JP3941715B2 - Engine exhaust throttle valve control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an engine exhaust throttle valve control device, and more particularly to an engine exhaust throttle valve control device having an exhaust particulate collection device in an exhaust passage.
[0002]
[Prior art]
Conventionally, when the engine temperature (for example, engine water temperature) is low and it is necessary to perform engine warm-up operation (engine operation control that actively increases the engine temperature), it is known to perform various warm-up operations. It has been.
[0003]
For example, Patent Document 1 below discloses closing an exhaust throttle valve provided in an exhaust passage when the engine water temperature is low.
[0004]
According to such a prior art, closing the exhaust throttle valve increases exhaust resistance and increases the fuel supply amount and air amount for maintaining the same engine speed, thereby increasing the heat generation amount of the engine. Thus, the engine temperature can be raised.
[0005]
Further, exhaust particulates are captured by a particulate filter disposed in an exhaust passage so that exhaust particulates (particulates) such as carbon contained in the exhaust gas are not released to the atmosphere.
[0006]
[Problems to be solved by the invention]
However, when the latter exhaust passage is provided with a particulate filter, when the warm-up operation control in which the former exhaust throttle valve is closed and the warm-up operation is applied is applied, the exhaust collected in the particulate filter If the exhaust throttle valve is closed in a state where the amount of fine particles is large, there arises a problem that engine combustion performance is deteriorated and fuel consumption is deteriorated.
[0007]
That is, simply combining the above two prior arts does not take into account the amount of exhaust particulate trapped in the particulate filter in the closing amount of the exhaust throttle valve, so the exhaust trapped in the particulate filter is not considered. If the amount of fine particles is large, in addition to the increase in exhaust pressure caused by closing the exhaust throttle valve, the increase in exhaust pressure in the particulate filter due to the large amount of exhaust fine particles is added, so the exhaust pressure will increase too much. Become.
[0008]
Then, the excessive increase in the exhaust pressure causes the internal EGR amount to become excessive and the combustion efficiency to be extremely lowered, so that the combustion state becomes unstable, causing worst and engine stall. In addition, the fuel supply amount necessary for maintaining the same rotational speed increases, resulting in deterioration of fuel consumption.
[0009]
The present invention has been made in consideration of the above-described problems, and its purpose is to warm up the engine by closing the exhaust throttle valve in an engine having exhaust particulate collection means such as a particulate filter in the exhaust passage. Exhaust throttle of the engine that can ensure warm-up performance while suppressing deterioration of combustion performance and deterioration of fuel consumption when exhaust particulate collection means has a large amount of exhaust particulate when applying warm-up operation control to be performed The object is to provide a valve control device.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides the following solution as a solution. That is, in the first configuration of the present invention, an exhaust particulate collection means that is provided in the exhaust passage of the engine and collects exhaust particulates in the exhaust gas;
Exhaust particulate amount detection means for detecting parameters related to the amount of exhaust particulate collected by the exhaust particulate collection means;
An operating state detecting means for detecting the operating state of the engine;
A warm-up operation necessity determination unit that determines whether the engine needs to be warmed-up based on the operation state detected by the operation state detection unit;
An exhaust throttle valve provided in the exhaust passage of the engine;
An exhaust throttle valve control means for controlling the exhaust throttle valve to reduce the exhaust passage area when the warm-up operation necessity determination means determines that the engine needs to be warmed up; In an engine exhaust throttle valve control device,
The exhaust throttle valve control means is configured to control the exhaust throttle valve so that the amount of decrease in the exhaust passage area is smaller when the exhaust particulate quantity detected by the exhaust particulate quantity detection means is large than when the exhaust particulate quantity is small. is there.
[0011]
According to the first configuration of the present invention, when the exhaust particulate amount detected by the exhaust particulate amount detecting means is large, the exhaust throttle valve is controlled so as to reduce the reduction amount of the exhaust passage area as compared with the case where the exhaust particulate amount is small. Therefore, an excessive increase in the exhaust pressure is suppressed, and warm-up performance can be ensured while suppressing a decrease in combustion performance and a deterioration in fuel consumption accompanying a decrease in combustion efficiency.
[0012]
In the second configuration of the present invention, the operating state detection means is configured to detect a parameter related to the engine water temperature,
The exhaust throttle valve control means is configured such that when the parameter related to the engine water temperature is high, the reduction amount of the exhaust passage area is made smaller than when the parameter is low.
[0013]
Even in a state where the engine water temperature is low and the warm-up operation is required, the engine water temperature gradually rises by executing the warm-up operation, and the required reduction amount of the exhaust passage area is also reduced. If the reduction amount of the exhaust passage area is uniformly set corresponding to the time when the initial engine water temperature is low in spite of the increase in the engine water temperature, the fuel consumption is worsened.
[0014]
According to the second configuration of the present invention, when the parameter related to the engine water temperature is high, the reduction amount of the exhaust passage area is reduced compared to the case where the parameter is low, so that the reduction of the exhaust passage area when the engine water temperature is high. It is possible to suppress the amount from being increased more than necessary, and to improve fuel consumption.
[0015]
In the first and second configurations of the present invention, the exhaust throttle valve control means further eliminates the need for a warm-up operation from a state where the warm-up operation is required by the warm-up operation necessity determination means. When the transition to the state is detected, the reduction control is released, and the reduction control is released more slowly when the exhaust particulate amount detected by the exhaust particulate amount detection means is larger than when it is small. The exhaust throttle valve is controlled to perform.
[0016]
When the warm-up operation is completed and the reduction control of the exhaust throttle valve is released, if it is released suddenly, the exhaust pressure changes abruptly and the combustion efficiency changes abruptly, resulting in a torque shock.
[0017]
Therefore, when releasing the reduction control of the exhaust throttle valve, it may be possible to release it gradually with a predetermined gradient. However, if the predetermined gradient is uniform, if the amount of exhaust particulates is different, torque shock is prevented and fuel consumption deterioration is prevented. Cannot be compatible.
[0018]
That is, the torque shock is caused by a difference in exhaust pressure before and after the reduction control of the exhaust throttle valve is released, but this difference in exhaust pressure differs depending on the amount of exhaust particulate collected by the exhaust particulate collection means. Specifically, when the amount of collected exhaust particulates is small, the exhaust pressure is low, and the exhaust pressure difference between before and after the release is large, so that the torque shock becomes large. In contrast, when the amount of collected exhaust particulates is large, the exhaust pressure is high and the exhaust pressure difference between before and after the release is reduced, and the torque shock is reduced. If the value is set to a moderate value corresponding to a small torque shock, the reduction control of the exhaust throttle valve is prolonged for longer than necessary, resulting in deterioration of fuel consumption.
[0019]
According to the above configuration of the present invention, the exhaust throttle valve is controlled so that the reduction control is released more gently when the exhaust particulate amount detected by the exhaust particulate amount detection means is small than when it is large. When the collected exhaust particulate amount is small and the exhaust pressure difference before and after the reduction control release is large, the reduction control is released relatively slowly, and torque shock can be suppressed and the collected exhaust particulate amount When the exhaust pressure difference before and after many reduction controls are released is small, the reduction control is released relatively quickly, and the deterioration of fuel consumption due to the reduction control being performed over a long period of time while suppressing the torque shock is prevented. Can do.
[0020]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, warm-up performance can be ensured, suppressing the fall of combustion performance in the state with many exhaust particulates collected by the exhaust particulate collection means, and a fuel consumption deterioration.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0022]
FIG. 1 is an overall configuration diagram relating to the present embodiment, in which 1 is a four-cylinder diesel engine, and an intake passage 2 and an exhaust passage 3 are connected to the diesel engine 1.
[0023]
In the intake passage 2, an air cleaner 4, an air flow sensor 5, a blower 6 a of a VGT turbocharger (variable geometry turbo) 6, an intercooler 7, an intake throttle valve 8, an intake air temperature are sequentially provided from the upstream side to the downstream side. A sensor 9 and an intake pressure sensor 10 are provided.
[0024]
The exhaust passage 3 includes a turbine 6b of a VGT turbocharger (variable geometry turbo) 6 in order from the upstream side to the downstream side thereof, a movable vane 6c for controlling the flow rate of exhaust gas flowing into the turbine 6b, and an exhaust throttle valve. 11, an oxidation catalyst 12 and a particulate filter 13 are disposed.
[0025]
Exhaust pressure sensors 14 and 15 are disposed upstream and downstream of the particulate filter 13, and the amount of exhaust particulates collected by the particulate filter 13 based on the differential pressure between the exhaust pressure sensors 14 and 15. Configured to detect.
[0026]
The particulate filter 13 is configured such that exhaust particulates are burned and removed when the amount of collected exhaust particulates reaches a saturation amount. For example, post-injection is performed during combustion by a burner (not shown), exhaust stroke after main injection, etc., and then the unburned fuel injected is supplied to the oxidation catalyst 12 to generate oxidation reaction heat, thereby increasing the exhaust temperature. By raising (for example, raising to 300 ° C. or higher), the exhaust particulates are removed by combustion.
[0027]
An exhaust gas recirculation passage 16 that connects the intake passage 2 and the exhaust passage 3 is provided, and an exhaust gas recirculation valve 17 of a negative pressure actuator type is disposed in the middle of the exhaust gas recirculation passage 16. .
[0028]
A fuel injection pump 18 supplies fuel from a fuel tank (not shown) to a common rail 19 as a pressure accumulating means.
[0029]
The common rail 19 is connected to a fuel injection valve 20 (only one is shown in FIG. 1) disposed in the combustion chamber 1a of each cylinder. The common rail 19 includes a fuel injection pressure sensor 21 and a common rail 19 inside. A safety valve 22 is provided for opening the valve when the pressure of the fuel accumulated in the tank reaches an allowable pressure or more and relieving the fuel on the fuel tank side.
[0030]
23 is a crank angle sensor for detecting the engine speed, 24 is an engine water temperature sensor for detecting the engine water temperature, and 25 is an accelerator opening sensor for detecting the opening of an accelerator pedal (not shown). is there.
[0031]
A control unit 30 includes a CPU, a RAM, a ROM, an interface, and the like. The air flow sensor 5, the intake air temperature sensor 9, the intake air pressure sensor 10, the exhaust air pressure sensors 14, 15, the crank angle sensor 23, the engine water temperature sensor 24, Signals detected by various sensors such as the accelerator opening sensor 25 are input. Based on the detected signals, the movable vane 6c of the VGT turbocharger (variable geometry turbo) 6 and the intake air Various actuators such as the throttle valve 8, the exhaust throttle valve 11, the exhaust gas recirculation valve 17, and the fuel injection valve 20 are controlled.
[0032]
Hereinafter, control of the exhaust throttle valve 11 according to the present invention will be described.
(Embodiment)
Next, an embodiment according to the present invention will be described with reference to FIGS.
[0033]
FIG. 2 is a control flowchart of the exhaust throttle valve 11 according to the embodiment, FIG. 3 is a basic target opening map showing the basic target opening of the exhaust throttle valve 13, and FIG. 4 is a correction coefficient K1 for the exhaust particulate amount. FIG. 5 shows a second correction coefficient table showing a correction coefficient K2 for the engine water temperature, and FIG. 6 shows an exhaust throttle valve opening degree when the exhaust throttle valve 11 is shifted from a closed state to an open state. It is a time chart.
[0034]
In this embodiment, when the engine water temperature is 80 ° C. or less and the warm-up operation is required, the opening of the exhaust throttle valve 11 is set to the basic target opening set based on the engine speed and the engine load, The correction coefficient K1 set according to the amount of exhaust particulates collected by the particulate filter 13 calculated based on the differential pressure between the exhaust pressure sensors 14 and 15 and the engine water temperature detected by the engine water temperature sensor 24. Based on the correction coefficient K2 set accordingly, the exhaust throttle valve 11 is closed based on the set opening, that is, the reduction control for reducing the exhaust passage area is performed, and the engine water temperature is set to 80. When the temperature exceeds 0 ° C. and the warm-up operation becomes unnecessary, a correction coefficient K3 for gradually opening the exhaust throttle valve from the closed state is calculated based on the differential pressure between the exhaust pressure sensors 14 and 15. An example is set based on the amount of exhaust particulate collected by the particulate filter 13 and the exhaust throttle valve 11 is gradually opened from the closed state, that is, the reduction control for reducing the exhaust passage area is released. Show.
[0035]
Details will be described below.
[0036]
In FIG. 2, first, in step S1, detection signals from various sensors are read. Specifically, the engine water temperature T detected by the engine water temperature sensor 24, the exhaust pressure P1 detected by the exhaust pressure sensor 14 disposed on the upstream side of the particulate filter 13, and the downstream side of the particulate filter 13 are arranged. Exhaust pressure P2 detected by the exhaust pressure sensor 15 provided, crank angle (engine speed N) detected by the crank angle sensor 23, engine water temperature T detected by the engine water temperature sensor 24, and accelerator opening sensor 25 The detected accelerator opening θ is read.
[0037]
Subsequently, in step S2, the differential pressure between the exhaust pressures P1 and P2 read in step S1 is calculated, and the exhaust particulate amount W collected by the particulate filter 13 is calculated based on the calculated differential pressure. That is, since there is a relationship in which the differential pressure between the exhaust pressures P1 and P2 increases as the amount of collected exhaust particulates increases, data indicating the relationship between the exhaust particulate amount W and the differential pressure can be obtained in advance by experiments. For example, the exhaust particulate amount W can be estimated and calculated from the above-described differential pressure.
[0038]
Next, in step S3, it is determined whether or not the engine water temperature T detected in step S1 is a temperature that requires a warm-up operation, for example, 80 ° C. or higher.
[0039]
When it is determined NO in step S3, that is, when the engine water temperature T is 80 ° C. or lower and the warm-up operation is necessary, the processing of steps S4 to S6 is performed to set the opening of the exhaust throttle valve 11, The exhaust throttle valve 11 is controlled to decrease in the valve closing direction based on the set opening.
[0040]
Specifically, the opening of the exhaust throttle valve 11 is based on the engine speed N and the engine load L (the fuel injection amount set based on the engine speed N and the accelerator opening θ) in step S4. To set the target basic opening. As shown in FIG. 3, the target basic opening is such that the lower the engine speed N and the engine load L, the more the exhaust throttle valve 11 is closed, and the engine speed N or the engine load L is greater than a predetermined value L1 or more. In this region, the opening degree of the exhaust throttle valve 11 is set so as to be fully opened. The reason for increasing the opening of the exhaust throttle valve 11 (decreasing the reduction amount of the exhaust passage area) as the engine speed N or the engine load L is larger is that the exhaust increases as the engine speed N and the engine load L are larger. This is to suppress an excessive increase in the exhaust pressure caused by a large gas flow rate and a high exhaust pressure.
[0041]
Next, in step S5, a correction coefficient K1 is set according to the exhaust particulate amount W calculated in step S2. As shown in FIG. 4, the correction coefficient K1 is set to a larger value as the calculated exhaust particulate amount W is larger, and the opening degree of the exhaust throttle valve 11 is increased as the exhaust particulate amount W is larger. The amount of reduction of the throttle valve 11 is reduced.
[0042]
Next, in step S6, the correction coefficient K2 is set according to the engine coolant temperature T read in step S1. As shown in FIG. 5, the correction coefficient K2 is set to a larger value as the engine water temperature T is higher, and the opening degree of the exhaust throttle valve 11 is increased as the exhaust particulate amount W is larger. The amount of decrease is reduced.
[0043]
And the opening degree of the exhaust throttle valve 11 is calculated | required as follows.
[0044]
Here, the larger the value of the exhaust throttle valve opening obtained by the above formula, the more the exhaust throttle valve 11 opens in the opening direction (the amount of decrease in the exhaust passage area is reduced).
[0045]
Further, when it is determined NO in step S3, that is, when the engine water temperature T becomes 80 ° C. or higher and it is necessary to cancel the reduction control in the closing direction of the exhaust throttle valve 11, it is possible to perform steps S7 to S11. The reduction control of the exhaust throttle valve 11 is gradually released.
[0046]
Specifically, first, in step S7, it is determined whether or not the exhaust particulate amount W calculated in step S2 is greater than a preset value α. Here, α is the amount of exhaust particulates that has almost no effect on torque shock, and can be obtained in advance by experiments.
[0047]
When YES is determined in step S7, that is, when the exhaust particulate amount W is larger than α and the exhaust pressure is originally high, the differential pressure before and after the reduction control of the exhaust throttle valve 11 is released is small, and the torque shock is affected. Therefore, the process proceeds to step S8, and the damping coefficient K3 (opening amount per unit time) for gradually opening the exhaust throttle valve 11 is set to a large value K3a.
[0048]
When YES is determined in step S7, that is, when the exhaust particulate amount W is smaller than α and the exhaust pressure is originally low, the differential pressure before and after the reduction control of the exhaust throttle valve 11 is released is large, and the torque shock is reduced. Since the influence is large, the process proceeds to step S9, and the attenuation coefficient K3 is set to a small correction coefficient K3b.
[0049]
In this embodiment, the correction coefficient K3 is shown in two steps depending on whether the exhaust particulate amount W is larger or smaller than α. However, the correction coefficient K3 may be set to change linearly according to the exhaust particulate amount W. Good.
[0050]
Further, when the exhaust particulate amount W is very large and there is almost no influence on the torque shock, the exhaust throttle valve 11 may be fully opened without setting the correction coefficient K3.
[0051]
Subsequently, in step S10, it is determined whether or not the exhaust throttle valve 11 is fully opened, that is, whether or not the reduction control of the exhaust throttle valve 11 has been completed.
[0052]
When it is determined NO in step S10, the process proceeds to step S11, and the exhaust throttle valve 11 is gradually opened until it is fully opened based on the damping coefficient K3a or K3b set in step S8 or step S9.
[0053]
That is, as shown in FIG. 6, when the exhaust particulate amount W is larger than α, the exhaust throttle valve 11 has a large damping coefficient because the differential pressure before and after releasing the reduction control of the exhaust throttle valve 11 is small and the torque shock is small. Fully opened quickly by K3a. Conversely, when the exhaust particulate amount W is less than α, the exhaust throttle valve 11 is gradually fully opened by the small damping coefficient K3b because the differential pressure before and after the reduction control release of the exhaust throttle valve 11 is large and the torque shock is large. The
[0054]
If it is determined as YES in step S10, the exhaust throttle valve 11 is opened to the fully open state by the process of step S11, so that the fully open state is maintained.
[0055]
As described above, according to the present embodiment, when the exhaust particulate amount W is large due to the correction of the opening of the exhaust throttle valve 11 based on the correction coefficient K1 that is set to be larger as the calculated exhaust particulate amount W is larger. Since the reduction amount of the exhaust passage area is reduced compared to the case where there is little, excessive increase of the exhaust pressure is suppressed, and the warm-up performance is secured while suppressing the deterioration of the combustion performance and the deterioration of the fuel consumption due to the reduction of the combustion efficiency. be able to.
[0056]
Further, by reducing the opening of the exhaust throttle valve 11 based on the correction coefficient K2 that is set to be larger as the engine water temperature T is higher, the reduction amount of the exhaust passage area is reduced when the engine water temperature T is high than when the engine water temperature T is low. Therefore, it is possible to suppress the reduction amount of the exhaust passage area when the engine water temperature T is high from being increased more than necessary, and to improve fuel efficiency.
[0057]
When the calculated exhaust particulate amount W is smaller than α, the reduction control of the exhaust throttle valve 11 is gently released based on the small damping coefficient K3b, and the torque shock accompanying the release control of the exhaust throttle valve 11 is reduced. When the calculated exhaust particulate amount W is larger than α, the reduction control of the exhaust throttle valve 11 is promptly released based on the large damping coefficient K3a. Therefore, the reduction control is performed while suppressing the torque shock. It is possible to prevent deterioration in fuel consumption due to being performed over a long period of time.
(Reference example)
Next, a reference example will be described based on FIG.
[0058]
FIG. 7 is a control flowchart of the exhaust throttle valve 11.
[0059]
In the above-described embodiment, an example in which the index is an opening degree is shown in the control of the exhaust throttle valve 11, but this reference example shows an example in which the exhaust pressure is controlled as an index.
[0060]
Specifically, as shown in FIG. 1, an exhaust pressure sensor A is provided in the exhaust passage 3 upstream of the particulate filter 13 and the exhaust throttle valve 11, and the exhaust pressure detected by the exhaust pressure sensor A is the target exhaust pressure. The opening degree of the exhaust throttle valve 11 is controlled so as to be described below, and will be described in detail below.
[0061]
In step S20 of FIG. 7, the engine water temperature T detected by the engine water temperature sensor 24 is read, and in step S21, the exhaust pressure P3 detected by the exhaust pressure sensor A is read.
[0062]
In step S22, it is determined whether or not the engine water temperature T detected in step S1 is a temperature that requires a warm-up operation, for example, 80 ° C. or higher.
[0063]
When NO is determined in step S22, that is, when the engine water temperature T is 80 ° C. or lower and the warm-up operation is necessary, the processing of steps S23 to S25 is performed, and the opening degree of the exhaust throttle valve 11 is set. The exhaust throttle valve 11 is controlled to decrease in the valve closing direction based on the set opening.
[0064]
Specifically, first, in step S23, the target exhaust pressure P0 is set based on the engine load (the fuel injection amount set based on the accelerator opening and the engine speed) and the engine speed.
[0065]
In step S24, the deviation between the exhaust pressure P3 read in step S21 and the target exhaust pressure P0 set in step S23 is calculated.
[0066]
In step S25, the exhaust throttle valve 11 is controlled to decrease based on the deviation calculated in step S24. That is, the opening degree of the exhaust throttle valve 11 is controlled so that the actual exhaust pressure P3 matches the target exhaust pressure P0.
[0067]
When NO is determined in step S22, that is, when the engine water temperature T becomes 80 ° C. or higher and it is necessary to cancel the decrease control in the closing direction of the exhaust throttle valve 11, the process proceeds to step S26. The throttle valve 11 is fully opened.
[0068]
As described above, according to this reference example, the opening degree of the exhaust throttle valve 11 is controlled such that the exhaust pressure P3 upstream of the exhaust throttle valve 11 and the particulate filter 13 matches the target exhaust pressure P0. Therefore, reduction control of the exhaust throttle valve 11 is performed in consideration of both an increase in exhaust pressure associated with the closing operation of the exhaust throttle valve 11 and an increase in exhaust pressure associated with the amount of exhaust particulate collected in the particulate filter 13, Excessive rise in exhaust pressure is suppressed, and warm-up performance can be ensured while suppressing deterioration in combustion performance and deterioration in fuel consumption accompanying reduction in combustion efficiency.
[0069]
In the present embodiment and the reference example, an example is shown in which whether or not the engine needs to be warmed up is determined based on the engine water temperature T. However, based on the intake air temperature in the intake passage 2. Alternatively, the determination may be made based on both the engine water temperature T and the intake air temperature.
[0070]
In the present embodiment and the reference example, the exhaust throttle valve 11 is disposed in the exhaust passage upstream of the particulate filter 13. However, the exhaust throttle valve 11 may be disposed in the exhaust passage downstream of the particulate filter 13.
[0071]
Further, in this embodiment and the reference example, the amount of exhaust particulates collected by the particulate filter 13 is detected based on the exhaust pressure difference between the exhaust pressure sensors 14 and 15 respectively disposed above and below the particulate filter 13. In addition, the upstream pressure sensor 14 is abolished, and the upstream exhaust pressure is estimated based on the engine speed and the operating state of the engine load, and is detected downstream from the estimated exhaust pressure. Detection may be performed based on the difference in exhaust pressure from the exhaust pressure.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram relating to an embodiment.
FIG. 2 is a control flowchart of an exhaust throttle valve according to the embodiment.
FIG. 3 is a diagram showing a basic target opening map showing a basic target opening of the exhaust throttle valve 13 according to the embodiment.
FIG. 4 is a view showing a first correction coefficient table showing a correction coefficient K1 for the exhaust particulate amount related to the embodiment.
FIG. 5 is a diagram showing a second correction coefficient table showing a correction coefficient K2 for engine water temperature according to the embodiment.
6 is a time chart post-injection timing map showing an exhaust throttle valve opening degree when the exhaust throttle valve 11 is shifted from a closed state to an open state according to the embodiment; FIG.
FIG. 7 is a control flowchart of an exhaust throttle valve according to a reference example.
[Explanation of symbols]
1: Diesel engine 11: Exhaust throttle valve 13: Particulate filter (exhaust particulate collection means)
14, 15, A: Exhaust pressure sensor 15: Exhaust gas recirculation passage 23: Crank angle sensor 24: Engine water temperature sensor (operating state detection means)
30: Control unit

Claims (2)

An exhaust particulate collection means provided in the exhaust passage of the engine for collecting exhaust particulates in the exhaust gas;
Exhaust particulate amount detection means for detecting parameters related to the amount of exhaust particulate collected by the exhaust particulate collection means;
An operating state detecting means for detecting the operating state of the engine;
A warm-up operation necessity determination unit that determines whether the engine needs to be warmed-up based on the operation state detected by the operation state detection unit;
An exhaust throttle valve provided in the exhaust passage of the engine;
An exhaust throttle valve control means for controlling the exhaust throttle valve to reduce the exhaust passage area when the warm-up operation necessity determination means determines that the engine needs to be warmed up. In an engine exhaust throttle valve control device,
The exhaust throttle valve control means includes:
When the exhaust particulate amount detected by the exhaust particulate amount detection means is large, the exhaust throttle valve is controlled so as to reduce the reduction amount of the exhaust passage area compared to the small amount ,
When the transition from the state where the warm-up operation is required to the state where the warm-up operation is unnecessary is detected by the warm-up operation necessity determination means, the decrease control is canceled and the decrease control is canceled. An exhaust throttle valve control device for an engine, wherein the exhaust throttle valve is controlled so that the exhaust particulate amount is more gently controlled when the exhaust particulate amount detected by the exhaust particulate amount detecting means is small than when the exhaust particulate amount is large . The operating state detecting means is configured to detect a parameter related to the engine water temperature,
The exhaust throttle valve control means includes:
When the parameter related to the engine water temperature is high, the exhaust throttle valve is controlled so as to reduce the reduction amount of the exhaust passage area compared with the case where the parameter is low .
When the transition from the state where the warm-up operation is required to the state where the warm-up operation is unnecessary is detected by the above-mentioned warm-up operation necessity determination means, the decrease control is canceled and the decrease control is canceled. 2. The exhaust throttle valve control for an engine according to claim 1, wherein the exhaust throttle valve is controlled so as to be performed more slowly than when the exhaust particulate amount detected by the exhaust particulate amount detecting means is small. Equipment .

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