JP2017106400A - Solenoid valve control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve controllability of behavior in closing a solenoid valve in a device for controlling the solenoid valve.SOLUTION: A solenoid valve control device (10) for controlling a solenoid valve operated by using electromagnetic force generated by a coil (L152), includes a switch circuit (Tr114) for switching ON/OFF of power supply to the coil, and a controller (142) for controlling energization current to the coil by controlling the switch circuit. The controller includes a map (map A) indicating a reduction amount target of an energization current effective value to the coil to reduce a valve opening of the solenoid valve in a desired mode, and further the controller detects a present energization current effective value of the coil, refers to the map on the basis of the detected present energization current effective value, and gradually reduces the energization current effective value at prescribed time intervals to control a valve closing motion of the solenoid valve.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a solenoid valve control device that controls the operation of a solenoid valve, and more particularly to a solenoid valve control device that can control in detail the operation when a solenoid valve is closed.

  Conventionally, as a technique for controlling the behavior of an electromagnetic fuel injection valve (hereinafter simply referred to as a fuel injection valve) that controls fuel injection into a cylinder in an internal combustion engine, a valve opening coil and a valve opening holding coil And a valve for closing the valve body and a spring for urging the valve body in the valve closing direction. When the valve is closed, the valve closing coil is energized and generated in the valve opening holding coil. An electromagnetic fuel injection device that eliminates or shortens the delay time during valve closing by quickly canceling the magnetic flux is known (Patent Document 1).

  However, the conventional fuel injection device described above merely shortens the valve closing time, and does not intend to finely control the movement of the valve body when the valve is closed.

  On the other hand, particularly in a diesel engine, it is desirable that the behavior of the fuel injection valve when it is closed can be finely controlled from the viewpoint of fuel consumption efficiency with respect to the output of the internal combustion engine.

JP 2000-265920 A

  From the above background, in order to further improve the efficiency of in-cylinder combustion with respect to engine output, it is desired to improve the controllability of the fuel injection amount by finely controlling the behavior of the fuel injection valve when the valve is closed.

One aspect of the present invention is an electromagnetic valve control device, which is an electromagnetic valve control device that controls an electromagnetic valve that operates using an electromagnetic force generated by a coil. And a controller that controls the switch circuit to control the energization current to the coil, and the controller reduces the valve opening of the solenoid valve in a desired manner. Comprising a map indicating a target of reduction of the current-carrying current effective value to the coil, and the controller detects a current-carrying current effective value of the coil, and based on the detected current-carrying current effective value, With reference to the map, the valve closing operation of the electromagnetic valve is controlled by decreasing the energization current effective value stepwise at predetermined time intervals.
According to another aspect of the present invention, the map is a predetermined value based on a magnetic saturation characteristic of the electromagnetic valve, and the effective current value for reducing the valve opening of the electromagnetic valve in a desired manner. Includes a map showing the reduction target.
According to another aspect of the present invention, the map indicates a current-carrying current effective value to be set after the predetermined time interval with respect to the current current-carrying effective value, and a coefficient to be multiplied with the current current-carrying current effective value. Is shown.
According to another aspect of the present invention, the controller controls the energization current by PWM controlling a current pulse energizing the coil, and sets the duty ratio used for the PWM control to the predetermined time interval. The valve closing operation of the electromagnetic valve is controlled by gradually changing the energizing current effective value at the predetermined time interval.
According to another aspect of the present invention, the switch circuit is provided between one terminal of the coil and a ground.
According to another aspect of the invention, the solenoid valve controls the fuel injection amount of the internal combustion engine.
According to another aspect of the invention, the map reduces the valve opening of the solenoid valve in a desired manner that is predetermined so that the internal combustion engine is fully closed when the internal combustion engine is at a desired crank angle. The map which shows the reduction amount target of the said energization current effective value for making it carry out is included.
Another aspect of the present invention is a vehicle electronic control device including any one of the above electromagnetic valve control devices.
Still another aspect of the present invention is a vehicle including any one of the above-described electromagnetic valve control devices.

It is a circuit diagram which shows an example of a structure of the solenoid valve control apparatus which concerns on one Embodiment of this invention. It is a figure which shows an example of the controller used for the solenoid valve control apparatus shown in FIG. It is a figure which shows an example of the map A used for the valve closing operation | movement in the controller shown in FIG. It is a timing diagram which shows operation | movement of the solenoid valve control apparatus shown in FIG. It is a flowchart which shows the operation | movement procedure of the valve closing operation unit in the controller shown in FIG. It is a figure which shows an example of the map B which can be used for the valve closing operation | movement in the controller shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings. The electromagnetic valve control device according to this embodiment is mounted on a vehicle and controls the operation of an electromagnetic fuel injection valve that is an electromagnetic valve that controls fuel injection into a cylinder of an internal combustion engine of the vehicle. However, the present invention is not limited to this, and can be widely applied to a device that controls the operation of a general electromagnetic valve (or solenoid valve, solenoid valve).

FIG. 1 is a diagram showing a configuration of a solenoid valve control device according to an embodiment of the present invention.
The electromagnetic valve control device 10 controls energization to a coil L152 included in an electromagnetic fuel injection valve that is an electromagnetic valve, thereby controlling fuel injection to a cylinder (not shown) of the internal combustion engine. In the following description, the coil L152 is also referred to as “electromagnetic valve L152”.

  The solenoid valve control device 10 includes a booster circuit 100 having a coil L102, a transistor Tr104, a diode D106, and an output capacitor C108, and a booster control circuit 140 that controls on / off of the transistor Tr104 of the booster circuit 100.

The booster circuit 100 receives power from a battery (not shown) and the transistor Tr104 is controlled to be turned on / off by the booster control circuit 140, whereby a predetermined voltage higher than the power supply voltage (power supply voltage) V _BAT (for example, 12V). The output capacitor C108 is charged up to a boosted voltage (for example, 40V), and the boosted voltage is output.

The electromagnetic valve control device 10 also includes a transistor Tr110 for turning on and off the energization of the boosted voltage output from the output capacitor C108 of the booster circuit 100 to one terminal (the upper terminal in the figure) of the solenoid valve L152; between the transistor Tr112 for driving the electromagnetic valve L152 a supply voltage V _BAT receives the power supply is energized to the one terminal of the solenoid valve L152, and ground with the other terminal of the solenoid valve L152 (terminal illustrated lower) A transistor Tr114 which is a switch circuit for controlling the connection of The operations of these transistors Tr110, Tr112, Tr114 are controlled by a controller 142 provided in the electromagnetic valve control device 10. Controller 142, a sensor signal representing the crank angle theta _c from the crank angle sensor for an internal combustion engine fuel injection amount is controlled by a solenoid valve L152 (not shown), from voltage division circuit constituted by the resistors R130 and R132 By controlling the respective gate voltages VG1, VG2, and VG3 of Tr110, 112, and 114 based on the actual value of the current flowing through the solenoid valve L152 obtained by converting the voltage (input from the illustrated MON terminal) The operation of the electromagnetic valve L152 is controlled.

Solenoid valve control device 10 also includes a capacitor C118 for removing noise for the battery supply voltage _{V BAT} with the on-off operation of the transistor Tr112 is prevented from varying, the output capacitor C108 when you turn on the Tr110 A diode D120 is included to prevent the boosted voltage supplied to the solenoid valve L152 from being applied to the Tr112.

  In the present embodiment, the Tr 112 is, for example, a P-channel MOSFET, and the Trs 104, 110, and 114 are, for example, N-channel MOSFETs. The transistors Tr104, Tr110, Tr112, and Tr114 are not limited to MOSFETs, and other types of transistors such as bipolar transistors can be used. Further, the boost control circuit 140 and the controller 142 can be configured by, for example, a microcomputer, an ASIC (Application Specific Integrated Circuit), or the like.

  FIG. 2 is a functional block diagram of the controller 142. In this embodiment, the controller 142 is a microcomputer having a processor such as a CPU (Central Processing Unit), a ROM (Read Only Memory) in which a program is written, a RAM (Random Access Memory) for temporary storage of data, and the like. And an I / O interface (hereinafter referred to as I / O-INF) 200 for exchanging signals with an external device, a valve opening control unit 202, a valve closing control unit 204, and a gate voltage control unit 206. And have. The valve closing control unit 204 includes a duty ratio calculation unit 208 and a drive pulse generation unit.

  Each unit provided in the controller 142 is realized by the controller 142 being a computer executing a program, and the computer program can be stored in any computer-readable storage medium. Alternatively, all or part of each of the above units can be configured by hardware including one or more electronic circuit components.

  The gate voltage control unit 206 controls (or determines) the gate voltages VG1, VG2, and VG3 of the Tr110, Tr112, and Tr114 based on instructions and signals from the valve opening control unit 202 and the valve closing control unit 204.

The valve opening control unit 202 is based on the crank angle θ _c acquired from the signal from the crank angle sensor, and when the current crank angle θ _c becomes the crank angle at which the valve opening should be started, the gate voltage control unit 206. By turning on the transistors Tr110 and Tr114 via the valve, the boosted voltage from the output capacitor C108 is applied to the solenoid valve L152 to quickly open the fuel injection valve driven by the solenoid valve L152, and then the Tr110 is turned off. Thus, the Tr112 is turned on / off to maintain the valve open state. Then, when the crank angle theta _c becomes the angle should begin closing, and passes control to a valve closing control unit 204.

  When the valve closing control unit 204 takes over control from the valve opening control unit 202, the Tr 112 is turned on, and the energization current of the electromagnetic valve L 152 is PWM-controlled by the Tr 114. In this PWM control, the effective value of the energization current of the solenoid valve L152 is changed stepwise by updating the duty ratio of the PWM control at the duty ratio update timing at a predetermined time interval, so that the solenoid valve L152 has a desired value. The valve closing operation (for example, along a desired valve opening decrease curve) is performed.

Specifically, the controller 142 sets the effective current value determined in advance in consideration of the magnetic saturation characteristic (BH hysteresis characteristic) of the electromagnetic valve L152 so that the electromagnetic force generated in the electromagnetic valve L152 decreases in a desired manner. The duty ratio calculation unit 208 holds a map A that indicates the decreasing mode, and the duty ratio calculation unit 208 calculates the map A based on the current effective value I _ec of the solenoid valve L152 converted from the voltage input from the MON terminal. Referring to this, the duty ratio to be set for the PWM control is calculated at the next duty ratio update timing, and is output to drive pulse generation unit 210.

FIG. 3 is a diagram illustrating an example of the map A. As illustrated in FIG. In FIG. 3, the horizontal axis represents the current energization current effective value I _ec flowing through the solenoid valve L152, and the vertical axis represents the energization current to be realized at the next duty ratio update timing according to the current energization current effective value I _ec. The ratio K (I _ec ) of the effective value I _en to the current energization current effective value I _ec is shown.

The duty ratio calculation unit 210 is realized at the next duty ratio update timing with reference to the map A based on the effective value I _{ec of the} current energizing current of the solenoid valve L152 converted from the voltage input from the MON terminal. obtains the energization current effective value I _en by the following equation (1) should, from I _en that the calculated, the duty ratio should be set at the next duty ratio update timing is calculated by the equation (2).
I _en = K × I _ec (1)
R _n = I _en / I _amp (2)
Here, Iamp is a current amplitude of a current pulse energized to the electromagnetic valve L152.

In general, in an electromagnetic valve (solenoid valve) that opens and closes a valve using electromagnetic force (for example, an electromagnetic fuel injection valve that opens and closes a fuel injection valve), an electromagnetic force F acting on a valve body made of a magnetic material is: Simply
F = kμI ² (3)
Determined by Here, k is a coefficient, μ is a magnetic permeability of the magnetic material constituting the valve body, and I is a current supplied to the coil constituting the electromagnetic valve.

  In general, the magnetic permeability μ of the magnetic material is not constant due to hysteresis characteristics in the BH curve of the magnetic material constituting the valve body. Further, the magnetic permeability μ of the magnetic material is a magnetic history up to the present time (that is, a history of current applied to the coil that applies an electromagnetic field to the valve body (for example, a magnetic field in the valve opening operation performed before closing the valve). It also depends on the saturation state and the valve opening maintaining operation time (ie, magnetic field application time))).

  As a result, due to the variable μ, even if the current I is simply reduced, the electromagnetic force acting on the valve element does not necessarily decrease by a desired amount. For this reason, even if the energization current I is decreased along the decrease curve of the energization current I proportional to the desired decrease curve with respect to the valve opening, the valve opening does not change along the desired decrease curve.

In the present embodiment, an instruction to decrease the effective current value determined in advance in consideration of the magnetic saturation characteristic (BH hysteresis characteristic) of the solenoid valve L152 so that the electromagnetic force generated in the solenoid valve L152 decreases in a desired manner is indicated. The map A to be held is held, and according to the map A, the duty ratio to be set at the next duty ratio update timing is calculated according to the current energization current effective value I _ec .

Here, as shown in FIG. 3, the ratio K indicated by the map A is a function of the current effective current effective value I _{ec because} the magnetic permeability μ of the valve body, which is a magnetic material, is the current applied magnetic field. Therefore, it depends on the current energization current effective value I _ec generating the magnetic field. More specifically, the map A is applied to the valve body in the valve opening operation and the valve opening maintaining operation before the valve closing operation, in addition to the magnetic saturation characteristics (BH curve, etc.) of the magnetic material that is the valve body. It is also determined based on the strength of the magnetic field and the application time (therefore, the magnitude of the energization current and the energization time to the electromagnetic valve L152 in the valve opening operation and the valve opening maintaining operation).

  Therefore, in applications where the mode of the valve opening operation or the valve opening maintaining operation changes greatly, a plurality of maps A may be provided and appropriately selected and used so as to cover the range of the change. The map A can be stored in a storage device (not shown) included in the controller 142, or can be described in a program executed by the controller 142, which is a computer, for example. it can.

  FIG. 4 is a timing chart showing the operation of the electromagnetic valve control device 10. 4, for the sake of illustration, the gate voltage VG1 of Tr110 (FIG. 3A), the gate voltage VG2 of Tr112 (FIG. 3B), and the gate voltage VG3 of Tr114 (FIG. 3C). Each change with time of the energization current effective value of the electromagnetic valve L152 ((d) of FIG. 3) and the valve opening degree of the electromagnetic valve L152 ((e) of FIG. 3) is shown.

  In FIG. 4, it is assumed that time flows from the left to the right in the figure. Hereinafter, for each transistor of Tr 110, 112, and 114, a gate voltage at which the transistor is turned on is referred to as an ON voltage, and a gate voltage at which the transistor is turned off is referred to as an OFF voltage. Here, since Tr112 is a P-channel FET, the ON voltage is lower than the OFF voltage, and the other transistors are N-channel FETs, so that the ON voltage is higher than the OFF voltage.

  In a state where the controller 142 is initialized after the electromagnetic valve control device 10 is turned on (the left side in the figure from the time T1), the VG1 to VG3 are all in the OFF voltage. Thereafter, the operation is started, and at time T1 when the crank angle reaches the angle to be opened, first, VG1 and VG3 are set to the ON voltage by the valve opening control unit 202, and Tr110 and Tr114 are turned on (FIG. 3 (a) (c)). Thereby, the output voltage (boosted voltage) of the output capacitor C108 of the booster circuit 100 is applied to the solenoid valve L152.

  Thereafter, the magnetic force of the electromagnetic valve L152 increases with the increase in the energization current of the electromagnetic valve L152 ((d) in FIG. 3), the valve opening increases rapidly, and the valve is quickly opened, and is determined by the characteristics of the electromagnetic valve L152. At time T2 when the delay time has elapsed, the valve opening reaches the fully open state ((e) in FIG. 3).

  At time T3 when a predetermined margin time has elapsed from time T2 at which the valve opening reaches full open, VG1 is set to the OFF voltage by the valve opening control unit 202, and Tr110 is turned off, and on / off control of Tr112 by VG2 Is started (FIGS. 3A and 3B). Thereby, the valve open state is maintained ((d) and (e) in FIG. 3).

  Thereafter, when the crank angle reaches a predetermined crank angle at which the valve closing operation is to be started at time T4, the control shifts from the valve opening control unit 202 to the valve closing control unit 204, and the valve closing control unit 204 is turned on by VG2. The voltage is set, and Tr114 is controlled to be turned on / off by VG4, thereby starting PWM control of the energization current of the solenoid valve L152.

  After the start of the PWM control, the valve closing control unit 204 changes the duty ratio of the voltage pulse of the gate voltage VG3 of the Tr 114 at a predetermined duty ratio update timing ((c) in FIG. 3), thereby the electromagnetic valve L152. Is changed (for example, non-linearly) (FIG. 3D), and the valve opening of the electromagnetic valve L152 is decreased in a desired manner (for example, linearly) (FIG. 3E). . Then, at time T5 when the valve opening reaches the fully closed state, one fuel injection cycle is completed (FIGS. 3D and 3E). Subsequently, the valve closing control unit 204 adjusts preparation for the next fuel injection cycle by turning off VG2 at time T6 when a predetermined margin time has elapsed from time T5.

  Next, an operation procedure in the duty ratio calculation unit 208 provided in the valve closing control unit 204 of the electromagnetic valve control device 10 will be described with reference to the flowchart shown in FIG. This process starts when the crank angle reaches a predetermined crank angle at which the valve closing operation should be started and control is transferred from the valve opening control unit 202 to the valve closing control unit 204.

When the process is started, first, the voltage input via the MON terminal of the I / O-INF 200 is converted to obtain the effective value (effective current value) I _ec of the energization current of the solenoid valve L152 (S100). However, the present invention is not limited to this, and the current amplitude of the solenoid valve L152 is acquired by converting the voltage input via the MON terminal, and the acquired current amplitude and the drive pulse generation unit 210 are currently set. and the duty ratio may be those obtained by calculating an effective current value I _ec solenoid valve L152 based on.

Next, the ratio (coefficient) K is determined with reference to the above-described map A based on the acquired current energizing current effective value _Iec , and the determined coefficient K and the equations (1) and (2) are used. Then, the duty ratio to be set at the next duty ratio update timing is calculated (S102).

  Next, it is determined whether or not the calculated duty ratio is equal to or smaller than a predetermined value (S104). If the calculated duty ratio is equal to or smaller than the predetermined value (S104, Yes), the duty ratio 0 (zero) is set in the drive pulse generation unit 210. Then, the process is terminated (S106). On the other hand, when the calculated duty ratio is larger than a predetermined value (S104, No), the calculated duty ratio is set in the drive pulse generation unit 210 (S108), and then waiting for a predetermined time to elapse. (S110), the process returns to step S102 and is repeated.

  As described above, the electromagnetic valve control device 10 according to the present embodiment provides the magnetic saturation characteristic (BH hysteresis characteristic) of the electromagnetic valve L152 so that the electromagnetic force generated in the electromagnetic valve L152 decreases in a desired manner. A map A showing a mode of decreasing the effective current value of the electromagnetic valve L152 determined in advance is provided, and when the valve is closed, the energizing current of the electromagnetic valve L152 is PWM-controlled to reduce the effective value of the energizing current and closed. When performing the valve operation, the duty ratio calculation unit 208 refers to the map A based on the current effective current value of the solenoid valve L152, and the duty to be set for the PWM control at the next duty ratio update timing. Determine the ratio.

  For this reason, in this electromagnetic valve control apparatus 10, the said valve opening degree can be accurately controlled so that the valve opening degree at the time of valve closing operation of the electromagnetic valve L152 may decrease in a desired manner.

As in the valve opening is completely closed at a predetermined crank angle, when calculating the energizing current effective value I _en, using the following equation (4) instead of the equation (1) described above, the current It is good also as what further multiplies the coefficient K 'according to a crank angle to the energization current effective value _Iec .
I _en = K × K ′ × I _ec (4)

In this case, for example, the controller 142 predetermines and holds a map B indicating a coefficient K ′ corresponding to the crank angle so that the valve is completely closed at a predetermined crank angle. The coefficient K ′ can be determined based on the current crank angle θ _c acquired from the crank angle sensor.

  For example, as shown in FIG. 6, the map B can be defined as a graph in which the horizontal axis indicates the crank angle and the vertical axis indicates the coefficient K ′ corresponding to the crank angle. Similarly to the map A, the map B can be stored in a storage device (not shown) included in the controller 142, or described in a program executed by the controller 142, which is a computer, for example. It can also be left.

  DESCRIPTION OF SYMBOLS 10 ... Solenoid valve control apparatus, 100 ... Boosting circuit, L102 ... Coil, Tr104, Tr110, Tr112, Tr114 ... Transistor, D106, D120 ... Diode, C108, C118 ... Capacitor, R130, R132... Resistor, 140... Boost control circuit, 142... Controller, L152.

Claims (9)

An electromagnetic valve control device that controls an electromagnetic valve that operates using electromagnetic force generated by a coil,
A switch circuit for turning ON / OFF the energization of the coil;
A controller for controlling the switch circuit to control a current flowing to the coil;
With
The controller includes a map indicating a target for reducing the amount of effective current applied to the coil for reducing the valve opening of the solenoid valve in a desired manner,
The controller detects a current conduction current effective value of the coil, refers to the map based on the detected current conduction current effective value, and gradually determines the conduction current effective value at predetermined time intervals. Controlling the valve closing operation of the solenoid valve by decreasing,
Solenoid valve control device. The map includes a map indicating a reduction amount target of the energization current effective value for reducing the valve opening of the solenoid valve in a desired manner, which is predetermined based on the magnetic saturation characteristics of the solenoid valve.
The electromagnetic valve control device according to claim 1. The map indicates a coefficient to be multiplied by the current energization current effective value, which indicates an energization current effective value to be set after the predetermined time interval with respect to the current energization current effective value.
The electromagnetic valve control device according to claim 1 or 2. The controller controls the energization current by PWM controlling a current pulse energized to the coil, and by changing the duty ratio used for the PWM control stepwise at the predetermined time interval, Controlling the valve closing operation of the solenoid valve by gradually reducing the energization current effective value at the predetermined time interval;
The solenoid valve control device according to any one of claims 1 to 3. The switch circuit is provided between one terminal of the coil and the ground.
The electromagnetic valve control device according to claim 1. The solenoid valve controls the fuel injection amount of the internal combustion engine.
The electromagnetic valve control device according to any one of claims 1 to 5. The map is a map of the effective value of the energizing current for reducing the valve opening of the solenoid valve in a desired manner, which is predetermined so that the internal combustion engine is fully closed when the crank angle is a desired value. Including a map showing reduction targets,
The electromagnetic valve control device according to claim 6.   An electronic control device for a vehicle comprising the electromagnetic valve control device according to any one of claims 1 to 7.   A vehicle comprising the electromagnetic valve control device according to any one of claims 1 to 7.

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