KR20180123814A - Flywheel ring gear control system of vehicle and conrol method of the same - Google Patents

Abstract

The present technology discloses an engine control device for a vehicle. The engine control device according to the present technology controls the stop position of a flywheel ring gear by performing post injection when an engine is stopped, and allows a position where a starter motor and the flywheel ring gear are engaged at the time of starting the engine to be evenly distributed over the entire circumferential surface of the flywheel ring gear. The engine control device includes: a crank position sensor; a fuel injection device; and an ECU.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control apparatus for a vehicle,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an engine control apparatus for a vehicle, and more particularly to an engine control apparatus for controlling a stop position of a flywheel ring gear so that a coupling position of a starter motor and a flywheel ring gear is uniformly distributed over an entire circumferential surface of the flywheel ring gear To an engine control apparatus and a control method thereof.

Recently released vehicles are equipped with an engine equipped with an idle stop and go (ISG) system to improve fuel efficiency and reduce exhaust gas.

The ISG system automatically turns off the engine at a predetermined condition such as when the idle state of the engine is maintained for a set time or the like, and then, when the driver depresses the accelerator pedal, the engine is turned on again (Go) The engine control system.

In this ISG system, an engine starting mechanism using a starter motor and a flywheel ring gear is also applied.

The engine starting mechanism of the starter motor according to the related art is such that the pinion of the starter motor is moved from the state of being separated from the flywheel ring gear to the flywheel ring gear while rotating, The wear of the pinion and the flywheel ring gear due to collision and friction occurs.

Generally, when the engine is stopped, the stop position of the flywheel ring gear becomes a position where the kinetic energy becomes zero due to the friction between the piston and the bearing inside the engine. This position is 2 positions in the case of the inline four- In the case of a cylinder engine, three positions are determined.

Therefore, the position where the pinion of the starter motor and the flywheel ring gear come into contact with each other when the engine is started is confined to the two or three positions so that wear is concentrated only at the corresponding position.

Furthermore, when the number of starting times is large as in the case of the ISG engine, there is a problem that the partial wear of the flywheel ring gear proceeds more frequently due to frequent engagement.

The present invention controls the stop position of the flywheel ring gear through post injection when the engine is stopped so that the position where the pinion of the starter motor and the flywheel ring gear are meshed with each other is evenly distributed on the entire circumferential surface of the flywheel ring gear, And to provide an engine control device for a vehicle that can increase the durability life of the gear.

The apparatus for controlling an engine of a vehicle according to an embodiment of the present invention includes a crank position sensor for sensing a rotation angle of a crankshaft and outputting a sensing signal indicating a rotation angle of the crankshaft; A fuel injector for injecting fuel into a cylinder of an engine; And an ECU for controlling the fuel injection device to perform a post injection upon stopping the engine based on a sensing signal from the crank position sensor to change the rotation angle of the crankshaft.

A method for controlling an engine of a vehicle according to an embodiment of the present invention includes: obtaining a current rotation angle of a crankshaft when the engine is stopped; Calculating a rotation angle for post injection by comparing a final rotation angle of the crankshaft at the time of immediately stopping the engine with the current rotation angle; And transmitting the information on the amount of fuel corresponding to the calculated rotation angle to the fuel injection device to control the generation of the post injection.

The technical problems of the present invention are not limited to the above-mentioned technical problems, and other technical problems which are not mentioned can be understood by those skilled in the art from the following description.

The present invention can increase the durability life of the flywheel ring gear.

1 is a configuration diagram showing a configuration of an engine control apparatus for a vehicle according to an embodiment of the present invention;
2 is a flowchart illustrating an engine control method according to an embodiment of the present invention;
3 is a view showing a state in which the entire circumferential surfaces of the flywheel ring gear are evenly divided in units of a certain section;

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the difference that the embodiments of the present invention are not conclusive.

1 is a configuration diagram showing the configuration of an engine control apparatus for a vehicle according to an embodiment of the present invention.

1 may include a crank position sensor (CPS: Crank Position Sensor) 10, an ECU (Electric Countrol Unit) 20, and a fuel injection device 30. The engine control device shown in Fig.

The crank position sensor 10 senses the rotational angle of the crankshaft by measuring the position of the crankshaft and outputs a sensing signal to the ECU 20 informing the sensed rotational angle. In particular, in the present embodiment, the crank position sensor 10 senses the rotation angle of the crankshaft at the time of engine stop and transmits the sensed value to the ECU 20. A method in which the crank position sensor 10 senses the rotation angle of the crankshaft may be the same as the conventional method.

The ECU 20 recognizes the crankshaft angle (CA: Crankshaft Angle) of the crankshaft when the engine is stopped through the sensing signal received from the crank position sensor 10, ) So that the final rotation angle of the crankshaft at the time of stopping the engine is sequentially changed by a predetermined angle in accordance with the order in which the engine is stopped. That is, the ECU 20 controls the crank position sensor 10 based on the sensing signal from the crank position sensor 10 at the time of engine stop so that the entire circumferential surface of the flywheel ring gear equally reaches the stop position (position where the starter motor meshes with the starter motor) The fuel injection device 30 is controlled so that the post injection for changing the rotation angle of the shaft is performed. For example, the ECU 20 sets the rotation angle of the crankshaft sensed by the crank position sensor 10 at the time of the first engine stop to a reference angle (CA = 0 DEG), and thereafter, The fuel injection device 30 controls the fuel injection device 30 to perform the post injection so that the fuel injection device 30 increases by 30 degrees. At this time, the amount of fuel injected during the post injection depends on the rotation angle (final rotation angle) of the crankshaft finally rotated by the post injection at the time of engine stop immediately before and the sensing signal from the crank position sensor 10 at the time of the current engine stop And can be determined based on the difference in the rotation angle of the crankshaft detected. The operation of the ECU 20 will be described later in more detail.

The fuel injection device 30 rotates the crankshaft by injecting fuel into the cylinder of the engine with the injector under the control of the ECU 20 so that combustion takes place in the cylinder. In particular, the fuel injection device 30 performs post injection to additionally inject fuel at the time of stopping the engine under the control of the ECU 20.

The memory 40 stores information (for example, post injection frequency) about the final rotation angle at which the crankshaft is rotated by the post injection. In addition, the memory 40 may store the amount of fuel required for post injection according to the rotation angle in the form of a mapping table.

FIG. 2 is a flow chart for explaining an engine control method according to an embodiment of the present invention, and FIG. 3 is a view showing a state in which the entire circumferential surfaces of the flywheel ring gear are evenly divided in units of a predetermined interval.

In the present embodiment, the entire circumferential surfaces (total teeth) of the flywheel ring gear are divided into 12 sections (1 to 12) as shown in FIG. 3 and then the stop position of the flywheel ring gear (1) to (12) are sequentially and repeatedly allocated to ((1) section → (2) section → (3) section → ...) → (12) section, (1) section, (2) section, ...) do.

To this end, the ECU 20 recognizes the rotation angle CA of the crankshaft at the time of the first engine stop using the sensing signal received from the crank position sensor 10, and sets the position to a reference angle CA = 0 (Step 210).

When CA = 0, the stop position of the flywheel ring gear may correspond to the section (1) in FIG. That is, in the present embodiment, it is assumed that a section of the flywheel ring gear is located at a position where the starter motor is meshed with CA = 0 °.

Next, the ECU 20 outputs a post injection control signal for controlling the fuel injecting device 30 to inject a certain amount of fuel through the injector to the fuel injecting device 30 so that the crankshaft rotates by 30 degrees (CA = 30) (step 220).

That is, since the flywheel ring gear is divided into twelve sections, the ECU 20 causes the crankshaft to rotate by 30 degrees (CA = 30 degrees) at the time of engine stop by the post injection of the fuel injection device 30, Rotate the gear by 30 ° to control the stop position of the flywheel ring gear from ① to ②. In this case, since it is the rotation by the first post injection, it is rotated by only 30 degrees.

To this end, the ECU 20 includes information on the amount of fuel injection capable of rotating the crankshaft by 30 degrees into the post injection control signal, and outputs the post injection control signal to the fuel injection device 30. [ Upon receiving the post injection control signal, the fuel injector 30 injects a corresponding amount of fuel into the cylinder and moves the piston of the cylinder to forcibly further rotate the crankshaft by 30 degrees from the engine stopping point (CA = 0 DEG) .

At this time, the post injection may be caused to occur in all of the cylinders (four or six) of the vehicle engine, or may be selectively generated in only some (e.g., one) cylinder. In addition, the amount of fuel required for the post injection may be stored in advance in the memory 40 in the form of a mapping table, which is necessary for each rotation angle. In such a case, the ECU 20 searches the mapping table of the memory 40 for the fuel amount corresponding to the angle according to the angle to be rotated, finds the fuel amount, finds the corresponding information in the post injection control signal, (30).

When the stop position of the flywheel ring gear is moved to the section ②, the position where the starter motor and the flywheel ring gear are engaged when the engine is started again is the section ②.

The ECU 20 stores in the memory 40 information about the final rotation angle (CA = 30 [deg.]) At which the crankshaft rotates through the post injection. For example, since the final rotation angle of the crankshaft changes by 30 degrees every post injection, the ECU 20 can count the number of post injection and store the count value in the memory 40. [

When the engine is stopped again after the engine is started (step 230), the ECU 20 again uses the sensing signal received from the crank position sensor 10 to calculate the rotation angle of the crankshaft (Step 240).

At this time, the current rotation angle may be a difference angle of the rotation angle detected using the reference angle at the time of the first engine stop and the sensing signal received from the crank position sensor 10 at the time of the current engine stop.

Next, the ECU 20 compares the current rotation angle of the crankshaft with the final rotation angle of the crankshaft due to the post injection at the immediately preceding stop of the engine stored in the memory 40, (3) The post injection of the fuel injector 30 is controlled so that the section is at the stop position (step 250).

To this end, the ECU 20 compares the final rotation angle of the crankshaft due to the post injection at the immediately preceding engine stop and the rotation angle sensed by the crank position sensor 10 at the time of the current engine stop, To calculate how much the final rotation angle at the time of stopping the current engine is an angle that is further rotated by 30 degrees than the final rotation angle at the time of stopping the immediately preceding engine. For example, since the final rotational angle of the crankshaft due to the post injection in the step S220 is 30 degrees, the final rotational angle of the crankshaft at the time of the current engine stop should be 60 degrees (30 degrees + 30 degrees). However, if the rotation angle of the crankshaft sensed by the crank position sensor 10 at the time of the current engine stop is 120 °, the crankshaft must be rotated by 300 ° in the same direction.

When the required rotation angle is calculated, the ECU 20 searches the mapping table stored in the memory 40 for the amount of fuel required to rotate the crankshaft by the calculated rotation angle, And sends it to the fuel injection device 30 to control the post injection.

That is, using the information stored in the memory 40, the ECU 20 confirms that the stop position of the flywheel ring gear at the immediately preceding stopping of the engine was the section (2), and therefore stops the flywheel ring gear In order to ensure that the position becomes the next section of the section & cir & section, it is calculated whether the crankshaft should be further rotated and the post injection of the fuel injector 30 is controlled accordingly.

When the stop position of the flywheel ring gear is changed to the section? By the above-described steps 240 and 250, the position where the starter motor and the flywheel ring gear are meshed with each other becomes the section? When the engine is started again. That is, the stop position of the flywheel ring gear was changed from the section (2) to the section (3), so that the engagement position at the engine start was changed from the section (2) to the section (3).

Every time the engine is stopped again, the ECU 20 repeats the above-described steps 240 and 250 so that the stop position of the flywheel ring gear is shifted from the position ③ to the position ④ the position ⑤ the position ⑤ the position ⑤. → ⑫ section → ① section → ② section → ③ section → ... , And such changes are repeatedly performed. Accordingly, the position where the starter motor and the flywheel ring gear mesh with each other also changes repeatedly in the same order as the stop position of the flywheel ring gear.

As in the above-described embodiment, the present invention divides the entire circumferential surface of the flywheel ring gear equally into 12 sections and sequentially allocates the stop positions of the flywheel ring gear to 12 sections, The positions where the gears are meshed are sequentially changed in 12 intervals correspondingly, thereby significantly improving the durability of the flywheel ring gear compared to the case where the stop position of the flywheel ring gear is conventionally limited to two positions or three positions .

In the above-described embodiment, the entire circumferential surface of the flywheel ring gear is divided into twelve regions. However, it is obvious that the present invention can be further divided into more or less intervals according to the accuracy of the post injection.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention.

Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims (11)

A crank position sensor for sensing a rotation angle of the crankshaft and outputting a sensing signal indicating a rotation angle of the crankshaft;
A fuel injector for injecting fuel into a cylinder of an engine; And
And an ECU for controlling the fuel injection device to perform post injection when the engine is stopped based on a sensing signal from the crank position sensor to change the rotation angle of the crankshaft. The system as claimed in claim 1, wherein the ECU
And the final rotation angle of the crankshaft at the time of stopping the engine is sequentially changed by a predetermined angle according to the order in which the engine is stopped. 2. The apparatus as claimed in claim 1, wherein the ECU
Calculating the amount of fuel for the post injection based on the difference between the final rotational angle of the crankshaft at the time of immediately preceding engine stop and the rotational angle of the crankshaft detected by the sensing signal from the crank position sensor at the time of the current engine stop And the engine control device of the vehicle. The method according to claim 1,
Further comprising a memory for storing information on a final rotation angle at which the crankshaft is rotated by post injection and information about a fuel amount required for post injection for each rotation angle. 5. The apparatus of claim 4, wherein the ECU
Counts the number of post injection times, and stores the count value in the memory. When the engine is stopped, obtaining a current rotation angle of the crankshaft;
Calculating a rotation angle for post injection by comparing a final rotation angle of the crankshaft at the time of immediately stopping the engine with the current rotation angle; And
And transmitting information about a fuel amount corresponding to the calculated rotation angle to a fuel injection device to control the generation of the post injection. The method according to claim 6,
Further comprising the step of detecting a rotation angle of the crankshaft when the engine is initially stopped and determining the rotation angle as a reference angle. 8. The method of claim 7, wherein the current rotation angle
Wherein the reference angle is a difference angle of a rotation angle detected through a sensing signal received from a crank position sensor at a current engine stop. 7. The method of claim 6,
And counting the number of post injections to find out. 7. The method of claim 6, wherein the information on the amount of fuel
Wherein the amount of fuel required for post injection is stored in advance in correspondence with the rotational angle. 7. The method of claim 6, wherein the rotational angle for the post injection
Wherein the rotation angle is a rotation angle that causes the final rotation angle of the crankshaft to change sequentially by a predetermined angle when the engine is stopped according to the order of stopping the engine.

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