JPH11224816A - Method and device for controlling electromagnetic load - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constitute a device which controls an electromagnetic load, for example, an electromagnetic valve for controlling fuel injection in such a way that a switch turning-on process can be accelerated at performing the second partial injection by shortening the interval between two partial injections. SOLUTION: A current, flowing through a load 100, is controlled so that the current becomes a first current value and a second current value at various control time phases. When the current is shifted to the second current value from the first current value, the energy stored in the load 100 is stored in a storing means 145 and transferred to the load 100, when the control is started. After the current has shifted to the second current value from the first current value, the current is raised to a value larger than the second current value at least once and then, the energy is successively supplied to the storing means 145.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling and / or adjusting a current flowing through a load so as to have a first current value and a second current value in various control phases. In the transition to the second current value, the energy stored in the load is stored in the storage means, and the energy is transferred to the load at the start of the control, at least one electromagnetic load, for example to the internal combustion engine, The present invention relates to a control method and a control device of an electromagnetic valve for controlling fuel injection.

[0002]

[Prior art] Patent application DE-OS 44 13
240 discloses a device for controlling at least one electromagnetic load. In the case of this device, the energy released when the switch is turned off is stored in the boosting capacitor. Then, when the next control is started, the stored energy is transferred to the load.

[0003] In addition, devices are known in which the current is switched on / off for a short time after the actual valve control, so as to additionally charge the capacitor. This process is commonly referred to as recharging or recharging. Such recharging must be as short as possible. This is usually because it can only be used for a very short time. This is especially true at high rotational speeds.

It is also known to transfer energy released by current adjustment to a capacitor.

[0005] If only one injection per cylinder is performed per metering cycle, generally known methods are sufficient. If, on the other hand, the injection operation is designed to be divided into at least a first partial injection and a second partial injection, then in a known manner a situation arises which is insufficient to charge the capacitor to a sufficient voltage. there is a possibility.

[0006] The interval between each partial injection is therefore limited, or the subsequent partial injection cannot be performed at an increased voltage, ie with the attendant advantages. . In the case of an injection system in which the injection operation is divided into two partial injections, the interval between both partial injections is necessary to charge the capacitor to a sufficiently high voltage and to accelerate the subsequent switch-on process. It cannot be chosen shorter than the time taken.

[0007]

SUMMARY OF THE INVENTION It is therefore an object of the invention to reduce the distance between two partial injections in an apparatus for controlling an electromagnetic load, whereby the switch-on process is accelerated in the second partial injection. It is to be configured to be performed.

[0008]

SUMMARY OF THE INVENTION According to the present invention, there is provided an object of the present invention, wherein after a transition from a first current value to a second current value, the current is increased at least once by a value greater than the second current value. And then supplying the storage means with energy.

[0009]

An advantage of the device according to the invention with the above-mentioned characteristics is that the distance between both partial injections can be chosen to be very short, while at the same time very fast switching in all partial injections. The process is to be possible.

Next, the device according to the present invention will be described in detail based on an embodiment shown in the drawings.

[0011]

The device according to the invention is preferably used in an internal combustion engine, for example a self-igniting internal combustion engine. At that time, the fuel metering is controlled by the solenoid valve. Such a solenoid valve will be referred to herein as a load. That said, the invention is not limited to such application cases,
It can be used wherever a fast switching load is required.

In the case of an internal combustion engine, for example, a self-ignition type internal combustion engine, the start and end of fuel injection to the cylinder are determined by the opening and closing times of the solenoid valve.

In this case, the injection operation is advantageously divided into a pre-injection and a main injection located before the actual main injection. Further, the post-injection can be performed after the original main injection. It is also possible to further divide the pre-injection, main injection and / or post-injection into a plurality of partial injections. In that case, the merit of the boosting capacitor must be utilized as it is in the subsequent partial injection.

FIG. 1 shows the basic components of a device according to the invention. The illustrated embodiment is a multi-cylinder internal combustion engine. In this case, one injection valve is associated with each load, and one cylinder of the internal combustion engine is assigned to each injection valve. If the internal combustion engine has a different number of cylinders, it is necessary to provide a corresponding number of valves, switching means and diodes.

Reference numerals 100, 101, 102, 103
Indicate four loads. Load 100 to 10
The third terminal is connected to the voltage supply unit 105 via the switching means 115 and the diode 110, respectively.

The diode 110 is arranged such that the anode is connected to the positive electrode and the cathode is connected to the switching means 115. In this case, the switching means 115 is, for example, a field effect transistor.

The second terminals of the loads 100 to 103 are respectively connected to second switching means 120, 121, 122,
It is connected to the resistance means 125 via 123. The switching means 120 to 123 are also, for example, field effect transistors. The switching means 120 to 123
Is called a low side switch, and the switching means 115
Is called a high-side switch. The second terminal of the resistance means 125 is connected to the second terminal of the voltage supply unit 105.

Diodes 130, 131, 132, and 133 are provided corresponding to the loads 100 to 103, respectively. Each of these diodes is connected to a connection point between the load and the low-side switch. At that time, the cathode terminal is connected to the capacitor 145 and another switching means 140. The second terminal of the switching means 140 is connected to the first terminals of the loads 100 to 103. The switching means 140 is also preferably a field effect transistor. This switching means 140 is also called a booster switch. Further, the second terminal of the capacitor 145 is also connected to the voltage supply unit 10.
5 is connected to the second terminal.

A control signal AH is applied from the control unit 160 to the high side switch 115. A control signal AL1 is applied to the switching means 120 from the control unit 160, a control signal AL2 is supplied to the switching means 121, and a control signal AL is supplied to the switching means 122.
Control signal AL4 is applied to switching means 123, and control signal A is applied to switching means 140.
C is added.

Switching means 115 and loads 100 to 1
A diode 150 is connected between a connection point between the first terminals 03 and a second terminal of the voltage supply unit 105. The anode of this diode is connected to the second terminal of the voltage supply unit 105. Note that the current flowing through the load can be obtained by using the resistor 125.

FIG. 2 shows control signals for various switching means on a time axis. In this case, on the time axis, the booster switch 140 is shown in FIG.
The control signal AC for the high-side switch 115 is shown in FIG.
2 shows the control signal AL for the low-side switch, FIG. 2d shows the current I flowing through the load, and FIG. 2e shows the voltage U dropping at the capacitor.

In this case, the control is divided into various phases. In phase 0 before the control of the load, the final stage is shut off. Control signals AC, AH, AL and signal AS
Are at a low level of potential. That is, the high-side switch 115, the low-side switches 120 to 123
And the booster switch 140 prevents current from flowing. Therefore, no current flows through the load. Capacitor 145 is charged to its maximum voltage U10. This voltage has a value of about 80V, while the voltage supply unit has a value of about 12V.

At the start of the control, in a first time phase called the booster mode, the conduction of the low-side switch assigned to the load for adjusting the fuel is controlled. That is, the signal AL takes a high level from the first time phase. At the same time, a high level signal is sent out via the line AC, and the switch 140 is controlled to be conductive by this signal. The conduction of the high-side switch 115 is not controlled, and the switch remains in the blocking state. By controlling the switching means in this manner, current flows from the capacitor 145 to the corresponding load via the booster switch 140, to the low-side switch assigned to the load, and further to the current measuring means 125. In this phase, the current I
Rises very rapidly in load. Capacitor 14
When the voltage of No. 5 becomes smaller than the predetermined value U2, the first time phase ends. During the first phase, the signal AS rises to a high level. This indicates that the voltage drop at the capacitor is smaller than a predetermined threshold value US.

The second phase, which can also be referred to as the input current adjustment time phase,
In the time phase, the high-side switch 115 receives the switch-on current, and the operation of the booster is stopped. That is, the control signal AC for the booster switch 140 is canceled in this second time phase, and as a result, the switch 140 is turned off. The control signals AH and AL for the high-side switch 115 and the low-side switch assigned to the load are high, which causes them to conduct current. Thus the current is
The voltage supply 105 returns to the voltage supply 105 via the diode 110, the high-side switch 115, the load, the corresponding low-side switch, and the current measuring resistor 125.

By controlling the timing of the low-side switch, the current captured through the current measuring resistor 125 can be adjusted so as to have a predetermined input current value IA. That is, when the applied current reaches the target current IA, the low-side switches 120 to 123 are controlled to be in the blocking state. Then, when the voltage falls below another threshold, the low-side switch becomes conductive again. Thus, when the low-side switches 120-123 are open, the current flows from the individual loads to the diodes 130-133 assigned to them.
To the capacitor 145, and the energy stored in the load is transferred to the capacitor 145. At the same time, the voltage U at the capacitor 145 increases.

To change the valve from one state to the other, it is necessary to apply a make-up current to the valve. In order to maintain the state of the valve, it is sufficient to apply a holding current to the valve.

When the end of the closing time phase is identified by the control unit 160, the second time phase ends. This is the case, for example, when the switching time detector has identified that the solenoid valve mover has reached its new final position.

In a third phase, also called the first quick reset phase, the control signal AL for the corresponding low-side switch is canceled. This allows the current to flow from the individual load to the diode 130 assigned to the load.
１３133 to the capacitor 145. At that time, the energy stored in the load is transferred to the capacitor 145. In this time phase, the current is reduced from the making current IA to the holding current value IH. At the same time, the voltage U applied to the capacitor 145 increases. When the target holding current value IH is reached, the third time phase ends. The energy released by the transition from the input current to the holding current is stored in the capacitor.

The third time phase is followed by a fourth time phase, also called a holding current time phase or a holding current adjustment time phase. Here, as in the second phase, the control signal for the high-level switch is maintained at its high level, ie the high-level switch is kept closed. By opening and closing the low-side switch, the current flowing through the load is adjusted to the holding current target value IH. When the low side switch is closed, current flows from the individual loads to the capacitors 145 via the diodes 130-133 assigned to the loads. This transfers the energy stored in the load to the capacitor.

In a subsequent fifth time phase, also referred to as a second quick reset time phase, the corresponding low-side switch is turned off and the high-side switch 115 is kept conductive. In this phase, the current flowing through the load also drops rapidly to a value of zero. At the same time, the voltage U at the capacitor 145 increases by a value smaller than the third time phase.

In the third time phase and the fifth time phase, the target current value I shifts from a high value to a low value. In this time phase, each of the low-side switches assigned to the load is controlled so that no current flows. The energy released at that time is transferred to the condenser 145. This causes the current to quickly reach its new target value.

In the second time phase and the fourth time phase, the current is adjusted by controlling the timing of the low-side switch. When the high side switch is in the blocking state, the freewheeling diode 150 is active. As a result, the released energy is transferred to the capacitor 145.

As a modified embodiment of the present invention, a configuration may be adopted in which conduction control is performed via a high-side switch. In this case, the current drops slowly,
As a result, the switching frequency decreases.

At the end of the sixth time phase, the final stage is inactive, and therefore no fuel metering is performed. That is, the control signal AC for the booster switch 140, the control signal AH for the high-side switch, and the control signal AL for the low-side switch all have a low level, and all the switches are in the blocking state. The current through the load is kept at zero and the voltage at capacitor 145 is maintained at that value.

In the seventh time phase after the conduction control, also called the post-timing time phase, the high-side switch 115 shifts to the conduction state again by the control signal AH. Closing the low-side switch returns the current flow to the initial state at one of the loads. The current flows through, for example, the diode 110, the switch 115, the load 100, the switching unit 120, and the current measuring unit 125, and returns to the voltage supply unit 105. When the target current value is selected so that the solenoid valve does not respond, the low-side switch is controlled to open. This again causes a rapid reset for the current path consisting of the load, one of the diodes 130-133 and the capacitor 145. This allows the capacitor 1
The voltage at 45 rises.

When the current falls below a predetermined value, the low side switch 120 becomes active again. This process is repeated until the voltage on the capacitor 145 gradually reaches the value U10 again. This process is called recharging.

Next, at time phase 8, all control signals are canceled and all switches are moved to the blocking state.
This phase coincides with phase 0.

It is particularly advantageous that during the adjustment of the holding current, the target value is set at least once to a value which is greater than the holding current value IH and then the storage means, ie the capacitor 1
45 to supply energy. At this time, it is advantageous to set the target value to the applied current value IA. Further, the target value may be set to a value larger than the applied current value IA, or may be set to a value between the applied current value IA and the holding current value IH.

In the embodiment shown, this is done in phase 4a. This phase 4a immediately follows the third phase. That is, after the current has decreased to the holding current value, the current is increased again to the closing current value IA. In each case, the energy released by decreasing to the holding current value IH is transferred to the booster capacitor 145, and as a result, the voltage U at the booster capacitor 145 increases. By doing this,
The recharged phase 7 of the capacitor 145 can be significantly reduced. Further, the configuration may be such that the current is increased many times to the increased value.

It is particularly advantageous for the current to rise only during the period AB for recharging, ie when the seventh phase is too short. This rise occurs when the interval between two injection times and / or the interval between two partial injection times is smaller than a threshold value. This is the case, for example, when the injection operation is divided into two partial injection operations. In this case, the rise is performed in all partial injections except the last partial injection. That is, in each partial injection subsequent to the partial injection, the current value is increased during the holding current time phase.

Furthermore, the increase may be performed under the operating conditions of the internal combustion engine where the interval between each injection operation and / or the interval between partial injections is small. This is especially true at high rotational speeds. That is, the current is increased when the rotational speed or an amount corresponding to the rotational speed is greater than the threshold value.

FIG. 3 illustrates the method according to the invention by way of example in a flow chart. First step 30
At 0, the program is returned to the initial state, for example, the counter Z is set to zero. In the following step 310, the counter Z is incremented by one. Counter Z
Counts the partial injections divided from one injection operation. If the injection operation is not divided into a plurality of partial injections, such a counter Z may be omitted. Next, in the inquiry step 320, it is checked whether or not the content of the counter Z is equal to or more than the value ZM. The value ZM corresponds to the number of partial injections. If it is greater than or equal to the value ZM, that is, if the counter Z has reached the value ZM, then it is the last partial injection, in which no current increase takes place. In this case, the program proceeds to step 380. Such an interrogation step causes a rise to occur in all partial injections except the last partial injection.

If it is not the last partial injection yet,
That is, if the count state Z is smaller than ZM, the process proceeds to the inquiry step 330. And this question step 3
At 30, it is checked whether the period AB for recharging, ie the seventh time phase, is too short. Period AB is threshold value S
If it is greater than W1, the program proceeds to step 340. If the period AB is smaller than the threshold value SW1,
Proceed to step 380. In the interrogation step 340, it is checked whether or not the operating state requires ascending. In the illustrated embodiment, it is checked in a query step 340 whether the rotational speed N is greater than a threshold value SW2. If not, the program proceeds to 380. If the rotation speed N is larger than the threshold value SW2, the target current value is increased in step 360.

In the illustrated embodiment, the interrogation steps 330 and 340 are coupled to each other such that the ascending takes place only when both conditions are both met. 1
According to one particular embodiment, query steps 330 and 3
40 is coupled such that an elevation occurs if one condition exists. It is particularly advantageous to check only one of the two conditions.

Such an increase occurs when the interval between two injection operations and / or the interval between two partial injections is smaller than a threshold value.

The circuit according to FIG. 1 is only an example. Thus, the approach according to the invention can also be used in different circuits and different control schemes. For example, it may not be necessary for energy to be returned to the capacitor at all phases. That is, the seventh phase may be omitted entirely in the manner according to the invention.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of an apparatus according to the present invention.

FIG. 2 is a diagram showing various signals on a time axis.

FIG. 3 is a flowchart illustrating the method according to the present invention as an example.

[Explanation of symbols]

 100 to 103 Load 105 Voltage supply unit 115 High side switch 120 to 123 Low side switch 140 Booster switch 160 Control unit AC Control signal for booster switch AH Control signal for high side switch AL Control signal for low side switch IA input Current IH Holding current U10 Maximum voltage of capacitor

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Bernhard Baruchjo Germany Eppingen Lerchenweg 2 (72) Inventor Harald Schuler Germany Backnang Bria Strasse 7

Claims (8)

[Claims] A current (I) flowing through a load varies between a first current value (IA) and a second current value (I) in various control phases.
H), the energy stored in the load is stored in the storage means (14) at the time of transition from the first current value (IA) to the second current value (IH).
5), wherein the energy is transferred to the load (100) at the beginning (1) of the control,
In the method for controlling the two electromagnetic loads (100), after shifting from the first current value (IA) to the second current value (IH), the current (I) is changed at least once by the second current value (IH). A method for controlling an electromagnetic load, characterized in that it rises to a value greater than IH) and subsequently supplies energy to the storage means. Increasing the current value to a value between the first current value and the second current value, to a value equal to the first current value, or to a value greater than the first current value; The method of claim 1. 3. The first current value is an input current required to change the state of the load, and the second current value is a holding current required to maintain the state of the load. The method according to claim 1, wherein 4. The method according to claim 1, wherein the current is increased when the interval between the next injections is smaller than a threshold value. 5. The method according to claim 1, wherein one injection operation is divided into at least a first partial injection and a second injection, and if another partial injection is further continued, the current is increased. The method of claim 1. 6. The method according to claim 1, wherein the current is increased many times.
The method according to claim 1. 7. The method according to claim 1, wherein the current is increased depending on operating conditions of the internal combustion engine. 8. A current (I) flowing through a load (100) is controlled by a first current value (IA) and a second current value (IA) in various control time phases.
Means for controlling and / or adjusting the current value (IH) of the first current value (IH) to the second current value (IH).
Energy stored in the load (100) is stored in the storage means (145), and the energy is transferred to the load (100) at the start (1) of the control, at least one electromagnetic load (100). In the control device, after the transition from the first current value (IA) to the second current value (IH), the current (I) is changed at least once to a value larger than the second current value (IH). A control device for an electromagnetic load, characterized in that means for raising are provided, followed by supplying energy to the storage means (145).