JP2006002618A - Ignition timing control device for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve startability and exhaust gas performance by enhancing appropriateness of ignition timing immediately after start. <P>SOLUTION: This ignition control device for an engine sets ignition timing to be fixed ignition timing at start of the engine, and switches the ignition timing to calculated ignition timing calculated based on an operating condition of the engine and set to be an advance angle side from the fixed ignition timing, when engine speed exceeds predetermined switching speed. When water temperature exceeds a predetermined value at start of the engine, the fixed ignition timing is advanced in phases along with increase in engine speed, and ignition frequency at a first stage in the fixed ignition timing is restricted. Moreover, in the ignition timing control device for the engine, in the case where the water temperature exceeds the predetermined value at start of the engine, when the ignition frequency in the fixed ignition timing reaches preset frequency, switching to the calculated ignition timing is performed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ignition timing control device for an engine. In particular, the ignition timing is set to a fixed ignition timing when the engine is started, and the engine ignition timing is switched when the engine speed exceeds a predetermined switching speed. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine ignition timing control device that improves the startability and exhaust gas performance by optimizing the ignition timing immediately after starting.

  Conventionally, in an electronically controlled ignition timing control device, a fixed ignition process for igniting at a constant ignition timing is performed during a certain period from the start state and until a predetermined period has elapsed from the end of the start. In addition, control for shifting to a calculation ignition process in which ignition is performed at an optimal ignition timing calculated based on the engine operating state is performed.

  At this time, the reason why the above-described fixed ignition process is performed is that the operation state parameters such as the intake pipe pressure are in an unstable state from the time of starting and from the time of completion of starting to the time of elapse of a predetermined period. Therefore, it is necessary to perform fixed ignition processing from the viewpoint of improving startability (see Japanese Patent Application Laid-Open No. 57-59058).

JP-A-6-137246 JP-A-8-189448 Japanese Patent Laid-Open No. 2000-9006

  By the way, in the conventional engine ignition timing control device, the ignition timing control at the time of starting is ignited (also referred to as “hard ignition”) at a timing synchronized with a crank signal as shown in FIG. The time is a fixed value (near TDC in FIG. 6).

  Further, after starting, when all the engine cylinders are in a state of complete explosion, control is performed so that an arbitrary ignition timing can be set by calculation from a crank signal (also referred to as “calculation ignition”).

  At this time, since the optimal ignition timing differs depending on the engine speed, etc., the calculated ignition is always the best, but the combustion is unstable at the time of starting, so the crank signal becomes an irregular interval and the calculation is performed. If done, errors are likely to occur. Therefore, hard ignition is performed at a fixed value at the start.

  Further, the determination at the start and after the start is determined based on the engine rotation speed. When the speed is usually 500 rpm or less, it is determined as the combustion unstable zone at the start.

  Here, in a multi-cylinder engine such as a four-cylinder engine, the engine water temperature is 25 degrees, and the number of ignitions at the start is about two times for each cylinder.

  Of these, when the first ignition of each cylinder completes the explosion, the engine speed increases, and the second ignition of each cylinder has the same ignition timing as the first. Being on the retarded side, combustion is worsened, and there are inconveniences such as poor startability and increased exhaust gas.

  For reference, as shown in FIG. 7, the starter motor is driven at the point ta0 at the start, and after the engine speed reaches the rotation S by the starter motor, the ignition timing is fixed to X by hard ignition. As the engine speed increases, the engine speed reaches the starting advance angle determination condition engine speed A at the point ta1.

  When the second ignition is performed at a point ta2 at a predetermined timing, the engine rotation speed further increases, and the engine rotation speed reaches the start / post-start determination engine rotation speed B at the point ta3. The hard ignition is shifted to the calculated ignition after starting. The ignition timing at the time of shifting to the calculated ignition after the start becomes the advance angle Z.

  However, since the second ignition at the point ta2 is the same ignition timing as the first, it is a fixed value and is on the retard side of the suitable ignition timing.

  Accordingly, in order to eliminate the above-described disadvantages, the present invention sets the ignition timing to a fixed ignition timing when starting the engine, and the engine speed exceeds the predetermined switching speed. In an engine ignition timing control device that is calculated based on an operating state and switches to a calculated ignition timing that is set to an advance side from the fixed ignition timing, when the water temperature is equal to or higher than a predetermined value when the engine is started, The fixed ignition timing is advanced in a stepwise manner as the rotational speed increases, and the number of initial ignitions at the fixed ignition timing is limited.

  Further, when starting the engine, the ignition timing is set to a fixed ignition timing, and when the engine speed exceeds a predetermined switching speed, the engine is calculated based on the engine operating state, and the fixed ignition timing is calculated. In an engine ignition timing control device that switches to a calculated ignition timing set to a more advanced side, when the water temperature is equal to or higher than a predetermined value when the engine is started, the number of ignitions at the fixed ignition timing reaches a preset number. In this case, switching to the calculated ignition timing is performed.

  As described above in detail, according to the present invention, when starting the engine, the ignition timing is set to the fixed ignition timing, and when the engine speed exceeds a predetermined switching speed, the engine operating state In the engine ignition timing control device that is calculated based on the engine ignition timing and is switched to the calculated ignition timing that is set to the advance side from the fixed ignition timing, when the water temperature is equal to or higher than a predetermined value when the engine is started, the engine speed increases. Along with this, the fixed ignition timing is advanced stepwise, and by limiting the initial number of ignitions at the fixed ignition timing, when each cylinder is completely ignited by the first ignition and the engine speed increases, The second ignition can be advanced in accordance with the demand of the internal combustion engine, and the startability and exhaust gas performance can be improved.

  In addition, when starting the engine, the ignition timing is set to a fixed ignition timing, and when the engine speed exceeds a predetermined switching speed, a calculation is made based on the engine operating state, and the ignition timing is advanced from the fixed ignition timing. In the engine ignition timing control device that switches to the calculated ignition timing set on the corner side, when the water temperature is equal to or higher than a predetermined value when the engine is started, when the number of ignition times at the fixed ignition timing reaches a preset number of times, By performing switching to the calculated ignition timing, it is possible to set the ignition timing required by the internal combustion engine immediately after the start by quickly switching to the calculated ignition timing.

  As a result of the invention as described above, when the water temperature is equal to or higher than a predetermined value at the start of the internal combustion engine, the fixed ignition timing is advanced stepwise as the rotational speed of the internal combustion engine increases, and the initial stage in the fixed ignition timing is increased. The number of ignitions is limited, and when each cylinder completes explosion by the first ignition and the rotation speed of the internal combustion engine rises, the second ignition is advanced according to the demand of the internal combustion engine, and startability and exhaust Gas performance is improved.

  In addition, when the water temperature is equal to or higher than a predetermined value when the internal combustion engine is started, when the number of ignitions at the fixed ignition timing reaches a preset number of ignitions, switching to the calculated ignition timing is performed, The ignition timing required by the internal combustion engine is set immediately after start-up by early switching.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  1 to 4 show a first embodiment of the present invention. In FIG. 2, reference numeral 2 denotes an ignition timing control device for the engine 4.

  An intake passage 6 is provided in communication with the intake system of the engine 4, and an exhaust passage 8 is provided in communication with the exhaust system.

  In the intake passage 6 of the engine 4, as shown in FIG. 2, an air cleaner 10, an air flow meter (also referred to as “AFM”) 12, and a throttle body 16 containing a throttle valve 14 are sequentially installed from the upstream side. Arrange.

  At this time, the air flow meter 12 is provided with an intake air temperature sensor (also referred to as “THA”) 18 for detecting the intake air temperature, and the throttle body 16 is provided with a throttle opening sensor (“TA”) for detecting the throttle opening. And an idle speed control valve (also referred to as “ISC”) 22, respectively, and an injector 24 is provided in the intake passage 6 on the downstream side of the throttle body 16.

  The engine 4 includes an ignition coil 26, an engine water temperature sensor (also referred to as “THW”) 28 that detects the engine water temperature, and a crank signal detection sensor (also referred to as “CRK”) 30 that detects a crank signal. And a cam signal detection sensor (also referred to as “CAM”) 32 for detecting the cam signal.

  Further, as shown in FIG. 2, a catalyst 34 and a muffler 36 are sequentially arranged in the exhaust passage 8 of the engine 4 from the upstream side, and an exhaust gas in the exhaust passage 8 between the engine 4 and the catalyst 34 is placed in the exhaust passage 8. An oxygen sensor 38 is provided for detecting the oxygen concentration.

  And the control means (it is also called "ECU") 40 which controls the said ignition timing control apparatus 2 is provided, The said air flow meter 12, the intake temperature sensor 18, and the input part 40-1 side of this control means 40, A throttle opening sensor 20, an engine water temperature sensor 28, a crank signal detection sensor 30, a cam signal detection sensor 32, and an oxygen sensor 38 are connected and provided on the output unit 40-2 side of the control means 40. Are provided by connecting an idle speed control valve 22, an injector 24, and an ignition coil 26, respectively.

  At this time, the control means 40 has a calculation processing unit 42 for performing CPU calculation. When the engine 4 is started, the ignition timing is set to a fixed ignition timing, and the rotation speed of the engine 4 is set to a predetermined value. When the switching rotational speed is exceeded, it has a function of being calculated based on the engine operating state and switching to the calculated ignition timing set to the advance side from the fixed ignition timing.

  In addition, when the water temperature is equal to or higher than a predetermined value when the engine 4 is started, the control means 40 advances the fixed ignition timing in a stepwise manner as the rotational speed of the engine 4 increases, and the fixed ignition It has a function to limit the number of times of the first stage ignition in the timing.

  Specifically, the number of ignitions in the first stage is set based on the water temperature of the engine 4, and the control unit 40 is provided with an ignition number counting unit 44 for counting the number of ignitions. The number of ignitions counted by the ignition number counting unit 44 Is reached, the fixed ignition timing is advanced to the next stage.

  That is, the number of ignitions in the first stage is set based on the water temperature of the engine 4, and after starting the starter motor at the point tb0 as shown in FIG. 4, the hard ignition at the start is fixed ignition timing (“ignition timing initial value”). It is also referred to as “X” and the number of ignitions after cylinder discrimination is counted by the ignition number counting means 44.

  The fixed ignition timing (also referred to as “ignition timing initial value”) X is set near the initial value TDC of the hard ignition timing.

  Then, at the point tb1 in FIG. 4, the engine speed (also referred to as “engine speed NE”) reaches the starting advance angle determination condition engine speed A (also referred to as “engine speed condition A”, for example, 300 rpm). When the number of ignitions counted by the ignition number counting means 44 is equal to or higher than a set value (also referred to as “the number of ignitions at the starting advance angle determination condition”) C, and the engine speed NE is When the engine rotational speed condition A is exceeded, that is, when the starting ignition timing advance condition is satisfied at the point tb2 in FIG. 4, the fixed ignition timing X is set to a set value ("ignition timing advance angle" based on the water temperature at the next stage. It is also referred to as “).

  The set value of the number of ignitions (also referred to as “the number of ignitions at the starting advance angle determination condition”) C and the set value of the ignition timing (also referred to as “the ignition timing advance”) Y are set for each water temperature. .

  Further, when the engine rotational speed NE increases and the engine rotational speed NE exceeds the engine rotational speed B at the time of starting / after starting (also referred to as “engine rotational speed condition B”, for example, 600 rpm) at a point tb3 in FIG. Then, it is determined that the engine has been started, and the process proceeds to the calculation ignition.

The start-time advance angle determination condition engine rotation speed A (also referred to as “engine rotation speed condition A”) and the engine rotation speed NE are determined at start / post-start determination engine rotation speed B (also referred to as “engine rotation speed condition B”). .)
A <B
Have the relationship.

  The number of ignitions after cylinder discrimination and the ignition timing of hard ignition are switched for each engine water temperature.

  Further, after ignition at the timing synchronized with the crank signal at the start, as shown in FIG. 3, the ignition timing can be advanced to the vicinity of the optimum ignition timing (also referred to as “MBT”) at the ignition timing at which all cylinders can be ignited.

  Next, the operation will be described along the control flowchart of the ignition timing control device 2 of the engine 4 in FIG.

  When the control program is started (102), it is determined (104) whether or not the cylinder determination process has been completed. If this determination (104) is NO, determination is made until the determination (104) becomes YES ( 104) is repeated, and if the determination (104) is YES, the process proceeds to a process (106) for setting the number of times of ignition to be shifted to the ignition advance according to the water temperature.

  Then, after the processing (106) for setting the number of times of ignition to shift to the ignition advance angle by the water temperature, hard ignition at the time of starting, that is, ignition by the fixed ignition timing (also referred to as “ignition timing initial value”) X, and cylinder A process (108) for starting the counting of the number of ignitions after the discrimination is performed, and a set value (the “starting advance angle determination condition ignition number”) that is the number of times the ignition number counted by the ignition number counting means 44 is set. The process proceeds to judgment (110) as to whether or not the engine rotational speed NE has exceeded the engine rotational speed condition A.

  Whether or not the number of ignitions counted by the ignition number counting means 44 is equal to or higher than a set value (also referred to as “the number of ignitions at the starting advance angle determination condition”) C, and the engine speed NE is In the determination (110) of whether or not the engine speed condition A has been exceeded, if the determination (110) is NO, the hard ignition at the time of starting, that is, the fixed ignition timing (also referred to as “ignition timing initial value”) X Returning to the process (108) for starting the ignition by and the counting of the number of ignition after cylinder discrimination, and the determination (110) is YES, the process for advancing the ignition timing to the set value Y based on the water temperature of the next stage ( 112), whether or not the engine rotational speed NE has exceeded the engine rotational speed B at start / post-start determination (also referred to as “engine rotational speed condition B”, for example, 600 rpm) ( To migrate to 14).

  When the determination (114) is NO in the determination (114) as to whether or not the engine rotation speed NE has exceeded the engine rotation speed B at the time of starting / after the determination (also referred to as “engine rotation speed condition B”, for example, 600 rpm). Returns to the process (112) for advancing the ignition timing to the set value Y based on the water temperature at the next stage. If the determination (114) is YES, the process proceeds to the process (116) for determining that the engine has been started and starting the calculation ignition. After the process (116) for starting the calculation ignition, the process is stopped, that is, the control program ends (118).

  Therefore, conventionally, when the internal combustion engine is started, the ignition timing is set to a fixed ignition timing, and when the internal combustion engine speed exceeds a predetermined switching speed, it is calculated based on the engine operating state, and the fixed ignition timing is set. In an ignition timing control device for an internal combustion engine that switches to a calculated ignition timing that is set to an advance side from the timing, switching from the fixed ignition timing to the calculated ignition timing is performed when the rotational speed of the internal combustion engine exceeds the switching rotational speed. The

  However, if the water temperature is equal to or higher than a predetermined value when the internal combustion engine is started, each cylinder is completely exploded by the first ignition at the fixed ignition timing, and the rotational speed of the internal combustion engine is increased. At this time, if the second ignition is performed at the same fixed ignition timing as the first ignition, the ignition timing is substantially retarded with respect to the optimal ignition timing, so that combustion deteriorates and startability and exhaust gas performance deteriorate. There was a problem to do.

  Therefore, in the first embodiment of the present invention, when the water temperature is equal to or higher than a predetermined value when the internal combustion engine is started, the fixed ignition timing is advanced stepwise as the rotational speed of the internal combustion engine increases, and the fixed ignition is performed. Since the number of times of the first stage ignition in the timing is limited, as described above, when each cylinder completes the explosion by the first ignition and the rotation speed of the internal combustion engine increases, the second ignition is advanced to meet the demand of the internal combustion engine. Thus, startability and exhaust gas performance can be improved.

  Further, the fixed ignition timing can be switched in accordance with the starting condition of the internal combustion engine by setting the number of ignitions in the first stage of the fixed ignition timing according to the water temperature of the internal combustion engine.

  FIG. 5 shows a second embodiment of the present invention. In the second embodiment, portions that perform the same functions as those of the first embodiment will be described with the same reference numerals.

  The feature of the second embodiment is that when the water temperature is equal to or higher than a predetermined value when the engine is started, when the number of times of ignition at the fixed ignition timing reaches a preset number of times, switching to the calculated ignition timing is performed. There is in point to carry out.

  That is, when the predetermined value D is set as the engine water temperature condition and the water temperature becomes equal to or higher than the predetermined value D when the engine is started, whether or not the number of ignitions at the fixed ignition timing is a predetermined number, for example, two or more. If this determination is affirmative, the hard ignition timing is switched to the calculated ignition timing.

  When the engine speed is determined at the time of start and after the start, in the region where the water temperature is high, the first ignition of each cylinder can sufficiently complete explosion, and the calculation ignition can be performed from the second time of each cylinder. Since it is possible, the determination at the time of start and after the start is made based on the number of ignitions after the cylinder determination, so that the required ignition timing can be set early.

  At this time, since the number of ignitions that complete explosion occurs at extremely low temperatures, the engine water temperature is detected by a water temperature sensor (not shown), and the engine water temperature exceeds a predetermined value D set as the engine water temperature condition. When the engine water temperature is equal to or lower than a predetermined value D, it is determined whether the engine is started or after the engine is started based on a set value E that is an engine speed condition. I do.

  Next, the operation will be described along the control flowchart of the engine ignition timing control device of FIG.

  When the control program is started (202), it is determined (204) whether or not the cylinder determination process has been completed. If this determination (204) is NO, determination is made until the determination (204) becomes YES ( 204) is repeated, and if the judgment (204) is YES, the hard ignition at the time of starting, that is, the ignition by the fixed ignition timing (also referred to as “ignition timing initial value”) and the number of ignition after the cylinder discrimination are counted. The process (206) to be started is started.

  Then, after the hard ignition at the start, that is, the ignition by the fixed ignition timing (also referred to as “ignition timing initial value”) and the process (206) for starting the count of the number of ignition after cylinder discrimination, the engine water temperature is a predetermined value. When the determination (208) is YES, the number of ignitions of each cylinder at the fixed ignition timing is two or more times that is a preset number. If the determination (208) is NO, the process proceeds to a determination (212) as to whether or not the engine speed NE has exceeded a set value E that is an engine speed condition. .

  In the determination (210) of whether or not the number of times of ignition of each cylinder at the above-described fixed ignition timing is a preset number of times or more (210), if this determination (210) is NO, the above-described start-up time When the determination (210) is YES, the processing returns to the hard ignition, that is, the ignition at the fixed ignition timing (also referred to as the “ignition timing initial value”) and the count of the number of ignition after the cylinder discrimination is started (206). The process proceeds to the process (214) for determining that the engine has been started and starting the calculated ignition. After the process (214) for starting the calculated ignition, the process is stopped, that is, the control program ends (216).

  Further, in the determination (212) of whether or not the engine speed NE described above has exceeded the set value E which is the engine speed condition, if this determination (212) is YES, it is determined that the engine has been started and the ignition is performed. The process proceeds to a process (214) to be started, and after the process (214) to start the calculation ignition, the process proceeds to a stop, that is, to the end (216) of the control program.

  In other words, conventionally, switching from the fixed ignition timing to the calculated ignition timing has been performed when the rotational speed of the internal combustion engine exceeds the switching rotational speed.

  However, when the water temperature at the start of the internal combustion engine is high, the cylinders are completely ignited by the first ignition and the rotation is stabilized, so that it is possible to switch to the calculated ignition timing even if the switching speed has not been reached. is there.

  Therefore, in the second embodiment of the present invention, when the water temperature is equal to or higher than a predetermined value at the start of the internal combustion engine, when the number of ignitions at the fixed ignition timing reaches a preset number of ignitions, the calculation ignition timing is reached. Therefore, the ignition timing required by the internal combustion engine can be set immediately after the start by quickly switching to the calculated ignition timing.

  The present invention is not limited to the first and second embodiments described above, and various application modifications can be made.

  For example, in the embodiment of the present invention, the fixed ignition timing is advanced stepwise as the engine speed increases, or the number of ignitions at the fixed ignition timing is preset according to the water temperature at the start of the internal combustion engine. However, it is also possible to adopt a special configuration in which the detected value is used in addition to the above water temperature.

  That is, any temperature can be used as long as it can detect the temperature state at the start of the internal combustion engine. Therefore, the intake air temperature, the outside air temperature, the oil temperature, or the like is used instead of the water temperature.

  Then, since the temperature state at the time of start-up of the internal combustion engine can be reliably grasped, startability and exhaust gas performance can be improved as in the first and second embodiments described above. .

It is a flowchart for control of the ignition timing control apparatus of the engine which shows 1st Example of this invention. 1 is a schematic system diagram of an ignition timing control device for an engine. It is a schematic explanatory drawing of the ignition timing of a cylinder. It is a time chart which shows the ignition control at the time of starting of the ignition timing control apparatus of an engine. It is a flowchart for control of the ignition timing control apparatus of the engine which shows 2nd Example of this invention. It is a schematic explanatory drawing of the ignition timing of the cylinder which shows the prior art of this invention. It is a time chart which shows the ignition control at the time of starting of the ignition timing control apparatus of an engine.

Explanation of symbols

2 Ignition timing control device 4 Engine 6 Intake passage 8 Exhaust passage 10 Air cleaner 12 Air flow meter (also referred to as “AFM”)
14 Throttle valve 16 Throttle body 18 Intake air temperature sensor (also referred to as “THA”)
20 Throttle opening sensor (also referred to as “TA”)
22 Idle speed control valve (also referred to as “ISC”)
24 Injector 26 Ignition coil 28 Engine water temperature sensor (also referred to as “THW”)
30 Crank signal detection sensor (also referred to as “CRK”)
32 Cam signal detection sensor (also referred to as “CAM”)
34 Catalyst 36 Muffler 38 Oxygen sensor 40 Control means (also referred to as “ECU”)
40-1 input unit 40-2 output unit 42 arithmetic processing unit 44 ignition count counting means

Claims (3)

  When starting the engine, the ignition timing is set to a fixed ignition timing, and when the engine speed exceeds a predetermined switching speed, a calculation is made based on the engine operating state, and the ignition timing is advanced from the fixed ignition timing. In the engine ignition timing control device that switches to the calculated ignition timing set on the corner side, when the water temperature is equal to or higher than a predetermined value at the time of starting the engine, the fixed ignition timing is stepped as the engine speed increases. And an ignition timing control device for an engine characterized by limiting the number of times of ignition at the first stage in the fixed ignition timing.   When the number of ignitions in the first stage is set based on the water temperature of the engine, and an ignition number counting means for counting the number of ignitions is provided, and when the number of ignitions counted by the ignition number counting means reaches the set number of times 2. The engine ignition timing control device according to claim 1, wherein the fixed ignition timing is advanced to the next stage.   When starting the engine, the ignition timing is set to a fixed ignition timing, and when the engine speed exceeds a predetermined switching speed, a calculation is made based on the engine operating state, and the ignition timing is advanced from the fixed ignition timing. In the engine ignition timing control device that switches to the calculated ignition timing set on the corner side, when the water temperature is equal to or higher than a predetermined value at the time of starting the engine, the number of ignition times at the fixed ignition timing reaches a preset number In addition, the engine ignition timing control device is characterized by switching to the calculated ignition timing.

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