JP4055991B2 - Engine stroke discrimination device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an engine stroke determination device, and more particularly to an engine stroke determination device including a starter motor.
[0002]
[Prior art]
In various engine controls, control parameters, control signal output timing, and the like are determined in relation to the engine stroke. For this purpose, various process determination methods have been considered. First, there is a first method that includes a sensor for detecting the rotation angle of the camshaft and a crank sensor, and determines the stroke based on the relationship between the outputs of both sensors.
[0003]
As a second method, there is a method that includes a sensor for detecting the pressure in the intake pipe and a crank sensor, and determines the stroke from the relationship between the crank angle and the intake pipe pressure. An example of this method is described in Japanese Patent Application Laid-Open No. 2000-337206.
[0004]
Furthermore, as a third method, in view of the fact that the crank angular speed fluctuates during the engine cycle, a crank sensor that outputs a pulse signal at every constant crank angle is provided, and the stroke is recognized by determining the interval of the pulse signal. There is something to do.
[0005]
[Problems to be solved by the invention]
In the first method, a camshaft sensor must be provided separately from the crank angle sensor. In the second method, a carburetor engine that does not have a sensor for detecting the intake pipe pressure requires a new intake pipe pressure sensor. Further, in the third method, the crank sensor has a structure in which a pulse signal is not output in a certain section in order to detect top dead center. In addition, since the pulse signal of the crank sensor is also used to determine the ignition timing, it is not possible to change a certain section in which the pulse signal is not output. Therefore, the sensor cannot be laid out such that the output of the crank sensor is detected during one revolution of the crank and the stroke is determined based on the detection result.
[0006]
In view of the above problems, an object of the present invention is to provide a stroke determination device that can accurately determine the stroke of an engine with a small number of sensors.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention divides an ignition pulser that outputs a pulser signal at a predetermined position near the top dead center of the engine, and one cycle of the engine into four equiangular sections. A means for measuring the crank angular velocity, and determining whether or not a change pattern in one cycle of the crank angular velocity detected for each of the four sections is a predetermined pattern in response to the pulsar signal. There is a first feature in that there is provided a means for determining the time when the pulsar signal is output when the change pattern is a predetermined pattern as the compression top dead center of the engine.
[0008]
Further, the present invention divides an ignition pulser that outputs a pulser signal at a predetermined position near the top dead center of the engine and a crank angle corresponding to one cycle of the engine into four equiangular sections, and the rotation time of each section And means for adding a positive sign in the case of increase and a negative sign in the case of reduction due to increase / decrease in the rotation time between the current section and the immediately preceding section for each section, and the four sections Is determined in response to the pulsar signal, and the output time of the pulsar signal when the codes of the four sections are scheduled is determined as the compression top dead center of the engine. There is a second feature in that it is provided with a means for performing.
[0009]
According to the first and second features, in the engine explosion stroke, the crank angular speed is faster than the other strokes and gradually decreases after the explosion stroke. When a change pattern in which the angular velocity increases and then gradually decreases is detected, this pulser signal is determined as an ignition pulse. That is, it is determined that the compression top dead center is when the pulsar signal is output.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 2 is a cross-sectional view of an engine starter motor to which a stroke determination device according to an embodiment of the present invention is applied. The starter motor 1 has a rotor 2 and a stator 3. The starter motor 1 is a starting means for an engine (not shown), and acts as a generator driven by the engine after the engine starts autonomous operation.
[0011]
The rotor 2 includes a cup-shaped yoke 4, a sleeve or hub 5 that couples the yoke 4 to an engine crankshaft (not shown), and a plurality of magnets 6 disposed along the inner periphery of the yoke 4. An annular sensor magnet 7 for detecting rotation is fitted on the outer periphery of the end portion of the sleeve 5. The sensor magnet 7 is magnetized with a magnetized band (angle detecting magnetized band) whose polarity is inverted every predetermined angle and one magnetized portion of one rotation or only one place with a different polarity. And a magnetized band (a magnetizing part for detecting a reference position or a magnetized band).
[0012]
The stator 3 includes a stator core 8 and a stator winding 10 wound around the stator core 8 via an insulating material 9. The stator winding 10 is a three-phase winding. The stator core 8 is fixed to the engine casing via a stator base (not shown). The stator 3 includes three first magnetic sensors 11 arranged to face the angle detection magnetizing band of the sensor magnet 7 and a second magnetic field arranged to face the reference position detecting magnetized portion or the magnetizing band. A sensor package 13 including the sensor 12 is provided.
[0013]
The first magnetic sensor 11 outputs a detection signal that alternates every predetermined angle corresponding to the magnetization band of the sensor magnet 7 whose polarity is changed every predetermined angle. Since this detection signal corresponds to a change in the crank angle, the first magnetic sensor 11 is hereinafter referred to as a crank angle sensor 11. Three crank angle sensors are arranged with a phase difference of an electrical angle of 120 ° corresponding to the U, V, and W phases of the starter motor 1. That is, the crank angle sensor 11 includes sensors 11U, 11V, and 11W.
[0014]
The second magnetic sensor outputs a pulse signal once every rotation corresponding to the reference position detecting magnetized portion or magnetized band. Since this pulse signal is used for detecting the ignition timing, hereinafter, the second magnetic sensor 12 is referred to as an ignition pulser 12.
[0015]
The sensor package 13 includes a crank angle sensor 11, a substrate 14 that supports the ignition pulser 12, and lead wires 15 that connect the sensors 11 and 12 to a control unit (not shown), and are fixed to the stator 3 with bolts 16.
[0016]
FIG. 3 is a system configuration diagram of a main part of a motorcycle engine including the starter motor. The ECU 17 includes a rectifier circuit 100 coupled to the three-phase windings 1U, 1V, and 1W of the starter motor 1 and switching elements (for example, FETs) constituting the rectifier circuit 100, and the crank angle sensors 11U, 11V, and 11W. And a switching circuit 200 that controls the output according to the output. Further, the ECU 17 includes a microcomputer (CPU) 300 that operates according to a scheduled program based on crank angle sensors 11U, 11V, and 11W, an ignition pulser 12, and detection signals from the sensors described later and switch switching.
[0017]
A main switch 18, a starter switch 19, a starter relay 20, an ignition coil 21, a throttle sensor 22, and a speed sensor 23 are connected to the ECU 17. The speed sensor 23 is formed so as to output a detection signal for each rotation of the crankshaft, and is disposed in the vicinity of the crankshaft. A spark plug 24 is connected to the secondary side of the ignition coil 21.
[0018]
A battery 25 is provided as a power source for each part described above, and current is supplied from the battery 25 to each part via the fuse 26 and the main switch 18.
[0019]
FIG. 4 is a diagram showing the phase relationship between the outputs of the crank angle sensor 11 and the ignition pulser 12. The crank angle sensor 11 outputs a pulse signal once every crank angle of 10 °. That is, when the crankshaft rotates once, the first magnetic sensor 11 outputs 36 pulse signals. Therefore, 72 pulses are output in one cycle of compression / explosion / exhaust / intake. A measurement section (1st to 4th sections) is set with a crank angle of 10 ° as one stage and 18 stages as one section, and one cycle is defined as 72 stages and 4 measurement sections.
[0020]
On the other hand, the ignition pulser 12 outputs a pulse signal once for each rotation of the crankshaft. A stage number is assigned from the stage (for example, 3 stages) scheduled from the falling edge of the output waveform of the ignition pulser 12 (the waveform after being shaped into a rectangular wave), and the crank rotation time for each measurement section is measured. Based on this rotation time, it is determined which of the outputs of the ignition pulser 12 is the ignition pulse of the compression stroke.
[0021]
FIG. 5 is a diagram illustrating a measurement example of the crank rotation time for each measurement section. In the same figure, the increase / decrease of the rotation time of each measurement section with respect to the rotation time of the immediately previous measurement section is determined. When the rotation time increases, the sign “+”, when the rotation time decreases, the sign “−”, Remember. Each time the detection signal of the ignition pulser 12 is output, the sequence of increase / decrease codes in the previous four measurement sections is determined. If the sequence of the codes is (−, +, +, +), the determination is made. It can be determined that the output pulse of the second magnetic sensor 12 is an ignition pulse. Increasing the measurement time means that the crank angular speed is decreasing, and the load gradually increases during one cycle of the engine, and the load becomes maximum at the ignition timing of the compression stroke. Match the characteristics.
[0022]
6 and 7 are flowcharts of stroke determination. In step S1 of FIG. 6, it is determined whether the ignition is turned on. If this determination is affirmative, the process proceeds to step S2, and the crank angle for two rotations is divided every 10 degrees to perform numbering of 1 to 72 stages. In step S3, it is determined whether or not the engine speed Ne is in a range not less than the idle speed Ni and not more than the target speed Nt. If step S3 is positive, it is determined in step S4 whether the rotation direction of the crank is normal rotation. If step S4 is affirmative, the routine proceeds to step S5, where it is determined whether the output (ignition pulse) of the ignition pulser 12 has risen to the minus (-) side. If step S5 is affirmative, the process proceeds to step S6, where it is determined whether a predetermined stage (for example, three stages) has elapsed since the ignition pulse rose to the negative side. If step S6 is positive, it is determined that the condition for determining the crank rotation time for stroke determination is satisfied, and the process proceeds to step S7 in FIG.
[0023]
In step S7 of FIG. 7, flags F1 to F4 are cleared (= 0). The flag F1 is a flag that is set (= 1) when the time required for the rotation of one section (18 stages) has decreased from the previous section. On the other hand, the flags F2 to F4 are flags that are set when the time required for the rotation of one section increases from the time of the previous section.
[0024]
In step S8, a time A in which the crank angle has advanced 18 stages (crank angle 180 °) from the first stage is measured and stored in the memory. Subsequently, in step S9, it is determined whether or not there is a measurement record of the time D of the previous section (fourth section of the immediately preceding cycle). Since there is no previous data at first, the process proceeds to step S12. If there is previous data, the process proceeds to step S10, where the time D is subtracted from the time A to determine whether the value is negative. If this determination is affirmative, the routine proceeds to step S11, where a flag (minus flag) F1 is set.
[0025]
In step S12, the time B during which the crank angle changes for the next 18 stages is measured and stored in the memory. In step S13, time A is subtracted from time B to determine whether the value is positive. If this determination is affirmative, the routine proceeds to step S14, where a flag (plus flag) F2 is set. If step S13 is negative, the process proceeds to step S15.
[0026]
In step S15, it is determined whether or not all the flags F1 to F4 are set. All the flags are set when the sequence of codes indicating the time increase / decrease in the latest four sections including the section is (−, +, +, +) at the time of the process of step S14. This arrangement is the same as the example shown in FIG. That is, if step S15 is positive, it is determined that the measurement start time of the section time four sections before is the end of the compression stroke, that is, the compression top dead center (TDC) (step S23). That is, the pulser signal at that time is an ignition pulse.
[0027]
Initially, it is not determined that all the flags are set (the flags F1 and F2 are only set at the maximum), so step S15 is negative. If step S15 is negative, the process proceeds to step S16.
[0028]
In step S16, the time C during which the crank angle changes for the next 18 stages is measured and stored in the memory. In step S17, time B is subtracted from time C to determine whether the value is positive. If this determination is affirmative, the routine proceeds to step S18, where a flag (plus flag) F3 is set. If step S17 is negative, the process proceeds to step S19.
[0029]
In step S19, the time D during which the crank angle changes for the next 18 stages is measured and stored in the memory. In step S20, time C is subtracted from time D to determine whether or not the value is positive. If this determination is affirmative, the routine proceeds to step S21, and a flag (plus flag) F4 is set. If step S20 is negative, the process proceeds to step S8.
[0030]
In step S22, it is determined whether all the flags F1 to F4 are set. If step S22 is affirmative, it will progress to step S24 and will determine with the pulsar signal at that time being an ignition pulse. Similar to the determination in step S15, the determination to set all the flags has not been completed at first, so step S22 is negative. If step S22 is negative, the process proceeds to step S8.
[0031]
When measurement is performed for each time A, B, C, and D after the second time, the previously held value is updated with the latest measurement result.
[0032]
FIG. 1 is a block diagram showing the main functions of the stroke determination device. The time A measuring unit 27 measures the crankshaft rotation time of the first section in one cycle. Similarly, the time B measuring unit 28 measures the crankshaft rotation time of the second section, the time C measuring section 29 measures the third section, and the time D measuring section 30 measures the crankshaft rotation time of the fourth section. The first subtracting section 31 subtracts the time of the first section from the time of the second section, and the second subtracting section 32 subtracts the time of the second section from the time of the third section. The third subtractor 33 subtracts the time of the third section from the time of the fourth section, and the fourth subtractor 34 subtracts the time of the fourth section from the first detected time of the first section.
[0033]
The first code memory 35, the second code memory 36, the third code memory 37, and the fourth code memory 38 are respectively a first subtraction unit 31, a second subtraction unit 32, a third subtraction unit 33, and a fourth subtraction unit. The sign of 34 subtraction results is stored. The arrangement determination unit 39 determines the arrangement of codes from the first code memory 35 to the fourth code memory 38 based on when the subtraction by the second subtraction unit 32 ends and when the subtraction by the fourth subtraction unit 34 ends. . That is, when the subtraction by the second subtracting unit 32 is finished, the arrangement of the codes in the first code memory 35 to the fourth code memory 38 is determined. As a result of the determination, if the code sequence is (−, +, +, +), the pulsar signal four intervals before is determined as the ignition pulse from the determination of the code sequence.
[0034]
If one pulser signal is determined to be an ignition pulse, the other pulser signal can be simultaneously determined to be a fire pulse. When the determination is completed, a confirmation flag is set to confirm the ignition pulse. Note that the above determination is performed as needed, and when the ignition pulse is detected twice in succession, the ignition pulse is updated regardless of the confirmation flag.
[0035]
When the ignition pulse is determined, the stage is numbered with reference to the rising edge. The stage number is incremented or decremented according to the forward rotation and reverse rotation of the starter motor, and the current stage number is always grasped. When the engine speed is equal to or higher than the engine speed Nt and the stage cannot be determined, the numbering is performed again based on the ignition pulse when the engine speed is equal to or lower than the engine speed Nt.
[0036]
When the rising edge of the ignition pulse to the plus side deviates from the stage number “0”, the numbering should be updated. In this case, the numbering is updated in a range where the engine speed is not less than the idle speed Ni and not more than the reference speed Nt.
[0037]
In the above embodiment, the compression top dead center is detected based on the change pattern of the time required for the crank to rotate in the four sections. This is representative of the crank angular speed of the four sections in terms of time, and the compression top dead center is determined by whether or not the change pattern of the crank angular speed is a predetermined pattern instead of the change pattern of time. Good.
[0038]
【The invention's effect】
According to the first and second aspects of the present invention, one of the pulser signals output twice during one cycle is compressed top dead center based on the change pattern during one cycle of the crank angular velocity for each scheduled section. It can be determined that the ignition pulse is output in the vicinity. This determination can be made by measuring a signal interval for each constant crank angle output from the crank angle sensor by a timer means or the like, and processing the measurement result for each output of the ignition pulser. Therefore, it is possible to accurately determine the stroke of the engine without providing a dedicated sensor separately from the sensor normally used for engine control conventionally.
[Brief description of the drawings]
FIG. 1 is a block diagram showing main functions of a stroke determination device according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of an engine starter motor to which a stroke determination device according to an embodiment of the present invention is applied.
FIG. 3 is a system configuration diagram of a main part of a motorcycle engine including a starter motor.
FIG. 4 is a diagram showing a phase relationship between outputs of a crank angle sensor and an ignition pulser.
FIG. 5 is a diagram illustrating a measurement example of a crank rotation time for each measurement section.
FIG. 6 is a flowchart (part 1) of stroke determination.
FIG. 7 is a flowchart (part 2) of stroke determination.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Motor, 2 ... Rotor, 3 ... Stator, 4 ... Yoke, 5 ... Sleeve, 6 ... Rotor magnet, 7 ... Sensor magnet, 10 ... Stator winding, 11 ... Crank angle sensor, 12 ... Ignition pulser, 27 ... Time A: Measurement unit 28: Time B measurement unit 29: Time C measurement unit 30 ... Time D measurement unit 31 ... First subtraction unit 32 ... Second subtraction unit 33 ... Third subtraction unit 34 ... Fourth Subtracting unit 35 ... 1st code memory 36 ... 2nd code memory 37 ... 3rd code memory 38 ... 4th code memory 39 ... Arrangement discrimination unit

Claims (2)

An ignition pulser that outputs a pulser signal at a planned position near the top dead center of the engine;
Means for dividing one cycle of the engine into four equiangular sections and measuring the crank angular speed of each section;
It is determined in response to the pulsar signal whether the change pattern of the crank angular speed detected every four sections is a predetermined pattern, and the change pattern of the crank angular speed in the four sections is changed to the predetermined pattern. An engine stroke discriminating apparatus comprising: means for determining a compression top dead center of the engine when the pulsar signal is output. An ignition pulser that outputs a pulser signal at a planned position near the top dead center of the engine;
Means for dividing the crank angle corresponding to one cycle of the engine into four equiangular sections and measuring the rotation time of each section;
Means for adding a positive sign in the case of increase and a negative sign in the case of reduction by increasing or decreasing the rotation time between the current section and the immediately preceding section for each section;
It is determined in response to the pulsar signal whether or not the codes of the four sections are in a predetermined sequence, and when the pulsar signal is output when the codes of the four sections are in a predetermined sequence, the compression dead of the engine An engine stroke discriminating apparatus comprising a means for judging points.

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