a small rank map. In the small rank map, only the cylinder deactivation region A exists when the required torque Tr is equal to or less than the torque threshold Trs, and the all cylinder region B does not exist.

Further, the third map shown in FIG. 4C is used when the weight rank or the gradient rank is large, and this is referred to as a large rank map. In the large rank map, only all cylinder areas B over the entire operating area exist, and cylinder deactivation area A does not exist.

Here, when the small rank map shown in FIG. 4A is used, the required torque Tr is limited to the torque threshold value Trs or less. That is, even if the actual required torque Tr obtained from the actual engine speed Ne and the accelerator opening Ac is larger than the torque threshold Trs, the calculated required torque Tr used for calculating the fuel injection amount Q is , It is limited to a value equal to the torque threshold Trs as a guard value.

This forces the driver to deactivate the cylinders, although they should be in all cylinders. However, in such a case, it is empirically known that even if the actual required torque Tr exceeds the torque threshold Trs once, it immediately returns to the torque threshold Trs or less. Therefore, the driver may be forced to endure or feel uncomfortable for a very short time, but instead, it is possible to eliminate the switching to all-cylinder operation and suppress the deterioration of the durability and reliability of the valve arrest device 50. ..

Further, once the actual required torque Tr exceeds the torque threshold Trs, it is preferable to maintain the cylinder deactivation operation rather than switching to the all-cylinder operation in terms of fuel efficiency. This is because when the required torque Tr is limited to the torque threshold Trs, the fuel injection amount is zero in the stationary cylinder and the fuel injection amount is maximum in the operating cylinder, and the thermal efficiency of the engine as a whole is good. On the contrary, when all cylinders are operated, the fuel injection amount is considerably smaller than the maximum in all cylinders, and the thermal efficiency of the engine as a whole is inferior to that in the cylinder deactivated operation.

Further, by maintaining the cylinder deactivation operation without switching to the all-cylinder operation, the torque shock associated with the switching can be eliminated.

Now, as an example of the simplest cylinder deactivation control, an example of switching the map based only on the weight rank will be described. In this case, when the weight rank is small, cylinder deactivation control is performed according to the small rank map shown in FIG. 4A, and the engine is always deactivated. Even if the actual required torque Tr exceeds the torque threshold Trs, the engine is forcibly deactivated.

When the weight rank is medium, cylinder deactivation control is performed according to the medium rank map shown in FIG. 4 (B) as usual, and cylinder deactivation operation and all cylinder operation are performed according to the comparison result of the required torque Tr and the torque threshold Trs. Is switched. When the weight rank is large, cylinder deactivation control is performed according to the large rank map shown in FIG. 4C, and the engine is always operated in all cylinders. Even if the actual required torque Tr becomes equal to or less than the torque threshold Trs, the engine is forcibly operated in all cylinders, and switching to cylinder deactivation operation is prevented.

In this way, by switching the three maps according to the load weight W detected by the weight detector, the cylinder deactivation operation and the all-cylinder operation are switched according to the load weight W. As a result, switching can be optimally performed according to the load weight W.

The same applies to the example of switching the map based only on the gradient rank. When the gradient rank is small, cylinder deactivation control is performed according to the small rank map shown in FIG. 4 (A). When the gradient rank is medium, cylinder deactivation control is performed according to the medium rank map shown in FIG. 4 (B). When the gradient rank is large, cylinder deactivation control is performed according to the large rank map shown in FIG. 4 (C).

In this way, by switching the three maps according to the gradient S detected by the gradient detector, the cylinder deactivation operation and the all-cylinder operation are switched according to the gradient S. Thereby, the switching can be optimally performed according to the gradient S.

In this embodiment, the map is switched based on both the weight rank and the gradient rank. An example of the switching method at this time is shown in FIG.

A small rank map is used when the weight rank is small and the gradient rank is small, that is, when the combination of weight rank and gradient rank is (small, small).

Similarly, when (small, medium), (small, large), (medium, small), (medium, medium), (medium, large), the medium rank map is used. When (Large, Small), (Large, Medium), (Large, Large), the large rank map is used.

Since the use of the small rank map is limited to (small, small), it is possible to prevent switching to all-cylinder operation without impairing drivability as much as possible. Moreover, since the large rank map is always used when the weight rank is large, a large engine output can always be stably obtained regardless of the gradient. In other cases, since the medium rank map is used, it is possible to perform preferable switching according to the required torque Tr.

However, the switching method described here is just an example, and other switching methods can be adopted.

The relationship between the weight rank, the gradient rank, and the map shown in FIG. 5 is stored in the ECU 100 in advance in the form of a table.

Next, the control routine in this embodiment will be described with reference to FIG. The illustrated routine is repeatedly executed by the ECU 100 every predetermined calculation cycle τ (for example, 720 ° CA).

First, in step S101, the ECU 100 acquires the detected or calculated values of the actual engine speed Ne, the required torque Tr, the load weight W, and the gradient S.

Next, in step S102, the ECU 100 compares the acquired load weight W and the gradient S with the corresponding threshold values to determine the weight rank and the gradient rank (see FIG. 3).

Next, in step S103, the ECU 100 selects a map corresponding to the weight rank and the gradient rank according to a predetermined table (see FIG. 5).

Next, in step S104, the ECU 100 causes the engine to operate in cylinder deactivation or all cylinders according to the selected map, and ends the routine.

As described above, according to the present embodiment, it is possible to optimally switch between cylinder deactivation operation and all-cylinder operation according to the load weight of the vehicle and the slope of the road surface. Then, unnecessary switching can be eliminated, the switching frequency can be optimized, and the deterioration of the durability and reliability of the valve deactivation device or the system can be suppressed.

Although the embodiments of the present disclosure have been described in detail above, various other embodiments and modifications of the present disclosure can be considered.

(1) In the large rank map shown in FIG. 4 (C), the entire region is the all cylinder region B, which means that the torque threshold Trs is substantially equal to zero.

However, it is not always necessary to set the torque threshold Trs', which is larger than zero and smaller than the torque threshold Trs of the medium rank map. Then, the all cylinder area B expanded to the low load side from all the cylinder area B of the medium rank map and the cylinder deactivation area A reduced to the low load side from the cylinder deactivation area A of the medium rank map are made into a large rank map. It may be set.

Even in this way, the frequency of switching from all-cylinder operation to cylinder deactivation operation can be reduced, so that the same effect as described above can be achieved.

(2) The size of the threshold value for determining each rank shown in FIG. 3 can be changed as appropriate. For example, the first gradient threshold value S1 shown in FIG. 3B may be equal to zero on flat ground or may be smaller than zero.

(3) In the above embodiment, the load weight and the gradient are ranked in three stages, and three maps are set corresponding to the ranks. However, the number of ranks and maps may be larger, and all cylinders may be used. The switching method between operation and cylinder deactivation operation may be changed in more stages.

(4) In the above embodiment, the load weight and the gradient are ranked in three stages, and the map is switched according to the ranks. However, the switching method between all-cylinder operation and cylinder deactivation operation may be changed steplessly without ranking. For example, the value of the load threshold (torque threshold Trs) of a single map may be changed according to the magnitude of at least one of the load weight and the gradient.

(5) Without using a map, the method of switching between all-cylinder operation and cylinder deactivation operation may be changed according to at least one value of the load weight and the gradient.

(6) In the above embodiment, the total number of cylinders (four) is bisected into a constantly operating cylinder and a restable cylinder, but it does not necessarily have to be bisected. The number of suspensionable cylinders may be larger or smaller than the number of constantly operating cylinders.

(7) All cylinders may be deactivated cylinders, and the cylinder number to be deactivated may be changed according to the engine operating state or the like during cylinder deactivated operation.

The configurations of the above-described embodiments and modifications can be combined partially or wholly, unless otherwise inconsistent. The embodiments of the present disclosure are not limited to the above-described embodiments, and all modifications, applications, and equivalents included in the ideas of the present disclosure defined by the claims are included in the present disclosure. Therefore, this disclosure should not be construed in a limited way and may be applied to any other technique that falls within the scope of the ideas of this disclosure.

1 Internal combustion engine (engine)
7 Injector 42 Weight sensor 43 Navigation system 50 Valve deactivation device 51 Valve deactivation mechanism 100 Electronic control unit (ECU)

Claims (4)

It is an internal combustion engine control device that is installed in a vehicle and can suspend some of all cylinders.
A weight detector that detects the loaded weight of the vehicle and
When the required load of the internal combustion engine is equal to or less than a predetermined load threshold value, the internal combustion engine is deactivated, and when the required load of the internal combustion engine is larger than the load threshold value, the internal combustion engine is operated in all cylinders. The configured control unit and
With
The control unit is
When the loaded weight detected by the weight detector is equal to or less than a predetermined first weight threshold value, the internal combustion engine is deactivated by cylinder even when the required load of the internal combustion engine is larger than the load threshold value.
When the loaded weight detected by the weight detector is larger than the predetermined second weight threshold value larger than the first weight threshold value, even when the required load of the internal combustion engine is equal to or less than the load threshold value. A control device for an internal combustion engine, characterized in that the internal combustion engine is operated in all cylinders. The control unit is
A plurality of maps that define the relationship between the rotation speed of the internal combustion engine and the load threshold value, the first map used when the load weight is equal to or less than the first weight threshold value, and the first map in which the load weight is the first. A plurality of maps including a second map used when the weight is greater than one weight threshold value and equal to or less than the second weight threshold value, and a third map used when the loaded weight is larger than the second weight threshold value. In advance,
The control device for an internal combustion engine according to claim 1, wherein the cylinder deactivation operation and the all-cylinder operation are switched according to the load weight by switching the plurality of maps according to the load weight detected by the weight detector. It is an internal combustion engine control device that is installed in a vehicle and can suspend some of all cylinders.
A gradient detector that detects the gradient of the road surface on which the vehicle travels, and
When the load of the internal combustion engine is equal to or less than a predetermined load threshold value, the internal combustion engine is operated in cylinder deactivation, and when the load of the internal combustion engine is larger than the load threshold value, the internal combustion engine is operated in all cylinders. Control unit and
With
The control unit is
When the gradient detected by the gradient detector is equal to or less than a predetermined first gradient threshold value, the internal combustion engine is deactivated by cylinder even when the load of the internal combustion engine is larger than the load threshold value.
When the gradient detected by the gradient detector is larger than a predetermined second gradient threshold value larger than the first gradient threshold value, the internal combustion engine is also when the load of the internal combustion engine is equal to or less than the load threshold value. An internal combustion engine control device characterized by operating the engine in all cylinders. The control unit is
A plurality of maps that define the relationship between the rotation speed of the internal combustion engine and the load threshold value, the first map used when the gradient is equal to or less than the first gradient threshold value, and the first gradient whose gradient is the first gradient. A plurality of maps including a second map used when the gradient is larger than the threshold value and equal to or less than the second gradient threshold value and a third map used when the gradient is larger than the second gradient threshold value are stored in advance. death,
The control device for an internal combustion engine according to claim 3, wherein the plurality of maps are switched according to the gradient detected by the gradient detector to switch between cylinder deactivation operation and all cylinder operation according to the gradient.

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