阅读说明：本技术 发动机装置 (Engine device ) 是由 伊东久幸 市川晃次 加藤宏和 山口正晃 于 2020-10-13 设计创作，主要内容包括：一种发动机装置,所述发动机装置具备：发动机；排气再循环装置,具有使所述发动机的排气管与进气管连通的连通管、和设置于所述连通管的阀；以及控制装置。所述控制装置构成为,在检测出所述阀产生的异物的卡入且停止所述发动机时,执行使所述阀开闭的异物排除控制。(An engine device, comprising: an engine; an exhaust gas recirculation device having a communication pipe that communicates an exhaust pipe and an intake pipe of the engine, and a valve provided in the communication pipe; and a control device. The control device is configured to execute foreign matter removal control for opening and closing the valve when the engine is stopped while the foreign matter generated by the valve is detected to be stuck.)

1. An engine device, characterized by comprising:

an engine;

an exhaust gas recirculation device having a communication pipe that communicates an exhaust pipe and an intake pipe of the engine, and a valve provided in the communication pipe; and

a control device for controlling the operation of the motor,

the control device is configured to execute foreign matter removal control for opening and closing the valve when the engine is stopped while the foreign matter generated by the valve is detected to be stuck.

2. The engine arrangement according to claim 1,

the valve is configured to vibrate when opening and closing.

3. The engine arrangement according to claim 2,

the valve is configured to be driven by a stepper motor.

4. The engine apparatus according to any one of claims 1 to 3,

the control device is configured to execute the foreign matter removal control after a system stop instruction is given and the rotation speed of the engine becomes equal to or less than a predetermined rotation speed.

5. The engine apparatus of claim 4,

the control device is configured to execute the foreign matter removal control after the system stop instruction is given and the engine is stopped.

6. The engine apparatus according to any one of claims 1 to 5,

further comprises a pressure sensor for detecting the pressure in the intake pipe as a pressure of the intake air,

the control device is configured to estimate a pressure in the intake pipe as an estimated intake pressure, and to determine whether or not the foreign matter is caught by the valve by comparing an intake pressure difference between the detected intake pressure and the estimated intake pressure with a threshold value.

7. The engine arrangement according to claim 1,

the control device is configured to execute the foreign matter removal control for opening and closing the valve when the valve is detected to be engaged with the foreign matter and the engine speed is 0.

Technical Field

The present invention relates to an engine device, and more particularly, to an engine device including an engine and an exhaust gas recirculation device.

Background

As an engine device, an engine device including an internal combustion engine, an EGR passage that communicates an intake passage and an exhaust passage of the internal combustion engine, and an EGR valve provided in the EGR passage has been proposed (see, for example, japanese patent application laid-open No. 2017-133372). In this engine device, when it is determined that foreign matter is caught between the valve element and the valve seat of the EGR valve, foreign matter removal control is executed in which the opening and closing operation of the EGR valve is repeated a plurality of times. In this way, foreign matter caught by the EGR valve is eliminated.

Disclosure of Invention

In the engine apparatus described above, since the foreign matter removal control is performed during the rotational driving of the internal combustion engine, there is a possibility that the rotational speed of the internal combustion engine may vary due to variation in the amount of exhaust gas flowing through the EGR passage caused by the opening and closing operation of the EGR valve, thereby giving the driver a sense of incongruity such as a sense of acceleration or a sense of deceleration. At this time, if the intake air amount of the internal combustion engine is increased in order to prevent the engine stall, the possibility of giving the driver an uncomfortable feeling becomes higher.

The invention provides an engine device capable of restraining discomfort brought to a driver.

The engine device of the present invention adopts the following means.

An engine device according to an aspect of the present invention includes: an engine; an exhaust gas recirculation device having a communication pipe that communicates an exhaust pipe and an intake pipe of the engine, and a valve provided in the communication pipe; and a control device. The control device is configured to execute foreign matter removal control for opening and closing the valve when the engine is stopped while the foreign matter generated by the valve is detected to be stuck.

According to the above aspect, when it is detected that the foreign matter is caught by the valve and the engine substantially stops rotating, the foreign matter removal control for opening and closing the valve is executed. Thus, when the foreign matter removal control is executed to remove the foreign matter, the variation in the rotation speed of the engine is less likely to occur, and therefore, the driver can be prevented from being given a sense of incongruity.

In the above aspect, the valve may be configured to vibrate when opening and closing.

In the above aspect, the valve may be configured to be driven by a stepping motor.

According to the above configuration, when the foreign matter removal control is executed, the foreign matter can be more reliably removed.

In the above aspect, the control device may be configured to execute the foreign matter removal control after a system stop instruction is given and the rotation speed of the engine becomes equal to or less than a predetermined rotation speed.

In the above aspect, the control device may be configured to execute the foreign matter removal control after the system stop instruction is given and the engine is stopped.

In the above aspect, the engine device may further include a pressure sensor for detecting a pressure in the intake pipe as a detected intake pressure. The control device may be configured to estimate a pressure in the intake pipe as an estimated intake pressure, and to determine whether or not the valve is stuck with foreign matter by comparing an intake pressure difference between the detected intake pressure and the estimated intake pressure with a threshold value.

In the above aspect, the control device may be configured to execute the foreign matter removal control for opening and closing the valve when the valve is detected to be engaged with the foreign matter and the engine speed is 0.

Drawings

Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like reference numerals represent like elements, and wherein:

fig. 1 is a schematic configuration diagram showing a general configuration of an engine device mounted on an automobile 10 according to an embodiment of the present invention.

Fig. 2 is a flowchart showing an example of a processing routine executed by the electronic control unit 70.

Fig. 3 is an explanatory diagram illustrating an example of a case where the foreign substance removal control is executed.

Detailed Description

Next, embodiments of the present invention will be described with reference to examples.

Fig. 1 is a schematic configuration diagram showing a general configuration of an engine device mounted on an automobile 10 according to an embodiment of the present invention. As shown in the drawing, the engine device mounted on the automobile 10 of the embodiment includes an engine 12, an exhaust Gas recirculation device (hereinafter referred to as an "egr (exhaust Gas recirculation) device") 50, a transmission 60 connected to a crankshaft 14 of the engine 12 and connected to drive wheels 64a and 64b via a differential gear 62, and an electronic control unit 70 that controls the entire vehicle.

The engine 12 is configured as an internal combustion engine that outputs power using fuel such as gasoline or light oil. This engine 12 takes in air cleaned by the air cleaner 22 into an intake pipe 23 and causes the air to flow in the order of a throttle valve 24 and a surge tank 25, and injects fuel from a fuel injection valve 26 on the downstream side of the intake pipe 23 from the surge tank 25 to mix the air with the fuel. The air-fuel mixture is drawn into a combustion chamber 29 through an intake valve 28, and is subjected to explosive combustion by an electric spark generated by an ignition plug 30. The reciprocating motion of the piston 32 pushed down by the energy generated by the explosive combustion is converted into the rotational motion of the crankshaft 14. The exhaust gas discharged from the combustion chamber 29 to the exhaust pipe 33 via the exhaust valve 31 is discharged to the outside air via the purification device 34, and is supplied (recirculated) to the intake pipe 23 via the EGR device 50, and the purification device 34 includes a catalyst (three-way catalyst) 34a that purifies harmful components of carbon monoxide (CO), Hydrocarbons (HC), and nitrogen oxides (NOx).

The EGR device 50 includes an EGR pipe 52 and an EGR valve 54. The EGR pipe 52 communicates the exhaust pipe 33 downstream of the purification device 34 with the surge tank 25 of the intake pipe 23. The EGR valve 54 is provided in the EGR pipe 52, and has a valve seat 54a and a valve body 54 b. The valve seat 54a has a hole with a diameter smaller than the inner diameter of the EGR pipe 52. The spool 54b is driven by a stepping motor 55 and moves in the axial direction (vertical direction in the drawing) of the spool 54 b. When the valve 54b moves to a side (lower side in the drawing) close to the valve seat 54a, the distal end portion (lower end portion in the drawing) of the valve 54b closes the hole of the valve seat 54a, and the EGR valve 54 is closed. When the valve 54b moves to a side (upper side in the drawing) away from the valve seat 54a, the tip end portion of the valve 54b moves away from the valve seat 54a to open the hole of the valve seat 54a, thereby opening the EGR valve 54. The EGR device 50 adjusts the opening degree of the EGR valve 54 by the stepping motor 55, and adjusts the amount of exhaust gas recirculation in the exhaust pipe 33 to recirculate the exhaust gas to the intake pipe 23. The engine 12 can thus draw a mixture of air, exhaust gas, and fuel into the combustion chamber 29. Hereinafter, the recirculation of the exhaust gas is referred to as "EGR", and the recirculation amount of the exhaust gas is referred to as "EGR amount".

The electronic control unit 70 is configured as a microprocessor including a CPU as a center, and includes a ROM that stores processing programs, a RAM that temporarily stores data, and input/output ports in addition to the CPU. Signals from various sensors required for controlling the operation of the engine 12 are input to the electronic control unit 70 via the input port.

Examples of the signal input to the electronic control unit 70 include a crank angle θ cr from a crank position sensor 40 that detects a rotational position of the crankshaft 14 of the engine 12, and a cooling water temperature Tw from a water temperature sensor 42 that detects a temperature of cooling water of the engine 12. The cam angles θ ci and θ co from the cam position sensor 44 that detects the rotational position of the intake camshaft that opens and closes the intake valve 28 and the rotational position of the exhaust camshaft that opens and closes the exhaust valve 31 may be mentioned. The throttle opening TH from the throttle position sensor 46 that detects the position of the throttle valve 24, the intake air amount Qa from the air flow meter 48 attached to the intake pipe 23, the intake air temperature Ta from the temperature sensor 49 attached to the intake pipe 23, and the detected intake air pressure Pind, which is a detected value of the pressure inside the surge tank 25 from the pressure sensor 57 attached to the surge tank 25, can also be cited. The air-fuel ratio AF from an air-fuel ratio sensor 35a attached to the exhaust pipe 33, and the oxygen signal O from an oxygen sensor 35b attached to the exhaust pipe 33 can be also mentioned₂. An ignition signal IG from the ignition switch 80 and a shift position SP from a shift position sensor 82 that detects an operation position of a shift lever 81 can be cited. The accelerator opening Acc from an accelerator pedal position sensor 84 that detects the amount of depression of an accelerator pedal 83, the brake pedal position BP from a brake pedal position sensor 86 that detects the amount of depression of a brake pedal 85, and the vehicle speed V from a vehicle speed sensor 88 can be cited.

Various control signals for controlling the operation of the engine 12 are output from the electronic control unit 70 via the output port. Examples of the signal output from the electronic control unit 70 include a control signal for the throttle motor 36 that adjusts the position of the throttle valve 24, a control signal for the fuel injection valve 26, a control signal for the ignition plug 30, and a control signal for the stepping motor 55 that adjusts the opening degree of the EGR valve 54. In addition, a control signal to the transmission 60 can be cited.

The electronic control unit 70 calculates the rotation speed Ne of the engine 12 based on the crank angle θ cr from the crank position sensor 40. The electronic control unit 70 obtains an estimated intake air pressure Pine, which is an estimated value of the pressure in the surge tank 25, based on the intake air amount Qa from the airflow meter 48. Here, the estimated intake air pressure pin can be obtained by applying the intake air amount Qa to a relationship between the intake air amount Qa and the estimated intake air pressure pin, which is determined in advance by an experiment and an analysis.

In the engine device mounted on the automobile 10 of the embodiment configured as described above, the electronic control unit 70 sets the target shift speed Gs of the transmission 60 based on the accelerator opening Acc and the vehicle speed V, and controls the transmission 60 such that the shift speed Gs of the transmission 60 becomes the target shift speed Gs. The target torque Te of the engine 12 is set based on the accelerator opening Acc, the vehicle speed V, and the shift speed Gs of the transmission 60, and the operation control (for example, intake air amount control, fuel injection control, ignition control, etc.) of the engine 12 and the control of the EGR device 50 are performed so that the engine 12 is operated based on the target torque Te.

Here, in the control of the EGR device 50, when the EGR condition is satisfied, the target EGR amount Vegr is set based on the operating point of the engine 12 (the target torque Te and the rotation speed Ne) and the like, the target opening degree Ov of the EGR valve 54 is set based on the target EGR amount Vegr, and the stepping motor 55 is controlled based on the target opening degree Ov of the EGR valve 54. On the other hand, when the EGR condition is not satisfied, the value 0 is set as the target opening degree Ov of the EGR valve 54, and the stepping motor 55 is controlled based on the target opening degree Ov of the EGR valve 54. As the EGR condition, a condition that warm-up of the engine 12 is completed, a condition that the target torque Te of the engine 12 is within the EGR execution region, and the like are used.

In the engine apparatus mounted on the automobile 10 according to the embodiment, when the diagnostic condition is satisfied, the electronic control unit 70 compares the differential intake pressure amount Δ Pin (═ Pind-Pine |) obtained as the difference between the detected intake pressure Pind and the estimated intake pressure Pin with the threshold value Δ Pinref, and thereby performs the diagnosis of whether or not the EGR valve 54 is stuck with a foreign object between the valve seat 54a and the valve body 54b, that is, the sticking diagnosis. In this engagement diagnosis, when it is determined that the EGR valve 54 has engaged a foreign object, the value 1 is set as the foreign object engagement flag Ff, and when it is determined that the EGR valve 54 has not engaged a foreign object, the value 0 is set as the foreign object engagement flag Ff. As the diagnostic condition, for example, a condition that the EGR condition is not satisfied (the target opening degree Ov of the EGR valve 54 is a value 0) or the like is used.

Next, the operation of the engine device mounted on the automobile 10 according to the embodiment configured as described above, particularly the operation when foreign matter is caught in the EGR valve 54, will be described. Fig. 2 is a flowchart showing an example of a processing routine executed by the electronic control unit 70. The routine is repeatedly executed.

When the processing routine of fig. 2 is executed, the electronic control unit 70 first inputs data of a foreign matter jam flag Ff, an ignition signal IG, a rotation speed Ne of the engine 12, and the like (step S100). Here, the foreign substance engagement flag Ff is input with the value set as described above. As for the ignition signal IG, a signal from the ignition switch 80 is input. A rotation speed Ne of the engine 12 is input with a value calculated based on the crank angle θ cr from the crank position sensor 40.

When data is input in this manner, the value of the foreign substance engagement flag Ff is checked (step S110). When the foreign matter engagement flag Ff is set to 0, it is determined that no foreign matter is engaged in the EGR valve 54, and foreign matter removal control, which will be described later, is not executed, and the routine is terminated.

When the foreign matter jam flag Ff has a value of 1 in step S110, it is determined that foreign matter is jammed in the EGR valve 54, it is determined whether an ignition OFF (OFF) instruction (system stop instruction) is given based on the ignition signal IG (step S120), and the rotation speed Ne of the engine 12 is compared with the threshold value Neref (step S130). When the ignition signal IG is off, the electronic control unit 70 determines that the ignition off instruction is given, and stops the operation of the engine 12 (fuel injection control, ignition control, and the like). Thereby, the rotation speed Ne of the engine 12 decreases to a value of 0. The threshold value Neref is a threshold value for determining whether the engine 12 has substantially stopped rotating, and for example, a value of 0 or a value slightly larger than 0 is used. When the ignition off instruction is not given and the rotation speed Ne of the engine 12 is greater than the threshold value Neref, the foreign matter removal control is not executed, and the routine is ended.

When the ignition off instruction is given in step S120 and the rotation speed Ne of the engine 12 is equal to or less than the threshold value Neref in step S130, the foreign matter removal control is executed (step S140), the foreign matter engagement flag Ff is updated to 0 (step S150), and the routine is ended. Here, in the foreign matter removal control, the target opening degree Ov is set so that the EGR valve 54 is repeatedly opened and closed (the opening degree of the EGR valve 54 is repeatedly increased and decreased), and the stepping motor 55 is controlled based on the set target opening degree Ov. The EGR valve 54 is driven by the stepping motor 55, and therefore vibrates slightly when opened and closed. Therefore, the EGR valve 54 slightly vibrates while opening and closing, and foreign matter caught by the EGR valve 54 between the valve seat 54a and the valve body 54b can be eliminated. When the EGR valve 54 is opened and closed during the rotational driving of the engine 12, there is a possibility that the rotation speed Ne of the engine 12 varies due to variation in the amount of exhaust gas flowing through the EGR pipe 52 caused by the opening and closing operation of the EGR valve 54, and the driver feels discomfort such as acceleration and deceleration. At this time, if the throttle opening TH is increased to increase the intake air amount Qa in order to prevent the engine stall, the possibility of giving the driver a sense of incongruity becomes higher. On the other hand, in the embodiment, the foreign matter removal control is executed when the engine 12 substantially stops rotating. Thus, when the foreign matter removal control is executed to remove the foreign matter, the variation in the rotation speed Ne of the engine 12 is less likely to occur, so that the driver can be prevented from being given a sense of incongruity.

Fig. 3 is an explanatory diagram illustrating an example of a case where the foreign substance removal control is executed. As shown in the drawing, when it is determined that the EGR valve 54 has caught the foreign object (time t1), the foreign object catching flag Ff is switched from the value 0 to the value 1 (time t 2). When the ignition off instruction is given (time t3), the operation of the engine 12 is stopped, and when the rotation speed Ne of the engine 12 becomes equal to or less than the threshold value Neref (time t4), the foreign matter removal control is executed. This makes it possible to remove foreign matter while suppressing discomfort given to the driver. When the foreign matter removal control is ended (time t5), the foreign matter engagement flag Ff is switched from the value 1 to the value 0. After that, the opening degree Ov of the EGR valve 54 substantially coincides with the target opening degree Ov.

In the engine apparatus of the embodiment described above, the foreign matter removal control is executed when the engine 12 is stopped while the jamming of the foreign matter generated by the EGR valve 54 is detected. Thus, since variation in the rotation speed Ne of the engine 12 is less likely to occur when the foreign matter removal control is executed, it is possible to suppress the driver from being given a sense of incongruity. Further, the EGR valve 54 slightly vibrates when opened and closed, so that foreign matter can be more reliably removed.

In the engine device mounted on the automobile 10 of the embodiment, the foreign matter removal control is executed when the ignition off instruction is given and the engine 12 substantially stops rotating. However, the foreign matter removal control may be executed ON condition that the engine 12 is stopped, even when the ignition switch is turned ON (ON). As a case where the ignition switch is turned on and the engine 12 is stopped, for example, in a vehicle capable of executing the idle stop control, the engine 12 is automatically stopped in response to satisfaction of an automatic stop condition (idle stop condition).

In the engine device mounted on the automobile 10 of the embodiment, the EGR valve 54 is driven by the stepping motor 55 and slightly vibrates when opened and closed. However, the EGR valve 54 may be driven by a motor or the like other than this. In addition, it is considered that: even when the EGR valve 54 does not vibrate slightly during opening and closing, foreign matter can be removed to some extent by repeated opening and closing of the EGR valve 54.

The engine device of the embodiment is an engine device mounted on an automobile 10 that travels using the output of the engine 12, but may be an engine device mounted on a hybrid vehicle that includes a motor for traveling in addition to the engine, or may be an engine device mounted on equipment that does not move, such as construction equipment.

The correspondence relationship between the main elements of the embodiments and the main elements of the invention described in the section of the means for solving the problems (contents of the invention) will be described. In the embodiment, the engine 12 corresponds to an "engine", the EGR device 50 corresponds to an "exhaust gas recirculation device", the EGR pipe 52 corresponds to a "communicating pipe", and the electronic control unit 70 corresponds to a "control device".

In addition, since the embodiments are examples for specifically explaining the embodiments of the invention described in the section of the means for solving the problem, the correspondence relationship between the main elements of the embodiments and the main elements of the invention described in the section of the means for solving the problem is not limited to the elements of the invention described in the section of the means for solving the problem. That is, the invention described in the section of the means for solving the problem is to be explained based on the description in the section, and the examples are merely specific examples of the invention described in the section of the means for solving the problem.

While the embodiments of the present invention have been described above with reference to the examples, the present invention is not limited to the examples, and can be implemented in various ways without departing from the scope of the present invention.

The present invention can be used in the manufacturing industry of engine devices and the like.