JP2006090218A - Internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform feedback control of engine speed by ignition timing such that the engine speed reaches target engine speed both in operating ranges and non-operating ranges during stop idle operation, in a spark ignition type internal combustion engine for a vehicle to which an automatic transmission is jointed. <P>SOLUTION: During stop idle operation, feedback control of engine speed is performed by ignition timing. When a shift selector (40) is in the operating ranges (R, D, 2, 1), a feedback gain is made large, and when the shift selector (40) is in the non-operating ranges (P, N), the feedback gain is made small. During shifting of the shift selector (40), the control is stopped. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a spark ignition internal combustion engine for a vehicle to which an automatic transmission is coupled, and more particularly to an apparatus for controlling the idling speed.

  When starting an engine for a vehicle, particularly during a cold start, combustion is likely to deteriorate, and the engine speed may become unstable. When combustion deteriorates, exhaust emission deteriorates, vibration due to unstable rotational speed, and the like occur. For this reason, various control devices for preventing the deterioration of combustion at the time of starting the engine and stabilizing the engine speed have been proposed. For example, there exists a thing of patent document 1.

By the way, at present, a vehicular engine is very often used in combination with an automatic transmission with a torque converter. Automatic transmissions are generally P (parking), R (reverse), N (neutral), D (drive, forward, 1st → 2nd → 3rd → 4th (4th with overdrive) )), 2 (forward, 1st speed → 2nd speed), 1 (1st speed).
Normally, starting is performed in the P range, and then the driver shifts to the D range or R range in preparation for starting.
Here, the P and N ranges are called non-driving ranges, and R, D, 2, and 1 are called driving ranges.

  The drive range is the state where the vehicle can be driven by releasing the brake and depressing the accelerator pedal, the power transmission is not cut off inside the automatic transmission, the turbine of the torque converter is connected to the stopped tire, The impeller of the torque converter is connected to the engine output shaft. Therefore, the fuel injection amount and the ignition timing are set so that the engine maintains a predetermined rotational speed against a load caused by fluid friction between the impeller of the torque converter and the turbine.

  On the other hand, in the non-driving range when the vehicle is stopped, the power transmission is cut off inside the automatic transmission, and the engine resists the load due to the rotational resistance to the front transmission gear group where the power transmission is cut off via the torque converter. Thus, the fuel injection amount and the ignition timing are set so as to maintain a predetermined rotational speed.

  When the load in the drive range is compared with the load in the non-drive range, the load in the drive range is larger. Therefore, the idling rotation in the driving range burns a larger amount of the air-fuel mixture than the idling rotation in the non-driving range. As a result, the change in the rotational speed when the ignition timing is changed by the same amount is smaller in the driving range than in the non-driving range. That is, the drive range is less sensitive to changes in ignition timing.

Therefore, when the ignition timing is changed by the same amount in the driving range and the non-driving range, the number of revolutions in the non-driving range changes more greatly than in the driving range. As a result, for example, when the drive range is switched to the non-drive range, the change in the rotation speed due to the change in the ignition timing is greater than in the drive range, which may cause the driver to feel uncomfortable or uncomfortable. is there.
However, in the apparatus of Patent Document 1, various methods for changing the rotational speed are explained, but the above-mentioned problem is not paid attention to and no solution is disclosed.

JP 2001-90851 A

  In view of the above problems, the present invention provides a spark ignition type internal combustion engine for a vehicle to which an automatic transmission is coupled so that the ignition timing can be reached in the same manner in the driving range and the non-driving range during the stop idling operation. The purpose is to feedback control the rotation speed.

According to a first aspect of the present invention, there is provided a spark ignition type internal combustion engine for a vehicle to which an automatic transmission is coupled, and switches between a driving range and a non-driving range in which the load on the engine is different while the automatic transmission is stopped. Where possible, an idle speed control device that feedback-controls the engine speed during stationary idling operation to the target speed by ignition timing,
An internal combustion engine is provided in which the feedback gain in the drive range and the feedback gain in the non-drive range of the idle speed control device are set to different values.
In the internal combustion engine configured as described above, the feedback gain in the driving range and the feedback gain in the non-driving range can be set to different values, so that the target is the same in the driving range and the non-driving range during the stop idling operation. The rotational speed can be reached.

  According to the invention of claim 2, in the invention of claim 1, the load of the drive range is larger than the load in the non-drive range, and the feedback gain in the drive range is set larger than the feedback gain in the non-drive range. An internal combustion engine is provided.

According to the invention of claim 3, in the invention of claim 1, the feedback gain in the drive range and the feedback gain in the non-drive range are set so that the convergence speed to the target rotational speed is the same. Is provided.
In the internal combustion engine configured as described above, the convergence speed to the target rotational speed is made the same in the driving range and the non-driving range.

  According to a fourth aspect of the present invention, there is provided an internal combustion engine according to the first aspect of the invention, wherein the idling speed of the driving range and the idling speed of the non-driving range are set to different values.

  According to a fifth aspect of the present invention, there is provided the internal combustion engine according to the first aspect, wherein the feedback correction amount is set to a constant value during the switching operation between the driving range and the non-driving range.

The invention described in each claim is a spark ignition internal combustion engine for a vehicle to which an automatic transmission is coupled, and switches between a driving range and a non-driving range in which the load on the engine is different while the automatic transmission is stopped. Although it is possible, it has an idle speed control device that feedback-controls the engine speed during stationary idling operation to the target speed by the ignition timing, and the feedback gain in the drive range of the idle speed control device and the non-drive range The feedback gain is set to a different value. Accordingly, it is possible to reach the target rotational speed in the same manner in the drive range and the non-drive range during the stop idle operation.
In particular, according to the invention of claim 3, the convergence speed to the target rotational speed is made the same in the drive range and the non-drive range.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
An internal combustion engine (hereinafter simply referred to as an engine) 10 is a spark ignition type and includes a spark plug 11. A high voltage current is supplied to the spark plug 11 from the coil 11 '. A crank angle sensor 12 calculates a rotational speed NE based on a signal from the crank angle sensor 12. Air is supplied to each cylinder 10 </ b> C of the engine 10 through an intake pipe 13. 14 is a throttle valve, and 15 is an ISCV (idle speed control valve) for supplying air during idling.
The throttle valve 14 is driven by a throttle motor 14a to change the opening, and the opening is detected by a throttle opening sensor 14b.

An output shaft 19 of the engine 10 is connected to an impeller 21 of a torque converter 20, a turbine 22 is fluidly connected to the impeller 21, and an input shaft 31 of an automatic transmission 30 is connected to the turbine 22.
An input shaft 31 of the automatic transmission 30 is connected to an output shaft 33 via a transmission gear group 32 indicated by a broken line, and a tire (not shown) is coupled to the output shaft 33. The transmission gear group 32 includes a planetary gear device 32p. A vehicle speed sensor 34 is attached adjacent to the output shaft 33.

  Reference numeral 100 denotes an electronic control unit (hereinafter referred to as ECU). The ECU 100 is formed by connecting an input port 101, an output port 102, a CPU 103, a ROM 104, a RAM 105, and the like with a common bus. A signal detected by each sensor is input to the ECU 100, and a control signal for performing control related to the present invention is sent to each actuator.

  An accelerator pedal 50 is provided with an accelerator opening sensor 50 'that generates a signal current corresponding to the amount of depression when the accelerator pedal 50 is depressed. The output of the accelerator opening sensor 50' is sent to the ECU 100. A signal is sent from the ECU 100 to the throttle motor 14a, and the throttle valve 14a is opened according to the depression amount of the accelerator pedal 50. A brake pedal 51 is provided with a brake switch 51 'that generates a signal current when the brake pedal 51 is depressed.

Reference numeral 40 denotes a shift selector that selects a gear position of the automatic transmission. The shift selector 40 includes six shift selectors P, R, N, D, 2, and 1 (or seven with an overdrive attached to D). Has a range.
In the P range and the N range, the input shaft 31 of the automatic transmission 30 is idled, the power transmission from the input shaft 31 to the output shaft 33 is cut off, and the engine 10 rotates idle.

  In the R range, D range, 2 range, and 1 range, power transmission from the input shaft 31 to the output shaft 33 is enabled, and the engine 10 idles unless the vehicle is braked and the accelerator pedal 51 is not depressed. When the braking of the vehicle is released and the accelerator pedal 51 is depressed, the vehicle travels backward in the R range and travels forward in the D range, 2 range, and 1 range.

  Since the power transmission is not interrupted in the transmission gear group 32 as described above in the drive range when the vehicle is stopped, the turbine 22 of the torque converter 20 is connected to the stopped tire. On the other hand, the impeller 21 of the torque converter 20 is connected to the output shaft 13 of the engine 10. Accordingly, the fuel injection amount and the ignition timing are set so that the engine 10 maintains a predetermined rotational speed against a load caused by fluid friction between the impeller 21 of the torque converter 20 and the turbine 22.

  On the other hand, in the non-driving range when the vehicle is stopped, the input shaft 31 of the transmission 30 rotates idly as described above, and the engine 10 is input to the input shaft 31 (including elements attached to the input shaft 31) via the torque converter 20. Is driven to rotate. Therefore, the fuel injection amount and the ignition timing are set so that the engine 10 maintains a predetermined rotational speed against the rotational resistance when the input shaft 31 is rotated.

The idle speed in the drive range is called a first idle speed, the load is called a first idle load, the idle speed in the non-drive range is called a second idle speed, and the load is called a second idle load. And it is set as follows.
1st target idle speed <2nd target idle speed 1st idle load> 2nd idle load

Hereinafter, the control of the embodiment of the present invention basically configured as described above will be described.
At first, the concept of this control will be explained. This control is feedback control of the rotation speed so that the ignition timing is adjusted to the target rotation speed during idling operation while the vehicle is stopped. And the non-driving range so that the convergence speed to the target rotational speed is the same.

FIG. 2 shows the case where the rotational speed is increased toward the target value, as an example of climbing a slope, where the height difference of the slope corresponds to the rotational speed difference, and the size of the luggage corresponds to the magnitude of the load. . The driving range corresponds to the case of carrying a large load on the back because the load is large, and corresponds to the case of carrying a load with a small inclination because the load is small in the non-drive range.
The target rotational speed of the non-driving range is larger than the target rotational speed of the driving range, but the comparison is performed with the same rotational speed difference.

  In order to make the convergence speed the same, the same altitude difference (= rotational speed deviation) must be climbed at the same climbing speed (= increase rate of rotational speed). Then, if the luggage is large, a large physical strength is required, and if the luggage is small, a small physical strength is sufficient. The feedback gain corresponds to this physical strength. Therefore, a large feedback gain is set in the driving range, and a small feedback gain is set in the non-driving range.

FIG. 3 is a flowchart of the embodiment of the present invention executed based on the above.
In step S1, each parameter, for example, the rotation speed, the vehicle speed, the shift position, etc. is read.
In step S2, it is determined whether or not the ignition timing feedback control may be executed. If the following (1) and (2) are satisfied at the same time, an affirmative determination is made, and if even one of the following is not satisfied, a negative determination is made.
(1) The vehicle is stopped. This is determined by the detection value of the vehicle speed sensor 34 being a predetermined value or less.
(2) The accelerator depression amount is zero. This is determined by the detected value of the accelerator opening sensor 50 '.

  When an affirmative determination is made in step S2, the process proceeds to step S3, and in step S3, the rotational speed deviation ΔNE is calculated by ΔNE = NEREF−NE. NEREF is the target rotation speed and is stored in a map as shown in FIG. 4 according to the cooling water temperature TW for the case of the driving range and the case of the non-driving range. If a negative determination is made in step S2, an open control, that is, no feedback control command is issued in step S12, and the process ends.

  In step S4, it is determined whether or not an elapsed time tshift after a shift change from the drive range to the non-drive range or from the non-drive range to the drive range is greater than a predetermined value ta. If an affirmative determination is made, the process proceeds to step S5. If a negative determination is made, the process proceeds to step S11. In step S11, a command for holding the feedback correction amount NEFBCORR is issued and the process ends. This step S11 corresponds to claim 5 so that the feedback correction amount is not changed while the shift selector 40 is in operation.

In step S5, it is determined whether or not it is a non-driving range.
If an affirmative determination is made in step S5, the process proceeds to step S6 to read the non-driving range gain GN. In step S7, the gain G for calculating the feedback correction amount FBCORR is replaced with the gain GN read in step S6. Proceed to S10.
If a negative determination is made in step S5, the process proceeds to step S8, and the driving range gain GD is read. In step S9, the gain G for calculating the feedback correction amount FBCORR is replaced with the gain GD read in step S8. Proceed to
The gain GN and the gain GD are stored in the ECU 100 as maps as shown in FIG. 5 as ignition advance amounts per unit rotational speed difference.

In step S10, the gain G obtained in steps S7 and S9 is multiplied by ΔNE obtained in step S3 to calculate the feedback correction amount NEFBCORR, and the process is terminated.
The embodiment of the present invention is configured and operates as described above, and can reach the target rotational speed at the same convergence speed.

  The present invention relates to a spark ignition internal combustion engine for a vehicle to which an automatic transmission is coupled, and can switch between a driving range and a non-driving range while the automatic transmission is stopped, and the driving range is a non-driving range. The present invention can be applied to a system in which the load applied to the internal combustion engine is larger than that, and the engine speed during the idling stop operation is feedback controlled to the target speed by the ignition timing.

It is a figure explaining the structure of embodiment of this invention. It is a figure explaining the view of control of an embodiment of the invention. It is a flowchart of control of an embodiment of the invention. It is a map of target rotation speed. It is a map which shows the example of the feedback gain of a drive range, and the feedback gain of a non-drive range.

Explanation of symbols

11 Spark plug 15 ISCV (idle speed control valve)
20 Torque Converter 21 Impeller 22 Turbine 30 Automatic Transmission 31 Input Shaft 32 Transmission Gear Group 33 Output Shaft 40 Shift Selector 41 Shift Position Sensor 50 Accelerator Pedal 51 Brake Pedal

Claims (5)

A spark ignition type internal combustion engine for a vehicle to which an automatic transmission is coupled, wherein the automatic transmission can switch between a driving range and a non-driving range with different loads on the engine while the vehicle is stopped.
An idle speed control device that feedback-controls the engine speed during stationary idling operation to the target speed by ignition timing,
The feedback gain in the drive range of the idle speed control device and the feedback gain in the non-drive range are set to different values.
An internal combustion engine characterized by that.   2. The internal combustion engine according to claim 1, wherein a load in the driving range is larger than a load in the non-driving range, and a feedback gain in the driving range is set larger than a feedback gain in the non-driving range.   2. The internal combustion engine according to claim 1, wherein the feedback gain in the driving range and the feedback gain in the non-driving range are set so that the convergence speed to the target rotational speed is the same.   2. The internal combustion engine according to claim 1, wherein the idling speed of the driving range and the idling speed of the non-driving range are set to different values.   The internal combustion engine according to claim 1, wherein the feedback correction amount is set to a constant value during the switching operation between the driving range and the non-driving range.

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