JPS6143209A - Valve control device of engine - Google Patents

Abstract

PURPOSE:To compensate the resistance change due to the temperature change, prevent the response delay, and correctly control a valve by correcting the excitation start timing to the coil of a solenoid actuator driving the valve in response to the temperature of the coil. CONSTITUTION:An intake valve 12 and an exhaust valve 14 are opened by solenoid coils 28 of solenoid actuators 15, 16 respectively. The opening timing and the closing timing of the intake valve 12 and exhaust valve 14 are controlled in response to the operational condition of an engine. The excitation of the solenoid coil 28 is started earlier than the target opening timing, the excitation start timing is corrected in response to the temperature of the solenoid coil 28: if the temperature is higher, the timing is accelerated earlier. The resistance change of the solenoid coil 28 due to the temperature change is compensated, the rise response of the valve is quick, and the valve opening timing is correctly controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) This invention relates to valve opening/closing of intake/exhaust valves of an engine.
The present invention relates to an engine valve control device in which the N side is configured and operated electrically by electromagnetic means.

(Prior art) Engine valve synchronization mechanisms are generally constructed mechanically, but in order to reduce engine weight and improve fuel efficiency, conventional valve mechanisms operate the engine's intake and exhaust valves using electromagnetic means. (for example, Japanese Patent Application Laid-Open No. 58-183
Publication No. 805).

Conventional 4 mentioned above! In the case of a construction, when the engine temperature rises due to a high load on the engine, the humidity of the electromagnetic means also increases due to the influence, which causes the molecules in the conductive material (for example, the coil) to oscillate, increasing the electrical resistance. Even when the electromagnetic means is energized, the operation of the valve tends to be delayed compared to normal times, resulting in the problem that the engine does not operate smoothly.

(Objective of the Invention) The object of the present invention is to correct the start timing of energization to the electromagnetic means earlier in accordance with the temperature rise of the electromagnetic means, thereby avoiding a delay in response to opening of the valve when the temperature of the electromagnetic means rises. The purpose of the present invention is to provide an engine valve control device.

(Structure of the Invention) This invention provides an energization control device that controls energization to the electromagnetic means, and includes an energization start means for starting energization to the electromagnetic means before the target valve opening timing. The present invention is characterized in that the engine valve control device is configured to correct the energization start timing in a direction earlier in accordance with a rise in temperature of the device.

(Effects of the Invention) According to this invention, if the temperature of the electromagnetic means rises, the energization timing is advanced in accordance with this rise, thereby eliminating the response delay due to the increase in electrical resistance due to the temperature rise, and timing the target valve opening time. The intake and exhaust valves can be opened accurately,
This ensures smooth engine operation.

(Example) An embodiment of the present invention will be described in detail below based on the drawings.

The drawing shows a valve control device for an engine. In FIG. 12, the engine 10 is composed of a single cylinder engine, and an intake valve 12 is provided on the intake passage 11 side of the engine 10, and an exhaust valve 14 is provided on the exhaust passage 13 side of the engine 10. Each is provided.

The above-mentioned intake and exhaust valves 12.14 are each provided to be driven by a solenoid 15.16, and each solenoid 15.16 is driven and controlled by drive signals Si, Se from the controller 17.

Temperature sensors 18 and 19 are attached to each solenoid 15 and 16 to detect the temperature of the solenoid itself, and these detection signals Ti and Te are input to the controller 17.

Each crank sensor 21 is provided in the output system of the crankshaft 20 of the engine 10, and the sensor 21 inputs a crank angle reference signal TDC to the controller 17.

Further, an accelerator opening signal Qa indicating the accelerator opening is inputted to the above-mentioned controller 17 from an accelerator opening sensor 22 provided on an accelerator (not shown).

FIG. 2 shows the structure of the above-mentioned intake and exhaust valves 12 and 14, including a valve retainer 24 fixed to the upper end of the valve stem 23 of each valve 12 and 14 and a lower retainer 25.
Each valve 12.14 is closed by a valve spring 26 interposed between the two, and the lower end of the spindle 27 of each solenoid 15.16 is in contact with the upper end of the valve stem 23.

Each of the above-mentioned solenoids 15, 16 is connected to the above-mentioned spindle 27.
and a coil 28, and when the coil 28 is energized, the spindle 27 moves and the valve 12.1
You can open the valve by pressing 4.

FIG. 3 shows the configuration of the above-mentioned controller 17, in which the MPU
(The same applies below to the abbreviation of microprocessor) 31 is ROM
The RAM 33 stores or reads necessary data, and the timer 34 keeps time.

The output signal TDC of the crank angle sensor 21 is waveform-shaped by a waveform shaping circuit 35 and inputted to the MPU 31, and output signals Qa and Ti of the accelerator opening sensor 22 and temperature sensors 18 and 19, respectively.

Te is A/D converted by A/D converters 36, 37, and 38 and input to the MPU 31.

Further, each solenoid 15, 16 is driven and controlled by a solenoid drive circuit 39, 40, respectively.

The operation of the valve control device configured as described above will be explained with reference to the time chart of FIG. 4 and the flow chart of FIG. 5.

In a first step 51, an initial rice is performed.

In a second step 52, it is determined whether or not the operating stroke of the engine 10 is an explosive stroke based on the output of the crank angle reference signal TDC of the crank angle sensor 21, and when this output is determined, in a third step 53. , since the time measured by the timer 34, that is, the start of the explosion stroke, is set at the output of the crank angle reference signal TDC, the TDC output time t2 at this time
Read. - In the fourth step 54, the previous TDC output time t1 is read from the RAM 33, and both times t2. t
The period TO of the explosion stroke is calculated by calculating the difference of 1.

In a fifth step 55, the previous TDC output time t1 is updated to the current TDC output time t2.

In a sixth step 56, the rotational speed ne of the engine 10 is calculated from the period TO of the explosion stroke calculated in the fourth step 54 described above.

This calculation is performed for engine 1 in accordance with the stepwise period TO.
A rotation speed of 0 is preset and stored in a map of the RAM 33, and the rotation speed nelfi corresponding to the above-mentioned period TO is read from this map.

In a seventh step 57, the accelerator opening signal Qa from the accelerator opening sensor 22 is read.

At the eighth step 58, the above-mentioned accelerator opening signal Qa,
To detect the operating state of the engine 10 based on the rotational speed ne of the engine 10 calculated in the sixth step 56 described above, and to open and close the intake/exhaust valves 12 and 14 corresponding to this operating state. Next, the basic timing for starting and stopping the energization of each solenoid 15 and 16, that is, the time for starting and stopping the energization with reference to the output time of the crank angle reference signal @TDC is calculated.

That is, intake valve 12 energization start time Ti 08 intake valve 1
2 energization stop time Ti 08 Exhaust valve 14 energization start time Te0B Exhaust valve 14 energization stop time TeCB Note that these calculations are made in accordance with the step-by-step operating state of the engine 10, and the energization start and energization stop times are The time is set in advance and stored in a map of the RAM 33, and the time corresponding to the above-mentioned operating state is read from this map.

In the ninth and tenth steps 59.60, each temperature sensor 18
, 19 are read.

In the eleventh and twelfth steps 61.62, the response delay time corresponding to the temperature change of the intake/exhaust solenoid 15.16 that opens and closes the intake/exhaust valve 12.14 is calculated.

That is, when the temperature of the coil 28 of the solenoid 15.16 increases, the electrical resistance increases due to the oscillation of the molecules inside the coil 28, which causes the coil 28 of the solenoid 15.16 to increase in temperature.
There is a time delay in operation between the start of energization and the stop of energization in step 16.

Therefore, in response to this temperature rise, it is necessary to correct the timing of starting and stopping energization earlier.

In these steps 61 and 62, the response delay time according to the temperature of the intake/exhaust solenoid 15.16 is calculated.
The response delay time is preset and stored in correspondence with the temperature No. 6, and the above-mentioned response delay time is read from this table.

That is, intake valve 12 energization start delay time TC1 Intake valve 1
2 energization stop delay time TC2 Exhaust valve 14 energization start delay time Td1 Exhaust valve 14 energization stop delay time 7d
2 In the 13th step 63, the time when the basic timing of opening and closing of the intake/exhaust valves 12 and 14 is corrected by the above-mentioned delay time, that is, the correction time based on the output point of the crank angle reference signal TDC. calculate.

i.e. Correction time Ti for starting energization of the intake valve 12.

Intake valve 12 energization stop correction time TiC exhaust valve 1
4, energization start correction time Te.

Calculation of energization stop correction time TeC for exhaust valve 14 Tio←Ti0B-TCI TiC4-Ti CB-Tc2 Teo<-Te OB -TdI Tea4-Te CB -Td2 In the 14th step 64, execution of drive control of each solenoid 15, 16 The time is calculated based on the time t2 updated in the fifth step 55.

i.e. Execution time ti for starting energization of the intake valve 12.

Intake valve 12 energization stop execution time tic exhaust valve 1
4 energization start execution time tea energization stop execution time tec calculation of exhaust pulp 14 tio←t2+ Tio Na3-t2+ Ti
cteo←t2+ Teo tec+-t2+
In the 15th step 65, the current time t is read from the timer 34, and the execution time t for starting energization of the exhaust valve 14 is read.
If the time tea is determined, the MPU 31 outputs the drive signal 3e for the exhaust solenoid 16 in a 16th step 66, and this drive signal Se is sent to the exhaust solenoid 16 via the solenoid drive circuit 40. The exhaust valve 14 is opened by driving the exhaust solenoid 16.

Note that if the time tea is not determined in the fifteenth step 65 described above, the fifteenth step 65 described above is skipped.

At the 17th step 67, the current time t is read from the timer 34, and it is determined whether the intake valve 120 energization start execution time Tio has arrived.If the time Tio is determined, at the 18th step 68, the MPtJ31 is 15 drive signal Si is output, and this drive signal Se is passed through the solenoid drive circuit 39 to the intake solenoid 15.
The intake valve 12 is opened.

Note that if the time tio is not determined in the 17th step 67 described above, the 18th step 68 described above is skipped.

At the 19th step 69, the current time t is read from the timer 34, and it is determined whether the exhaust valve 14 energization stop execution time tea has arrived.If the time tec is determined, at ta20 step 70, the MPU 31 starts the exhaust valve 14. The output of the drive signal Se of the solenoid 16 is stopped, and with this output stop, the exhaust solenoid 16 is turned OFF, and the exhaust valve 1 is turned off.
4 is closed by the elasticity of the valve spring 26.

Note that if the time tec is not determined in the nineteenth step 69 described above, the twentieth step 70 described above is skipped.

In the 21st step 71, the current time [ is read from the timer 34, and it is determined whether the current time tic has come to stop the energization of the intake valve 12. If the time tic is determined, in the 22nd step 72, the MPLI 31 is activated for the intake valve 12. The output of the drive signal Si of the solenoid 15 is stopped, and with this output stop, the intake solenoid 15 is turned OFF, and the intake valve 1 is turned off.
2 is closed by the elasticity of a valve spring 26.

Note that if the time Nc is not determined in the 21st step 71 described above, the 22nd step 72 described above is skipped. .

When the opening/closing control of the intake/exhaust valves 12, 14 is completed as described above, the process returns to the second step 52.

As described above, as the temperature of the intake/exhaust solenoids 15 and 16 rises, if the energization start and energization stop timings are corrected to be earlier, the response delay in the actual valve opening timing and valve closing timing can be corrected. As a result, a smooth operating condition of the engine 10 can be obtained.

In the above embodiment, the temperature of the solenoids 15 and 16 was directly detected by the temperature sensors 18 and 19;
It may be detected indirectly using a water temperature sensor of 0.

Furthermore, a second embodiment described below shows valve control that deals with a delay in response of a solenoid due to a battery voltage drop, and the same components as in the first embodiment described above are given the same reference numerals. The explanation will be omitted.

For the sake of explanation, in this embodiment, only the valve control of the intake valve is explained, but since the valve control of the exhaust valve is also configured equivalently, its explanation is also omitted.

In FIG. 6, battery 41 inputs its voltage signal VB to controller 17, and the voltage drop is checked.

@7 As shown in the figure, the power supply voltage of the battery 41 is input to the power supply circuit 42, and the power supply circuit 42 supplies power to each circuit device. Also, the power signal VB of the battery 41 is △/D
The signal is A/D converted by the converter 43 and input to the controller 17 .

The operation of the valve control device configured as described above will be explained with reference to the time chart of FIG. 8 and the flow chart of FIG. 9.

In a first step 81, an initial rice is performed.

In the second step 82, it is determined whether the operating stroke of the engine 10 is the explosion stroke (TOI) based on the output of the crank angle reference signal TDC of the crank angle sensor +j21, and when this output is determined, the third step At 83, the time measured by the timer 34, that is, the current TDC output time [2] is read.

In the fourth step 84, the previous TDC output time t1 is RA
Read from M33, both times t2. The period TO of the explosion stroke TOI is calculated by calculating the difference in t1.

In a fifth step 85, the time of the previous explosion stroke Top, that is, the previous TDC output time t1, is updated to the current TDC output time t2.

In a sixth step 86, the rotational speed ne of the engine 10 is calculated from the period TO of the explosion stroke TOI calculated in the fourth step 84 described above.

That is, the engine 10 corresponds to the stepwise period TO.
From the map in which the rotation speed of is set in advance, the above-mentioned period TO
Read out the rotational speed ne corresponding to .

In a seventh step 87, the accelerator opening signal Qa from the accelerator opening sensor 22 is read.

In an eighth step 88, the above-mentioned accelerator opening signal Qa,
The operating state of the engine 10 is detected based on the rotational speed ne of the engine 10 calculated in the sixth step 86 described above, and a solenoid is activated to open or close the intake valve 12 corresponding to this operating state. 15, that is, the times of starting energization and stopping energization with reference to the output time of the crank angle reference signal TDC.

That is, energization start time Ti of intake valve 12 OB intake valve 1
In addition, in these calculations, the time corresponding to the above-mentioned operating state is read from a map in which the energization start and energization stop times are set in advance in accordance with the operating state of the engine 10. .

In a ninth step 89, the voltage signal VB of the battery 41 is read.

In a tenth step 90, the response delay time of the solenoid 15 to the voltage drop of the battery 41 is calculated.

That is, when the voltage of the battery 41 drops, it takes time for the solenoid 15 to operate, causing the intake valve 12 to open,
There is a time discrepancy between the valve closing and operation.

Therefore, it is necessary to compensate for this voltage drop by adjusting the timing of starting and stopping the energization earlier.

Response delay times for operations are set and stored in the table of the RAM 33 in correspondence with stepwise voltage drops, and the above-mentioned response delay times are read from this table.

That is, Delay time Td for starting energization of the intake valve 12.

Intake valve 12 energization stop delay time Tdc In an eleventh step 91, the correction time of the intake valve 12 corrected for the above-mentioned delay time, that is, the correction time based on the output point of the crank angle reference signal TDC is calculated.

i.e. Correction time Ti for starting energization of the intake valve 12.

Calculation of energization stop correction time Tic for intake valve 12 Tio←Ti0B-Td.

Tic<-Ti C3-Tdc At the twelfth step 92, the execution time for driving and controlling the solenoid 15 is calculated based on the time t2 updated at the fifth step 85.

i.e. Execution time ti for starting energization of the intake valve 12.

Intake valve 12 energization stop execution time tic calculation tio←t2+Tio tic+t2+Tic At the thirteenth step 93, the current time t is read from the timer 34, it is determined whether the energization start execution time tio of the intake valve 12 has arrived, and the time tio is determined. If so, in a fourteenth step 94, the MPU 31 outputs the drive signal 3i for the solenoid 15, this drive signal Si drives the solenoid 15 via the solenoid drive circuit 40, and the intake valve 12 is opened.

Note that in the thirteenth step 93 described above, time ti is set.

If it is not determined, the fourteenth step 94 described above is skipped.

In a 15th step 95, the current time t is read from the timer 34, and it is determined whether the current time Tic has arrived to stop the energization of the intake valve 12. If the time Tic is determined, in a 16th step 96, the MPU 31 controls the solenoid 15. When the output of the drive signal Si is stopped, the solenoid 15 is turned off and the intake valve 12 is closed.

Note that if the time tic is not determined in the fifteenth step 95 described above, the sixteenth step 96 described above is skipped.

When the opening/closing control of the intake valve 12 is completed as described above, the process returns to the second step 82.

As described above, as the voltage of the battery 41 drops,
If the energization start and energization stop timings are corrected to be earlier, the actual response delay in valve opening timing and valve closing timing will be corrected.
A smooth operating state of the engine 10 can be obtained.

In the first and second embodiments described above, the intake and exhaust valves 12.14 are closed by the valve spring 26 and opened by the solenoid 15.16, but the intake and exhaust valves 12. 14 may be opened by the valve spring 26 and closed by the solenoids 15 and 16. Further, the intake/exhaust valves 12 and 14 may both be opened and closed using solenoids.

Regarding the correspondence between the configuration of this invention and the configuration of the first embodiment, the electromagnetic means of the invention corresponds to the solenoids 15 and 16 of the embodiment, and the temperature sensor corresponds to the temperature sensors 18 and 19. , the energization control device performs the eighth and fourteenth steps 5 of the controller 17.
The energization starting means corresponds to the processing of steps 8.64 and 9th to 13th steps 59 to 63 of the controller 17.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, FIG. 1 is a configuration diagram of an engine valve control device of the first embodiment, FIG. 2 is a sectional view of an intake/exhaust valve, and FIG. 3 is a circuit of the valve control device. Block diagram, Fig. 4 is a time chart regarding valve opening/closing, Fig. 5 is a flow chart of valve control, Fig. 6 is a configuration diagram of the valve control device of the second embodiment, and Fig. 7 is its circuit block diagram. , FIG. 8 is a time chart regarding opening and closing of the valve, and FIG. 9 is a flow chart of valve control. 10...Engine 12...Intake valve 14
...Exhaust valve 15.16...Solenoid 17
... Controller 18.19 ... Temperature sensor 31
...MPU

Claims (1)

[Scope of Claims] 1. An engine whose intake or exhaust valves are operated by electromagnetic means, comprising: a temperature sensor that detects the temperature of the electromagnetic means; and an energization control device that controls energization of the electromagnetic means. The energization control device has an energization start means for starting energization to the electromagnetic means before the target valve opening timing, and the energization start means advances the energization start time in accordance with a temperature rise of the electromagnetic means. 1. A valve control device for an engine, characterized in that it is configured to correct the direction.