JP2018076900A - Electronic control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic control device excellent in the controllability of an electromagnetic valve even at a cold time.SOLUTION: At the time of no control request for opening and closing an electromagnetic valve, there is executed a control, in which the electromagnetic valve is driven at a duty ratio of no opening of the electromagnetic valve, and in which the electromagnetic valve is opened when there is a control request for opening and closing the electromagnetic valve, so that the electromagnetic valve is controlled by a duty drive.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an electronic control device that controls a solenoid valve.

  Conventionally, in order to reduce the operation variation due to the temperature dependence of the solenoid in the solenoid valve, the solenoid resistance value is calculated, the output duty ratio is corrected, and feedback control is performed. For example, a pull-down resistor is provided to calculate a resistance value, and a small voltage is applied when the duty output circuit is stopped, that is, during the off period of the driving transistor (Patent Document 1).

JP-A-9-178026

However, in the above configuration, it is necessary to change the circuit to provide a pull-down resistor. Furthermore, since the solenoid resistance fluctuates greatly during cold weather, accurate feedback control is required, so a large-scale software change is required. It becomes.
The present invention has been made in view of the above problems, and an object of the present invention is to provide an electronic control device in which the controllability of the electromagnetic valve is good even when cold.

  According to the first aspect of the present invention, when there is no control request for opening and closing the solenoid valve, the electronic control device (13) performs control to drive the solenoid valve at a duty ratio at which the solenoid valve does not open. When the control request is executed to open and close the solenoid valve, the solenoid valve is duty-driven by performing control to drive the solenoid valve at a duty ratio at which the solenoid valve opens.

  According to this configuration, the solenoid valve is preheated by driving in a state in which the solenoid valve is not opened by driving in the preheating mode, and thus exhibits operating characteristics at a high temperature. For example, EVRV (Electric Vacuum Regulating Valve) When there is a control request, the EVRV opening does not shift. Further, since the solenoid does not operate during preheating and the EVRV does not open, the turbocharger supercharging pressure controlled by the EVRV is not changed. Therefore, the controllability of the solenoid valve is improved, and the control of the equipment controlled using the solenoid valve, for example, the turbocharger supercharging pressure control becomes more accurate.

Schematic configuration diagram of diesel engine with variable displacement turbocharger and its intake / exhaust system Schematic diagram of EVRV Diagram showing temperature dependence of EVRV The flowchart which shows the control which concerns on 1st Embodiment. The flowchart which shows the control which concerns on 2nd Embodiment. The flowchart which shows the control which concerns on 3rd Embodiment. The flowchart which shows the control which concerns on 4th Embodiment Timing chart

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In each embodiment, substantially the same elements are denoted by the same reference numerals, and description thereof is omitted.
(First embodiment)
As shown in FIG. 1, a piston 30e is provided in a cylinder block 30a of a diesel engine 30 as an internal combustion engine so as to be able to reciprocate. The cylinder block 30a is provided with a path through which cooling water (not shown) is passed, and the engine 30 is cooled by this cooling water. The cylinder block 30a functions as a cooling unit that cools the engine 30 with cooling water.

  The piston 30e is connected to a crankshaft 30g provided at the lower part of the engine 30 via a connecting rod 30f. The reciprocating motion of the piston 30e is converted into the rotational motion of the crankshaft 30g by the connecting rod 30f. A water temperature gauge 31 is provided in the cylinder block 30 a and measures the temperature of the cooling water that cools the engine 30.

  A cylinder head 30b is provided at the upper end of the cylinder block 30a, and a space surrounded by the inner peripheral side surface of the cylinder head 30b and the upper end surface of the piston 30e is a combustion chamber 30h. The cylinder head 30b is provided with a fuel injection nozzle 38 that injects fuel into the combustion chamber 30h. The cylinder head 30b is provided with an intake port 30c and an exhaust port 30d so as to communicate with the combustion chamber 30h. An intake valve and an exhaust valve (not shown) are provided between the intake port 30c and the exhaust port 30d and the combustion chamber 30h, and the intake port 30c, the exhaust port 30d and the combustion chamber 30h are opened and closed at a predetermined timing. It is connected and cut off by driving.

  An intake pipe 22 and an exhaust pipe 28 are connected to the intake port 30c and the exhaust port 30d, respectively. An intake passage 22a is formed in the intake port 30c and the intake pipe 22. The intake pipe 22 and the intake passage 22 a function as an intake section that intakes air introduced into the engine 30. The exhaust port 30d and the exhaust pipe 28 serve as an exhaust passage 28a. The upstream portion of the intake passage 22a and the downstream portion of the exhaust passage 28a are connected to the turbocharger 18, respectively.

  The turbocharger 18 includes a compressor wheel (not shown) for pressurizing and discharging air to the downstream side of the intake passage 22a, and a turbine wheel (not shown) that is rotated by the flow of exhaust gas passing through the exhaust passage 28a. The compressor wheel and the turbine wheel are connected to each other by a rotor shaft (not shown) and are configured to rotate integrally. Accordingly, the compressor wheel is rotated by the rotation of the turbine wheel rotated by the force of exhaust gas, and air is pressurized and discharged. .

  The crankshaft 30g is driven by being connected to a drive shaft of a fuel injection pump (not shown), sucks fuel from the fuel tank 32, and pressurizes the fuel toward the fuel injection nozzle 38 by pressurizing with the common rail 34. The fuel injection nozzle 38 injects the fuel fed from the common rail 34 into the combustion chamber 30h. The fuel injected into the combustion chamber 30h is combusted by the compression of the air-fuel mixture not in the combustion chamber 30h by the piston 30e, and exhaust gas is generated. The exhaust gas is discharged to the exhaust port 30d.

  Exhaust gas discharged from the combustion chamber 30h reaches the turbocharger 18 through the exhaust passage 28a, and rotates a compressor wheel (not shown) by rotating a turbine wheel (not shown). Sent downstream. The amount of air sucked into the combustion chamber 30h is increased by the pressurization of the air. When the amount of air in the combustion chamber 30h increases, the amount of fuel combustible in the combustion chamber 30h also increases. Therefore, the amount of fuel injected from the combustion injection nozzle 38 can be increased.

  In this manner, the fuel charging efficiency in the combustion chamber 30h is increased, so that the output of the engine 30 can be improved. The exhaust pipe 28 connected to the downstream side of the turbocharger 18 is provided with a catalyst 26, and the exhaust gas is further discharged outward downstream thereof.

  An electronic throttle 14 connected to an accelerator (not shown) is provided in the intake passage 22a upstream of the intake pipe 22 from the intake port 30c, and the amount of air passing through the intake passage 22a is adjusted by opening and closing the electronic throttle 14. ing. An intercooler 16 is disposed further upstream of the intake pipe 22, and the end thereof is connected to the turbocharger 18.

  An air flow meter 20 is disposed further upstream from the turbocharger 18. The air flow meter 20 incorporates an intake air temperature sensor (not shown). The air flow meter 20 can measure the amount of air passing through the intake pipe 22, that is, the amount of intake air, and the temperature of air, that is, the temperature of intake air.

  An actuator 44 is connected to the turbocharger 18 via a rod 44a, and an EVRV 42 is connected to the actuator 44 via a communication pipe 42a. Further, the EVRV 42 is connected to the negative pressure tank 46 through the communication pipe 42b. The EVRV 42 is connected to an ECU (Electronic Control Unit) 13 and is controlled by the ECU 13.

  The ECU (electronic control unit) 13 is mainly configured by a microcomputer having a storage unit such as a CPU, a ROM and a RAM, an I / O, and the like. The ECU 13 executes processing for the EVRV 42 by executing a computer program stored in the ROM, and controls the valve opening / closing of the EVRV 42.

  As shown in FIG. 2, the EVRV 42 is an electromagnetic valve that is configured by a housing 50 that includes a solenoid 52, a movable iron core 53, and a movable valve 54 therein. The solenoid 52 is configured to generate an electromagnetic force under the control of the ECU 13, and the movable iron core 53 is configured to be able to reciprocate by the electromagnetic force generated by the solenoid 52. The movable valve 54 is configured to be integrally fixed to the movable iron core 53, and is configured to be able to open and close a communication pipe 42a and a communication pipe 42b, which will be described later, by reciprocating movement of the movable iron core 53.

  The casing 50 is connected to the communication pipe 42 a and the communication pipe 42 b, and communicates with the turbocharger 18 and the negative pressure tank 46, respectively. The housing 50 is provided with an intake 60 that communicates with the atmosphere, that is, an air intake.

  The EVRV 42 is configured to be able to open and close the ends of the communication pipe 42 a and the communication pipe 42 b by reciprocating movement of the movable valve 54. The movable valve 54 is urged so as to close the upper side, that is, the communication pipe 42 a and the communication pipe 42 b in FIG. 2 by the action of the spring 56 and the spring receiving portion 58. At this time, the EVRV 42 is closed when the upper surface of the movable valve 54 is in close contact with the ends of the communication pipe 42 a and the communication pipe 42 b, and the communication pipe 42 a and the communication pipe 42 b are not in communication with the inside of the housing 50.

  In a state where the EVRV 42 is opened, the movable valve 54 moves downward in FIG. 2, and the communication pipe 42a and the communication pipe 42b communicate with the inside of the housing 50, thereby communicating with the atmosphere via the intake 60. Atmospheric pressure is introduced into 42a and the communication pipe 42b. Thus, the negative pressure introduced into the communication pipe 42a, that is, the actuator 44 is controlled. These operations are controlled by the ECU 13 connected to the EVRV 42.

  The actuator 44 is a known negative pressure type in which the operation amount of the actuator varies depending on the magnitude of the negative pressure introduced from the outside. When the opening degree of the EVRV 42 is adjusted, the negative pressure applied from the negative pressure tank 46 toward the actuator 44 is adjusted. As a result, a displacement portion (not shown) in the actuator 44 is displaced, and the protruding position of the rod 44a provided at the displacement portion is appropriately changed.

  The rod 44a is connected to a vane (not shown) provided in the turbine, and the angle of the vane is adjusted appropriately. The vane is configured such that the angle with respect to the flow of the exhaust gas is variable, and the supercharging pressure of the air fed into the combustion chamber 30h by the turbocharger 18 is adjusted by adjusting the vane angle. That is, the turbocharger 18 is a variable capacity turbocharger.

  FIG. 3 shows the operating characteristics of the EVRV 42 at high temperature and low temperature. The operating characteristic graph indicated by the solid line is the operating characteristic A at normal time, that is, at high temperature, and the operating characteristic graph indicated by the broken line is the operating characteristic B at low temperature. The low temperature is, for example, a cold time of 0 ° C. or lower. The high temperature means a state in which the solenoid 52 of the EVRV 42 is warmed and exhibits the operation characteristic A at a high temperature, and is a temperature range exceeding approximately 0 ° C.

  As illustrated in FIG. 3, at the time of normal operation, that is, at a high temperature, the opening degree of the EVRV 42 is 0% when driving at a driving duty ratio of 0% to 20%. This is a drive state at a drive duty ratio in which the EVRV 42 is not opened. The EVRV 42 starts to be driven at a driving duty ratio of 20%, and the opening degree of the EVRV 42 increases linearly as the driving duty ratio increases from 20% to 80%. When the drive duty ratio is 80% or more, the EVRV42 opening is 100%.

  Next, at the time of low temperature, the opening degree of the EVRV 42 becomes 0% when driving at a driving duty ratio of 0% to less than 10%. This is drive control at a drive duty ratio at which the EVRV 42 is not opened. At a driving duty ratio of 10%, the EVRV 42 starts to drive, that is, open the valve. In the drive control from the drive duty ratio of 10% to 70%, the opening degree of the EVRV 42 increases linearly as the drive duty ratio increases. When the drive duty ratio is 70% or more, the opening degree of the EVRV 42 is 100%. As described above, the opening degree of the EVRV 42 is deviated between the low temperature and the high temperature even if the same drive duty ratio is given.

  The above phenomenon is caused by the temperature dependence of the operation of the EVRV 42, that is, when the temperature is low, the electric resistance in the coil portion of the solenoid 52 in the EVRV 42 becomes low, so that current flows easily and the EVRV 42 is driven with a smaller driving duty ratio. . For the same drive duty ratio, the opening degree of the EVRV 42 is larger at the low temperature than at the high temperature. This is a phenomenon that occurs in a temperature range of approximately 0 ° C. or less.

  As shown in FIG. 3, for example, when the EVRV 42 is driven at a drive duty ratio of 50%, the opening degree is 50% at a high temperature, but the opening degree is 70% at a low temperature, and the ECU 13 is the same. Even if the control is performed, a deviation occurs in the opening degree of the EVRV 42. As a result, the turbocharger 18 cannot be controlled to the target supercharging pressure at low temperatures.

  The driving state in which the opening degree of the EVRV 42 is 0%, that is, the driving state in which the valve is not opened, means a driving state in which the EVRV 42 is driven and controlled with a predetermined driving duty ratio but does not enter the valve opening state. To do. In addition, execution of drive and control of the EVRV 42 includes execution of drive and control of the solenoid 52 included in the EVRV 42.

  In the present embodiment, the ECU 13 controls the EVRV 42 as shown in FIG. First, the ECU 13 determines whether or not there is a control request for opening and closing the EVRV 42 (S101). A control request for the EVRV 42 is transmitted by an engine ECU (not shown). Here, the control request of the EVRV 42 is, for example, a request mainly according to engine control while the vehicle is traveling, and is a request for controlling the supercharging pressure for the engine 30 by the EVRV 42.

  If there is a control request for the EVRV 42 (S101: YES), the ECU 13 calculates a normal drive duty ratio (S102). The normal drive duty ratio is calculated according to the EVRV42 opening requested by the ECU 13 based on the table map prepared in advance by associating the EVRV42 opening with the drive duty ratio. This is set based on the operating characteristic A of the EVRV 42 at a high temperature in FIG.

  Here, the normal drive duty ratio means a drive duty ratio when the solenoid 52 is driven so that the movable valve 54 of the EVRV 42 actually opens. The ECU 13 outputs the calculated normal drive duty ratio to the EVRV 42 (S104), thereby executing control to drive the EVRV 42 at a drive duty ratio that does not open the valve. As a result, the EVRV 42 is driven with the content requested by an engine ECU (not shown) to control the actuator 44, thereby controlling the supercharging pressure supercharged by the turbocharger 18. Hereinafter, calculating the normal drive duty ratio (S102) and then controlling the EVRV 42 with the calculated normal drive duty ratio is referred to as a normal drive mode.

  When there is no control request for the EVRV 42 in S101 (S101: NO), the ECU 13 calculates a preheating duty ratio (S103). Here, when there is no control request of the EVRV 42, for example, immediately after turning on an ignition switch (hereinafter referred to as an ignition SW) of the vehicle, the engine 30 is in an idling state, or a door is opened when a person gets on Sometimes, the turbocharger 18 by the EVRV 42 is in a state where the engine 30 is not loaded, such as immediately after the door courtesy switch (hereinafter referred to as the door courtesy SW) is turned on, such as when the engine 30 is started, when idling, or when the vehicle is running at a low speed. This means the case where the supercharging pressure control is not performed.

  The preheating duty ratio means a driving duty ratio in a driving state in which the opening degree of the EVRV 42 is 0%, that is, a driving duty ratio at which the EVRV 42 does not open. For example, in FIG. The drive duty ratio is in the range of 0% to less than 10% in the graph.

  The ECU 13 outputs the calculated preheating duty ratio to the EVRV 42 (S104), and drive control is executed at a drive duty ratio at which the EVRV 42 does not open. Hereinafter, calculating the preheating duty ratio (S103) and then controlling the EVRV 42 with the calculated preheating duty ratio (S104) is referred to as a preheating mode. Since the EVRV 42 is preheated by driving in the preheating mode and the temperature rises, the operation characteristics A at a high temperature shown in FIG. 3 are shown.

  According to the first embodiment, since the EVRV 42 is preheated by driving in the preheating mode and exhibits the operating characteristic A at a high temperature, the drive duty calculated when there is a control request for the EVRV 42 (S101: YES). Even if it drives by ratio, the opening degree of EVRV42 does not shift. Further, since the solenoid does not operate during the driving in the preheating mode and the EVRV 42 does not open, the supercharging pressure of the turbocharger 18 is not changed. As described above, even when it is cold, there is no deviation in the control of the EVRV 42 and the controllability is improved, so that the supercharging pressure control of the turbocharger 18 becomes more accurate.

(Second Embodiment)
Next, a second embodiment will be described. In the second embodiment, as shown in FIG. 5, before the preheating duty calculation (S103), the ECU 13 determines whether the engine coolant temperature or the intake air temperature is equal to or higher than a predetermined value (S201). When the engine coolant temperature or the intake air temperature is equal to or higher than a predetermined value (S201: YES), it is determined that the EVRV 42 is in a high temperature state and exhibits the operating characteristic A at a high temperature, and thus no preheating is necessary. Therefore, it returns to S101, without performing control (S103-> S104) of EVRV42 by the preheating mode.

  On the other hand, when the engine coolant temperature or the intake air temperature is less than the predetermined value (S201: NO), the EVRV 42 is in a low temperature state and is judged to exhibit the operation characteristic B at the low temperature, and therefore preheating is necessary. Therefore, in this case, the EVRV 42 is preheated by controlling the EVRV 42 in the preheating mode (S103 → S104).

  According to the second embodiment, the same effect as in the first embodiment is obtained. In addition, when the temperature of the EVRV 42 is low and the operation characteristic B at the low temperature is exhibited, the control in the preheating mode can be surely performed. Therefore, the temperature of the EVRV 42 is increased to show the operation characteristic A at the high temperature. be able to. Thereby, in preparation for the case where there is a control request of the EVRV 42 (S101: YES), it is possible to prepare the EVRV 42 so as to exhibit the operating characteristic A at a high temperature, so that the drive duty ratio calculated according to the request is driven. Even so, there is no deviation in the opening of the EVRV 42. As a result, the controllability of the EVRV 42 becomes good even when cold, so that the turbocharger 18 can generate the target boost pressure, and the boost pressure control becomes more accurate.

(Third embodiment)
Next, a third embodiment will be described. In the third embodiment, as shown in FIG. 6, it is first determined whether or not the ignition SW or the door courtesy SW is turned on (S301). If the ignition SW or the door courtesy switch is OFF (S301: NO), the process returns to S301 again, and waits for the detection of the ignition SW or the door courtesy switch being turned on. When the ignition switch or the door courtesy switch is turned on (S301: YES), it is determined whether or not there is a control request for the EVRV 42 (S101). Other configurations are the same as those of the second embodiment.

  According to the third embodiment, the same effects as those of the first and second embodiments are obtained. Further, since the drive control in the preheating mode is started when the ignition SW or the door courtesy SW is turned on, the EVRV 42 can be preheated at an earlier time. Accordingly, since the controllability of the EVRV 42 is improved from an earlier time even when it is cold, the supercharging pressure control of the turbocharger 18 can be made accurate from an earlier time.

(Fourth embodiment)
Next, a fourth embodiment will be described. In the fourth embodiment, as shown in FIG. 7, when NO is determined in S201, a predetermined time T1 for driving with the preheating duty ratio is calculated (S401). Here, the predetermined time T1 is set as follows.

  ECU13 acquires the temperature of a cooling water from the water temperature gauge 31 provided in the cylinder block 30a. The ECU 13 is previously provided with a table map in which the cooling water temperature is associated with the driving time in the preheating mode. The predetermined time T1 is set as a time sufficient for the EVRV 42 to exhibit the operating characteristic A at a high temperature by driving in the preheating mode. The ECU 13 calculates a predetermined time T1 corresponding to the acquired cooling water temperature (S401). The predetermined time T1 may be calculated by preparing a table map in which the intake air temperature measured by the intake air temperature sensor built in the air flow meter 20 is associated with the driving time in the preheating mode.

  Next, the ECU 13 determines whether or not the vehicle is driven in the preheating mode for a predetermined time T1 or more (S402). As shown in FIG. 8, this determination is made by monitoring the driving time in the preheating mode with a preheating mode driving counter, and determining whether or not the driving time has reached a predetermined time T1 or more. The preheating mode drive counter is virtually configured by the CPU executing a program stored in the ROM of the ECU 13.

  When the driving in the preheating mode is less than the predetermined time T1 (S402: NO), the preheating duty ratio is calculated (S103), and the drive duty output is performed on the EVRV 42 (S104). Thereafter, the control from S301 starts again. If there is no control request for the EVRV 42 (S101: NO), the control enters the second preheating mode control (S201 to S104), but since the predetermined time T1 has already been given, S401 is not executed after the second time. Further, if there is a control request for the EVRV 42 again in the control from S301 (S101: YES), it is considered that the engine 30 is driven with a load applied. The temperature rises. Therefore, the engine cooling water temperature or the intake air temperature is determined to be equal to or higher than a predetermined value in the second preheating mode control (S201: YES), and thereafter, the control returns to S101 without performing the control in the preheating mode.

When the driving in the preheating mode is longer than or equal to the predetermined time T1 (S402: YES), the control in the preheating mode is terminated and the process returns to S101.
According to the fourth embodiment, the same effects as those of the first, second and third embodiments are obtained. Further, unnecessary driving of the preheating mode is not performed, so that unnecessary operation of the ECU 13 can be reduced.

(Other embodiments)
In the above embodiment, the EVRV 42 provided with the solenoid 52 is described as an example of the electromagnetic valve. However, the present invention is not limited to this. It can be widely applied to other solenoid valves using solenoids. For example, the present invention may be applied to an EGR (Exhaust Gas Recirculation) valve including a solenoid.
In addition, with respect to how to give the drive duty ratio in the preheating mode, for example, control is performed to change the drive duty ratio in accordance with the rising temperature while monitoring the engine coolant temperature or the intake air temperature. May be.

  Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments and structures. The present disclosure includes various modifications and modifications within the equivalent range. In addition, various combinations and forms, as well as other combinations and forms including only one element, more or less, are within the scope and spirit of the present disclosure.

  DESCRIPTION OF SYMBOLS 13 ... ECU (electronic controller), 30 ... Diesel engine (internal combustion engine), 42 ... EVRV (solenoid valve), 52 ... Solenoid, 54 ... Movable valve

Claims (5)

An electronic control device for controlling the driving of the solenoid valve (42),
When there is no control request to open and close the solenoid valve, the control is performed to drive the solenoid valve with a duty ratio that the solenoid valve does not open,
When there is a control request to open and close the solenoid valve, an electronic control device that controls the duty of the solenoid valve by executing control to drive the solenoid valve at a duty ratio that the solenoid valve opens ( 13).   When the temperature of the cooling water for cooling the internal combustion engine (30) or the intake air temperature of the air taken into the internal combustion engine is equal to or lower than a predetermined temperature, the drive of the solenoid valve is controlled with a duty ratio that does not open the solenoid valve The electronic control device according to claim 1.   3. The electronic control device according to claim 1, wherein when the ignition switch or the door courtesy switch is turned on, driving of the electromagnetic valve is started at a duty ratio at which the electromagnetic valve does not open.   A time for driving the solenoid valve at a duty ratio at which the solenoid valve does not open is calculated in advance as a predetermined time, and after the solenoid valve is driven at a duty ratio at which the solenoid valve is not opened for the predetermined time, the solenoid valve The electronic control device according to any one of claims 1 to 3, wherein the control for driving at a duty ratio that does not open the valve is terminated. The electronic control device according to claim 4, wherein the predetermined time is calculated corresponding to a temperature of cooling water for cooling the internal combustion engine or an intake air temperature of air taken into the internal combustion engine.

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