BR102013004736A2 - fuel injection system - Google Patents

Abstract

tensioner rail for a traction mechanism of a combustion engine and traction mechanism. The invention relates to a tensioner rail (1) for a combustion engine clamping mechanism, wherein it has a sliding surface (2) made of a first material with a support surface of the traction means (3) for the contact of a traction means such as a belt or chain, and it further has a support body (4) made of a second material with a rear side (5) facing away from the support surface of the traction means (3), wherein the sliding surface (2) is made of a plastic material and is fixed to the support body (4), the support body (4) being made of spring steel. The invention also relates to a traction mechanism with a traction means that can be moved along such a tensioner rail.

Description

FIELD OF THE INVENTION The present invention relates to fuel injection systems for internal combustion engines and, in particular, to such fuel injection systems provided with fuel injectors, each integrated with: a sensor to transmit a signal indicative of a level of a measured parameter in correlation with fuel injection characteristics of the corresponding fuel injector; and communications functions with other devices.

BACKGROUND OF THE INVENTION

Fuel injectors, each incorporating a pressure sensor for transmitting the fuel pressure itself and a communications device for communicating with other devices, are known for internal combustion engines, referred to simply as engines, installed in vehicles. A pressure sensor for a fuel injector is an example of a sensor that transmits a signal indicative of a value of a parameter correlated with the fuel injection characteristics of the corresponding fuel injector.

A fuel injector such as this is capable of spraying an appropriate amount of fuel into the combustion chamber of an engine cylinder at an appropriate timing; the amount of fuel to be sprayed and the timing being controlled by an ECU (Electronic Control Unit). A fuel injector like this is also capable of sending an output signal from a pressure sensor to an ECU; the output signal representing the fuel pressure at the fuel injector. A fuel injector such as this is additionally capable of communicating data with the ECU via the communications device.

Specifically, a fuel injector pressure sensor measures the fuel pressure at the fuel injector and sends a signal indicating the measured pressure to the ECU. The ECU receives the signal sent from the pressure sensor and monitors the change in fuel pressure at the fuel injector caused by fuel spraying. Based on the monitored change in fuel injector fuel pressure, the ECU computes an actual fuel spray start time and an actual amount of fuel sprayed from the fuel injector.

In these fuel injectors, a type of fuel injectors, which incorporates a memory in themselves, is also known. In the memory of each fuel injector of this type, parameter values correlated with the fuel injector fuel injection characteristics are previously measured to be stored at the time of shipment. Thus, if a fuel injection system is provided with fuel injectors of this type for an engine, an ECU is able to access the fuel injector memories through its communication devices to recognize the characteristic values of each injector's parameters. of fuel. Thus, the ECU is capable of controlling the fuel injectors based on variations in the characteristic values of the parameters of the respective fuel injectors. There are two different approaches to how to communicate communicatively between a plurality of fuel injectors and an ECU in a fuel injection system. The first approach is to individually connect the respective sensors of the plurality of fuel injectors to the ECU via respective sensor output lines and to individually connect the respective communication devices of the plurality of fuel injectors to the ECU via respective communication lines. The second approach is to individually connect the respective sensors of the plurality of fuel injectors to the ECU via respective sensor output lines and to connect the respective communications devices of the plurality of fuel injectors to the ECU via a common communications line. The second approach reduces the number of communications lines and communications ports compared to the first approach and therefore the second approach is superior to the first approach at the point of fuel injection system simplification.

In the fuel injection system established based on the second approach, communications data sent from the ECU is received by the communications devices of all fuel injectors. Thus, if the ECU wishes to send communications data to a specified fuel injector as its destination, the ECU adds, in the communications data to be sent, a node ID that uniquely identifies the specified fuel injector. As a result, if the fuel injector communications device receives communications data containing the node ID, the communications device determines whether the received communications data is directed to the corresponding fuel injector using the node ID contained in the communications data received.

For example, these unique node IDs are assigned to their fuel injectors, and correlations between unique node IDs and their fuel injectors are stored in advance in the ECU. This makes it possible for the ECU to communicate with each of the fuel injectors according to a corresponding node ID of the node IDs.

Here, consider the following: A first fuel injector with a first node ID must be attached to a first cylinder, and a second fuel injector with a second node ID must be attached to a second cylinder. Correlations between the first and second node IDs and their respective first and second fuel injectors are recorded in advance in the ECU.

In this regard, if the first fuel injector was erroneously attached to the second cylinder and the second fuel injector was erroneously attached to the first cylinder, the actual correlations between the first node ID and the second fuel injector and between the second node ID and the first fuel injector would differ from the correlations recorded earlier in the ECU.

Furthermore, in this regard, if the first fuel injector was replaced by a third fuel injector with a third node ID after system shipment, the actual correlations between the third node ID and the third fuel injector and between The second node ID and the second fuel injector would also differ from the correlations recorded earlier in the ECU. In order to address these problems, a fuel injection system disclosed in Japanese Patent Application Publication 2012-2212 is known. As stated, the known fuel injection system is provided with a plurality of fuel injectors, each incorporating a pressure sensor and a communications device, and an ECU is individually connected to: the respective fuel injector pressure sensors via respective sensor output lines; and the respective fuel injector communications devices via a common communications line.

In addition, the well-known fuel injection system is configured to perform a task of giving single node IDs to the respective fuel injectors after the electrical connections between the ECU and the fuel injectors have been completed.

In particular, the fuel injection system is provided with a state setting circuit configured to set the state of each sensor output line to one of: a normal state in which metered signals are allowed to be transferred via one line. corresponding output line of the sensor output line; and a specific state in which measured signals are disabled from being transferred via a corresponding output line of the sensor output line. The ECU controls the state setting circuit such that a sensor output line connected to a fuel injector selected as a target to set node ID is set to the normal state and the remaining sensor output lines connected to the injectors. remaining fuel sources not selected as the target for setting node IDs are set in the specific state. Subsequently, the ECU sends an ID definition instruction that includes a node ID corresponding to the selected fuel injector via the normal state sensor output line. Thus, upon receipt of an ID setting instruction, each fuel injector queries the state of the sensor output line connected to it and determines whether the received ID setting instruction is directed to the corresponding fuel injector based on it. in the query results. Thus, even if an ID setting instruction does not include information indicative of the target fuel injector for setting node IDs, it is possible to easily give node IDs to the respective fuel injectors.

SUMMARY OF THE INVENTION

It has been found that there are requirements that must be met in the known fuel injection system.

Specifically, if there were abnormalities in some circuits of the corresponding pressure sensors up to the ECU, regular control of the state setting circuit may not switch the sensor output lines included in the abnormal circuits between the normal state and the specific state.

For example, in this abnormal case, the sensor output line connected to the target fuel injector to which an ID assignment instruction is directed may not be switched from the normal state to the specified state. As another example, in this abnormal case, one or more sensor output lines connected to non-target fuel injectors to which an ID assignment instruction is not directed may be erroneously switched from the normal state to the specified state.

Furthermore, in this abnormal case, additional control of the state setting circuit to switch the state of the sensor output lines included in the abnormal circuits may cause the abnormal circuits to be additionally faulted.

In view of the foregoing circumstances, an aspect of the present invention seeks to provide a fuel injection system provided with a plurality of fuel injectors, each incorporating a sensor for transmitting a signal indicative of a level of a measured parameter in correlation with a fuel injection characteristic of the corresponding fuel injector; The fuel injection system is designed to meet at least one of the above requirements.

Specifically, an alternative aspect of the present invention is to provide a fuel injection system such as this which may reduce, even if there is an abnormality in at least one circuit that electrically connects a corresponding sensor and controller, including adverse effects due to the abnormality. in the fuel injection system.

In accordance with an exemplary aspect of the present invention, there is provided a fuel injection system in which a controller is communicatively connected to a plurality of injectors via a common communication line and drives the plurality of injectors to inject fuel into an engine. . The fuel injection system includes a plurality of sensors incorporated into the plurality of injectors, respectively, and electrically connected to the controller by a plurality of circuits including a plurality of output lines (LS), respectively. Each sensor is designed to transmit to the controller, via a corresponding line of output lines, a signal indicative of a level of a measured parameter in correlation with a fuel injector characteristic of a corresponding injector of the plurality of injectors. The fuel injection system includes a concession unit for providing communications data destination information to each injector via a corresponding line of output lines by forcibly varying the output signal from at least one of the sensors via of at least one corresponding line of the output lines. The fuel injection system includes a sending unit for sending the communications data to each injector via the common communications line while the communications data destination information is being granted to each injector or has been completely granted. to each of the injectors. The fuel injection system includes a first determination unit provided on each injector to receive the communications data and to determine whether a task based on the communications data is performed as a function of the destination information given to a corresponding injector of the injectors. injectors. The fuel injection system includes a diagnostic unit to diagnose if there is an abnormality in at least one of the circuits before the granting unit provides the communications data destination information to each injector. The fuel injection system includes a second determination unit for determining whether the communication data destination information granting unit is disabled for each of the injectors based on a diagnostic result.

Specifically, the fuel injection system according to the exemplary aspect of the present invention is configured such that each injector is equipped with a sensor and the sensors of the respective injectors are electrically connected to the controller via respective output lines. . The injectors are communicatively connected to the controller via the common communications line.

In this fuel injection system, the concession unit provides communications data destination information to each injector via a corresponding line of output lines by forcibly varying the output signal from at least one of the sensors by means of at least one corresponding line of output lines. Thus, when the first determining unit of each injector receives the communications data sent from the sending unit, the first determining unit determines whether the task is based on the communications data as a function of the destination information given to a corresponding injector injector.

At this time, if there is an abnormality in a circuit that connects one of the sensors to the controller via a corresponding line of output lines before the granting unit provides the communications data destination information to each of the injectors, the unit Diagnostic diagnostics diagnose if there is such an abnormality in the circuit. Then, the second determination unit determines whether the communication data destination information granting unit is disabled for each of the injectors based on a diagnostic result. For example, because it is diagnosed by the diagnostic unit that there is such an abnormality in the circuit, the second determining unit may disable the granting unit of the communication data destination information to each of the injectors.

Thus, this fuel injection system avoids adverse effects due to forced signal variation operation and concession operation by the concession unit, and prevents forced variation of the output signal from at least one of the sensors by at least a corresponding line of the output lines.

BRIEF DESCRIPTION OF DRAWINGS

Other aspects of the present invention will be apparent from the following description of an embodiment with respect to the accompanying drawings, in which: Fig. 1 is a general schematic structure of a fuel injection system for an internal combustion engine according to a first embodiment of the present invention; Fig. 2 is a schematic structure of an injector and that of an ECU illustrated in Fig. 1; Fig. 3 is a timing graph schematically illustrating an ID assignment routine according to the first embodiment; Fig. 4 is a flowchart schematically illustrating an ID grant routine in the ID assignment routine performed by the ECU according to the first embodiment; Fig. 5 is a flow chart illustrating schematically a subroutine of an abnormality diagnostic task in step SI05 of Fig. 4; Fig. 6 is a flowchart schematically illustrating an ID acceptance routine in the ID assignment routine performed by a communications processor of each injector illustrated in Fig. 1; Fig. 7 is a timing graph schematically illustrating how voltages on respective sensor output lines vary for each of the first case of voltages being abnormal and the second case of voltages being normal; Fig. 8 is a timing graph schematically illustrating an ID assignment routine according to a second embodiment of the present invention; Fig. 9 is a flowchart schematically illustrating an ID grant routine in the ID assignment routine performed by the ECU according to the second embodiment; Fig. 10 is a flowchart schematically illustrating an ID acceptance routine in the TD assignment routine performed by a communications processor of each injector according to the second embodiment; Fig. 11 is a flowchart schematically illustrating an ID grant routine in an ID assignment routine performed by the ECU according to a modification of the second embodiment; and Fig. 12 is a flowchart schematically illustrating an ID acceptance routine in the ID assignment routine performed by a communications processor of each injector according to the modification of the second embodiment.

DETAILED DESCRIPTION OF THE INVENTION MODES

Embodiments of the present invention will be described below with reference to the accompanying drawings. In these embodiments and their modifications, equal parts thereof, to which equal reference characters are assigned, are omitted or simplified to avoid redundant description.

First Mode A fuel injection system which is installed on a vehicle equipped with a four-cylinder engine as an example of multi-cylinder engines in accordance with a first embodiment of the present invention will be described below. The fuel injection system includes an ECU, and drives, under ECU control, a plurality of fuel injectors to deliver an appropriate amount of fuel within the combustion chamber of a selected cylinder of an internal combustion engine. This burns the mixture of compressed air and fuel in the combustion chamber thus changing the fuel energy to mechanical energy used to drive the vehicle.

Referring to Fig. 1, the fuel injection system includes an injector, i.e. a fuel injector 10 provided for each engine cylinder, an EDU (Electronic Drive Unit) 30 controllably connected to each injector 10 and an ECU 50 to control the EDU 30 to individually control the drive of each injector 10.

Note that in this embodiment, the engine is designed as a four-cylinder engine, and four injectors 10 are provided for the respective four-cylinder engine. Thus, in order to uniquely identify the injectors 10, the four cylinders are represented as first to fourth cylinders # 1 through # 4, and the injector 10 provided for the first cylinder will also be referred to as an injector 10 (# 1). . Similarly, injectors 10 provided for respective second, third and fourth cylinders No. 2, No. 3 and No. 4 will also be referred to as an injector 10 (No. 2), an injector 10 (No. 3) and an injector 10. (# 4). Paragraphs 1 to 4 shall be referred to as cylinder numbers.

For example, each of the injectors 10 is configured to directly inject highly pressurized fuel supplied from a common rail, such as a fuel accumulator, into which highly pressurized fuel is charged.

Specifically, each injector 10 includes an electric VM valve member composed of a spray bore 10a formed at one end of its housing, a nozzle needle 10b, and an electric actuator such as an electromagnetic actuator or piezoelectric actuator 10c. The nozzle 10a of each injector 10 communicates with the compression chamber of a corresponding cylinder; Highly pressurized fuel is supplied to spray hole 10a from a common rail into which highly pressurized fuel is loaded. Nozzle needle 10b is designed to open or close spray hole 10a when activated. Electric actuator 10c is designed to activate nozzle needle 10b when energized to open or close spray hole 10a by moving nozzle needle 10b thereby injecting a controlled amount of highly pressurized fuel into the compression chamber. in a controlled timing.

Furthermore, each injector 10 includes a pressure sensor 11, a memory 13, a communications driver 15, a communications processor 17 and a voltage detector 19. The pressure sensor 11 is operative for measuring the pressure of fuel in a corresponding injector. Specifically, the pressure sensor 11 is comprised of a sensor element 1a and an output circuit 12. The sensor element 10a is connected to the output circuit 12 and provided near the nozzle 10a spray hole 10. The sensor element 11a is operative for measuring fuel pressure in spray hole 10a as a fuel injector characteristics parameter of the corresponding injector and transmitting an analog voltage signal indicative of the measured fuel pressure in spray hole 10a to output circuit 12.

Output circuits 12 of injectors 10 (# 1), 10 (# 2), 10 (# 3), and 10 (# 4) are individually connected to ECU 50 via their respective LS sensor output lines. , that is, LS No. 1, LS No. 2, LS No. 3 and LS No. 4. Each of the output circuits 12 is operative to receive a voltage signal transmitted from a corresponding sensor element 10a and transmitting the transmitted voltage signal from a corresponding sensor element 10a as a Vout output voltage to ECU 50 via a corresponding LS sensor output line.

Referring to Fig. 2, the output circuit 12 of an injector 10 comprises an operational amplifier 12a, a feedback resistor Rf and resistors R1, R2, R3. Operational amplifier 12a has a non-inverting input terminal, an inverting input terminal and an output terminal. The non-inverting input terminal is connected to the output of sensor element 11a and the output terminal is connected to one end of resistor R1 and one end of resistor R2. At the other end of resistor R1, a power supply voltage Vc, for example 5 V is applied from a power supply source (not shown). The other end of resistor R2 is connected to the LS sensor output line. One end of resistor R3 is connected to the other end of resistor R2, and the other end of resistor R3 is grounded. The other end of resistor R2 is connected to the inverter input terminal of operational amplifier 12a via feedback resistor Rf. That is, operational amplifier 12a, feedback resistor Rf, and resistors R1 through R3 serve as temporary storage and a voltage limiter.

That is, because the output terminal of the operational amplifier 12a is negatively feedback at its inverter input terminal, the operational amplifier 12a serves as a temporary storage for adjusting an output voltage Vout to depend on the voltage level of the voltage signal. inserted into the non-inverting input terminal of operational amplifier 12a. Because the 5 V power supply is connected to the output terminal of operational amplifier 12a via resistor R1 and the output terminal is grounded via resistor R3, the output voltage range Vout is limited between 0 V and 5 V; This range is expressed as: 0 V <Vout <5 V. For example, in this mode, the range of the output voltage Vout is limited to between 0.8 V and 4.8 V inclusive; This range is expressed as: 0.8 V <Vout <4.8 V.

Like memory 13, an electrically rewritable nonvolatile memory is used. For example, in this embodiment, an EEPROM® is used as memory 13. A volatile memory, such as an SRAM, may be used as memory 13. In memory 13 of each of the injectors 10, unique information of a corresponding injector 10 is stored in advance. The unique information of an injector 10 includes unique pressure sensor 11 characteristics such as its input-output characteristics, unique injector 10 characteristics such as its input-output characteristics, and an individual number assigned to injector 10. For example, in this embodiment, predetermined individual numbers No. 1 through No. 4 are assigned to the respective injectors 10 (No. 1) through 10 (No. 4) to be stored in their memories 13. Communications trigger 15 is electrically connected to the communications processor 17 so that the communications trigger 10 communicates data with the communications processor 17. The communications trigger 15 is electrically connected to the ECU 50 via an LC communication line. Communications driver 15 is operative to receive communications data transmitted from ECU 50, transmit communications data received to communications processor 17, receive communications data input from communications processor 17 and send communications data input. ECU 50 via the LC communications line. These communications driver 15 operations allow communications between injector 10 and ECU 50. The LC communications line is shared by all injectors 10 (# 1) through 10 (η ° 4). In other words, the communication drivers 15 of the respective injectors 10 (# 1) through 10 (# 4) are communicatively connected to the ECU 50 via the common LC communication line which serves as a common gateway, ie a bus. . The communications processor 17 is designed, for example, as a microcomputer consisting, for example, of a CPU, a ROM, a RAM, an IO (not shown) interface, and the like. The communications processor 17 is operative to receive communications data via the communications driver 15 transmitted from the ECU 50 and to perform various tasks based on the received communications data. For example, upon receiving an instruction signal indicative of the transmission of unique characteristics of injector 10 from ECU 50, the communications processor 17 reads the unique characteristics of injector 10 stored in memory 13. Then, the communications processor 17 sends the unique characteristics of the injector read 10 as response data to the communications data received at the ECU 50 via the LC communications line. Furthermore, upon receipt of an instruction signal indicative of updating of the unique characteristics of injector 10 from the ECU 50, the communications processor 17 records learned characteristics for injector 10 included in the instruction signal in memory 13. This updates the previous injector 10 unique features stored in memory 13 for the learned features of injector 10 as the new unique features of this. Voltage detector 19 is electrically connected to the communications processor 17 and the LS sensor output line at a point Pd. The functions of voltage detector 19 will be described later.

That is, the fuel injection system according to this embodiment is configured such that: communication data transfer between the injectors 10 and the ECU 50 is carried out via the common communication line LC, and transfer of signals from voltage transmitted from the pressure sensors 11 installed on the respective injectors 10 is carried out separately from the common LC communication line by means of the respective LS sensor output lines individually provided for the respective injectors 10. The ECU 50 is composed of a communications driver 51, a microcomputer 53, and input circuits 55. The communications driver 51 is electrically connected to the microcomputer 53 and the communication triggers 15 of the respective injectors 10 via the common communications line LC. Input circuits 55 are electrically connected to the LS sensor output lines, respectively, and are electrically connected to microcomputer 53. Microcomputer 53 is operative for receiving communications data including, for example, unique information from an injector 10 and receiving a voltage signal transmitted from the pressure sensor 11 of an injector 10 by means of a corresponding input circuit 55.

Thus, microcomputer 53 is operative to perform individual fuel injection control for each of the injectors 10. Specifically, microcomputer 53 individually computes an appropriate amount of fuel to be sprayed from each of the injectors 10 and a spray timing fuel level for each of the injectors 10 based on the received communications data and output voltages. The microcomputer 53 then generates fuel injection control signals, that is, injector drive signals, based on the computation results individually for the respective injectors 10, and transmits the fuel injection control signals to the EDU 30. The EDU 30 is electrically connected to the actuators 10c of the respective injectors 10. The EDU 30 is operative to individually send instructions to the actuators 10c of the respective injectors 10, thereby individually energizing their actuators 10c based on the respective injection control signals. of fuel. Each of the energized actuators 10c activates the nozzle needle 10a, thereby injecting an appropriate amount of fuel computed by the ECU 50 into the combustion chamber of a corresponding cylinder at an appropriate timing computed by the ECU 50.

Referring to Fig. 2, microcomputer 53 is integrated with A / D converters 53a provided for respective input circuits 55 and a memory 53b which serves as a data storage unit. A / D converters 53a are electrically connected at the output ends of the respective input circuits 55. Note that in Fig. 2, only one input circuit 55 and corresponding A / D converter 53a are illustrated for simple illustration of ECU 50. Each of the A / D converters 53a is operative to receive the analog voltage signals transmitted from the output circuits 12 of the respective injectors 10 through the respective input circuits 55 and to convert the received analog voltage signals into digital voltages. . Digital voltages representing the fuel pressures measured at the respective injectors 10 are used for microcomputer 53 to control the fuel injection to the respective injectors using the digital voltages.

For example, microcomputer 53 corrects the digital voltage transmitted from each injector 10, that is, the measured fuel pressure transmitted from it, to a digital voltage based on the unique characteristics of a corresponding injector 10 read from it by common LC communication line. The microcomputer 53 then individually controls the fuel injection for each of the injectors 10 as a function of a corrected digital voltage corresponding to the corrected digital voltages.

Like memory 53b, any memory capable of storing data itself can be used. For example, nonvolatile memory or volatile memory can be used as memory 53b. In this embodiment, an SRAM is used as memory 53b so that data is stored in memory 53b while power is supplied to memory 53b from a power supply and data stored in memory 53b is lost when the power supply is locked to memory 53b.

In memory 53b, unique information from each injector 10, which was read from a corresponding injector 10 via the LC common communication line, is stored. As stated, the unique information of an injector 10 includes unique pressure sensor 11 characteristics, such as its input - output characteristics, unique injector 10 characteristics, such as its input - output characteristics, and an individual injector 10 number. That is, the unique characteristics of the pressure sensor 11 of each of the injectors 10 and the unique characteristics of a corresponding injector 10 are stored in memory 53b to correlate with the individual number of a corresponding injector 10 injector. Unique information for each of the injectors 10 will also be referred to below as "management data" for each of the injectors 10.

In the fuel injection system according to this embodiment, the communication drivers 15 provided on the respective injectors 10 and the communication driver 51 provided on the ECU 50 are connected to each other via the common communication line LC. For this reason, when communications data is sent from ECU 50 to injectors 10, communications data is received by all injectors 10. However, ECU 50 has a need to send communications data to some injectors 10 specified as target injectors. . In order to address such a need, the fuel injection system according to this embodiment is configured such that communications data to be communicated between the ECU 50 and an injector 10 as a target injector include a node ID assigned solely to the target injector 10 as target injector identification information 10. Thus, upon receiving the ECU 50 communications data, an injector 10 checks whether the node ID included in the received communications data matches its node ID, making it possible that injector 10 determines whether incoming communications data is directed to it. Furthermore, upon receipt of the injector side communications data 10, the ECU 50 checks which of the node IDs of all injectors 10 match the node ID contained in the received communications data, making it possible for the ECU 50 to determine from which of the injectors 10 the received communications data were sent.

Specifically, the fuel injection system according to this embodiment is configured to perform an ID assignment routine to assign a single node ID to each of the injectors 10 upon completion of the electrical connections between all injectors 10 and the ECU. 50. Next, the ID assignment routine according to this embodiment will be described. The ID assignment routine according to this embodiment includes an ID submission routine for the ECU 50 to send a single node ID to each of the injectors 10 and an ID acceptance routine for each injector 10 to accept an ID. corresponding node ID granted to injector 10 and set the accepted node ID to its node ID. Specifically, the microcomputer 53 of the ECU 50 is programmed to perform the ID granting routine and the communications processor microcomputer 17 of each injector 10 is programmed to perform the ID acceptance routine.

During the start of the ID assignment routine of the ID assignment routine, the ECU 50 microcomputer 53 sends to a target injector an ID assignment instruction that includes a target node ID corresponding to the target injector as communications data. through the common communications line LC, thereby granting the target node ID to the target injector.

For example, in this embodiment, an ID assignment instruction to be sent from the ECU 50 includes, as a target node ID, one of the node IDs to be assigned to the respective injectors 10 (no. 1) to 10 (no. 4), and causes a target injector corresponding to the target node ID to assign the target node ID to the target injector itself as its node ID. However, if ECU 50 has sent an ID assignment instruction that includes a target ID to injectors 10 (# 1) through 10 (# 4) without any devices, neither injector 10 can determine if the ID assignment instruction received is directed to a corresponding injector 10 injector itself.

In view of such a circumstance, the ID granting routine is designed to switch the voltage on each of the LS sensor output lines to one of a first level and a second level other than the first level when sending a ID definition statement. The first level in an LS sensor output line represents that the corresponding injector is not a target injector as the destination of the ID assignment instruction. The second level in an LS sensor output line represents that the corresponding injector is a target injector as the destination of the ID assignment instruction.

That is, information indicating whether the first level or second level is defined on each of the LS sensor output lines represents whether the ID assignment instruction is directed to a corresponding injector injector 10. Thus, the information will be referred to. as the destination information of the ID assignment instruction, and the process for setting the voltage on each of the LS sensor output lines at one of the first level and second level serves as the destination information granting device. The ID granting routine is also designed to send an ID assignment instruction as communication data to the injectors 10 via the common LC communication line while destination information is being applied to each of the injectors 10; The process for sending the ID assignment statement serves as the sending device. The ID acceptance routine of the ID assignment routine is designed so that each injector 10 queries the target information of a corresponding LS sensor output line and determines, depending on the query results, whether to accept an assignment instruction. ID received to perform it; the process serves, for example, as the first determining device. Thus, each injector 10 is able to determine whether a received ID assignment instruction is directed to it by querying the destination information from a corresponding LS sensor output line without checking the information included in the received ID assignment instruction.

More specifically, as shown in Fig. 2, transistors Tr 11 are connected to respective output lines of sensor LS # 1 through LS # 4 and provided on ECU 50. Each of the Tr 11 transistors serves as a switching device. voltage to switch the voltage on a corresponding output line from LS # 1 to LS # 4 sensor output lines to one of the first level and the second level. Moreover, the voltage detectors 19 are provided on the respective injectors 10 (# 1) to 10 (# 4). Each of the voltage detectors 19 serves as a voltage sensing device for measuring voltage on a corresponding output line from sensor lines LS # 1 through LS # 4.

To send an ID assignment instruction to a target injector 10, the ECU 50 microcomputer 53 is configured to: disconnect the Tr 11 transistors connected to the remaining injectors, i.e., non-target injectors 10 to which the ID assignment instruction thus, it is not directed by setting the voltage on each of the LS sensor output lines connected to non-target injectors 10 in the first level; and forcibly wiring the transistors Tr 11 connected to the target injector 10 to which the ID assignment instruction is directed, thereby setting the voltage at the LS sensor output line connected to the target injector 10 at the second level, regardless of the measured sensor level. pressure

LS sensor output lines connected to non-target injectors 10 will be referred to as non-target LS sensor output lines and LS sensor output line connected to target injector 10 will be referred to as target LS sensor output line. The on and off control of the Tr 11 transistor connected to each of the LS sensor output lines provides target information to a corresponding injector injector 10. Thus, the on-off Tr 11 transistor control serves as a concession device. of destination information. The microcomputer 53 of the ECU 50 also serves as a sending device for sending the ID assignment instruction to the injectors 10 via the common LC communications line while the voltages of the non-target sensor output lines are kept at the first level and the voltage of the target sensor output line is kept at the second level. The ID assignment instruction is received by the communications processor 17.

When the communications processor 17 of each of the injectors 10 receives the ID assignment instruction, the voltage detector 19 of each of the injectors 10 is configured to measure voltage on a corresponding output line of the LS sensor output lines. connected to it. The communications processor 17 of each of the injectors 10 then serves as the first determining device for determining whether the voltage measured on a corresponding output line of the LS sensor output lines is maintained at the first level or the second level. Upon determining that the voltage measured at the LS sensor output line is maintained at the first level, the communications processor 17 of an injector 10, that is, a non-target injector 10, discards the received ID assignment instruction. Otherwise, upon determining that the voltage measured at the LS sensor output line is maintained at the second level, the communications processor 17 of an injector 10, i.e. target injector 10, performs the received ID assignment instruction to register the node ID included in the ID assignment statement received in memory 13 as the node ID of the target injector itself 10.

Like transistors Tr 11, NPN Tr 11 transistors serving as a voltage switching device are provided in respective input circuits 55 (see Fig. 2).

Specifically, each of the input circuits 55 is comprised of resistors R11, RI2, transistor NPN Tr 11, and capacitor C11. At one end of resistor RI 2, a power supply voltage Vc, for example 5 V, is applied from a power supply source (not shown). The other end of resistor RI 2 is connected to the transistor collector Tr 11, and the connection point between the other end of resistor RI2 and the transistor collector Tr 11 is connected to the LS sensor output line. The connection point between the other end of resistor RI 2 and the transistor collector Tr 11 is connected at one end of resistor RI 1, and the other end of resistor RI 1 of each of the input circuits 55, which serves as a output end of a corresponding input circuit 55 is connected to microcomputer 53. The connection lines between respective input circuits 55 and microcomputer 53 are grounded via respective capacitors C1 1. The base of each transistor Tr 11 is connected to a microcomputer trigger terminal 53, and the emitter of each of the Tr 11 transistors is grounded. Microcomputer 53 is configured to send a command signal to the base of each of the Tr 11 transistors, thereby changing the voltage on a corresponding LS sensor output line to a level between the first level and the second level, including .

Specifically, when applying a high voltage level Hi on the basis of a Tr 11 transistor provided for an injector 10, the Tr 11 transistor is connected so that a corresponding LS sensor output line connected to the injector 10 is defined in 0 V, regardless of the measured voltage level of pressure sensor 11; 0 V corresponds to the second level exposed. The 0 V, that is the second level, of the LS sensor output line disables a Vout output voltage to be communicated between ECU 50 and injector 10 via the LS sensor output line.

In contrast, when applying a low voltage level Lo to the base of transistor Tr 11 provided for an injector 10, transistor Tr 11 is disconnected so that a corresponding LS sensor output line connected to injector 10 is defined in high level greater than 0 V. The high level, ie the first level, of the LS sensor output line enables a Vout output voltage to be communicated between ECU 50 and injector 10 via the sensor output line. LS For example, the first level is set to be in the Vc power supply voltage range from 0 V to 5 V.

Note that, as shown in Fig. 2, each of the input circuits 55 is provided with a filter circuit composed of resistor R1 1 and capacitor Cl1. The output voltage Vout is transferred via the LS sensor output line. from a pressure sensor 11 is inserted via the filter circuit into the A / D converter 53a connected to the LS sensor output line.

Each of the voltage detectors 19 is designed to measure the voltage on a corresponding LS sensor output line connected to it based on the Vout output voltage of a corresponding pressure sensor 11. For example, the voltage detector 19 provided on a injector 10 is composed of a comparator 19a. The point Pd of the LS sensor output line on injector 10 is connected to a non-inverting input terminal of comparator 19a so that the output of output circuit 12 is supplied as the output voltage Vout of sensor element 1 la of pressure sensor 11. At a comparator inverter input terminal 19a, a preset threshold voltage, which is, for example, set to be close to and higher than 0 V, is entered. An comparator output terminal 19a is connected to the communications processor 17.

That is, the Vout output voltage of sensor element 11a on the LS sensor output line is set at the first level in the range 0 V to 5 V when the transistor Tr 11 connected to it is OFF and is set at the second level, ie is 0 V when the Tr 11 transistor connected to the LS sensor output line is ON.

Thus, when the Vout output voltage input to the non-inverting input terminal is equal to or higher than the preset threshold voltage, comparator 19a transmits a high voltage level Hi to the communications processor 17. Otherwise, when the voltage output voltage inserted into the non-inverting input terminal is less than the preset threshold voltage, comparator 19a transmits a low voltage Lo level to the communications processor 17. The communications processor 17 is configured to determine if the output line of the LS sensor connected to each of the injectors 10 is in a normal state or in a specified state. The normal state on an LS sensor output line corresponds to the first level higher than 0 V, at which the Vout output voltage can be transferred from pressure sensor 11 to ECU 50. In contrast, the state specified on an input line. LS sensor output corresponds to the second level, ie 0 V, at which the Vout output voltage cannot be transferred from pressure sensor 11 to ECU 50.

Note that in this embodiment, the output circuit voltage 12 is configured to be inserted into voltage detector 19 as the output voltage Vout, but the sum of the voltage at the output circuit input 12 and that at its output can be configured to be inserted into voltage detector 19. The ID assignment routine will be described in more detail with respect to the timing graph shown in Fig. 3. Note that in this embodiment, the ID assignment routine is designed to assign Unique node IDs 1, 2, 3, and 4 to their injectors 10 (# 1), 10 (# 2), 10 (# 3), and 10 (# 4), in that order. However, Fig. 3 shows how node IDs 1 and 2 are assigned to the respective injectors 10 (# 1) and 10 (# 2), in this order, for simple illustration of the ID assignment routine. The ID assignment routine is initiated, for example, each time the ECU 50 is activated in response to the ignition of a vehicle ignition key, but may be performed in response to the insertion of an external executive instruction. Normally, that is, initially the potential at the base of each of the transistors Tr 11 is kept at the low voltage level Lo so that the transistors Tr are kept deactivated, ie they are in the normal state.

When ECU 50 is activated, the Vout output voltage of each of the injectors 10 (# 1) and 10 (# 2) shows a pressure measured by a corresponding pressure sensor 11a. ECU 50 Microcomputer 53 selects injector 10 (# 1) as a target injector for assigning node ID 1 on all injectors 10 (# 1) to 10 (# 4), and switches transistor Tr 11 from the input circuit 55 connected on the LS # 1 sensor output line to the activated state from the disabled state at time t10. Switching transistor Tr 11 to the activated state results in voltage at the LS # 1 sensor output line being switched to 0 V, ie the second level from the first level.

After time 10, microcomputer 53 sends an ID assignment instruction to communications triggers 15 of respective injectors 10 (# 1) through 10 (# 4) using communications trigger 51 via the common communications line LC at time tll; The ID assignment instruction includes node ID 1 for target injector 10 (# 1).

Subsequently, when the ID assignment instruction sent from the microcomputer 53 is inserted into the communication processors 17 of the respective injectors 10 (# 1) through 10 (No. 4), the communications processor 17 of each of the injectors 10 (# 1) through 10 (# 4) receives the ID assignment statement. Then, the communications processor 17 of each of injectors 10 (# 1) through 10 (# 4) determines whether the LS sensor output line connected to a corresponding injector from injectors 10 (# 1) to 10 ( No. 4) is in the normal state in which a corresponding Vout output voltage can be reported or in the specified state in which a corresponding Vout output voltage cannot be reported. In other words, the communications processor 17 of each of the injectors 10 (# 1) through 10 (# 4) determines whether a corresponding Vout output voltage is equal to or higher than or below the preset threshold voltage. to limit voltage.

At this time, because the Tr 11 transistors connected on the LS sensor # 2 to # 4 output lines from injectors 10 (# 2) to 10 (# 4) are turned OFF, the communications processor 17 of each One of the injectors 10 (# 2) through 10 (# 4) determines that a corresponding output line from sensor output lines LS # 2 through LS # 4 is in the normal state. Thus, the communications processor 17 of each of the injectors 10 (# 2) through 10 (# 4) discards the received ID assignment instruction without performing the routine, that is, the ID acceptance routine, defined by ID assignment instruction received at time tl2.

In contrast, because transistor Tr 11 connected to injector 10 LS # 1 (# 1) sensor output line is ON, injector 10 (# 1) communications processor 17 determines that LS sensor # 1 output is in the specified state. Thus, the injector 10 communications processor 17 (No. 1) performs the ID acceptance routine defined by the ID assignment instruction received at time t2. Like the ID acceptance routine, injector 10 (# 1) communications processor 17 reads individual number # 1 stored in memory 13 and sends read individual number 1 to ECU 50 via the communications line. common LC as response data at time tl2. Subsequently, injector 10 communications processor 17 (# 1) assigns a node ID 1 (included in the received ID assignment instruction) to injector 10 (# 1) and records node ID 1 in memory 13 in time tl3. Note that in this mode, injector 10 communications processor 17 (# 1) sends individual number 1 to ECU 50 before registering node ID 1 in memory 13. However, injector communications processor 17 10 (# 1) can simultaneously perform a task of sending individual number # 1 to ECU 50 and a task of registering node ID 1 in memory 13, or it can register node ID 1 in memory 13 before send individual number 1 to ECU 50.

When individual number # 1 is sent over the LC communications line, the ECU 50 microcomputer 53 receives individual number # 1 sent to the target injector, i.e. injector 10 (# 1), and stores individual number no. 1 received in memory 53b as information from injector 10 (no. 1) at time tl3. If injector 10 (# 1) information has been stored in memory 53b, microcomputer 53 updates previously stored # 10 injector information to individual number # 1 received as new injector 10 information at time tl3. Subsequently, microcomputer 53 switches transistor Tr 11 connected on the LS # 1 sensor output line to the deactivated state from the time activated state tl4. Thus, the assignment of node ID 1 to the corresponding injector 10 (No. 1) is completed.

After assigning node ID to injector 10 (# 1), assigning node ID 2 to injector 10 (# 2) is performed in the same approach as assigning node ID 1 to injector 10 (# 1) .

Specifically, the microcomputer 53 of the ECU 50 switches transistor Tr 11 of the input circuit 55 connected on the LS # 2 sensor output line to the activated state from the disabled state at time tl5. Microcomputer 53 then sends an ID assignment instruction to communications triggers 15 of respective injectors 10 (# 1) through 10 (# 4) using communications trigger 51 via common LC communication line at time t16 ; The ID assignment instruction includes node ID 2 for target injector 10 (# 2) at time tló.

When the ID assignment instruction sent from the microcomputer 53 is inserted into the communication processors 17 of the respective injectors 10 (# 1) through 10 (No. 4), the communication processor 17 of each of the injectors 10 (No. 1) up to 10 (# 4) receives the ID assignment instruction. Then, the communications processor 17 of each of injectors 10 (# 1) through 10 (# 4) determines whether the LS sensor output line connected to a corresponding injector from injectors 10 (# 1) to 10 ( # 4) is in the normal state or in the specified state.

At this time, because of the Tr 11 transistors connected to the LS # 1, LS # 3, and LS # 4 sensor output lines from injectors 10 (# 1), 10 (# 3), and 10 (No. 4) OFF, the communications processor 17 of each of the injectors 10 (# 1), 10 (# 3), and 10 (# 4) determines that a corresponding output line from the LS sensor output lines No. 1, LS No. 3 and LS No. 4 is in the normal state. Thus, the communications processor 17 of each of the injectors 10 (# 1), 10 (# 3), and 10 (# 4) discards the received ID assignment instruction without performing the routine, that is, the routine. Acceptance ID, defined by the ID assignment instruction received at time tl 7.

In contrast, because the Tr 11 transistor connected to injector 10 LS # 2 (# 2) sensor output line is turned ON, injector 10 (# 1) communications processor 17 determines that the output line of sensor LS # 2 is in the specified state. Thus, the communications processor 17 of injector 10 (# 2) performs the ID acceptance routine defined by the ID assignment instruction received at time t7 in the same approach as the ID acceptance routine for injector 10 (# 1). ) exposed. Thus, individual number # 2 sent by the ID acceptance routine is received by ECU microcomputer 53 to be stored or updated in memory 53b as information from injector 10 (# 2) at time tl 8.

Subsequently, microcomputer 53 switches transistor Tr 11 connected on the LS # 2 sensor output line to the deactivated state from the time activated state tl9. Thus, assignment of node ID 2 to the corresponding injector 10 (No. 2) is completed.

If there is an abnormality, such as a ground fault and a short circuit, in the path that connects the sensor element 11a of an injector 10 to the A / D converter 53a, the sensor output line connected to the abnormal injector 10 may be at the different from the normal state, even though the base potential of the corresponding transistor Tr 11 is set to low Lo.

Similarly, if there is an abnormality, such as a ground fault and a short circuit, in the path that connects the sensor element 1a of an injector 10 to the A / D converter 53a, the sensor output line connected to the abnormal injector 10 may be in a state other than the specified state, even though the base potential of the corresponding Tr 11 transistor is set to the high Hi level.

For example, if there was a ground fault on the LS # 1 sensor output line connected to injector 10 (# 1), the LS # 1 sensor output line will be grounded so that the voltage on the output line LS # 1 sensor is fixed at 0 V. Therefore, injector 10 (# 1) may not determine whether the LS # 1 output line ground connection results from a ground fault in the LS sensor # 1 or Tr 11 transistor activation connected to the LS # 1 sensor output line. Thus, in this case, injector 10 (# 1) will always identify that it is a target injector for Node ID based on voltage at LS sensor # 1 output line, so that node ID assignment to injector 10 (# 1) is performed each time an ID assignment instruction is sent to injectors 10 (# 1) to 10 (# 4). This can make it difficult to assign injector 10 (# 1) a different node ID than the node IDs of other injectors 10 (# 2) to 10 (# 4). This will result in some injectors, including injector 10 (# 1), having the same node ID assigned to them.

For example, if the ID assignment routine for assigning unique node IDs 1 through 4 to the respective injectors 10 (# 1) through 10 (# 4), in this order, is performed while the LS sensor output line is not If 1 was grounded, node ID 4 last assigned to injector 10 (No. 4) will be assigned to injector 10 (No. 1), to which node ID 1 should normally be assigned. In this case, injector 10 (# 1) may be mistakenly activated in response to an instruction sent to injector 10 (# 4) from EDU 30 at timing when injector 10 (# 4) is scheduled to be activated. . This can make it difficult to drive injectors 10 (# 1) through 10 (# 4) in the scheduled order, resulting in an adverse effect on engine operations.

If there was a ground fault on the LS # 1 sensor output line connected to injector 10 (# 1), the precise node ID 1 may not be assigned to injector 10 (# 1) even though the base of the transistor Tr 11 connected to the LS # 1 sensor output line is turned on by the ECU 50. This may waste the wiring operation of the transistor Tr 11 by the ECU 50.

If the # 1 LS sensor output line connected to injector 10 (# 1) is shorted, the # 1 LS sensor output line may be in a state other than the state determined based on the potential at the base of the transistor. Tr 11 connected to the LS # 1 sensor output line. This can make it difficult for injector 10 (# 1) to identify if it is a target injector for node ID assignment, resulting in difficulty in giving the node ID. single node 1 to injector 10 (# 1).

In particular, if the # 1 LS sensor output line connected to injector 10 (# 1) is shorted to the power supply to supply 5 V Vc power supply voltage to the LS # sensor output line. 1, the power supply may cause a large amount of current to flow through the LS # 1 sensor output line in the direction of transistor Tr 11 connected to the LS # 1 sensor output line. large amount of current has exceeded a maximum acceptable value designed for a circuit that electrically connects injector 10 (No. 1), ie pressure sensor 11, to ECU 50, ie AID 53a, by means of LS # 1 sensor output line, the circuit may fail. In order to address these circumstances, the fuel injection system according to this embodiment is configured to: diagnose whether a circuit that connects each of the injectors 10 (# 1) to 10 (# 4) to ECU 50 via a corresponding output line from LS # 1 to LS # 4 sensor output lines fails, based on the voltage on a corresponding output line from LS # 1 to LS # 4 sensor output lines; and disabling ECU 50 microcomputer 53 from performing the ID granting routine. In the following, specific operations of the ID assignment routine including the ID grant routine and the ID accept routine performed by the microcomputer 53 and the communications processor 17 of each injector 10 will be described with reference to Figs. 4 through 6. First, specific operations of the ID granting routine will be described below with respect to Fig. 4. The ID granting routine is performed by the ECU 50 microcomputer 53 at each predetermined cycle after initialization of the routine. ID assignment

In the ID granting routine, microcomputer 53 determines whether it has already performed an abnormality diagnostics task that diagnoses whether there is a voltage abnormality in each of the LS # 1 through LS # 4 sensor output lines for the injectors. 10 (# 1) to 10 (# 4) in step SI00. In this embodiment, an indicator F1 is previously stored in memory 53b; The F1 indicator represents whether the abnormality diagnostic task has been performed. The F1 indicator is, for example, in the form of a bit (ie 0 or 1). An initial value of indicator F1 is set to 0, which represents that the abnormality diagnostics task has not yet been performed. When the F1 indicator is set to 1, this represents that the abnormality diagnostics task has been performed.

Specifically, in step S100, microcomputer 53 queries indicator F1 stored in memory 53b and determines whether indicator F1 is set to 1 based on query results. By determining that the F1 indicator is set to 1 (YES in step SI00), microcomputer 53 determines that the abnormality diagnostics task has been performed, so the ID granting routine skips step S105, going to step S110.

Otherwise, upon determining that the F1 indicator is set to 0 (NOT in step S100), microcomputer 53 determines that the abnormality diagnostics task has not yet been performed, so the ID granting routine proceeds to step SI05. In step SI05, microcomputer 53 performs a subroutine that represents operations specific to the abnormality diagnostic task of step SI05. In the following, the abnormality diagnostics task will be described in relation to Fig. 5. Note that the abnormality diagnostics task subroutine serves, for example, as a diagnostic device.

During launch of the subroutine illustrated in Fig. 5, microcomputer 53 determines whether it is performing the abnormality diagnostics task for any of injectors 10 (# 1) through 10 (# 4) in step S200. In other words, microcomputer 53 determines whether it is sampling a digital voltage value obtained by A / D converter 53a for any of the injectors 10 (# 1) through 10 (# 4) in step S200. Upon determination that microcomputer 53 is not sampling digital voltage values obtained by A / D converter 53a for either of injectors 10 (# 1) through 10 (# 4) (NOT in step S200), the subroutine proceeds. to step S205. At step S205, microcomputer 53 selects one of the injectors 10 that was not subjected to the abnormality diagnostics task as a diagnostic target injector 10 at step S205. Next, in step S210, microcomputer 53 initializes variables Ns and Nd to zero. Variable Ns represents the number of sampled digital voltage values obtained by A / D converter 53a for diagnostic target injector 10. Variable Nd represents the number of increments of an index to determine the abnormality.

Following step S210, microcomputer 53 repeatedly samples a digital voltage value obtained from A / D converter 53a to the diagnostic target injector 10 Nn times; Nn is a predetermined positive value equal to or greater than 2. Microcomputer 53 then determines whether the change in a currently sampled digital voltage value from a previously sampled digital voltage value is greater than a preset value. for each of the Nn times (see steps S220 through S250). Note that if microcomputer 53 samples a digital voltage value obtained by A / D converter 53a for diagnostic target injector 10 for the first time in this subroutine, a previously sampled digital voltage value is set to zero.

Specifically, in step S220, microcomputer 53 increments variable Ns by 1. Next, microcomputer 53 samples a digital voltage value obtained by A / D converter 53a for diagnostic target injector 10 and determines whether the variation by one value The currently sampled digital voltage to a previously sampled value is greater than a preset level in step S230. In other words, the microcomputer 53 determines whether the change in a currently measured value of the output voltage Vout of the pressure sensor 11 of the diagnostic target injector 10 to a previously measured value of the output voltage Vout of this is greater than one level. preset in step S230.

By determining that the change in the currently sampled value of the digital voltage from its previously sampled value is equal to or less than the preset level, so that the output voltage Vout of the pressure sensor 10 of the diagnostic target injector 10 is unlikely. varies (YES in step S230), the subroutine proceeds to step S240. In step S240, microcomputer 53 increments variable Nd by 1 and subsequently performs the operation of step S250.

Otherwise, by determining that the change in the currently sampled digital voltage value from its previously sampled value is greater than the preset level, so that the output voltage Vout of pressure sensor 11 of the diagnostic target injector 10 varies (NOT at step S230), the subroutine skips step S240, going to step S250.

In step S250, microcomputer 53 determines whether the value of variable Ns representing the number of sampled digital voltage values obtained by A / D converter 53a for diagnostic target injector 10 is equal to or greater than the predetermined positive value Nn .

By determining that the value of variable Ns is less than the value of the predetermined positive value Nn (NOT in step S250), microcomputer 53 completes the subroutine diagnostic task. Subsequently, microcomputer 53 repeatedly performs the subroutine diagnostic task until the value of variable Ns, that is, the number of sampled digital voltage values, is equal to that of the predetermined positive value Nn (see steps S200 to S250).

If the value of variable Ns is equal to or greater than the value of the predetermined positive value Nn (YES in step S250), the subroutine proceeds to step S260. In step S260, microcomputer 53 determines whether the value of variable Nd representing the number of index increments for determining abnormality exceeds a preset threshold value in step S260.

By determining that the value of variable Nd exceeds the preset limit value, that is, the number of times the Vout output voltage 10 of the diagnostic target injector 10 hardly varies at step S230 exceeds the preset limit value. -adjusted (YES in step S260), the subroutine proceeds to step S270. In step S270, microcomputer 53 determines that there is a voltage abnormality in the LS sensor output line connected to the diagnostic target injector 10.

Specifically, the microcomputer determines that there is an abnormality in the circuit that electrically connects the diagnostic target injector 10 to ECU 50 via the LS sensor output line connected to the diagnostic target injector by determining that: pressure 10 of diagnostic target injector 10 remains unchanged at 0 V; or the output voltage Vout of the pressure target 10 of the diagnostic target injector 10 remains unchanged at the power supply voltage Vc, for example 5 V; or the output voltage Vout of the pressure target 10 of the diagnostic target injector 10 remains unchanged between 0 V and the power supply voltage Vc, for example 5 V.

After the operation of step S270 is completed, the stanza proceeds to step S285.

Otherwise, upon determination that the value of variable Nd exceeds the preset limit value, that is, the number of times the Vout output voltage 10 of the diagnostic target injector 10 hardly varies in step S230 does not exceed preset limit value (NOT in step S260), the subroutine proceeds to step S280. In step S280, microcomputer 53 determines that there are no voltage abnormalities in the LS sensor output line connected to the diagnostic target injector 10.

Following steps S270 or S280, microcomputer 53 determines whether all injectors 10 (# 1) through 10 (# 4) were subjected to the abnormality diagnostic task in step S285. By determining that not all injectors 10 (# 1) through 10 (# 4) have still been subjected to the abnormality diagnostics task (NOT at step S285), the subroutine resumes for step S200 and repeats operations at steps S200 to S285. Otherwise, upon determination that all injectors 10 (# 1) through 10 (# 4) were subjected to the abnormality diagnostics task (YES in step S285), the subroutine proceeds to step S290. At step S290, microcomputer 53 sets indicator F1 to 1. Subsequently, the subroutine resumes for step S110 in the main routine, that is, the ID granting routine illustrated in Fig. 4.

Upon completion of the diagnosis of abnormality of all injectors 10 (# 1) to 10 (# 4), the microcomputer 53 serves, for example, as a second determination device to determine if there are no abnormalities in the sensor output lines. LS # 1 through LS # 4 of all injectors 10 (# 1) to 10 (# 4) in step SI 10.

By determining that there are no anonymities in the LS # 1 through LS # 4 sensor output lines of all injectors 10 (# 1) to 10 (# 4) (YES in step SI 10), microcomputer 53 enables the following ID grant task (the following operations from steps S120 through SI55). Otherwise, upon determination that there is an abnormality in at least one of the LS # 1 to LS # 4 sensor output lines from injectors 10 (# 1) to 10 (# 4) (NOT in step SI 10) , microcomputer 53 disables the following ID granting task, terminating the ID granting routine.

After affirmative determination, in step SI 10, microcomputer 53 performs the ID granting task.

Specifically, in step SI20, microcomputer 53 selects one of the injectors 10 to which the corresponding node IDs have not yet been granted as an ID assignment target injector. Next, microcomputer 53 serves, for example, as a granting device. to switch the potential at the base of transistor Tr 11 of the input circuit 55 connected to the ID 10 assignment target injector, that is, the corresponding LS sensor output line, to the high voltage level Hi from the low level voltage Lo thus connecting transistor Tr 11 in step SI25. The operation of step SI25 switches the voltage at the LS sensor output line connected on the ID 10 assignment target injector to the second level, that is, 0 V, from the first level, that is, a level higher than 0. V. In other words, the operation of step SI25 switches the LS sensor output line connected on the ID assignment target injector 10 to the specified state from the normal state.

Note that, as stated, the potential at the base of each of the Tr 11 transistors is initially maintained at the low voltage Lo level, so that sensor output lines 10 connected to the other injectors 10 except for the target assignment injector. ID 10, be set at the first voltage level greater than 0 V.

Following step SI25, microcomputer 53 generates an ID assignment instruction that includes a node ID to be assigned to the ID assignment target injector 10, that is, a node ID defined based on the cylinder number corresponding to the injector ID assignment target 10 in step S130. The microcomputer 53 then serves, for example, as a sending device for sending the ID assignment instruction to the common communications line LC using the communications trigger 51 while keeping transistor Tr 11 connected to the ID assignment target injector 10 at enabled state and keeps the Tr 11 transistors connected to the other injectors 10 in the disabled state in step S130.

Subsequently, microcomputer 53 waits until a predetermined period has elapsed since the ID assignment instruction was sent and determines whether response data, such as a response from the sent ID assignment instruction, was received from the communications processor. 17 of the ID assignment target injector 10 for the predetermined period in step SI35.

In this embodiment, as discussed, each injector 10 is designed to send its individual number to ECU 50 as response data to an ID assignment instruction when operating normally.

Upon determining that the individual ID 10 targeting injector number has been received for the predetermined period (YES in step S135), the ID granting routine proceeds to step S140. In step SI40, microcomputer 53 updates the management data for the ID assignment target injector 10 stored in memory 53b using the individual number received from the ID assignment target injector 10. Specifically, as exposed, as the management data, the unique characteristics of the pressure sensor 11 of each of the injectors 10 and the unique characteristics of a corresponding injector 10 injector are thus stored in memory 53b to correlate with the individual number of a corresponding injector 10 injector.

Thus, microcomputer 53 updates the individual number of the ID assignment target injector 10 stored in memory 53b to the individual number received in step SI40. Subsequently, the ID grant routine proceeds to step SI50.

Otherwise, upon determination that the individual ID 10 targeting injector number was not received for the predetermined period (NOT in step SOS), the ID granting routine proceeds to step S145. In step SOS, microcomputer 53 updates the management data for the ID assignment target injector 10 stored in memory 53b by rewriting the individual number of management data for the ID assignment target injector 10 to an error code. Subsequently, the ID granting routine proceeds to step S150.

In step SI50, microcomputer 53 resumes the LS sensor output line connected to the ID assignment target injector 10 to the normal state from the specified state. Specifically, in step SI50, microcomputer 53 switches the potential at the base of transistor Tr 11 of input circuit 55 connected to the ID assignment target injector 10 to low voltage level Lo from high voltage level Hi, thus, turning off transistor Tr 11. Subsequently, the ID granting routine proceeds to step SI55.

In step SI55, microcomputer 53 determines whether the corresponding node IDs have been granted to all injectors 10 (# 1) through 10 (# 4).

By determining that the corresponding node IDs have not yet been granted to all injectors 10 (# 1) through 10 (# 4) (NOT in step SI55), the ID grant routine resumes for step SI20 and performs the step operations SI20 through SI55 until the corresponding node IDs have been granted to all injectors 10 (# 1) through 10 (# 4).

In step SI55, upon determining that the corresponding node IDs have been granted to all injectors 10 (# 1) through 10 (# 4) (YES in step S155), the ID granting routine is terminated. In the following, specific operations of the ID acceptance routine will be described with respect to Fig. 6. The ID acceptance routine is performed by the communications processor 17 of each injector 10 at each predetermined cycle. Note that the ID acceptance routine illustrated in Fig. 6 serves, for example, as the first determining device.

During the initiation of the ID acceptance routine, the communications processor 17 of each injector 10 determines whether communications data is received by communications trigger 15, and the received communications data comprises an ID assignment instruction in step S310. Upon determining that none of the communications data has been received by communications trigger 15 or that the communications data received does not comprise an ID assignment instruction (NOT in step S310), the ID acceptance routine is terminated.

Otherwise, upon determining which communications data is received by communications trigger 15, and the received communications data comprises an ID assignment instruction (YES in step S310), the ID acceptance routine proceeds to step S320.

At step S320, the communications processor 17 measures the voltage at the LS sensor output line connected to a corresponding injector injector 10. For example, at step S320, the communications processor 17 determines whether the high voltage level Hi or the Low voltage level Lo is entered from voltage detector 19.

By determining that the high voltage level Hi is entered from voltage detector 19 (NOT in step S320), communications processor 17 determines that the LS sensor output line connected to a corresponding injector 10 injector is in the state normal. The communications processor 17 then discards the ID assignment instruction received in step S325. Subsequently, the ID assignment routine skips steps S330 and 340, and exits.

Otherwise, upon determining that the low voltage level Lo is entered from voltage detector 19 (YES in step S320), the communications processor 17 determines that the LS sensor output line connected to a corresponding injector 10 injector is in the specified state. Then, the communications processor 17 performs the operation of step S330, for example according to the ID assignment instruction received to read from memory 13, the individual number stored in memory 13, and sends the individual number to the ECU. 50 through communications trigger 15 and common LC communications line in step S330. Next, the communications processor 17 performs the operation of step S340, for example according to the received ID assignment instruction to register the node ID included in the received ID assignment instruction in memory 13 as the node ID of. a corresponding injector from injectors 10. Subsequently, the ID acceptance routine exits. Fig. 7 schematically illustrates how the Vout output voltages of the respective injectors 10 (# 1) and 10 (# 2) vary during the execution of the ID assignment task, as follows: the first case where there is no abnormalities in the circuits that electrically connect injectors 10 (# 1) and 10 (# 2) to ECU 50 via their respective LS # 1 and LS # 2 sensor output lines; and the second case where there is an abnormality in the circuit that electrically connects injector 10 (# 1) to ECU 50 via the LS # 1 sensor output line. Fig. 7 also schematically illustrates how transistors Tr 11 in the respective injectors 10 (No. 1) and 10 (No. 2) are operated in the first and second cases.

For example, as an example of the second case, the LS # 1 sensor output line is shorted to the power supply to supply the 5 V power supply voltage.

Note that, in Fig. 7, the variations in Vout output voltages of the respective injectors 10 (# 1) and 10 (No. 2) and activated-deactivated waveforms from transistors Tr 11 to the respective injectors 10 (No. 1) and 10 (No. 2) in the first case are illustrated by dashed - dotted lines. Moreover, in Fig. 7, the variations in Vout output voltages of the respective injectors 10 (# 1) and 10 (No. 2) and activated-deactivated waveforms from the Tr 11 transistors to the respective injectors 10 (No. 1) and 10 (# 2) in the second case are illustrated by solid lines. Fig. 7 demonstrates that after the ECU 50 is activated in response to the ignition switch on, the sensor Vout output voltage on the LS # 1 sensor output line varies depending on the variation in pressure measured by the corresponding sensor. pressure sensor 1 la in the first case.

However, even after the ECU 50 is activated in response to the ignition switch switching on, the sensor Vout output voltage on the LS # 1 sensor output line is fixed at the 5 V independent Vc power supply voltage. the change in pressure measured by the corresponding pressure sensor 1 la in the second case.

As described above, in the second case, the fuel injection system is configured to disable the potential at the base of each of the transistors 10 (# 1) through 10 (# 4) to be set at the high voltage level Hi, that is, it disables the Tr 11 transistors for all injectors 10 (# 1) through 10 (# 4) to be connected.

Note that if it is diagnosed that there is a voltage abnormality in the LS sensor output line connected to one of injectors 10 (# 1) through 10 (# 4), the fuel injection system according to this mode is set to: disable assignment of node IDs to all injectors 10 (# 1) through 10 (# 4), regardless of the execution of the ID assignment routine; and perform control of the operations of individual injectors 10 (# 1) to 10 (# 4) to spray appropriate amounts of fuel into their respective # 1 through # 4 cylinder compression chambers without regard to management data, such as pressure sensor characteristics 11 and injector characteristics 10 (# 1) to 10 (# 4).

As a modification of this configuration, the fuel injection system can be configured to perform control of individual injector operations 10 (# 1) through 10 (# 4), while still considering management data using the node IDs assigned to respective injectors 10 (# 1) through 10 (# 4) in the previous ID assignment routine.

As detailed above, the fuel injection system according to this embodiment is configured to: diagnose if there is an abnormality in a circuit that electrically connects each of the injectors 10 (# 1) to 10 (# 4) to ECU 50 via a corresponding output line of sensor output lines LS # 1 through LS # 4 (see step SI05 of Fig. 4 and steps S200 to S290 of Fig. 5); enable the execution of the ID assignment task, that is, the ID assignment task, by determining that there are no abnormalities in all circuits connecting injectors 10 (# 1) to 10 (# 4) to ECU 50 (see YES in step SI 10 and steps S120 through S155); and disabling the execution of the ID assignment task, that is, the ID assignment task, by determining that there is an abnormality in at least one circuit connecting at least one injector 10 corresponding to ECU 50 (see NO in step S110) . The setting reduces even if there is an abnormality in at least one circuit that connects at least one injector 10 corresponding to ECU 50, adverse effects due to the abnormality occurring in at least one circuit.

Specifically, the configuration prevents adverse effects due to the bonding of transistor Tr 11 connected to the corresponding at least one injector 10 during the occurrence of an abnormality in at least one circuit. For example, even if an LS sensor output line is shorted, the configuration prevents a large amount of current from flowing through the shorted sensor output line due to activation of an injector connected to the shorted sensor output line. .

In addition, the configuration prevents node IDs from being erroneously assigned to their injectors 10 due to an abnormality occurring in a circuit that connects an injector 10 to ECU 50, thus preventing injectors from being triggered in an unscheduled order. .

Moreover, even if there is an abnormality in a circuit that connects an injector 10 to the ECU 50, the configuration prevents a wasted process for connecting the transistor Tr 11 connected to the abnormal circuit, although the node ID cannot be properly assigned to the injectors. 10. There is a certain amount of time required for an ID assignment instruction sent from the ECU 50 to be received by an ID assignment target injector 10; the period will be referred to below as an instruction transfer period.

In the fuel injection system configuration, which sends an ID assignment instruction to an ID assignment target injector while a corresponding target LS sensor output line is set in the normal or specified state, the transistor Tr is required. 11 connected to the target LS sensor output line is in the activated state for at least the instruction transfer period. At this time, if there is a voltage abnormality in the target LS sensor output line, so that destination information from the ID assignment instruction may not be sent through the target LS sensor output line, the process for turning on the Tr 11 transistor connected to the target LS sensor output line will be wasted, and the instruction transfer period will be wasted. In particular, if an LS sensor output line is shorted to a part of the fuel injection system, current may flow unnecessarily through a shorted passage due to the Tr 11 transistor connected to the shorted sensor output line. LS

However, as stated, the fuel injection system configuration disables the execution of the ID assignment task, that is, the ID assignment task, by determining that there is an abnormality in at least one circuit that connects at least one injector. 10 corresponding to ECU 50. Thus, it is possible to prevent the wasted process, wasted period and unnecessary current flow from occurring.

If an ID assignment instruction was merely sent to injectors 10 via the common LC communication line, each of the injectors 10 may not determine whether the received ID assignment instruction is directed to a corresponding injector 10 injector. because each of the injectors 10 may not determine whether a node ID included in the received ID assignment instruction is directed to which of the injectors 10.

However, the fuel injection system according to this embodiment is configured to: grant destination information of an ID assignment instruction to be sent to each of the injectors 10 as communication data via a corresponding output line of the LS sensor; and sending the ID assignment instruction to the injectors 10 via the common LC communication line while the destination information is being granted to each of the injectors 10.

Because the destination information for one of the injectors 10 specifies one of the injectors 10 as an ID assignment target injector 10 to which the ID assignment instruction is directed, it is possible to precisely assign a desired single node ID to each one. This will properly trigger the injectors 10 according to their timings and scheduled fuel quantities using the precisely assigned node IDs.

Assume that the abnormal diagnostic routine illustrated in Fig. 5 determines that there is a voltage abnormality in an LS sensor output line connected to an injector 10. In this regard, the Tr 11 transistor ligament connected to a sensor output line LS connected to an ID assignment target injector 10 as the destination of an ID assignment instruction may cause some LS sensor output lines to be in the specified state. This can make it difficult to assign unique node IDs to the respective injectors 10 connected to the LS sensor output lines that are in the specified state.

In view of this point, the fuel injection system according to this embodiment is configured to disable the execution of the ID assignment task, ie the ID assignment task, by determining that there is an abnormality in at least one circuit. connecting at least one injector 10 corresponding to the ECU 50.

This setting prevents injectors 10 from improperly triggering according to their timings and unscheduled fuel quantities using node IDs improperly assigned to their injectors 10.

Second Mode A fuel injection system according to a second embodiment of the present invention will be described below. The structure and / or functions of the fuel injection system according to the second embodiment are mainly identical to those of the fuel injection system according to the first embodiment except for the following points. Then the main different points will be described below. The fuel injection system according to the first embodiment is configured to turn each Tr 11 transistor on or off. This sets a second voltage level on a target LS sensor output signal connected to an ID assigning target injector. , referred to simply as a target injector, 10 to which communications data is directed, and a first voltage level at each of the other LS sensor output signals of the other injectors, i.e. non-target injectors, 10 to which communications are not directed. Setting the second voltage level on the target LS sensor output line connected to the target injector 10 provides target information to the target injector 10 to which communications data is directed. Similarly, setting the first voltage level on non-target LS sensor output lines connected to non-target injectors 10 gives destination information to non-target injectors 10 to which communications data is not directed. The fuel injection system according to the first embodiment is also configured to send an injector 10 ID assignment instruction via the common LC communications line as communications data while destination information is being granted to each injector. 10 thus assigning a node ID to the target injector 10.

In contrast, a fuel injection system according to the second embodiment is configured to individually turn on or off the Tr 11 transistors connected to the respective injectors 10. This provides information correlated with a node ID to each of the injectors 10 as input information. so that each of the injectors 10 is configured to recognize a corresponding node ID based on the granted destination information, and assigns an identified node ID to a corresponding injector injector 10. The fuel injection system is thereafter According to the second embodiment it is configured to send communications data to the injectors 10 based on their assigned node IDs.

Specifically, the ECU 50 microcomputer 53 is configured to individually turn on or off the Tr 11 transistors connected to the respective injectors 10 to individually adjust a duration of each of the LS sensor output lines connected to the second level Tr 11 transistors, that is, the specified state, such that the durations of the respective LS sensor output lines that are in the specified state are different from each other. The different lengths of the respective LS sensor output lines which are in the specified state allow communications data destination information to be provided to the respective injectors 10 via the corresponding LS sensor output lines as unique node IDs. That is, the aforementioned configuration of the microcomputer 53 serves, for example, as a destination information granting device.

Thus, each of the injectors 10 is configured to identify a single node ID based on the length of a corresponding output line of LS sensor output lines that are in the specified state and to assign the identified node ID to a corresponding injector. of the injectors 10.

Subsequently, the ECU 50 serves, for example, as a sending device for sending injectors 10, over the common communications line LC, a number sending instruction that requests a target injector 10 to send its individual number as communications data. . Specifically, the send number instruction includes a target injector node ID 10 which must perform the send number instruction. Each of the communications processors 17 of the injectors 10 serves, for example, as the first determining device for receiving the send number instruction, queries the node ID included in the send number instruction, and determines whether the queried node ID matches to the node ID assigned to a corresponding injector injector 10. Upon determining that injector 10 communications processor 17 has a node ID that corresponds to the read node ID, injector 10 communications processor 17 performs the send instruction thus sending their individual number to ECU 50.

An ID assignment routine based on the fuel injection system operations according to this embodiment will be described in more detail with respect to a timing graph shown in Fig. 8 and the flow charts shown in Figs. 9 and 10. Note that in this embodiment, the ID assignment routine is programmed to assign unique node IDs 1, 2, 3, and 4 to the respective injectors 10 (# 1), 10 (# 2), 10 ( 3) and 10 (4), in that order. The fuel injection system ID assignment routine is started, for example, every time the ECU 50 is activated and, for example, is performed cyclically. Normally, that is, initially the potential at the base of each of the transistors Tr 11 is kept at the low voltage level Lo so that the transistors Tr are kept deactivated, ie they are in the normal state. In addition, Tr 11 transistors connected on the respective sensor output lines LS # 1 through LS # 4 will be referred to as Tr 11 # 1, Tr 11 # 2, Tr 11 # 3 and Tr 11 # transistors. 4.

When ECU 50 is activated, the Vout output voltage from each of the injectors 10 (# 1) to 10 (# 4) shows a pressure measured by a corresponding pressure sensor 1 la. The ECU 50 microcomputer 53 determines whether an abnormality diagnostics task has already been performed that diagnoses whether there is a voltage abnormality in each of the LS # 1 through LS # 4 sensor output lines for injectors 10 (# 1). 1) up to 10 (no. 4) in step S100 as described in the first embodiment.

By determining that indicator F1 is set to 1 (YES in step SI00), microcomputer 53 determines that the abnormality diagnostics task has been performed, then the ID assignment routine in the ID assignment routine illustrated in Fig. 9 skips step SI05, going to step S110.

Otherwise, upon determining that the F1 indicator is set to 0 (NOT in step SI00), microcomputer 53 determines that the abnormality diagnostics task has not yet been performed, so the ID granting routine proceeds to step SI05. In step S105, microcomputer 53 performs the subroutine representing operations specific to the abnormality diagnostic task of step SI05 illustrated in Fig. 5.

Upon completion of diagnosing abnormalities for all injectors 10 (# 1) through 10 (# 4), Microcomputer 53 determines that there are no abnormalities in the LS # 1 through LS # 4 sensor output lines. injectors 10 (# 1) to 10 (# 4) in step SI 10.

By determining that there are no abnormalities in the LS # 1 through LS # 4 sensor output lines of all injectors 10 (# 1) through 10 (η ° 4) (YES in step SI 10), microcomputer 53 enables the following ID grant task (the following operations from steps S300 through S350). Otherwise, upon determination that there is an abnormality in at least one of the LS # 1 to LS # 4 sensor output lines from injectors 10 (# 1) to 10 (# 4) (NOT in step SI 10) , microcomputer 53 disables the following ID granting task, terminating the ID granting routine.

After affirmative determination, in step SI 10, microcomputer 53 sends an ID grant start instruction to injectors 10 via the common communications line LC at time t30 (step S300 of Fig. 9). Subsequently, microcomputer 53 switches the transistors Tr 11 connected on the LS sensor output lines of all injectors 10 to the time-activated state t31 (step S310), thereby forcibly switching the voltages on the LS sensor output lines of the respective injectors 10 to 0 V, that is, the second level from the first level. This results in the occurrence of a falling edge in the voltage at the LS sensor output line of each of the injectors 10 at time t31.

When a period T (# 1) has elapsed since time t31 at which the falling edge occurs at the voltages in the LS sensor output lines of all injectors 10, the ECU 50 deactivates transistor Tr 11 at time t32. # 1 connected to injector 10 LS # 1 output line (# 1) (see step S320). The period T (No. 1) was uniquely determined corresponding to a node ID, i.e. 1, of injector 10 (No. 1) to be assigned. This results in a rising edge on the voltage on the injector 10 LS # 1 (# 1) LS sensor output line.

On the other hand, upon receipt of the ID grant start instruction, the communications processor 17 of each of the injectors 10 initiates an ID acceptance routine illustrated in Fig. 10 and begins to monitor the voltage on an output line. corresponding to the LS sensor output lines at time t30 (step S400 of Fig. 10). At step S410, the communications processor 17 of each of the injectors 10 determines that a falling edge occurs at voltage at a corresponding output line of the LS sensor output lines at time t31. At time t31, the communications processor 17 of each of the injectors 10 begins to measure time while monitoring the voltage on a corresponding output line of the LS sensor output lines (step S410).

When a rising edge occurs at the voltage at injector 10 LS # 1 (# 1) sensor output line at time t32, injector 10 communications processor 17 (# 1) determines the rising edge to occur at time t32 (step S420). The injector 10 (No. 1) communications processor 17 is then time-metered to thereby determine the time period t31 to time t32 (step S420). In step S430, injector 10 communications trigger 17 (# 1) determines a node ID 1 to be assigned to it based on the time period t31 through time t32 determined, and stores the assigned node ID 1 in the memory 13 (step S430).

Similarly, when a period T (n ° x; x = 2, 3 or 4) has elapsed since time t31 at which the falling edge occurs at the voltage on the injector 10 LS sensor output line, the ECU 50 turns off the transistor Tr 11 connected to an LS # n (x = 2, 3, or 4) LS sensor output line from an injector 10 (n. x; x = 2, 3, or 4) (see steps S310 and S320).

Specifically, each of the periods T (# 2), T (# 3), and T (# 4) was uniquely determined corresponding to a corresponding node ID of node IDs 2, 3, and 4 of injectors 10 (n 2), 10 (3) and 10 (4) to be allocated.

In this embodiment, when period T (# 2) has elapsed since time t31 at which the falling edge occurs at the voltages on the LS sensor output lines of all injectors 10, the ECU 50 deactivates at time t33 the transistor Tr 11 No. 2 (see step S320). When period T (# 3) has elapsed since time t31 at which the falling edge occurs at the voltages in the LS sensor output lines of all injectors 10, the ECU 50 deactivates transistor Tr 11 at time t34. No. 3 (see step S320). When period T (# 4) has elapsed since time t31 at which the falling edge occurs at the voltages in the LS sensor output lines of all injectors 10, the ECU 50 deactivates transistor Tr 11 at time t35. No. 4 (see step S320).

Thus, when a rising edge occurs at the voltage on the injector 10 LS # 2 (# 2) sensor output lines at time t33, the injector 10 (# 2) communications processor 17 determines the occurrence of the edge rise in time t33 (see step S420). Then, injector 10 communications processor 17 (No. 2) for time measurement to thereby determine the time period t31 to time t33 (see step S420). Next, injector 10 communications trigger 17 (No. 2) determines a node ID 2 to be assigned to it based on the time period t31 to the determined time t33, and stores the assigned node ID 1 in memory. 13 (see step S430).

Similarly, when a rising edge occurs at the voltage on the injector 10 LS # 3 (# 3) sensor output lines at time t34, the injector 10 (# 3) communications processor 17 determines the occurrence of the edge rise in time t34 (see step S420). Then, injector 10 communications processor 17 (No. 3) for time measurement to thereby determine the time period t31 to time t34 (see step S420). Next, injector 10 communications trigger 17 (No. 3) determines a node ID 3 to be assigned to it based on the time period t31 to the determined time t34, and stores the assigned node ID 3 in memory. 13 (see step S430).

In addition, when a rising edge occurs at the voltage on injector 10 LS # 4 (# 4) sensor output lines at time t35, injector 10 (# 4) communications processor 17 determines the occurrence rising edge at time t35 (see step S420). Then, injector 10 communications processor 17 (No. 4) for time measurement to thereby determine the time period t31 to time t35 (see step S420). Next, injector 10 communications trigger 17 (No. 4) determines a node ID 4 to be assigned to it based on the time period t31 to the determined time t35, and stores the assigned node ID 4 in memory. 13 (see step S430).

Upon deactivation of the Tr 11 transistor # 4 at time t35, microprocessor 53 of the ECU 50 sends an ID termination instruction to the injectors 10 over the common LC communications line at time t36 in step S330. Upon receipt of the ID lease submission instruction, the communications processor 17 of each injector 10 for voltage monitoring on a corresponding LS sensor output line in step S440.

Subsequently, the microprocessor 53 of the ECU 50 sends to a target injector 10 a number send instruction requesting that the target injector 10 send its individual number as communications data at time t37 in step S340. Specifically, the send number instruction includes a target injector node ID 10 which must perform the send number instruction. After sending the number sending instruction, upon receipt of the individual number sent from the target injector 10, the microcomputer 53 of the ECU 50 receives the individual number of the target injector 10 in step S350 and terminates the routine illustrated in Fig. 9

Upon receipt of the send number instruction, the communications processor 17 of each injector 10 queries the node ID included in the send number instruction and determines whether the queried node ID corresponds to the node ID assigned to a corresponding injector. injectors 10 at step S450.

Upon determining that the node ID of an injector 10 corresponds to the read node ID, the communications processor 17 of injector 10, i.e. target injector 10, carries out the number send instruction, thereby sending its individual number to ECU 50 at time t38 in step S460, ending the routine illustrated in Fig. 10.

Otherwise, upon determination that the node IDs of the remaining injectors 10 differ from the node ID read, the communications processors 17 of the remaining injectors 10, that is, the non-target injectors 10, discard the number send instructions received in time. t38 at step S470. Subsequently, the communications processors 17 of the non-target injectors 10 terminate the routine illustrated in Fig. 10.

As detailed above, the fuel injection system according to this embodiment is configured to perform an abnormality diagnostic task (see Fig. 5). The abnormality diagnostics task diagnoses whether there is an abnormality in a circuit that electrically connects each of the injectors 10 (# 1) through 10 (# 4) to the ECU 50 via a corresponding output line from the output lines of the LS sensor # 1 through LS # 4 before sending an ID grant start instruction, that is, before time t30 (see Figs. 8 and 9).

By determining that there are no abnormalities in all circuits that connect injectors 10 (# 1) through 10 (# 4) to the ECU 50 (see YES in step SI 10), the ECU 50 individually switches the voltages on the 10 respective lines. LS # 1 to LS # 4 output from the first level to the second level. This assigns the unique node IDs to their nozzles # 1 through # 10.

Otherwise, upon determination that there is an abnormality in a circuit that connects at least one injector 10 to ECU 50 (see NO in step SI 10), ECU 50 disables switching of voltages on the respective LS # 1 sensor output lines. up to LS # 4 from first level to second level. In other words, the ECU 50 disables operations from steps S300 through S350 at time t30, and after it.

Thus, the fuel injection system according to this mode achieves the same effects as the fuel injection system according to the first mode. The present invention is not limited to the descriptions of the above embodiments and, therefore, the present invention may be modified as follows.

In each of the first and second embodiments, the ECU 50 is provided with an abnormality diagnostics device for diagnosing whether there is an abnormality in a circuit that electrically connects each of the injectors 10 to the ECU via a line. corresponding output line of the LS sensor output lines. However, the present invention is not limited to structure.

Specifically, the communications processor 17 of each injector 10 may be functionally equipped with abnormality diagnostics device 17a corresponding to the operations of steps S200 to S280 of Fig. 5 (see dashed lines in Fig. 5). Of course, the abnormality diagnostics device 17a may be eliminated from the fuel injection system according to each of the first and second embodiments.

Specifically, in step S205, the communications processor 17 of each injector 10 selects a corresponding injector 10. Moreover, after operation of steps S270 or S280 as a result of the diagnosis, the communications processor 17 of each injector 10 sends the diagnostic results of an injector 10 corresponding to the ECU 50 via the common LC communications line.

For example, consider that the voltage detector 19 output of an injector 10 was fixed at low voltage level Lo for a preset period (see YES in step S230 and YES in step S260). In this regard, injector 10 communications processor 17 determines that there is an abnormality, that is, a ground fault, in the circuit that connects injector 10 to ECU 50 (see step S270). The communications processor 17 then sends the diagnostic results to the ECU 50 via the common LC communications line.

While receiving diagnostic results from each injector 10, the ECU 50 microcomputer 53 performs steps S120 through S155 operations or steps S300 through S350 operations only provided that: the diagnostic results of all injectors 10 represent no abnormalities in the LS # 1 through LS # 4 sensor output lines of all injectors 10 (# 1) to 10 (# 4) in step SI 10. The fuel injection system according to with the second mode is configured to individually adjust a duration of each of the LS sensor output lines connected to transistors Tr 11 which are at the second level, that is, in the specified state, such that the durations of the respective output lines LS sensors that are in the specified state differ from each other. The different lengths of the respective LS sensor output lines which are in the specified state allow communications data destination information to be provided to the respective injectors 10 via the corresponding LS sensor output lines as unique node IDs. However, the present invention is not limited to configuration as long as the present invention is configured to forcibly control how to change the voltage on each of the injector LS sensor output lines 10.

For example, a modified fuel injection system based on the fuel injection system according to the second embodiment will be described below. The output circuit 12 of each of the injectors 12 of the modified fuel injection system is configured to variously determine its Vout output voltage in the range of 0 V to the power supply voltage Vc, for example 5 V.

An ID assignment routine based on the modified fuel injection system operations will be described in more detail with respect to the flow charts illustrated in Figs. 11 and 12. In the ID assignment routine according to the modified fuel injection system, equal steps in the ID assignment routine according to the second embodiment, to which equal step numbers are assigned, are omitted or simplified to avoid redundant description.

After affirmative determination, in step SI 10, the ECU 50 sends a scan instruction to the communications processors 17 of all injectors 10 (# 1) through 10 (# 4) via the common LC communications line. The scan instruction instructs the communications processors 17 of each of injectors 10 (# 1) through 10 (# 4) to sweep the voltage on a corresponding output line from LS # 1 to LS sensor output lines. No. 4 from a preset start level, for example 0 V (step S500 of Fig. 11).

Subsequently, the ECU 50 individually activates the Tr 11 # 1 through # 4 transistors connected to their respective LS # 1 through LS # 4 sensor output lines at their respective unique timings after the scan instruction is sent (step S510 ). This determines each period from the scan instruction send delay to the delay at which the voltage swept on a corresponding output line of the LS sensor output lines becomes 0 V.

After deactivating all Tr 11 # 1 through Tr # 4 transistors, the ECU 50 sends a scan termination instruction to the injectors 10 via the common LC communications line in step S520. Subsequently, the ECU 50 performs the operations of the exposed S340 and S350 steps.

On the other hand, while receiving the scan instruction, the communications processor 17 of each injector 10 scans the voltage on a corresponding LS sensor output line and begins monitoring the voltage swept on a corresponding LS sensor output line ( see step S600).

Subsequently, in step S610, the communications processor 17 of each injector 10 determines that a falling edge occurs at the swept voltage on a corresponding LS sensor output line. The communications processor 17 of each injector 10 then determines a corresponding node ID based on the level of voltage scanned on a corresponding LS sensor output line at the timing of the occurrence of a falling edge in step S620.

At step S620, the communications processor 17 of each of the injectors 10 may determine a corresponding node ID based on a corresponding period from the start of voltage monitoring on a corresponding LS sensor output line until a leading edge occurs. voltage drop on a corresponding LS sensor output line.

Subsequently, upon receipt of the scan termination instruction, the communications processor 17 of each injector 10 terminates the voltage scan on a corresponding LS sensor output line, and for voltage monitoring on an LS sensor output line. corresponding to step S630. Subsequently, the communications processor 17 of each injector 10 performs the operations of exposed steps S450 through S470.

As described above, the modified fuel injection system is different from the fuel injection system according to the second embodiment in how to change the voltage on each of the injector 10 LS sensor output lines. Thus, the injection system The modified fuel injection system achieves the same effects achieved by the fuel injection system according to the second mode. The fuel injection system according to the first embodiment is configured to send an ID assignment instruction that includes a target node 1D to the injectors 10 via the common communications line LC as communications data, but the present invention does not. is limited to this one.

Specifically, the fuel injection system according to the first embodiment may be configured to send another instruction, such as a read instruction and a write instruction, which includes a target node ID to injectors 10 via the common LC communications as communications data. The reading instruction instructs the communications processor 17 of a corresponding target injector 10 to read the characteristics of the corresponding target injector 10 and / or those of the corresponding pressure sensor 11 from memory 13 as communications data and to send the data of communications to the ECU 50 via the common LC communications line. The write instruction instructs the communications processor 17 of a target injector 10 to write learned values for the characteristics of the corresponding target injector 10 to memory 13 as communications data.

In each of the first and second embodiments, a voltage switching unit for switching the voltage on each of the LS sensor output lines to the first level or second level, such as transistor Tr 11, is provided on ECU 50. That is, the voltage switching unit is controlled by the ECU 50 to switch the voltage on each of the sensor output lines to the first level or second level, thereby assigning a node ID to each of the injectors 10. However, the present invention is not limited to configuration. Specifically, a voltage switching unit may be provided on each of the injectors 10 and may be controlled by the communications processor 17 to switch the voltage on a corresponding output line of the LS sensor output lines to a given level.

For example, the output circuit 11 of each of the injectors 10 may serve as a voltage switching unit to randomly select one of a plurality of preset levels and apply the selected voltage level to a corresponding output line of the lines. LS sensor output. The levels selected for injectors 10 are different from each other.

Upon receipt of an ID assignment instruction that includes information indicating a voltage level from the ECU 50 while a corresponding LS sensor output line is set at the selected level, the communications processor 17 of each injector 10 compares the voltage level included in the ID assignment instruction handles the voltage level defined on a corresponding LS sensor output line. The voltage level included in the ID assignment instruction is identical to the voltage level on the LS sensor output line connected to a target injector 10.

If the voltage level included in the read ID assignment instruction matches the voltage level defined on the LS sensor output line, the target injector 10 communications processor 17 assigns a node ID included in the ID assignment instruction to itself. otherwise, if the voltage level included in the read ID assignment instruction deviates from the voltage levels defined in the LS sensor output lines connected to non-target injectors 10, the communications processor 17 of each injector no targets 10 discards the ID assignment statement.

In each of the first and second embodiments, as a sensor for measuring a parameter correlated with the fuel injection characteristics of each injector 10, the pressure sensor 11 for measuring the fuel pressure in a corresponding injector 10 is used. However, another device, such as a temperature sensor for measuring fuel temperature, may be used for the present invention as a sensor for measuring a parameter correlated with fuel injection characteristics of each injector 10.

Although illustrative embodiments of the present invention have been described herein, the present invention is not limited to the embodiments described herein, but includes any and all embodiments having modifications, omissions, combinations (e.g., aspects through various embodiments), adaptations and / or changes, which will be appreciated by those skilled in the art based on the present disclosure. Limitations on the claims should be interpreted broadly based on the language employed in the claims and not limited to the examples described in this specification or during the application process, the examples of which should be construed as not unique.

Claims (5)

1. Fuel injection system in which a controller (50) is communicatively connected to a plurality of injectors (10) via a common communication line (LC) and drives the plurality of injectors (10) to inject fuel into a characterized in that the fuel injection system comprises: a plurality of sensors (11) incorporated into the plurality of injectors (10), respectively, and electrically connected to the controller (50) by a plurality of circuits including a plurality of output lines (LS), respectively, each of the sensors (11) being designed to transmit to the controller (50) by means of a corresponding line of output lines (LS), a signal indicative of a level of a parameter measured in correlation with a fuel injector characteristic of a corresponding injector of the plurality of injectors (10); lease device (Tr 11, steps SI20 and SI25, steps S300 through S320, steps S500 through S510) to grant communications data destination information to each of the injectors (10) via a corresponding line of output lines ( LS) by forcibly varying the output signal from at least one of the sensors (11) by means of at least one corresponding line of the output lines (LS); sending device (step S130, step S330, step S620) to send the communications data to each of the injectors (10) via the common communications line (LC) while the destination information of the communications data is being granted to each of the injectors (10) or was completely granted to each of the injectors (10); first determining device (step S320, step S450) provided on each of the injectors (10) for receiving the communications data and determining whether a task based on the communications data is performed as a function of the destination information given to an injector corresponding to the injectors (10); diagnostic device (steps S200 through S290) to diagnose if there is an abnormality in at least one of the circuits before the grant device (Tr 11, steps S120 and S125, steps S300 through S320, steps S500 through S510) grant the target information communication data to each injector (10); and second determining device (step SI 10) to determine whether the granting device (Tr 11, steps SI20 and S125, steps S300 to S320, steps S500 to S510) of granting communications data destination information to each injector (10) based on a diagnostic result. Fuel injection system according to claim 1, characterized in that: the concession device (Tr 11, steps S120 and S125, steps S300 to S320, steps S500 to S510) is configured to: forcibly set the output signal through an output line on the output lines (LS) at a specified level, regardless of the measured parameter level, to an output line being connected to a pressure sensor on the pressure sensors (11) as a line output destination, which is a destination of the communications data, the remaining output lines being defined as non-target output lines, which are not communications data destinations, the specified level or the measured level of the output signal in each of the output lines (LS) by granting the communications data destination information to a corresponding injector injector (10), the sending device (step S130, step S330, step S620) is configured for: and sending the communications data to each injector (10) via the common communications line (LC), while the specified level or measured level of the output signal is maintained on each of the output lines (LS), and the first determining device (step S320, step S450) provided on each of the injectors (10) is configured to: receive communications data, determine to perform the task based on communications data if a corresponding injector (10) is connected target output line (LS) as a target injector, and determine not to perform the task based on the communications data if a corresponding injector (10) is connected to a corresponding line of non-target output lines (LS) as an injector. not targeted. Fuel injection system according to claim 2, characterized in that: the sending device (step SOO, step S330, step S620) is configured to: send, as the communications data, an instruction including an ID for the target injector to each of the plurality of injectors (10) via the common communications line (LC), the instruction instructing the target injector to assign the ID included in the instruction to the target injector. Fuel injection system according to claim 1, characterized in that: the concession device (Tr 11, steps S120 and S125, steps S300 to S320, steps S500 to S510) is configured to: forcibly set the output signal through each of the output lines (LS) at a specified level, regardless of the parameter level measured, such that output signal durations through the respective output lines (LS) that are at the specified level are different from each other, the sending device (step S130, step S330, step S620) is configured to: send the communications data to each of the injectors (10) via the common communications line (LC), while the information communications data destination has been completely granted to each of the injectors (10), and the first determining device (step S320, step S450) provided on each of the injectors (10) is configured to: receiving the communications data, and identifying an ID to be assigned to a corresponding injector injector (10) based on the duration of the output signal through a corresponding line of output lines (LS). Fuel injection system according to claim 1, characterized in that: the concession device (Tr 11, steps SI20 and SI25, steps S300 to S320, steps S500 to S510) is configured to: forcibly sweep the output signal through each of the output lines (LS), regardless of the level of the measured parameter; Forcibly defining the output signals scanned across their output lines (LS) at a level specified in their unique timings, the sending device (step SI30, step S330, step S620) is configured to: send the communications data to each one of the injectors (10) via the common communications line (LC), while the destination information of the communications data was completely granted to each of the injectors (10), and the first determining device (step S320, step S450 ) provided on each of the injectors (10) is configured to: monitor the unique timing of the scanned output signal across a corresponding line of output lines (LS); receiving the communications data, and obtaining an ID to be assigned to a corresponding injector injector (10) based on the monitored timing of the output signal scanned across a corresponding line of output lines (LS).