JP2009085067A - Variable valve control unit and engine control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a control unit for controlling a variable valve train, disposed independently of an engine control unit, to execute various types of processing while maintaining power supply after an ignition key is turned off. <P>SOLUTION: Electric power is supplied to both of a microcomputer 402 in the engine control unit 400 and a microcomputer 202 in the variable valve control unit 200, via a unit power relay 304 driven by a relay drive circuit 403 provided in the engine control unit 400. Upon completion of processing after the ignition key is turned off, the variable valve control unit 200 then transmits a power supply shutoff enable signal to the engine control unit 400. The engine control unit 400 turns off the unit power relay 304, provided that processing to be executed after the ignition key is turned off has been completed with the power supply shutoff enable signal already received. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a variable valve control unit and an engine control system. More specifically, the present invention relates to a control unit that controls a variable valve mechanism that changes lift characteristics of intake and exhaust valves of an engine, and a control system including the control unit. About.

2. Description of the Related Art Conventionally, as a variable valve mechanism for changing lift characteristics of intake / exhaust valves of an engine, one using an electric drive means (electric actuator) such as an electric motor or an electromagnetic actuator is known.
For example, in Patent Document 1, a lever that contacts a rocker arm and forms a fulcrum of the rocker arm, and a fulcrum of the rocker arm is changed by engaging the lever and changing its swinging position. There is disclosed a valve operating control device that includes a lift control cam that variably controls lift characteristics, and a motor that rotates the lift control cam to a predetermined rotational position according to engine operating conditions.

In the valve control device of Patent Document 1, a battery as a power source is connected to the motor drive circuit via a DC / DC converter, and the output voltage to the motor is controlled by controlling the DC / DC converter. It is supposed to be.
JP 62-159709 A

By the way, in the control of the variable valve mechanism, after the engine key is turned off, it may be necessary to write various learning values related to the variable valve mechanism in the EEPROM or to drive to the lift characteristics at the start. .
On the other hand, when a dedicated control unit with a function to control the variable valve mechanism is provided independently of the engine control unit, the dedicated control unit implements various processes after key-off as described above. Therefore, it is required to continue power supply after key-off.

  The present invention has been made in view of the above circumstances, and in a control unit for controlling a variable valve mechanism provided independently of an engine control unit, it is possible to execute various processes by continuing power supply after key-off. The purpose is to do.

  Therefore, in the first aspect of the present invention, in the variable valve control unit including a calculation unit that calculates the operation amount of the variable valve mechanism that changes the lift characteristics of the intake and exhaust valves of the engine, Power is supplied to the arithmetic unit through a power relay that is driven by another control unit provided independently and supplies power to the other control unit.

  According to the above invention, the power supply to the variable valve control unit (arithmetic unit) is cut off at the same time by turning off the power relay after the key off and executing the self-shutoff. The power supply to the calculation unit of the variable valve control unit is continued until the control unit after the key is turned off until the self-shutoff is executed.

Therefore, in the variable valve control unit, after the key-off, various processes such as writing various learning values to the EEPROM and driving to the lift characteristics at the start can be executed.
According to a second aspect of the invention, in the first aspect of the invention, the variable valve control unit transmits a power supply stop permission signal for permitting the power relay to be turned off to the other control unit. I made it.

According to the above invention, for example, when the variable valve control unit transmits a power supply stop permission signal based on the completion of processing after key-off, the other control unit that receives the power supply stop permission signal is a power relay. Is turned off, and the power supply to the calculation unit of the variable valve control unit is shut off.
Therefore, for example, even if processing after key-off in another control unit is completed, if processing after key-off in the variable valve control unit is not completed, power supply is continued by not transmitting a power supply stop permission signal. Thus, the power supply can be reliably continued until the processing after key-off in the variable valve control unit is completed.

  According to a third aspect of the present invention, a calculation unit and a relay drive circuit that drives a power relay that supplies power to the calculation unit are provided, and the calculation unit changes the lift characteristics of the intake and exhaust valves of the engine. In the variable valve control unit that calculates the operation amount of the variable valve mechanism and controls the relay drive circuit, a power supply stop request from another control unit provided independently of the variable valve control unit The arithmetic unit controls the relay drive circuit to turn off the power relay on condition that a signal is received.

According to the above invention, the power supply relay for the self-shutoff of the variable valve control unit is provided, but the self-shutoff of the variable valve control unit has received the power supply stop request signal from the other control unit. Done on the premise.
Therefore, the variable valve control unit can perform self-shutoff in conjunction with the self-shutoff after key-off in another control unit, and wait for completion of processing after key-off in the variable valve-control unit. Power off can be executed.

  According to a fourth aspect of the present invention, there is provided a first drive circuit including a drive circuit for an electric drive means of a variable valve mechanism for changing lift characteristics of an intake / exhaust valve of an engine, a first calculation unit, and a first relay drive circuit. The control unit and the first control unit are provided independently of each other, and are driven by the second arithmetic unit and the second control unit including the second relay drive circuit, and the first relay drive circuit, and the drive A first power supply relay that supplies power to the circuit, and a second power supply relay that is driven by the second relay drive circuit and supplies power to the first calculation unit and the second calculation unit. A control system was configured.

According to the above invention, when the second power supply relay is turned off by the second relay driving circuit provided in the second control unit, the second arithmetic unit provided in the second control unit and the first control unit are provided. In addition, power supply to the first arithmetic unit is interrupted.
That is, power supply to the first control unit is cut off in synchronization with the self-shutoff by the second control unit.

The first control unit drives a drive circuit of an electric drive means of a variable valve mechanism that changes lift characteristics of an intake / exhaust valve of an engine, and a first power supply relay that drives a first power supply relay that supplies power to the drive circuit. Since the relay drive circuit and the first calculation unit are provided, the first control including the control of the electric drive means is performed after the key-off until the power supply to the first calculation unit is cut off by the self-shutoff of the second control unit. In the invention according to claim 4, the first control unit and the second control unit each include a communication circuit for performing mutual communication. On the condition that the second control unit has received a power supply stop permission signal from the first control unit, the second relay drive. The second power supply relay is turned off by the dynamic circuit to cut off the power supply to the first calculation unit and the second calculation unit.

According to the above invention, when the first control unit transmits a power supply stop permission signal based on, for example, completion of processing after key-off, the second control unit that receives the power supply stop permission signal receives the second power supply. The relay is turned off to cut off the power supply to the first arithmetic unit of the first control unit and the second arithmetic unit of the second control unit.
Therefore, for example, when the processing after the key-off in the second control unit is completed but the processing after the key-off in the first control unit is not completed, the power supply stop permission signal is not transmitted to both control units. Power supply can be continued, and power supply can be reliably continued until the processing after key-off in the first control unit is completed.

  According to the sixth aspect of the present invention, the drive circuit of the electric drive means of the variable valve mechanism for changing the lift characteristics of the intake / exhaust valves of the engine, the first arithmetic unit, the first relay drive circuit, and the second relay drive A first control unit having a circuit; a first power supply relay driven by the first relay drive circuit to supply power to the drive circuit; and driven by the second relay drive circuit; A second power supply relay for supplying power to the second control unit, a second control unit provided independently of the first control unit, and having a second arithmetic unit and a third relay drive circuit; and the third relay The engine control system includes a third power relay that is driven by a drive circuit and supplies power to the second arithmetic unit.

According to the above invention, the first control unit can realize the self-shutoff by turning off the second power supply relay by the second relay drive circuit, while the second control unit can achieve the third power supply by the third relay drive circuit. Self-shutoff can be realized by turning off the relay.
Therefore, the first and second control units can perform self-shutoff independently of each other, and the first control unit that controls the drive of the variable valve mechanism completes the processes related to the variable valve mechanism after the key-off. After that, self-shutoff can be performed.

According to a seventh aspect of the invention, in the sixth aspect of the invention, the first control unit and the second control unit each include a communication circuit for performing mutual communication.
On condition that the first control unit has received a power supply stop request signal from the second control unit, the second relay drive circuit turns off the second power supply relay, The power supply was cut off.

According to the above invention, the power relay for self-shutoff of the first control unit is provided. The self-shutoff of the first control unit is based on the assumption that the power supply stop request signal from the second control unit has been received. Done.
Therefore, in conjunction with the self-shutoff after the key-off in the second control unit, it is possible to execute the self-shut-off of the first control unit and eliminate the need for mutual communication. The self-shutoff of the first control unit can be executed when the self-shutoff of the first control unit does not affect the first control unit.

According to an eighth aspect of the present invention, in the third or seventh aspect of the present invention, the power supply stop request signal is transmitted when mutual communication between the control units becomes unnecessary.
According to the above invention, for example, when data reception from another control unit or data transmission to another control unit is required for processing after key-off, the other control unit performs its own self-shutoff. To prevent this, the power supply stop request signal is output after communication is no longer necessary.

Therefore, it is possible to prevent the post-key-off process from being disabled by the communication partner executing self-shutoff.
According to a ninth aspect of the present invention, in the second or fifth aspect of the present invention, the power supply stop permission signal is transmitted on condition that the processing after key-off is completed.
According to the above invention, after the processing after key-off in the control unit that controls the variable valve mechanism is completed, the power supply stop permission signal is output, and the power is shut off by the other control unit.

  Therefore, it is possible to prevent the power from being shut off by another control unit before the processing after key-off in the control unit that controls the variable valve mechanism is completed.

Embodiments of the present invention will be described below.
FIG. 1 shows a first embodiment of a variable valve control unit and an engine control system according to the present invention.
The variable valve control unit (first control unit) 200 controls the drive of an electric motor 300 that is an electric drive means of a variable valve mechanism described later, and includes a power supply IC 201 and a microcomputer that receives power supply from the power supply IC 201. (First operation unit) 202, a drive circuit 203 of the electric motor 300, a relay drive circuit (first relay drive circuit) 204, and a network driver (communication circuit) 205 are configured.

The microcomputer 202 includes a CPU, RAM, ROM, I / O, and the like.
The relay drive circuit 204 is a circuit for driving a motor power relay (first power relay) 301 provided outside according to a control signal from the microcomputer 202, and the motor power relay is driven by the relay drive circuit 204. When the switch 301 is turned on, the battery 303 and the motor drive circuit 203 are connected as power via the motor power relay 301, power is supplied to the motor drive circuit 203, and the motor drive relay 301 is turned off by the relay drive circuit 204. Then, the battery 303 and the motor drive circuit 203 are disconnected as a power source, and the power supply to the motor drive circuit 203 is cut off.

The variable valve control unit 200 may include a circuit other than the above, and power may be supplied from the power supply IC 201 to the circuit.
2 and 3 show an example of a variable valve mechanism that uses the electric motor 300 as an electric drive means.
The variable valve mechanism 112 shown in FIGS. 2 and 3 is a mechanism that continuously changes the valve lift amount of the intake valve and / or the exhaust valve of the engine together with the operating angle. The case where it is used variably is shown.

In FIG. 2, an intake drive shaft 3 that is rotationally driven by a crankshaft 120 is supported above the intake valve 105 so as to be rotatable along the cylinder row direction of the engine.
A swing cam 4 that contacts the valve lifter 105a of the intake valve 105 and opens and closes the intake valve 105 is fitted on the intake drive shaft 3 so as to be relatively rotatable.
A variable valve mechanism 112 for continuously changing the operating angle and valve lift amount of the intake valve 105 is provided between the intake drive shaft 3 and the swing cam 4.

  As shown in FIGS. 2 and 3, the variable valve mechanism 112 has a circular drive cam 11 (drive eccentric shaft portion) that is eccentrically fixed to the intake drive shaft 3 and a relative rotation with the drive cam 11. A ring-shaped link 12 (first link) that fits externally, a control shaft 13 that extends substantially parallel to the intake drive shaft 3 in the cylinder row direction, and a circular control that is fixedly provided eccentrically to the control shaft 13. A cam 14 (control eccentric shaft portion), a rocker arm 15 that is externally fitted to the control cam 14 so as to be relatively rotatable, and one end of which is connected to the tip of the ring-shaped link 12, and the other end of the rocker arm 15 and a swing cam 4 and a rod-shaped link 16 (second link) connected to 4.

The control shaft 13 is rotationally driven by the electric motor 300 via the gear train 18.
With the above configuration, when the intake drive shaft 3 rotates in conjunction with the crankshaft 120, the ring-shaped link 12 moves substantially in translation through the drive cam 11, and the rocker arm 15 swings around the axis of the control cam 14. Then, the swing cam 4 swings through the rod-shaped link 16 and the intake valve 105 is driven to open and close.

Further, by driving and controlling the electric motor 300 to change the angular position of the control shaft 13, the axial center position of the control cam 14 serving as the rocking center of the rocker arm 15 is changed, and the posture of the rocking cam 4 is changed. To do.
As a result, the operating angle of the intake valve 105 and the valve lift amount continuously increase or decrease while the central phase of the operating angle of the intake valve 105 remains substantially constant.

A detection signal from an angle sensor 133 that detects the rotation angle of the control shaft 13 is input to the variable valve control unit 200 (microcomputer 202), and the control shaft 13 is positioned at a target angular position corresponding to a target lift amount. , The motor control signal (operation amount) is calculated based on the detection result of the angle sensor 133, and the motor drive circuit 203 is controlled.
The variable valve mechanism using the electric drive means is not limited to the variable valve mechanism 112 described above, and the intake / exhaust valve of the engine using an electric drive means such as an electric motor or an electromagnetic actuator. Can be widely applied to variable valve mechanisms that change the lift characteristics (valve lift amount, operating angle, opening / closing timing).

For example, as disclosed in Japanese Patent Application Laid-Open No. 2004-270606, a variable operation that makes the rotational phase of the camshaft relative to the crankshaft variable and the valve timing of the intake and exhaust valves variable by applying a braking force by an electromagnetic brake. It can also be applied to a valve mechanism.
As described above, the variable valve mechanism 112 is driven and controlled by the variable valve control unit 200. However, the engine control unit 400 controls the fuel injection amount in the engine, that is, the air-fuel ratio manipulated variable. It has become.

The engine control unit (second control unit) 400 is provided independently of the variable valve control unit 200, and includes a power supply IC 401, a microcomputer (second arithmetic unit) 402 that receives power supply from the power supply IC 401, a relay drive circuit. 403 and a network driver (communication circuit) 404 are configured.
The microcomputer (microcomputer) 402 includes a CPU, a RAM, a ROM, an I / O, and the like.

The network driver 205 and the network driver 404 enable mutual communication between the variable valve control unit and the engine control unit 400.
The relay drive circuit 403 corresponds to a second relay drive circuit as an embodiment corresponding to claims 4 and 5.

Further, the engine control unit 400 may include a circuit other than the above, and power may be supplied from the power supply IC 401 to the circuit.
The relay drive circuit 403 is a circuit for driving an external unit power supply relay 304 in response to a control signal from the microcomputer 402. When the unit power supply relay 304 is turned on by the relay drive circuit 403, The battery 303 and the power supply ICs 201 and 401 of the control units 200 and 400 are connected as power sources via the unit power supply relay 304, and the power is supplied to the microcomputers 202 and 402 of the control units 200 and 400 to drive the relays. When the unit power supply relay 304 is turned off by the circuit 403, the connection between the battery 303 as a power source and the power supply ICs 201 and 401 of the control units 200 and 400 is disconnected, and the microcomputers 202 and 402 of the control units 200 and 400 are disconnected. Power supply is cut off.

The unit power relay 304 corresponds to a second power relay as an embodiment corresponding to claims 4 and 5.
The power supply ICs 201 and 401 are supplied with battery power via the unit power relay 304 and battery power via an engine key switch.

  When the engine key switch is turned on and power is supplied, the engine control unit 400 can turn on the unit power relay 304 by the relay drive circuit 403 and maintain the power supply state even after the key switch is turned off. When predetermined processing (such as learning value backup and various diagnostic processing) is performed after the key switch is turned off, the unit power supply relay 304 is turned off and the power supply is cut off by itself to perform self-shutoff.

As the predetermined processing after the key switch is turned off, the engine control unit 400 includes a throttle sensor reference position learning and a backup processing of the learning result. In the variable valve control unit 200, the angle control For example, the reference position learning of the sensor 133 is performed and the learning result is backed up.
When the engine control unit 400 executes self-shutoff to turn off the unit power supply relay 304, the power supply to the variable valve control unit 200 is simultaneously cut off. In this case, power supply is continued after the key switch is turned off. While the power supply is continued, a predetermined process (such as backup of the learning value or driving to a lift characteristic suitable for starting) is performed. It can be carried out.

Therefore, the variable valve control unit 200 can perform post-key-off processing, while the variable valve control unit 200 does not require a relay drive circuit for self-shutoff, simplifying the system and reducing costs. Can be achieved.
Here, when the time required for the processing after the key-off in the engine control unit 400 is longer than the time required for the processing after the key-off in the variable valve control unit 200, the engine control unit 400 performs its own key-off post-processing. If the unit power supply relay 304 is turned off based on the completion, the processing after the key-off in the variable valve control unit 200 has already been completed at that time. The power supply is cut off after both processes are completed.

  However, conversely, if the time required for processing after key-off in the engine control unit 400 is shorter than the time required for processing after key-off in the variable valve control unit 200, the engine control unit 400 performs its own key-off post-processing. If the unit power supply relay 304 is immediately turned off upon completion, the power supply to the variable valve control unit 200 (microcomputer 202) is cut off during the key-off post-processing on the variable valve control unit 200 side. It will be.

As a case where the time required for processing after key-off in the variable valve control unit 200 becomes long, there is a case where learning of the reference position of the angle sensor 133 does not end within the time due to the movement of the variable valve mechanism 112 or the like. .
Therefore, in the present embodiment, when the variable valve control unit 200 completes the processing after key-off by mutual communication between the engine control unit 400 and the variable valve control unit 200 using the network drivers 205 and 404, A power supply stop permission signal for permitting the unit power relay 304 to be turned off is transmitted to the engine control unit 400 side. The engine control unit 400 has completed its post-key-off processing, and outputs the power supply stop permission signal. The unit power supply relay 304 is turned off (self-shut off) on the condition that it is received.

FIG. 4 shows processing after key-off in the variable valve control unit 200. In step S501, it is determined whether or not an engine key switch (ignition switch) is turned off. If the key is turned off, the process proceeds to step S502.
In step S502, a predetermined process (end sequence) after key-off, such as backup of the learned value and driving to a lift characteristic suitable for start-up, is executed. In step S503, the predetermined process (end sequence) after the key-off is completed. Determine whether or not.

  When the predetermined processing (end sequence) after the key-off is completed, the process proceeds to step S504, and a power supply stop permission signal for permitting the unit power relay 304 to be turned off (self-shutoff) is transmitted to the engine control unit 400. Furthermore, in step S505, the motor drive relay 301 is turned off to cut off the power supply to the motor drive circuit 203.

FIG. 5 shows processing after key-off in the engine control unit 400. In step S601, it is determined whether or not an engine key switch (ignition switch) is turned off. If the key is turned off, the process proceeds to step S602.
In step S602, a predetermined process (end sequence) after key-off such as backup of learned values and failure diagnosis is executed. In step S603, it is determined whether or not the predetermined process (end sequence) after key-off is completed.

  When the predetermined processing (end sequence) after the key-off is completed, in step S604, it is determined whether a power supply stop permission signal is received from the variable valve control unit 200 side, and the power supply stop permission signal is displayed. If it has been received, the process proceeds to step S605, where the unit power relay 304 is turned off, self-shutoff is executed, and the power supply to the variable valve control unit 200 (microcomputer 202) is cut off.

  If the time required for processing after key-off in the engine control unit 400 is surely longer than the time required for processing after key-off in the variable valve control unit 200, transmission / reception of the power supply stop permission signal, and The reception confirmation of the power supply stop permission signal can be omitted, and the unit power relay 304 can be turned off when the engine control unit 400 completes its own key-off post-processing.

FIG. 6 shows a second embodiment of the variable valve control unit and the engine control system according to the present invention.
The variable valve control unit (first control unit) 200 controls the drive of the electric motor 300 that is the electric drive means of the variable valve mechanism described above. As in the first embodiment, the power supply IC 201, A microcomputer (first arithmetic unit) 202 that receives power from the power IC 201, a motor drive circuit 203 of the electric motor 300, and a motor power relay (first power relay) 301 that turns on / off the power supply to the motor drive circuit 203 A relay drive circuit (first relay drive circuit) 204 and a network driver 205 are also provided, and a relay drive circuit 206 is provided as a circuit added to the first embodiment.

  The relay drive circuit 206 is a circuit for driving a variable valve side power supply relay 305 provided outside in accordance with a control signal from the microcomputer 202, and the variable valve side power supply relay is driven by the relay drive circuit 206. When 305 is turned on, the battery 303 and the power supply IC 201 are connected as power sources via the variable valve side power supply relay 305, power is supplied to the microcomputer 202, and the variable valve side power supply relay 305 is supplied by the relay drive circuit 206. Is turned off, the connection between the battery 303 and the power supply IC 201 as the power source is cut off, and the power supply to the microcomputer 202 is cut off.

The variable valve-side power supply relay 305 corresponds to the second power supply relay in the inventions according to claims 6 and 7, and the relay drive circuit 206 corresponds to the second relay drive circuit in the inventions according to claims 6 and 7. To do.
As described above, by providing the variable valve side power supply relay 305 and the relay drive circuit 206, the variable valve control unit 200 can perform self-shutoff independently.

  On the other hand, the engine control unit (second control unit) 400 is provided independently of the variable valve control unit 200, and, similarly to the first embodiment, a power supply IC 401 and a microcomputer that receives power supply from the power supply IC 401 ( (Second operation unit) 402, a relay drive circuit 403, and a network driver 404 are configured, but the configuration of the power relay driven by the relay drive circuit 403 is different from that of the first embodiment.

  That is, the relay drive circuit 403 is a circuit for driving an engine-side power supply relay 306 provided outside in response to a control signal from the microcomputer 402, and the engine-side power supply relay 306 is driven by the relay drive circuit 403. When turned on, the battery 303 and the power supply IC 401 are connected as power via the engine side power relay 306, power is supplied to the microcomputer 402, and when the engine side power relay 306 is turned off by the relay drive circuit 403, The battery 303 and the power supply IC 401 are disconnected as a power source, and the power supply to the microcomputer 402 is interrupted.

  That is, in the first embodiment, the power supply to the variable valve control unit 200 is simultaneously cut off by the self-shutoff means of the engine control unit 400, but in the second embodiment, the engine control unit 400 and Each of the variable valve control units 200 has its own self-shutoff means so that self-shutoff can be performed independently of each other.

The relay drive circuit 403 in the second embodiment corresponds to the third relay drive circuit in the invention according to claims 6 and 7, and the engine-side power relay 306 is the third power relay in the invention according to claims 6 and 7. Equivalent to.
Also in the second embodiment, battery power is supplied to the power ICs 201 and 401 via the variable valve side power relay 305 and engine side power relay 306, and battery power is supplied via an engine key switch. Is to be supplied.

  When the engine key switch is turned on and power is supplied, the engine control unit 400 turns on the engine-side power relay 306 by the relay drive circuit 403 and maintains the power supply state even after the key switch is turned off. When a predetermined process (such as learning value backup or various diagnostic processes) is performed after the key switch is turned off, the engine-side power supply relay 306 is turned off and the power supply is cut off to perform self-shutoff.

  On the other hand, the variable valve control unit 200 also turns on the variable valve side power supply relay 305 by the relay drive circuit 206 when the engine key switch is turned on and power is supplied, and even after the key switch is turned off. When the power supply state can be maintained and predetermined processing (such as learning value backup or driving to a lift characteristic suitable for start-up) is performed after the key switch is turned off, the variable valve side power supply relay 305 is turned off. Cut off the power supply by itself and perform self-shutoff.

  Here, the engine control unit 400 ends the learning process and various diagnoses just before turning off the engine-side power supply relay 306 and performing self-shutoff, or after key-off, and with the variable valve control unit 200. When transmission / reception (communication) between them becomes unnecessary, a power supply stop request signal is transmitted to the variable valve control unit 200.

When the predetermined processing after the key switch is turned off is completed and the power supply stop request signal is received, the variable valve control unit 200 turns off the variable valve side power supply relay 305 and performs self-shutoff. .
As described above, if the variable valve control unit 200 executes the self-shutoff on condition that the power supply stop request signal is received from the engine control unit 400, for example, the engine control unit 400 When data transmission from the variable valve control unit 200 is required in the processing after the key-off, the variable valve control unit 200 side self-shuts off before transmission / reception of necessary data is completed. Can be prevented.

  Further, if the engine control unit 400 transmits a power supply stop request signal when transmission / reception with the variable valve control unit 200 becomes unnecessary after key-off, the engine control unit 400 is in a power supply state. In the variable valve control unit 200, self-shutoff can be executed independently, power consumption after key-off can be reduced, and the battery load can be reduced.

FIG. 7 shows processing after key-off in the variable valve control unit 200 in the second embodiment. In step S701, it is determined whether or not an engine key switch (ignition switch) is turned off. Proceed to
In step S702, a predetermined process (end sequence) after key-off such as backup of the learning value and driving to a lift characteristic suitable for start-up is executed. In step S703, the predetermined process (end sequence) after the key-off is completed. Determine whether or not.

When the predetermined processing (end sequence) after the key-off is completed, in step S704, it is determined whether or not a power supply stop request signal from the engine control unit 400 side has been received.
When the power supply stop request signal is received from the engine control unit 400 side, the process proceeds to step S705, where the motor drive relay 301 is turned off by the relay drive circuit 204 and the variable drive circuit 206 is operated by the relay drive circuit 206. The valve-side power supply relay 305 is turned off and self-shutoff is executed.

FIG. 8 shows processing after key-off in the engine control unit 400 in the second embodiment. In step S801, it is determined whether or not an engine key switch (ignition switch) is turned off. If the key is turned off, the process proceeds to step S802. .
In step S802, predetermined processing (end sequence) after key-off, such as learning value backup and failure diagnosis, is executed. In step S803, it is determined whether or not the predetermined processing (end sequence) after key-off is completed.

When the predetermined processing (end sequence) after the key-off is completed, in step S804, a power supply stop request signal is transmitted to the variable valve control unit 200. Subsequently, in step S805, the relay drive circuit 403 causes the engine-side power relay 306 is turned off and self-shutoff is executed.
FIG. 9 shows another example of post-key-off processing in the engine control unit 400 in the second embodiment. In step S901, it is determined whether or not the engine key switch (ignition switch) is turned off. The process proceeds to S902.

In step S902, a predetermined process (end sequence) after key-off such as backup of learned values and failure diagnosis is executed. In step S903, it is determined whether or not the predetermined process (end sequence) after key-off is completed.
If the predetermined process (end sequence) after the key-off has not been completed, the process proceeds to step S904, and determination of the flag F that is set to 1 when the power supply stop request signal is transmitted to the variable valve control unit 200. I do.

  When the flag F is 0 and the power supply stop request signal is not transmitted to the variable valve control unit 200, the process proceeds to step S905, and data transmission / reception (communication) with the variable valve control unit 200 is necessary. If the data transmission / reception is unnecessary, the process proceeds to step S906 to transmit a power supply stop request signal to the variable valve control unit 200. Subsequently, in step S907, the flag F Set 1 to.

When the flag F is set to 1, when the process proceeds from step S903 to step S904, it is determined that the flag F = 1, so that the process bypasses steps S905 to S907 and returns to step S902.
That is, when data transmission / reception (communication) with the variable valve control unit 200 is not required during the predetermined processing after key-off in the engine control unit 400, a power supply stop request signal can be issued at that time. This is transmitted to the variable valve control unit 200 to permit self-shutoff on the variable valve control unit 200 side.

On the other hand, if it is determined in step S903 that the predetermined process (end sequence) after the key-off has been completed, the process proceeds to step S908, and it is determined whether or not 1 is set in the flag F.
If the flag F = 0 and the power supply stop request signal is not transmitted to the variable valve control unit 200, transmission / reception of data to / from the variable valve control unit 200 is not required upon completion of the end sequence. In step S909, the power supply stop request signal is transmitted to the variable valve control unit 200. Subsequently, in step S910, the relay drive circuit 403 turns off the engine-side power supply relay 306. Execute self-shutoff.

  On the other hand, if it is determined in step S908 that the flag F = 1, the transmission of the power supply stop request signal to the variable valve control unit 200 has been completed during the end sequence. The process bypasses S909 and proceeds to step S910, where the relay drive circuit 403 turns off the engine-side power supply relay 306 to execute self-shutoff.

The circuit diagram which shows 1st Embodiment of a variable valve control unit and an engine control system. The perspective view which shows the variable valve mechanism in embodiment. The principal part side view of the variable valve mechanism shown in FIG. The flowchart which shows the key-off process by the side of the variable valve control unit in 1st Embodiment. The flowchart which shows the key-off process by the side of the engine control unit in 1st Embodiment. The circuit diagram which shows 2nd Embodiment of a variable valve control unit and an engine control system. The flowchart which shows the key-off process by the side of the variable valve control unit in 2nd Embodiment. The flowchart which shows the key-off process by the side of the engine control unit in 2nd Embodiment. The flowchart which shows another example of the key-off process by the side of the engine control unit in 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 200 ... Variable valve control unit, 201 ... Power supply IC, 203 ... Microcomputer, 203 ... Motor drive circuit, 204 ... Relay drive circuit, 205 ... Network driver, 300 ... Electric motor, 301 ... Motor power relay, 303 ... Battery, 304 ... Unit power supply relay, 305 ... Variable valve side power supply relay, 306 ... Engine side power supply relay, 400 ... Engine control unit, 401 ... Power supply IC, 402 ... Microcomputer, 403 ... Relay drive circuit, 404 ... Network driver

Claims (9)

  A variable valve control unit including a calculation unit for calculating an operation amount of a variable valve mechanism for changing lift characteristics of an intake / exhaust valve of an engine, provided independently of the variable valve control unit A variable valve control unit that is driven by another control unit and that supplies power to the arithmetic unit via a power relay that supplies power to the other control unit.   The variable valve control unit according to claim 1, wherein the variable valve control unit transmits a power supply stop permission signal for permitting the power relay to be turned off to the other control unit.   A calculation unit, and a relay drive circuit that drives a power supply relay that supplies power to the calculation unit, wherein the calculation unit determines an operation amount of a variable valve mechanism that changes a lift characteristic of an intake / exhaust valve of the engine. A variable valve control unit that calculates and controls the relay drive circuit, and that a power supply stop request signal is received from another control unit provided independently of the variable valve control unit. As a condition, a variable valve control unit characterized in that the calculation unit controls the relay drive circuit to turn off the power supply relay. A drive circuit for electrical drive means of a variable valve mechanism that changes the lift characteristics of the intake / exhaust valves of the engine, a first calculation unit, and a first control unit comprising a first relay drive circuit;
A second control unit that is provided independently of the first control unit, and includes a second arithmetic unit and a second relay drive circuit;
A first power relay driven by the first relay driving circuit and supplying power to the driving circuit;
A second power relay that is driven by the second relay drive circuit and supplies power to the first arithmetic unit and the second arithmetic unit;
An engine control system composed of The first control unit and the second control unit each include a communication circuit for performing mutual communication,
On condition that the second control unit has received a power supply stop permission signal from the first control unit, the second power supply relay is turned off by the second relay drive circuit, and the first arithmetic unit and 5. The engine control system according to claim 4, wherein power supply to the second arithmetic unit is cut off. A first control unit comprising a drive circuit for an electric drive means of a variable valve mechanism for changing the lift characteristics of an intake / exhaust valve of an engine, a first arithmetic unit, a first relay drive circuit, and a second relay drive circuit When,
A first power relay driven by the first relay driving circuit and supplying power to the driving circuit;
A second power relay driven by the second relay drive circuit and supplying power to the first arithmetic unit;
A second control unit that is provided independently of the first control unit, and includes a second arithmetic unit and a third relay drive circuit;
A third power relay driven by the third relay drive circuit and supplying power to the second arithmetic unit;
An engine control system composed of The first control unit and the second control unit each include a communication circuit for performing mutual communication,
On condition that the first control unit has received a power supply stop request signal from the second control unit, the second relay drive circuit turns off the second power supply relay, 7. The engine control system according to claim 6, wherein the power supply is cut off.   The variable valve control unit or the engine control system according to claim 3 or 7, wherein the power supply stop request signal is transmitted when mutual communication between the control units becomes unnecessary.   6. The variable valve control unit or the engine control system according to claim 2, wherein the power supply stop permission signal is transmitted on condition that the processing after key-off is completed.

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