JP2008175119A - Injector control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure high durability of an injector by enabling avoidance of generation of excessive electromagnetic attraction force without deteriorating controllability of the injector in injector control of a fuel injection system. <P>SOLUTION: The injector control device 10A opening the injector 21A by electromagnetic attraction force of a solenoid 21 and performing opening/closing control by switching ON/OFF of fuel injection signal, is provided with a valve opening retard time calculation means having a valve opening detection signal input therein from a vibration detector 2 which is a valve opening detection means detecting valve opening completion of the injector 20A and calculating a valve opening retard time from the output of fuel injection signal to the detection of the valve opening detection signal, and adjusting means for adjustment of valve opening retard time to a target valve opening retard time, and executes control in a direction to keep the minimum necessary voltage apply time for materializing the target valve opening retard time while securing positive valve opening operation. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an injector control device for realizing accurate fuel injection by controlling opening and closing of an injector (fuel injection valve) in a fuel injection system of an internal combustion engine.

  Conventionally, in a known internal combustion engine fuel injection system 1B as shown in FIG. 4, an injector 20B incorporating a solenoid 21 is turned on by an open loop control method or the like for an injector control device 10B that detects an operating state of the engine or the like. By performing the / OFF operation, the open / close control is electromagnetically performed to achieve an accurate fuel injection and an optimal fuel injection amount.

  In such a control method, as shown in the waveform diagram of FIG. 3, the solenoid applied voltage / solenoid drive current is changed by switching the fuel injection signal between the high side (ON side) and the low side (OFF side). While controlling, the valve opening / closing operation of the injector is executed to achieve a desired duty ratio.

  However, in this fuel supply system 1B, when the voltage value of the battery 30 is lowered, the applied voltage to the solenoid of the injector is lowered, the valve body suction force is lowered, and the valve opening operation of the injector is not performed. In some cases, sufficient opening / closing control becomes difficult, and a desired fuel supply amount cannot be realized.

  Therefore, as described in Japanese Patent Application Laid-Open Nos. 2001-317394 and 2002-295293, in order to secure a predetermined level of valve body suction force, control is performed using the detected battery voltage value as a parameter. It has been known. That is, in order to obtain a suction force equivalent to that before the battery voltage decreases, it is necessary to lengthen the voltage time supplied to the solenoid, but the solenoid power is supplied to the solenoid so as to realize a predetermined suction force according to the detected battery voltage. The voltage supply time is controlled to be changed.

  However, it is known that the attraction force of the solenoid, which is the force acting in the valve opening direction of the injector, varies due to various causes in addition to the variation of the applied voltage value. For example, the solenoid has a temperature characteristic in which current does not easily flow at high temperatures and current easily flows at low temperatures. Also, the solenoid fluctuates due to deterioration over time, such as deterioration of the components that make up the injector. This is caused by variations in performance during manufacturing, such as discrepancy in the set stroke amount.

Therefore, in general, the voltage application time is determined so that at least the injector opens even under the worst conditions in consideration of such fluctuations in the injector control. Therefore, the voltage applied amount exceeds the actual required amount, leading to excessive power consumption, and generating excessive electromagnetic attraction force on the solenoid results in excessive load on the injector. As a result, the deterioration of the component parts and the increase in the amount of wear are caused and the durability is greatly impaired.
JP 2001-317394 A JP 2002-295293 A

  The present invention is intended to solve the above-described problems. In the injector control in the fuel injection system, it is possible to avoid the generation of an excessive electromagnetic attractive force without impairing the controllability of the injector. It is an object to ensure durability.

  Accordingly, the present invention provides an injector control device that is disposed in a fuel injection system of an internal combustion engine and opens and closes the injector while switching on / off of a fuel injection signal while opening the injector by electromagnetic attraction of a solenoid by applying a voltage. The valve opening detection signal from the valve opening detecting means for detecting the completion of the valve opening of the injector is input, and the valve opening delay time for calculating the valve opening delay time from when the fuel injection signal is output until the valve opening detection signal is detected is calculated. A delay time calculating means; and an adjusting means for adjusting the valve opening delay time to a target valve opening delay time, and a target valve opening delay time while ensuring a reliable valve opening operation. The control is executed in the direction of the minimum voltage application time required to realize the above.

  The valve opening delay time, which is the time required from the output of the fuel injection signal to the end of the valve opening, varies depending on the temperature of the solenoid, the aging of the injector, the performance variation during the manufacture of the injector, etc. in addition to the decrease in the battery voltage value. The controllability of the injector (valve response / accuracy) is maintained by adjusting the valve opening delay time based on the detected valve opening delay time, even if these fluctuation factors exist. At the same time, by controlling the minimum required voltage application time to achieve this target valve opening delay time, the generation of excessive electromagnetic attractive force is avoided and the durability of the injector is ensured. It can be easy.

  Further, in this case, the adjustment means sequentially detects the valve opening detection time and adjusts the valve opening delay time by sequentially correcting the voltage application time in a feedback manner based on the valve opening delay time calculated sequentially. It is easy to achieve an accurate valve opening delay time smoothly.

  Further, if the valve opening detecting means for outputting the valve opening detection signal is a vibration detecting means attached to the injector for detecting vibration at the time of valve opening completion, the valve opening detecting means can be reliably opened with a relatively simple configuration. Can be detected. In this case, if the vibration detecting means is attached and connected to the injector control device and controlled to open and close and provided as an injector that outputs a valve opening detection signal, the above-described system can be easily realized. it can.

  According to the present invention, the valve opening delay time is obtained based on the detected valve opening detection signal, and the control is performed with the minimum voltage application time required to achieve an accurate valve opening delay time. It is possible to avoid the generation of an excessive electromagnetic attractive force without damaging, and it is possible to ensure high durability of the injector.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

    FIG. 1 shows a simplified layout of a fuel injection system 1A in which an injector control device 10A of the present embodiment is arranged. The fuel injection system 1A includes an injector 20A for injecting fuel into an internal combustion engine, and Injector control apparatus 10A for performing injector control (fuel injection control) by opening valve by applying drive voltage from battery 30 to solenoid 21 that is electrically connected to injector 20A and electromagnetically attracts the valve body. Is arranged.

  The injector control device 10A includes an interface 11 to which various detection signals and driving power are input, and a microcomputer 12 connected to the interface 11 and connected to the injector 20A. This injector control device 10A is an injector control device in which a control program for executing an injector control method described in detail below is stored in an electronic control unit (ECU) having various functions such as other engine control. It may also serve as.

  Then, a vibration detector 22 as a valve opening detecting means is attached to the injector 20A that is connected to the injector control device 10A and performs drive control thereof, and the detection signal is input to the injector control device 10A. This is a characteristic part on the bird face in the present invention. The vibration detector 22 detects and outputs a specific vibration of a predetermined frequency that is generated when the movable core on the valve shaft base end side is attracted and moved by an excited solenoid and collides with a stopper when the valve is opened. It is.

  On the other hand, in the injector control method executed by the injector control apparatus 10A, the part described in detail below is the characteristic part of the software aspect of the present invention. That is, in the conventional example, the voltage application time required to obtain a predetermined adsorption force for opening the injector 20B is determined based on the detected battery voltage value, and the voltage is applied to cope with other fluctuation factors. The problem was that an excessive load was applied to the injector 20B by setting the application time more than necessary.

  On the other hand, in the present embodiment, not only the battery voltage value is detected and the voltage application time is determined, but the valve opening detection signal detected by the vibration detector 22 is used to open the fuel injection signal from the output time. Adjusting means for calculating the valve opening delay time until the valve detection signal is detected by the valve opening delay time calculating means and adjusting the valve opening delay time so as to realize a target accurate valve opening delay time based on the valve opening delay time. In addition, the control is executed in the direction of the minimum voltage application time that can ensure a reliable valve opening operation while realizing an accurate valve opening delay time.

  The microcomputer 12 stores a control program for executing the injector control method of the present embodiment, and the microcomputer 12 functionally realizes the above-described means by this control program. The valve opening delay time calculating means has a timer function, and measures the time when the fuel injection signal is output and the time when the valve opening detection signal is detected, and calculates the valve opening delay time therefrom. .

  Then, the adjustment means uses the detected valve opening detection signal and the valve opening delay time calculated from the detected valve opening delay time in order to lead the detected actual valve opening delay time to the target accurate valve opening delay time. Thus, the valve opening delay time is adjusted by successively correcting the voltage application time in a feedback manner toward the target valve opening delay time. The target valve-opening delay time is set to a target value that is the most appropriate valve-opening time for the condition by a predetermined derivation method from various detected data, in addition to the case where a predetermined numerical value is set in advance. If it is set, more accurate control can be realized.

  The software features of the present invention will be described in more detail with reference to the flowchart of FIG. 2 and the time chart waveform diagrams of various signals in FIG. First, the injector control device 10A applies a solenoid drive voltage determined based on the detected battery voltage (A1). Then, as shown in FIG. 3, a delay time is generated until the injector 20A opens, but the completion of the valve opening is detected and detected by the vibration detector (A2).

  Then, the injector control device 10A calculates a valve opening delay time that is a delay time from the application of the voltage by the valve opening delay time calculating means to the completion of the valve opening (A3). The minimum necessary voltage application time required to realize an accurate valve opening delay time is derived (A4), and control is performed with the voltage application time adjusted from the output of the next fuel injection signal (A5).

  By adopting such control, even if there are fluctuation factors other than fluctuations in the battery voltage value, accurate injector control is performed by setting the minimum necessary voltage application time to achieve an accurate valve opening delay time. can do. Further, since the minimum voltage application time is set as described above, an excessive electromagnetic attraction force is not generated in the solenoid 21, so that an excessive load is avoided on the components of the injector 20A. It is possible to prevent a decrease in durability due to deterioration or wear.

  As described above, according to the present invention, the injector control in the fuel injection system can avoid the generation of an excessive electromagnetic attractive force without impairing the controllability of the injector, and the high durability of the injector can be secured.

The system layout figure of embodiment in this invention. The flowchart for demonstrating the effect | action of the injector control apparatus of FIG. The waveform diagram of each signal common to the present invention and the conventional example. The system arrangement | positioning figure of a prior art example.

Explanation of symbols

1A fuel injection system, 10A injector control device, 11 interface, 12 microcomputer, 20A injector, 21 solenoid, 22 vibration detector, 30 battery

Claims (4)

  An injector control device, which is disposed in a fuel injection system of an internal combustion engine and opens and closes an injector while switching on / off of a fuel injection signal while opening the injector by electromagnetic attraction force of a solenoid by applying a voltage. A valve opening delay time for calculating a valve opening delay time from when the fuel injection signal is output until the valve opening detection signal is detected after the valve opening detection signal from the valve opening detecting means for detecting valve completion is input. A calculation means; and an adjustment means for adjusting the valve opening delay time to the target valve opening delay time, and the target valve opening delay time while ensuring a reliable valve opening operation. An injector control device that performs control based on a minimum voltage application time required to achieve the above.   The adjustment means adjusts the valve-opening delay time by sequentially correcting the voltage application time in a feedback manner based on the valve-opening delay time sequentially detected and sequentially calculated from the valve-opening detection signal. 1. The injector control device according to 1.   The injector control device according to claim 1 or 2, wherein the valve-opening detecting means is a vibration detecting means that is attached to the injector and detects vibration when the valve-opening is completed. An injector that is provided with the vibration detecting means, is connected to the injector control device according to claim 3, is controlled to open and close, and outputs a valve opening detection signal.

Images