JP2004108273A - Electric device and control system with the electric device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow individual data corresponding to the injection characteristics of injectors to be surely detected by a control unit making a pair with the individual data. <P>SOLUTION: This electric device comprises an individual data storage part 5 storing the individual data in the injectors 11 and a switching part 4 switched so as to connect either of the solenoid 3 of the injector 11 or the individual data storage part 5 to a terminal part 2 receiving signal lines 131 and 132 connecting the injector 11 to an ECU 12 according to control signals inputted from the ECU 12. By this, the signal lines 131 and 132 are shared between those for driving the solenoid 3, for feeding power to the individual data storage part 5, and for outputting individual data to facilitate the structure. Also, the individual data is transmitted to the ECU 12 in the state of the injector connected to the ECU 12 so that the individual data of the ECU 12 can be aligned with the injector 11. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electric device having an actuator function and a sensor function and a control system having the same, and more particularly to a reduction in variation between electric devices.
[0002]
[Prior art]
2. Description of the Related Art Today, an internal combustion engine of a vehicle includes an engine assembly mounted in an engine room including various electric devices. As the electric devices, there are an injector having an actuator function that operates in response to a drive signal, a throttle valve, and the like. There are various sensors having a sensor function of outputting a detection signal. These injectors and sensors are connected to a control unit in the vehicle cabin via a signal line, and form a control system with the control unit. The control unit captures detection signals from various sensors, and outputs a drive signal to an injector or the like based on the detection signals.
[0003]
By the way, in order to improve the accuracy of fuel injection, it is important that the characteristics of components such as injectors have small variations among individuals, and much effort has been made in terms of component production technology, but also in terms of control. Various contrivances have been made. That is, the injection characteristics of each injector are tested in advance, and individual data of each injector based on the characteristic test results are stored in the control unit of the fuel injection control system in which the injector is used, and the individual data is stored in the individual data. There is a technology that corrects the drive signal based on the above, and cancels out the variation in the injection characteristics of the injector. In this technique, means for specifying the injection characteristics of each injector are provided. For example, there is one in which individual data is encoded and represented on the injector surface. In this example, the code is read by a code reader, and the data of the read code is written to the ROM of the control unit, so that the individual data of the injector can be used for correction by the control unit (see Patent Document 1).
[0004]
[Patent Document 1]
JP-A-7-332142
[Problems to be solved by the invention]
By the way, an injector and a control unit having a ROM in which individual data of the injector are stored must always be paired. However, unlike the engine assembly mounted in the engine room, the control unit having the ROM is mounted in the vehicle interior, so that the injector and the control unit are assembled in a separate process. For this reason, there is a possibility that the injector and the control unit having the ROM in which the individual data is stored may be inconsistent, and a considerable burden is imposed on the operator when reading the code or writing the ROM.
[0006]
Also, after the control unit comes to market, it is necessary to plan measures for product failures and system failures, and to make small changes to improve the level, and it is necessary to rewrite data every time, ROM writers and code readers must be deployed in the market.
[0007]
The present invention has been made in view of the above circumstances, and has as its object to provide an electric device and a control system in which the correspondence between the electric device and the control unit is accurate and which has a simple configuration.
[0008]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided a function unit provided with an actuator function that operates by receiving a drive signal from the outside via a terminal unit or a sensor function of outputting a detection signal to the outside via a terminal unit; In an electric device having an individual data storage unit capable of storing individual data corresponding to the characteristics of the functional unit and outputting the individual data,
There is provided switching means for switching either the functional unit or the individual data storage unit so as to be connected to the terminal unit in accordance with the type of a control signal input from the outside via the terminal unit.
[0009]
In a state where the electric device and the control unit are connected by a signal line, the control unit takes in the individual data of the electric device, so that the individual data used for correction in the control unit and the individual data connected to the control unit are connected. The combination with the electric device is correctly determined.
[0010]
Further, in the terminal portion, a terminal for outputting individual data from the individual data storage portion or a terminal for supplying power to the individual data storage portion can be shared with a terminal for a drive signal or a detection signal of the functional portion, The configuration can be simplified.
[0011]
According to a second aspect of the present invention, in the configuration of the first aspect, the terminal portion includes a pair of terminals,
The pair of terminals are positive and negative terminals for the drive signal or the detection signal of the functional unit,
And one terminal of the pair of terminals is a terminal for supplying power to the individual data storage unit and the switching unit;
The other terminal of the pair of terminals is a terminal for outputting the individual data.
[0012]
Both the output terminal of the individual data and the power supply terminal of the individual data storage unit can be shared with the drive signal or detection signal terminal of the functional unit, so that the configuration can be further simplified.
[0013]
According to a third aspect of the present invention, the control system is connected to the electric device according to any one of the first and second aspects, and the terminal device is connected to the electric device via a signal line, and a drive signal for the functional unit is provided. And a control unit for receiving an output or a detection signal.
[0014]
By constructing a control system using the small-sized electric device having a terminal portion, the number of signal lines can be reduced, and the configuration of the control system can be simplified.
[0015]
According to a fourth aspect of the present invention, in the configuration according to the third aspect of the present invention, the control unit is supplied with a power supply through the signal line and a terminal of the electric device, to the functional unit having a different voltage value. Power supply switching means for switching between a power supply and a power supply of the individual data storage unit;
The switching means of the electric device is provided with voltage detecting means for detecting a power supply voltage supplied via a terminal portion as the control signal. The connection destination of the terminal unit is switched between the unit and the unit.
[0016]
Since the switching of the power supply directly changes the type of the control signal, there is no need to separately output a control signal on the signal line, and the configuration of the control system can be further simplified.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a fuel injection control system for an engine to which an electric device and a control system according to the present invention are applied. The injector 11 is mounted as one of electric devices on an engine assembly mounted in an engine room, and injects, for example, high-pressure fuel from a common rail into a cylinder. The injector 11 is an actuator that switches between injection and stop by raising and lowering a needle in a nozzle by an attractive force generated by excitation of a solenoid 3 as a functional unit. Although only one cylinder is illustrated, injectors having substantially the same configuration are provided for each cylinder in a one-to-one correspondence, and an ECU 12 which is a control unit common to all injectors, and a fuel injection control system Is composed. Hereinafter, as for the injector, for convenience of description, only the illustrated injector 11 will be appropriately referred to. The ECU 12 is mounted on the vehicle compartment side separated from the engine room, and is connected to the injector 11 by signal lines 131 and 132.
[0018]
There are basically two signal lines 131 and 132 for each injector, and one end thereof is electrically connected to a pair of terminals 21 and 22 of the injector 11 in a one-to-one correspondence. The terminal section 2 of the injector 11 is constituted only by these terminals 21 and 22. The terminals 21 and 22 and one ends of the signal lines 131 and 132 are connected by a connector structure at the base end of the injector 11 as in a general injector. The other ends of the signal lines 131 and 132 are electrically connected to the terminals of the ECU 12. One of the two signal lines 131, 132 is assembled in the middle to form a single signal line, which the ECU 12 receives at a single terminal. Hereinafter, the signal line 131 is referred to as a common signal line 131 and the signal line 132 is referred to as a cylinder-specific signal line 132, as appropriate.
[0019]
The ECU 12 basically has a microcomputer configuration, and includes a CPU 61, an injector drive current generation unit 71 that is a power supply for driving the solenoid 3, and the like. In addition to the injector 11, it is connected to various sensors (not shown) of each part of the engine assembly. The CPU 61 determines the drive timing and drive time of the solenoid 3 corresponding to the fuel injection timing and the injection amount based on the detection signals of the engine state such as the throttle opening based on these sensors, the engine speed, the fuel pressure in the common rail, and the like. The injector drive current generator 71 outputs a drive signal to the solenoid 3 via the signal lines 131 and 132 and the terminal 2 based on the calculation result. The drive signal is a voltage output of 12 V or 24 V which is a battery voltage. During the output period, the injector 11 is opened by excitation of the solenoid 3 and fuel is injected. The voltage output to the solenoid 3 is output with the terminal 21 side of the injector 11 being positive. Hereinafter, the terminal 21 is referred to as a positive terminal 21 and the terminal 22 is referred to as a negative terminal 22 as appropriate. Further, the description will be made on the assumption that the voltage value of the drive signal is 12V.
[0020]
In the calculation of the drive timing and the drive time, individual data corresponding to the injection cylinder number is read from the backup RAM 62, and the drive timing and the drive time of the solenoid 3 are corrected. The individual data is, for example, an offset amount between the drive timing and the drive time, and a method known as a known fuel injection control correction method can be employed.
[0021]
Next, a configuration that is a characteristic part of the injector 11 and the fuel injection control system and is used for transmitting individual data from the injector 11 will be described. The injector 11 has an individual data storage unit 5 for storing individual data of the injector 11. The individual data storage unit 5 includes a data storage circuit 51 and a data communication circuit 52.
[0022]
The data storage circuit 51 includes an EEPROM, into which individual data is written in the last step of the manufacturing process of the injector 11. That is, a characteristic test relating to fuel injection is performed for each completed injector 11, and a deviation from the reference fuel injection characteristic is determined from the characteristic test. A correction amount is set based on the deviation, and the correction amount is written as individual data in the EEPROM.
[0023]
The data communication circuit 52 is a circuit for transmitting individual data, and the output part of the individual data is connected to the negative terminal 22 of the terminal unit 2. When power supply to the individual data storage unit 5 is started, the individual data is transmitted on the cylinder-specific signal line 132 via the negative terminal 22 at a predetermined timing, and is received by the ECU 12. Power is supplied to the individual data storage unit 5 from the ECU 12 via a switch circuit 41 and a positive terminal 21 described later.
[0024]
As described above, the terminal unit 2 including only the two terminals 21 and 22 is used not only for supplying power to the solenoid 3 but also for supplying power to the individual data storage unit 5 and for outputting individual data. Can be A switching unit 4 is provided as switching means for connecting either the solenoid 3 or the individual data storage unit 5 to the terminal unit 2.
[0025]
FIG. 2 shows an electrical configuration in the injector 11. The switching unit 4 includes a switch circuit 41 and a voltage detection circuit 42 as voltage detection means. The switch circuit 41 has a switch 413 connected in series to the solenoid 3 and turns on and off the application of voltage to the solenoid 3 from between the terminals 21 and 22. Further, two transistors 411 and 412 are connected in series between the positive terminal 21 and the individual data storage unit 51, and constitute a switch circuit 41 together with the switch 413. The power supply from the first terminal 21 to the individual data storage unit 5 is turned on / off by the transistors 411 and 412. The circuit in the injector 11 is grounded by body earth.
[0026]
The power supply voltage of the individual data storage unit 5 that is turned on and off by the transistors 411 and 412 is a control signal for the switch 413. The switch 413 is a normally closed switch, and is turned off (open) when the transistors 411 and 412 are turned on.
[0027]
The voltage detection circuit 42 switches on and off the transistors 411 and 412, and comparators 421 and 422 that supply output currents to the bases of the transistors 411 and 412 are provided in one-to-one correspondence with the transistors 411 and 412. It is. The potential obtained by dividing the potential of the positive terminal 21 by the resistors 423 and 424 is input to the + input terminal of the first comparator 421, and the positive terminal 21 is input to the − input terminal of the second comparator 422. Is input by the potential divided by the resistors 425 and 426. The resistance values of the resistors 423 to 426 will be described later.
[0028]
Further, the potential of the positive terminal 21 is dropped and input by the voltage drop of the resistor 427 to the minus input terminal of the first comparator 421 and the plus input terminal of the second comparator 422. . The input voltage to the − input terminal of the first comparator 421 and the input voltage to the + input terminal of the second comparator 422 are made constant by the Zener diode 428.
[0029]
Next, resistance values of the resistors 423 to 426 will be described. Hereinafter, description will be made assuming that the breakdown voltage of the Zener diode 428 is set to 0.6V. The resistors 423 and 424 that define the input voltage to the + input terminal of the first comparator 421 are such that the resistor 423 on the positive terminal 21 side is 6.5 kΩ and the resistor 424 on the ground side is 1 kΩ. Therefore, when the potential of the positive terminal 21 exceeds 4.5 V, the potential of the + input terminal of the first comparator 421 exceeds 0.6 V and the first transistor 411 is turned on.
[0030]
On the other hand, the resistors 425 and 426 for defining the input voltage to the-input terminal of the second comparator 422 are those in which the resistor 425 on the positive terminal 21 side is 8.2 kΩ and the resistor 426 on the ground side is 1 kΩ. is there. Therefore, when the potential of the positive terminal 21 falls below 5.52V, the potential of the-input terminal falls below 0.6V in the second comparator 422, turning on the second transistor 422.
[0031]
Therefore, when the potential of the positive terminal 21 falls within the range of 4.50 V to 5.52 V, both the transistors 421 and 422 are turned on, the switch 423 is turned off, and power supply to the individual data storage unit 5 is started. You. Then, the individual data is transmitted on the signal line 132 via the negative terminal 22.
[0032]
On the other hand, when a voltage output of 12 V appears as a drive signal for the solenoid 3 at the positive terminal 21, the switch 423 keeps the ON state, the drive voltage is applied to the solenoid 3, and the individual data storage unit 5 Does not work. In this case, since the input voltage to the + input terminal of the first comparator 421 and the input voltage to the − input terminal of the second comparator 422 increase, the potential of the positive terminal 21 is considered in consideration of the specifications of the comparators 421 and 422. The resistance values of the resistors 423 to 426 that determine the voltage ratio and the breakdown voltage of the Zener diode 428 are set.
[0033]
Switching of the output voltage to the common signal line 131 in the ECU 12 will be described. The connection of the common signal line 131 is switched by the first switch 81 to one of the injector drive current generator 71 and the 5V power supply 72 for the CPU 61 and the like.
[0034]
On the other hand, the cylinder-specific signal line 132 for each injector 11 is connected to the cylinder-selection transistor 83 provided in one-to-one correspondence with the cylinder-specific signal line 132 and a common second switch 82. It is connected to one of the injector drive current generator 71 and the CPU 61.
[0035]
The first and second switches 81 and 82 are linked, and are controlled by the CPU 61 to switch. When the first switch 81 is on the injector drive current generator 71 side, the second switch 82 is switched to the injector drive current generator 71 side. When the first switch 81 is on the 5V power supply 72 side, the second switch 82 is switched to the CPU 61 side. The circuit in the ECU 12 is also grounded by body earth.
[0036]
FIG. 3 is a timing chart showing an operation state of the present fuel injection control system. The first half is a time when the transmission process of the individual data is executed, and the second half is a time when the normal fuel injection is performed. The transmission processing of the individual data is executed when the ignition key is turned on. First, the first switch 81 is switched to the 5V power supply 72 side, and the second switch 82 is switched to the CPU 61 side. Further, the cylinder selection switch 83 of the # 1 cylinder is turned on. As a result, a voltage of 5 V is applied from the common signal line 131 to the positive terminal 21 of the injector 11 of the # 1 cylinder, and the individual data storage unit 51 is activated and outputs individual data for the # 1 cylinder as described above. . At this time, since the switch 413 is turned off, the current flowing through the first signal line 131 is prevented from flowing back to the second signal line 132, so that the second signal line 132 is switched from “1” and “0”. It works only for the transmission of individual data. In addition, the disconnection of the solenoid 3 from the common signal line 131 prevents the malfunction of the injector 11. The individual data transmitted to the CPU 61 is stored in the backup RAM 62.
[0037]
In the individual data transmission process, the individual data transmission process is executed when the injector 11 or the ECU 12 is replaced or the control program in the CPU 61 is replaced. Note that the storage area for the individual data does not necessarily need to be the backup RAM, and in that case, the transmission processing of the individual data may be executed every time the ignition key is turned on.
[0038]
When the transmission of the individual data of the # 11 injector 11 is completed, the CPU 61 turns off the # 1 cylinder selection switch 83 and turns on the next, for example, # 3 cylinder selection switch 83. Thus, as in the case of the # 1 cylinder, the individual data of the injector 11 of the # 3 cylinder is transmitted from the individual data storage unit 51 of the injector 11 and written into the backup RAM 62. The individual data output timing of the individual data storage unit 5 of each injector 11 is controlled by timer control based on when the first and second switches 81 and 82 are switched to the 5V power supply 72 and the CPU 61 side. Alternatively, the output time of the individual data from each injector 11 may not overlap, or a multiplex communication system may be constructed by the individual data storage unit 5 and the CPU 61 so that the individual data is sequentially output. . In this way, when the individual data of the actually mounted injector 11 is sequentially written into the backup RAM 62 for all cylinders, the first and second switches 81 and 82 are switched to the injector drive current generator 71 side.
[0039]
As a result, the voltage applied to the positive terminal 21 of the injector 11 becomes 0 V again, the switch 413 is turned on, and the solenoid 3 can be driven. Then, at a predetermined injection timing, a drive signal is output from the injector drive current generation unit 71, a voltage of 12 V is applied to both ends of the solenoid 3, the injector 11 opens, and fuel is injected.
[0040]
As described above, in the present control system, the ECU 12 takes in the individual data of the injector 11 in a state where the injector 11 and the ECU 12 are connected by the signal lines 131 and 132. The combination with the injector 11 connected to the ECU 12 is correctly determined.
[0041]
In addition, if an individual data storage unit is provided on the electric device side, in principle, two terminals and signal lines of the terminal unit of the electric device are used for driving the functional unit (corresponding to a solenoid here). According to the present invention, the positive terminal 21 and the common signal line 131 are used for driving the solenoid 3, one for power supply of the unit and one for output of individual data. The common configuration is used for the power supply of the individual data storage unit 5, and the negative terminal 22 and the signal line 132 for each cylinder are commonly used for driving the solenoid 3 and for outputting the individual data, thereby simplifying the configuration. be able to.
[0042]
When the potential of the positive terminal 21 switches between 5 V and 12 V, this is detected by the voltage detection circuit 42, and the connection of the terminal unit 2 between the solenoid 3 and the individual data storage unit 51 is performed. Therefore, it is not necessary to separately output a control signal for switching to the signal line, and the configuration of the control system can be simplified.
[0043]
Note that the divided voltages of the resistors 423 to 426 of the voltage detection circuit 42 may be input to the comparators 421 and 422 via a delay circuit configured by an integration circuit or the like. In this case, it is possible to prevent the outputs of the comparators 421 and 422 from being inverted while the potential of the positive terminal 21 rises toward 12 V by the output of the drive signal from the injector drive current generation unit 71, and the reliability is improved. Is improved.
[0044]
Although the number of signal lines is reduced by half, an independent signal line may be provided for individual data output depending on required specifications. Even in this case, the number of signal lines is one less than that of four in principle. Further, since the negative terminal and the signal line for each cylinder are specialized for the solenoid, the switch 413 can be omitted on condition that the injector does not operate at 5V. In addition, an independent signal line may be provided for supplying power to the individual data storage unit 5. Even in this case, the number of signal lines can be reduced.
[0045]
Further, the connection of either the solenoid 3 or the individual data storage unit 5 to the connection unit 2 is switched depending on whether the potential of the positive terminal 21 is 5V or 12V. However, the present invention is not limited to this, and a control signal may be separately input to the terminal unit via a signal line, and switching may be performed according to the type.
[0046]
The specific specifications of the present invention are not limited to those described in the above embodiment, and are arbitrary as long as they do not depart from the gist of the present invention.
[0047]
In addition, although attention has been paid to the injector as one requiring correction by individual data, an electric device having another actuator function may be used. Alternatively, the oxygen and NO _x and the like of the pressure sensor and the exhaust gas to detect the fuel pressure in the common rail may be an electrical device having a sensor function of outputting a detection signal as a gas sensor for detecting a gas concentration of a specific component. This is because the operating characteristics vary between individuals.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a fuel injection control system to which the present invention is applied.
FIG. 2 is an electrical configuration diagram of an injector constituting the fuel injection control system.
FIG. 3 is a timing chart showing an operation state of the fuel injection control system.
[Explanation of symbols]
11 Injector (electric device)
12 ECU (control unit)
131 Common signal line (signal line)
132 Cylinder-specific signal lines (signal lines)
2 Terminal part 21 Positive terminal (one terminal)
22 Negative terminal (the other terminal)
3 solenoid 4 switching unit (switching means)
41 switch circuit 42 voltage detection circuit (voltage detection means)
5 Individual data storage unit 61 CPU
62 Backup RAM
71 Injector drive current generator 725 5V power supply 81 Switch (power supply switching means)
82 switch (power switching means)
83 cylinder selection switch

Claims (4)

A function unit provided with an actuator function that receives an external drive signal via a terminal unit or a sensor function that outputs a detection signal to the outside via a terminal unit, and an individual unit according to the characteristics of the function unit In an electric device having an individual data storage unit capable of storing data and outputting the individual data,
Switching means for switching either the functional unit or the individual data storage unit to be connected to the terminal unit according to the type of a control signal input from the outside via the terminal unit is provided. Electric device. The electric device according to claim 1, wherein the terminal portion includes a pair of terminals,
The pair of terminals are positive and negative terminals for the drive signal or the detection signal of the functional unit,
And one terminal of the pair of terminals is a terminal for supplying power to the individual data storage unit and the switching unit;
An electric device, wherein the other terminal of the pair of terminals is a terminal for outputting the individual data. 3. An electric device according to claim 1, further comprising: a control unit connected to the electric device via a signal line at the terminal unit, and outputting a drive signal of the functional unit or receiving a detection signal. Control system. 4. The control system according to claim 3, wherein the control unit is configured to supply power supplied through the signal line and a terminal of the electric device to a power supply of the functional unit having a different voltage value and a power supply of the individual data storage unit. Power supply switching means for switching between a power supply and
The switching means of the electric device is provided with voltage detecting means for detecting a power supply voltage supplied via a terminal portion as the control signal. A control system configured to switch a connection destination of the terminal unit between the terminal unit and the terminal unit.

Images