JP4253615B2 - Start control device for internal combustion engine - Google Patents

Description

  The present invention relates to an internal combustion engine start control device capable of starting an internal combustion engine by operating a start device.

  Conventional examples of start control of an internal combustion engine are disclosed in Patent Documents 1 and 2. In the hybrid vehicles of Patent Literatures 1 and 2, when the internal combustion engine in a stopped state is started by operating the generator as an electric motor, the cranking rotational speed of the internal combustion engine is increased to the idle rotational speed. This suppresses sudden fluctuations in the rotational speed when the internal combustion engine starts a self-sustained operation, thereby reducing rattling noise and vibration.

  As other background art, start control of an internal combustion engine according to Patent Documents 3 to 5 is disclosed.

Japanese Patent Laid-Open No. 9-1117012 JP 11-315735 A JP-A-9-203364 Japanese Patent Laid-Open No. 6-147069 Japanese Patent Laid-Open No. 10-339251

  When an abnormality occurs in the electric motor that starts the internal combustion engine and its drive circuit, and the electric motor is driven and fails (on-failure), it is desirable to be able to detect the failure. However, in Patent Documents 1 and 2, it is difficult to detect an on-failure because it does not have a function of determining whether or not an electric motor (generator) for starting an internal combustion engine or an abnormality of its drive circuit has occurred. There is a problem.

  An object of the present invention is to provide a start control device for an internal combustion engine that can determine abnormality of the start device with a simple configuration.

An internal combustion engine start control device according to the present invention is an internal combustion engine start control device capable of starting an internal combustion engine by operating the start device, wherein the cranking rotational speed of the internal combustion engine is higher than the set idle rotational speed. Start control means for performing start control for starting the internal combustion engine by operating the starter so as to increase the fixed amount, and when the internal combustion engine is started by the start control, the rotational speed of the internal combustion engine is set to the set idle rotational speed. A state in which the starter remains driven by comparing the rotation speed of the internal combustion engine and the set idle rotation speed after finishing the start control and the idle control means for performing the idle control to substantially match And an abnormality determination means for determining an abnormality due to an on-failure that fails in the above.

  In the present invention, when the internal combustion engine is started so that the cranking rotational speed of the internal combustion engine is higher than the set idle rotational speed by a predetermined amount, the rotational speed of the internal combustion engine is set to the set idle speed when the internal combustion engine is started. Idle control is performed to approximately match the rotation speed. Then, after the start control is completed, the abnormality of the starter can be determined with a simple configuration by comparing the rotation speed of the internal combustion engine with the set idle rotation speed.

In starting control apparatus for an internal combustion engine according to the present invention, the abnormality determining means, when the difference is greater than the threshold value of the rotational speed and the set idle rotational speed of the internal combustion engine, the starting device is abnormal by the ON failure It can also be determined.

An internal combustion engine start control device according to the present invention is an internal combustion engine start control device capable of starting an internal combustion engine by operating the start device, wherein the cranking rotational speed of the internal combustion engine is a set idle rotational speed. A start control means for starting the internal combustion engine by operating the starter so as to be higher by a predetermined amount, and when the internal combustion engine is started by the start control, the rotational speed of the internal combustion engine is set to the set idle An idle control means for performing idle control to substantially match the rotational speed, and after the start control is finished, the rotational speed of the internal combustion engine and the cranking rotational speed are compared to keep the starter driven. And an abnormality determining means for determining an abnormality due to an on-failure that fails in the state of the above.

  In the present invention, when the internal combustion engine is started so that the cranking rotational speed of the internal combustion engine is higher than the set idle rotational speed by a predetermined amount, the rotational speed of the internal combustion engine is set to the set idle speed when the internal combustion engine is started. Idle control is performed to approximately match the rotation speed. Then, after the start control is finished, the abnormality of the starter can be determined with a simple configuration by comparing the rotation speed of the internal combustion engine with the cranking rotation speed.

In starting control apparatus for an internal combustion engine according to the present invention, the abnormality determining means, when the difference between the rotational speed of the cranking rotation speed and the engine is less than a threshold, the starting device is abnormal by the ON failure It can also be determined.

In starting control apparatus for an internal combustion engine according to the present invention, when the starting device is determined to be abnormal by the ON failure by the abnormality determining means, and having an output means for outputting a signal indicating an abnormality You can also. By so doing, it is possible to notify the operator of an abnormality in the starting device.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

  FIG. 1 is a diagram schematically illustrating a configuration of a vehicle drive system including an internal combustion engine that is a control target of a start control device according to an embodiment of the present invention. The drive system in the present embodiment includes a starter 10, an engine 12, a transmission 14, a starter relay 16, and a control device 30, and the engine 12 in a stopped state can be started by rotating the starter 10. The torque generated by the engine 12 after starting can be transmitted to drive wheels (not shown) via the transmission 14.

  The rotation shaft 10-1 of the starter 10 is connected to the rotation shaft 12-1 of the engine 12 through a one-way clutch 18 and a belt 20. When the starter 10 tries to drive the engine 12 in a stopped state, the starter 10 can start the engine 12 by operating the one-way clutch 18 to be engaged. On the other hand, when the engine 12 after the self-supporting operation tries to rotationally drive the starter 10 in the stopped state, the starter 10 remains in the stopped state and is not rotationally driven by operating the one-way clutch 18 to be in the released state. .

  The starter relay 16 is provided between the starter 10 and a power source (not shown). When the starter relay 16 is in the on state, the starter 10 and the power source are electrically connected, and the starter 10 is driven to rotate. On the other hand, when the starter relay 16 is in the off state, the starter 10 and the power source are not connected, and the rotation drive of the starter 10 is stopped. On / off switching of the starter relay 16 can be performed by a start control signal output from the control device 30.

  The engine rotation speed sensor 32 detects the rotation speed of the engine 12. A detection signal from the engine speed sensor 32 is input to the control device 30.

  The control device 30 controls the output / stop of the start control signal to the starter relay 16 based on the operation of the operator, the vehicle operating state such as the accelerator opening, the vehicle speed, and the like. When the start control signal is output to the starter relay 16, the starter relay 16 is turned on and the starter 10 is rotationally driven, whereby the engine 12 in the stopped state is started. In the present embodiment, the starter 10 is rotationally driven so that the cranking rotational speed Nc of the engine 12 is higher than the set idle rotational speed Ni by a predetermined amount δN1 (δN1> 0). As described above, the control device 30 can perform start control for starting the engine 12 by outputting the start control signal to the starter relay 16.

  On the other hand, when the output of the start control signal to the starter relay 16 is stopped, the starter relay 16 is turned off and the rotation drive of the starter 10 is stopped. Thus, the control device 30 can stop the rotation drive of the starter 10 by stopping the output of the start control signal to the starter relay 16. That is, the start control can be stopped.

  Further, the control device 30 outputs an idle control signal to the engine 12 when the engine 12 is started by the start control, so that the rotation speed Ne of the engine 12 substantially matches the set idle rotation speed Ni. It can be performed.

  Here, for example, when the starter relay 16 is stuck in the ON state, even if the starter control signal output is stopped, the starter 10 remains in the state of being driven to rotate (on failure). It is desirable to be able to detect faults. Therefore, in the present embodiment, the control device 30 determines whether or not an on-failure has occurred, and when detecting the occurrence of an on-failure, outputs a failure warning signal indicating the occurrence of an abnormality and turns on a warning lamp (not shown) To inform the operator of the occurrence of an abnormality.

  Hereinafter, an abnormality determination routine for determining whether or not an ON failure has occurred by the control device 30 will be described with reference to the flowchart shown in FIG. This abnormality determination routine is executed when the stopped engine 12 is started based on the operation of the operator or the vehicle driving state.

  First, in step (hereinafter referred to as S) 1, output of a start control signal to the starter relay 16 is started. As a result, the starter relay 16 is switched to the on state, the rotational drive of the starter 10 is started, and the start control for starting the engine 12 is started. Here, the start control is performed so that the cranking rotational speed Nc of the engine 12 is higher than the set idle rotational speed Ni by a predetermined amount δN1 (δN1> 0). Then, the process proceeds to S2.

  In S2, it is determined whether or not a predetermined time t1 has elapsed since the start of the output of the start control signal. The predetermined time t1 here is set based on the time required for the autonomous operation of the engine 12, and can be set experimentally, for example. If the predetermined time t1 has not yet elapsed, that is, if the determination result of S2 is NO, the determination of S2 is repeated until the determination result of S2 becomes YES. On the other hand, if the predetermined time t1 has elapsed, that is, if the determination result in S2 is YES, the process proceeds to S3.

  In S3, the output of the start control signal to the starter relay 16 is stopped. As a result, the starter relay 16 is switched to the OFF state, and the rotation drive of the starter 10 is stopped. That is, the start control is stopped. Then, the process proceeds to S4.

  In S4, it is determined whether or not the rotational speed Ne (detected by the engine rotational speed sensor 32) Ne of the engine 12 after the start control is stopped is greater than a predetermined value X1. The predetermined value X1 here is set as a threshold value for determining whether or not the engine 12 has started a self-sustained operation, and is set to a value sufficiently smaller than, for example, the set idle rotational speed Ni. If the determination result in S4 is NO, it is determined that the engine 12 has not started the self-sustained operation, the process returns to S1, and the start control is performed again to start the engine 12. On the other hand, if the determination result in S4 is YES, it is determined that the engine 12 has started a self-sustaining operation, and the process proceeds to S5.

  In S5, an idle control signal is output to the engine 12. As a result, idle control for making the rotational speed Ne of the engine 12 substantially coincide with the set idle rotational speed Ni is performed. Then, the process proceeds to S6.

  In S6, it is determined whether or not the rotational speed Ne (detected by the engine rotational speed sensor 32) Ne of the engine 12 after the start of the idle control is greater than the set idle rotational speed Ni. Here, when the rotation drive of the starter 10 is stopped because the output of the start control signal is stopped, that is, when no on-failure has occurred, the rotational speed Ne of the engine 12 is set to the set idle rotational speed Ni. Almost matches. On the other hand, when the starter 10 is still driven to rotate despite the output of the start control signal being stopped, that is, when an on-failure occurs, the engine 12 is still driven to rotate by the starter 10, The rotational speed Ne of the engine 12 is greater than the set idle rotational speed Ni.

  From the above, it can be determined whether or not an on-failure has occurred by determining whether or not the rotational speed Ne of the engine 12 after the start of idle control is greater than the set idle rotational speed Ni. If the determination result in S6 is NO, it is determined in S7 that no on-failure has occurred, and the execution of this routine is terminated. On the other hand, if the determination result in S6 is YES, it is determined in S8 that an on-failure has occurred, and the process proceeds to S9.

  In S9, a failure warning signal indicating the occurrence of abnormality is output and a warning lamp (not shown) is turned on to notify the operator of the occurrence of abnormality. Then, the execution of this routine is terminated.

  Regarding the abnormality determination of S6 in the above routine, the difference Ne−Ni between the rotational speed Ne of the engine 12 after the start of the idle control and the set idle rotational speed Ni is determined by a predetermined amount δN2 in consideration of the control deviation during the idle control. You may make it determine whether it is larger than ((delta) N2> 0). If this determination result is NO, the process proceeds to S7 (determines that it is normal), and if this determination result is YES, the process proceeds to S8 (determines that an abnormality has occurred).

  The predetermined amounts δN1 and δN2 described above are set in consideration of a control deviation during start control and idle control, and can be set experimentally, for example.

  As described above, in the present embodiment, the start control for starting the engine 12 is performed so that the cranking rotational speed Nc of the engine 12 is higher than the set idle rotational speed Ni by a predetermined amount δN1 (δN1> 0). Then, after the start control is finished, the on-failure can be detected with a simple configuration by comparing the rotational speed Ne of the engine 12 after the start of the idle control with the set idle rotational speed Ni. When an on failure is detected, a failure warning signal is output and a warning lamp (not shown) is lit to notify the operator of the occurrence of an abnormality.

  In the present embodiment, the startability of the engine 12 can be improved by rotating the starter 10 so that the cranking rotational speed Nc of the engine 12 is higher than the set idle rotational speed Ni.

  In the above description of the present embodiment, a case has been described in which the presence or absence of an on-failure is determined by comparing the rotational speed Ne of the engine 12 after the start of idle control with the set idle rotational speed Ni. However, in the present embodiment, it is possible to determine whether or not an on-failure has occurred by comparing the rotational speed Ne of the engine 12 after the start of the idle control with the cranking rotational speed Nc.

  Here, when the rotation drive of the starter 10 is stopped because the output of the start control signal is stopped, that is, when the on-failure has not occurred, the rotational speed Ne of the engine 12 is the cranking rotational speed Nc. It is lower by a predetermined amount δN1. On the other hand, if the starter 10 remains rotationally driven even when the output of the start control signal is stopped, that is, if an on-failure occurs, the cranking rotational speed Nc and the rotational speed Ne of the engine 12 are The difference Nc−Ne is smaller than δN1.

  Therefore, in S6 of the flowchart of FIG. 2, the difference Nc−Ne between the cranking rotational speed Nc and the rotational speed Ne of the engine 12 after the start of the idle control is determined by a predetermined amount δN3 in consideration of the control deviation during the idle control. Whether or not an on-failure has occurred can also be determined by determining whether or not it is smaller than (δN3> 0). If this determination result is NO, the process proceeds to S7 (determines that it is normal), and if this determination result is YES, the process proceeds to S8 (determines that an abnormality has occurred). Note that the predetermined amount δN3 is set in consideration of a control deviation during start control or idle control, and can be set experimentally, for example.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not limited to such embodiment at all, and it can implement with a various form in the range which does not deviate from the summary of this invention. Of course.

It is a figure which shows the outline of a structure of the drive system of the vehicle containing the internal combustion engine which is a control object of the starting control apparatus which concerns on embodiment of this invention. It is a flowchart explaining the abnormality determination routine performed by the control apparatus.

Explanation of symbols

  10 starter, 12 engine, 14 transmission, 16 starter relay, 18 one-way clutch, 20 belt, 30 control device, 32 engine rotation speed sensor.

Claims (5)

An internal combustion engine start control device capable of starting an internal combustion engine by operating a start device,
Start control means for performing start control for starting the internal combustion engine by operating the starter so that the cranking rotation speed of the internal combustion engine is higher than the set idle rotation speed by a predetermined amount;
Idle control means for performing idle control for making the rotational speed of the internal combustion engine substantially coincide with the set idle rotational speed when the internal combustion engine is started by the start control;
An abnormality determination means for determining an abnormality due to an on-failure in which the starter is still driven , by comparing the rotation speed of the internal combustion engine and the set idle rotation speed after the start control is completed;
A start control device for an internal combustion engine, comprising: An internal combustion engine start control device according to claim 1,
The abnormality determining means, when the difference is greater than the threshold value and the rotational speed of the internal combustion engine the set idle rotational speed, the starting of the internal combustion engine in which the starting device is characterized in that it determined to be abnormal by the ON failure Control device. An internal combustion engine start control device capable of starting an internal combustion engine by operating a start device,
Start control means for performing start control for starting the internal combustion engine by operating the starter so that the cranking rotation speed of the internal combustion engine is higher than the set idle rotation speed by a predetermined amount;
Idle control means for performing idle control for making the rotational speed of the internal combustion engine substantially coincide with the set idle rotational speed when the internal combustion engine is started by the start control;
An abnormality determination means for determining an abnormality caused by an on-failure in which the starter is left driven by comparing the rotation speed of the internal combustion engine and the cranking rotation speed after the start control is completed,
A start control device for an internal combustion engine, comprising: An internal combustion engine start control device according to claim 3,
The abnormality determining means, when the difference between the rotational speed of the cranking rotation speed and the engine is smaller than the threshold value, the start of the internal combustion engine in which the starting device is characterized in that it determined to be abnormal by the ON failure Control device. A start control device for an internal combustion engine according to any one of claims 1 to 4,
The abnormality when the determining means the starting device is determined to be abnormal by the ON failure, and start control system for the internal combustion engine and having an output means for outputting a signal indicating the abnormality.

Images