JP3721597B2 - Control device for fuel injection pump - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a control device for a fuel injection pump, and more particularly to a control device that has a storage element that stores correction data related to machine differences in the fuel injection pump and controls the fuel injection pump using the correction data. It is.
[0002]
[Prior art]
Japanese Patent Publication No. 4-28901 discloses a technique for correcting variations in machine differences in a control device for a fuel injection pump that supplies fuel to a diesel engine. This is because the difference data of the fuel injection pump is stored in a memory provided in the fuel injection pump, and the control device obtains correction data by communication means and uses this correction data to inject fuel according to the engine operating condition. The pump is driven.
[0003]
[Problems to be solved by the invention]
However, data communication includes a method of performing synchronization in synchronization with a clock, a method of transmitting a communication request signal and determining data head timing, and transmitting data. However, in any case, one wire is necessary separately from the data wire, and it is desirable to reduce the wire from the viewpoint of cost.
[0004]
Accordingly, an object of the present invention is to provide a control device for a fuel injection pump that can easily determine the start of communication with a simple configuration.
[0007]
[Means for Solving the Problems]
  Claim 1The invention described in (1) includes a storage element that is mounted on a fuel injection pump that supplies fuel to a diesel engine, stores data on machine differences for each fuel injection pump, and a communication means for transferring data stored in the storage element. A pump-mounted device having the storage element that is not mounted on the fuel injection pump and outputs a communication start command of data stored in the storage element, and is transferred by the communication means according to the communication start command A fuel injection pump control apparatus comprising a non-pump-equipped device having control means for driving a fuel injection pump in accordance with an engine operating state using data, wherein a clock signal serving as a power source is not pumped The power / clock signal line sent from the mounted device to the pump mounted device and the clock signal that is provided in the non-pump mounted device and that is the power source A clock signal output stage for outputting the power supply clock signal line, provided on the pump mounting side instrument monitors the power supply and clock signal lineThe received clock signal is converted into electric power by a signal-power conversion circuit, and by determining whether the electric power obtained by the conversion has reached a predetermined value,The prescribed power has been sentDeterminedThe gist of the present invention is a control device for a fuel injection pump comprising communication start determining means for determining data communication on the assumption that a communication start command is sometimes output.
[0008]
  The invention according to claim 2 is the claim1In the described invention, a fuel injection pump control device provided in a non-pump mounted device and provided with an abnormality determining means for determining that there is a communication abnormality when no data is received within a predetermined time after instructing communication start. The gist.
[0013]
[Action]
  Claim1According to the invention, the clock signal output means outputs the clock signal to the power supply / clock signal line. The communication start determining means monitors the power source / clock signal line and determines that the communication is started when a predetermined power is sent. Thus, the start of communication is determined using the power / clock signal line, and a dedicated line becomes unnecessary.
[0014]
  Then, the difference data for each fuel injection pump in the storage element is transferred by the communication means, and the control means drives the fuel injection pump according to the engine operating state using the transferred data.Here, the communication start determining means determines whether or not the power obtained by converting the clock signal sent through the communication line reaches a predetermined value, and when determining that the predetermined value has been reached, the communication start signal is input. As a result, communication is started. Accordingly, since the start of communication is reliably determined and the data is transferred, it is very preferable for a vehicle having a severe environment.
[0015]
  Claim2According to the invention described in claim1In addition to the operation of the described invention, the abnormality determining means determines that there is a communication abnormality when no data is received within a predetermined time after instructing the start of communication.
[0016]
【Example】
(First embodiment)
A first embodiment of the present invention will be described below with reference to the drawings.
[0017]
This embodiment is embodied in a control device for a fuel injection pump in a diesel engine mounted on an automobile. FIG. 1 shows the overall configuration of a fuel injection pump control device.
[0018]
A diesel fuel injection pump 1 (control target) for supplying fuel to a diesel engine is provided with an injection amount control actuator 2 and an injection timing control actuator 3 for electronic control of the fuel injection amount and fuel injection timing. ing. The control device for controlling the diesel fuel injection pump 1 includes a pump-mounted control device 4 (characteristic variation storage device) mounted on the pump 1 and a non-pump-mounted control device 5 (control device main body) not mounted on the pump 1. It consists of.
[0019]
The pump mounting side control device 4 and the pump non-mounting side control device 5 can perform asynchronous serial communication, and the correction data stored in the EEPROM 6 of the pump mounting side control device 4 is the pump non-mounting side control device. 5 and stored in the backup memory 19 of the non-pump-equipped control device 5, and the actuators 2 and 3 are driven and controlled using this correction data.
[0020]
The details will be described below.
The pump-mounted control device 4 includes an EEPROM (characteristic variation storage element) 6 as a storage element, a serial communication interface 7 as a communication means, a filter circuit 8, a communication buffer 9, and a comparison circuit 10. The EEPROM 6 stores information on machine differences for each fuel injection pump. This data was obtained by actually injecting fuel during the shipping process from the factory of the fuel injection pump 1 to examine the injection characteristics, and storing data regarding deviation from the injection characteristics of a standard pump as correction data. It is.
[0021]
The filter circuit 8 is constituted by a CR circuit comprising a resistor 11 and a capacitor 12. A filter circuit 8 is connected to a power supply line L1 connecting the pump mounting side control device 4 and the pump non-mounting side control device 5, and the filter circuit 8 is connected to a power input terminal P1 of the serial communication interface 7. The comparison circuit 10 as a communication start determination means includes a comparator 10a, and one input terminal is connected to a connection point a upstream of the filter circuit 8 in the power supply line L1. The comparison voltage Vref is applied to the other input terminal of the comparator 10a. In this embodiment, the comparison voltage Vref has a value (2.5 volts) that is ½ of the output voltage Vcc of the power supply circuit 14 described later. The output terminal of the comparator 10a is connected to the communication start detection terminal PSTA of the serial communication interface 7. The communication buffer 9 is composed of passive elements such as resistors and capacitors. The input terminal of the communication buffer 9 is connected to the data communication terminal P2 of the serial communication interface 7, and the output terminal is connected to the non-pump mounted control device 5 through the data communication line L3. The pump mounting side control device 4 and the pump non-mounting side control device 5 are connected by a ground line L2.
[0022]
Thus, the control device 4 is mounted on the diesel fuel injection pump 1, and even if the diesel fuel injection pump 1 is replaced, there is no need to readjust the control unit, and the control unit 4 is integrated with the diesel fuel injection pump 1. Managed.
[0023]
The non-pump-mounted control device 5 performs various calculations related to the control of the diesel fuel injection pump 1, and includes a CPU 13, a power supply circuit 14, a PNP transistor 15, and an NPN transistor 16 as control means and voltage level changing means. A communication buffer 17, an actuator drive circuit 18, and a backup memory 19 are provided. The power supply circuit 14 receives supply of electric power (12 volts) from the battery B, generates a predetermined voltage (5 volts), and supplies the generated voltage (5 volts) to all devices (circuits) of the non-pump mounted control device 5. The power supply circuit 14 is connected to a power supply line L1 via a PNP transistor 15, and the base terminal of the PNP transistor 15 is connected to the CPU 13. An NPN transistor 16 is connected to the collector terminal side of the PNP transistor 15, and an emitter terminal of the NPN transistor 16 is grounded. The base terminal of the NPN transistor 16 is connected to the CPU 13.
[0024]
The CPU 13 takes in various sensor signals. This sensor signal includes an accelerator opening signal from an accelerator opening sensor, an engine speed signal from an engine speed sensor (crank angle sensor), an intake pressure signal from an intake pressure sensor, an intake air temperature signal from an intake air temperature sensor, It is a water temperature signal from an engine cooling water temperature sensor.
[0025]
The ROM 13a built in the CPU 13 stores conformance data (control data when there is no difference between pumps) for each engine model. That is, the ROM 13a functions as a storage element for storing central value control data.
[0026]
The input terminal of the communication buffer 17 is connected to the data communication line L3, and the output terminal is connected to the CPU 13.
The PNP transistor 15 can supply the power supply voltage Vcc (5 volts) generated by the power supply circuit 14 through the power supply line L1 for communication with the pump-mounted control device 4 in the ON operation. This electric power is sent to the serial communication interface 7 through the filter circuit 8. The NPN transistor 16 is for making a data communication request by turning on instantaneously while power (5 volts) is being supplied from the power supply line L1. When there is a data communication request, the serial communication interface 7 of the pump-mounted control device 4 transfers the correction data stored in the EEPROM 6 to the CPU 13 via the communication buffer 9 and the communication buffer 17 via the data communication line L3. In this way, correction data is communicated using the data communication line L3.
[0027]
The backup memory 19 stores correction data transferred from the EEPROM 6 of the pump-mounted control device 4. This is to store the correction data once received through communication to minimize the frequency of communication. That is, the backup memory 19 functions as a correction data storage memory element.
[0028]
The actuator drive circuit 18 of the non-pump mounted control device 5 and the injection amount control actuator 2 of the diesel fuel injection pump 1 are connected by a drive line 20a, and the actuator drive circuit 18 and the injection timing control actuator. 3 is connected by a drive line 20b.
[0029]
The CPU 13 of the non-pump-mounted control device 5 performs a calculation using compatible data (data when there is no pump difference) stored in the ROM 13a by various sensor signals, and based on the calculation result. In addition, an injection amount control actuator drive signal SG1 and an injection timing control actuator drive signal SG2 are output via the actuator drive circuit 18 so that the fuel injection amount and fuel injection timing required according to the engine operating state are obtained. The drive signal SG1 and SG2 drive the injection amount control actuator 2 and the injection timing control actuator 3.
[0030]
At this time, since the diesel fuel injection pump 1 has characteristic variations among individuals due to machining accuracy, assembly accuracy, etc., even if the same drive signal is output in the same engine operating state, the actual fuel The injection amount and fuel injection timing vary depending on the fuel injection pump machine difference. Therefore, correction is performed using correction data stored in the EEPROM 6 stored in the backup memory 19 to finely correct the characteristic variation, thereby improving the performance of the engine as much as possible by the fuel injection amount and fuel injection timing.
[0031]
In this way, the CPU 13 drives and controls the actuators 2 and 3 of the diesel fuel injection pump 1 using the information on the machine difference for each fuel injection pump in the EEPROM 6.
Details of the operation of the control device for the fuel injection pump will be described below.
[0032]
FIG. 2 shows a flow of correction data communication processing processed by the CPU 13, which is started by turning on the ignition switch, and thereafter started every predetermined time.
[0033]
FIG. 3 is a timing chart showing the potential at the connection point a, the potential at the connection point b in FIG. 1, the communication status through the data communication line L3, and the output of the comparison circuit 10 (communication start signal).
[0034]
When the ignition switch is turned on, the CPU 13 checks whether the check code of the backup memory 19 (correction data storage memory element) is normal in step 101 of FIG. This check code is for checking whether the data stored in the backup memory 19 is valid. If normal, the CPU 13 terminates without performing any processing in order to minimize the communication frequency. When the check code is abnormal (when the correction data has never been read), the CPU 13 proceeds to step 102 to turn on the PNP transistor 15 and use the power supply voltage Vcc generated by the power supply circuit 14 as the power supply line L1. To the pump-mounted control device 4 (timing t1 in FIG. 3).
[0035]
With this power supply, the output voltage of the filter circuit 8 (CR circuit) gradually increases and reaches a saturation voltage at the timing t2 in FIG.
The CPU 13 determines whether or not the predetermined time T1 has elapsed after turning on the PNP transistor 15 in step 103 of FIG. 2, and ends the processing of FIG. 2 if not. Here, the predetermined time T1 is the time from the start of power supply until the pump-equipped control device 4 finishes preparing for communication, that is, a time longer than the time constant of the filter circuit 8 (CR circuit) (2 to 3 times) ).
[0036]
Then, when the predetermined time T1 has elapsed after turning on the PNP transistor 15 (timing t3 in FIG. 3), the CPU 13 proceeds to step 104 to perform a data communication start command and instantaneously turns on the NPN transistor 16. In FIG. 3, this is represented as an on period from t3 to t4.
[0037]
Due to the momentary ON operation of the NPN transistor 16, the potential of the power supply line L1 (potential at point a) becomes the ground potential. The comparison circuit 10 compares the potential at the point a with the comparison potential Vref. When the potential at the point a becomes smaller than the comparison potential Vref, an H level signal indicating a communication start command is detected by the serial communication interface 7. Output to terminal PSTA. In response to this signal, the serial communication interface 7 detects a communication start command, and transfers the correction data stored in the EEPROM 6 to the CPU 13 in the serial asynchronous manner via the communication buffer 9 and the communication buffer 17 via the data communication line L3 (FIG. 3). T5 to t6).
[0038]
Here, the ON period of the NPN transistor 16 is sufficiently shorter than the time constant of the filter circuit 8 (CR circuit) in which the voltage drop of the power supply (point b) of the pump-equipped control device 4 does not affect the operation of the circuit. Power is secured. The ON period of the NPN transistor 16 is a time that can be detected by the comparison circuit 10 (1/10 of the time constant).
[0039]
Further, the ON operation (communication start) of the NPN transistor 16 is performed excluding an unstable period when the power supply is turned on.
In FIG. 2, the CPU 13 receives the response data in step 105, confirms the received data in step 106, and if normal, stores the received data in the backup memory 19 in step 107, and then turns on the PNP transistor 15 in step 108. Turn off (timing at t7 in FIG. 3).
[0040]
On the other hand, if the received data is abnormal in step 106, the CPU 13 sets a machine difference variation data abnormality flag in step 109 and terminates the process so that communication is performed again when the ignition switch is turned on next time. In this case, since there is no data to be reflected in the correction, the CPU 13 continues to execute control based on the central value control data (standard value) stored in the ROM 13a of the non-pump-mounted control device 5.
[0041]
FIG. 4 is a data flowchart showing processing up to the calculation of the fuel injection amount in the CPU 13 of the non-pump mounted control device 5 (control device main body).
First, the basic injection amount calculation unit 21 calculates a basic injection amount Qa based on the accelerator opening and the engine speed. On the other hand, the basic maximum injection amount calculation unit 22 calculates the basic maximum injection amount Qb based on the engine speed and the intake pressure, and the correction calculation unit 23 further calculates the basic maximum injection based on the correction coefficient K1 based on the intake air temperature and the correction coefficient K2 based on the water temperature. The corrected basic maximum injection amount Qb ′ (= Qb · K1 · K2) is calculated by correcting the amount Qb. The selector 24 selects the smaller one of the basic injection amount Qa and the corrected basic maximum injection amount Qb ', and the adding unit 25 performs acceleration correction based on the accelerator opening with respect to the minimum value.
[0042]
On the other hand, the machine difference correction calculation unit 26 calculates a machine difference variation correction value ΔQ from the correction data received as serial communication data by the pump-equipped control device 4, the engine speed, and the basic injection amount Qa by the basic injection amount calculation unit 21. Is calculated. The addition / subtraction unit 27 adds or subtracts the machine difference variation correction amount ΔQ from the machine difference correction calculation unit 26 to the output value of the addition unit 25 to perform correction according to the machine difference variation for each injection pump. Further, the addition / subtraction unit 28 adds / subtracts various correction values to / from the output value of the addition / subtraction unit 27, and then outputs a calculation result as the final injection amount.
[0043]
In this way, correction according to the machine difference variation for each injection pump based on the characteristic variation correction data received as serial communication data by the pump-mounted control device 4 is performed and reflected in the final injection amount.
[0044]
Regarding the fuel injection timing, the method is not particularly limited, but the same correction can be performed. Also, based on the respective calculation results, pulse output ON / OFF timing, ON / OFF duty, etc. are directly converted into a signal form for driving the actuators 2 and 3 and output, but at that time the correction data is reflected and the actuator Characteristics such as a few responsiveness can also be corrected.
[0045]
As described above, in this embodiment, in the clock asynchronous communication system, the activation trigger signal is transmitted using the power supply line L1, and the transmission of the correction data is started based on the activation trigger signal. In other words, the CPU 13 (voltage level changing means) in the non-pump-mounted control device 5 forcibly changes the voltage level by the power supply line L1 at the start of communication, and the comparison circuit 1 (communication start determination) Means) monitors the voltage of the power supply line L1 and detects the change of the voltage level to determine the start of communication. Therefore, the wire (cable) between the pump-mounted control device 4 and the pump-unmounted control device 5 is used. ) Includes three power lines (5 volts) L1, a ground line L2, and a data communication line L3, which eliminates the need for a communication start command line and reduces the number of wires.
[0046]
The ground line L2 may be deleted by dropping it on the body.
(Second embodiment)
Next, the second embodiment will be described focusing on the differences from the first embodiment.
[0047]
FIG. 5 shows the overall configuration of the control device for the fuel injection pump. In this embodiment, synchronous serial communication using a clock signal can be performed.
The comparison circuit 10 and the NPN transistor 16 in the first embodiment are deleted, and the pump mounting side control device 4 and the pump non-mounting side control device 5 are connected by a clock signal line L4. The pump mounting control device 4 is provided with an edge detection circuit 29 as communication start determination means, and the edge detection circuit 29 is connected to the clock signal line L4. The output terminal of the edge detection circuit 29 is connected to the communication start detection terminal PSTA of the serial communication interface 7. The edge detection circuit 29 detects the rising edge of the clock signal and outputs a signal to that effect to the communication start detection terminal PSTA of the serial communication interface 7.
[0048]
Details of the operation of the control device for the fuel injection pump will be described below.
FIG. 6 shows a flow of correction data communication processing processed by the CPU 13, which is started by turning on the ignition switch, and thereafter started every predetermined time.
[0049]
FIG. 7 is a timing chart showing the potential at the connection point a, the potential at the connection point b, the clock signal, the communication status through the data communication line L3, and the output (communication start signal) of the edge detection circuit 29 in FIG. Show.
[0050]
The CPU 13 as the clock signal output means checks whether the check code of the backup memory 19 (correction data storage memory element) is normal in step 201 of FIG. 6, and if the check code is abnormal, the process proceeds to step 202. The PNP transistor 15 is turned on and the power supply voltage Vcc generated by the power supply circuit 14 is sent to the pump-mounted control device 4 through the power supply line L1 (timing t11 in FIG. 7).
[0051]
With this power supply, the output voltage of the filter circuit 8 (CR circuit) gradually increases and reaches the saturation voltage at the timing t12 in FIG.
The CPU 13 determines whether or not the predetermined time T1 has elapsed after turning on the PNP transistor 15 in step 203 of FIG. 6, and ends the processing of FIG. 6 if not. Here, the predetermined time T1 is the time from the start of power supply until the pump-equipped control device 4 finishes preparing for communication, that is, a time longer than the time constant of the filter circuit 8 (CR circuit) (2 to 3 times) ).
[0052]
Then, when a predetermined time T1 has elapsed after turning on the PNP transistor 15 (timing at t13 in FIG. 7), the CPU 13 proceeds to step 204 to transmit a clock signal in order to issue a data communication start command.
[0053]
The edge detection circuit 29 monitors the clock signal line L4. When the rising edge of the clock signal is detected, an H level signal indicating the start of communication is output to the communication start detection terminal PSTA of the serial communication interface 7. By this signal, the serial communication interface 7 detects the start of communication and transfers the correction data stored in the EEPROM 6 to the CPU 13 serially and in clock synchronization via the communication buffer 9 and the communication buffer 17 via the data communication line L3 (FIG. 7 between t14 and t15).
[0054]
In FIG. 6, the CPU 13 receives the response data in step 205, confirms the received data in step 206, and if normal, stores the received data in the backup memory 19 in step 207, and then stores the PNP transistor 15 in step 208. The output is turned off and the output of the clock signal is finished (timing at t16 in FIG. 7). On the other hand, if the reception data is abnormal in step 206, the CPU 13 sets a machine difference variation data abnormality flag in step 209 and terminates the process so that communication is performed again when the ignition switch is turned on next time.
[0055]
As described above, in this embodiment, in the clock synchronous communication system, transmission of correction data is started at the rising edge of the clock signal. That is, the CPU 13 (clock signal output means) in the non-pump mounted control device 5 outputs a clock signal from the clock signal line L4 at the start of communication, and the pump mounted control device 4 uses the edge detection circuit 29 (communication start determination means). ) Monitors the clock signal line L4 and detects the edge of the clock signal to determine the start of communication. Therefore, the wire between the pump-mounted control device 4 and the non-pump-mounted control device 5 is connected to the power line ( 5 volts) L1, the ground line L2, the data communication line L3, and the clock signal line L4, so that the communication start command line can be dispensed with and the number of wires can be reduced.
(Third embodiment)
Next, the third embodiment will be described focusing on the differences from the second embodiment.
[0056]
FIG. 8 shows the overall configuration of the control device for the fuel injection pump. In this embodiment, synchronous serial communication using a clock signal can be performed.
The power supply line L1 in the second embodiment is deleted, and the filter circuit 8 is connected to the power supply / clock signal line L5 via the diode 30 in the pump-mounted control device 4. That is, the clock signal is rectified by the diode 30 and used as a power source.
[0057]
The pump-mounted control device 4 is provided with a pulse counter 31 as communication start determination means, and the pulse counter 31 is connected to the power / clock signal line L5. The output terminal of the pulse counter 31 is connected to the communication start detection terminal PSTA of the serial communication interface 7. The pulse counter 31 counts the number of clock signals, and outputs a signal to that effect to the communication start detection terminal PSTA of the serial communication interface 7 when the predetermined count number is reached.
[0058]
Details of the operation of the control device for the fuel injection pump will be described below.
FIG. 9 shows a flow of correction data communication processing processed by the CPU 13, which is started by turning on the ignition switch, and thereafter started every predetermined time.
[0059]
FIG. 10 is a timing chart, showing the clock signal, the potential at the connection point b in FIG. 8, the communication status by the data communication line L3, the count value of the pulse counter 31, and the output (communication start signal) of the pulse counter 31. Indicates.
[0060]
The CPU 13 checks whether or not the check code of the backup memory 19 (correction data storage memory element) is normal in step 301 in FIG. 9, and if the check code is abnormal, the CPU 13 proceeds to step 302 and starts sending the clock signal. And sent to the pump mounting side control device 4 through the power / clock signal line L5 (timing t21 in FIG. 10).
[0061]
With this power supply, the output voltage of the filter circuit 8 (CR circuit) gradually increases and reaches a saturation voltage at the timing t22 in FIG.
The pulse counter 31 monitors the power / clock signal line L5. When N clock signals are sent (five in FIG. 10) (timing at t23 in FIG. 10), the H level indicates the start of communication. The signal is output to the communication start detection terminal PSTA of the serial communication interface 7.
[0062]
That is, when a time (2 to 3 times) longer than the time constant of the filter circuit 8 (CR circuit) elapses from the start of power supply until the pump-mounted control device 4 finishes preparation for communication, An H level signal is output from the pulse counter 31.
[0063]
By this signal, the serial communication interface 7 detects the start of communication and transfers the correction data stored in the EEPROM 6 to the CPU 13 serially and in clock synchronization via the communication buffer 9 and the communication buffer 17 via the data communication line L3 (FIG. 10 t24 to t25).
[0064]
The CPU 13 determines in step 303 in FIG. 9 whether or not N clock signals (five in FIG. 10) have been sent, and if it is less than N (five in FIG. 10), the processing in FIG. That is, in step 303, it is determined whether or not a predetermined time T1 necessary for communication preparation has elapsed after the clock signal is transmitted.
[0065]
When the CPU 13 sends N clock signals (five in FIG. 10) in step 303 (timing t23 in FIG. 10), the process proceeds to step 304 to receive response data, and in step 305, the received data is confirmed and normal. If so, the received data is stored in the backup memory 19 in step 306, and then the output of the clock signal is terminated in step 307 (timing t26 in FIG. 10). On the other hand, if the received data is abnormal in step 305, the CPU 13 sets a machine difference variation data abnormality flag in step 308 and ends the process.
[0066]
As described above, in this embodiment, in the clock synchronous communication system, transmission of correction data is started by counting the number of clocks. That is, the CPU 13 (clock signal output means) in the non-pump-mounted control device 5 outputs a clock signal to start communication when a predetermined number of clock signals are sent to the power / clock signal line L5, and the pump-mounted control device 4, the pulse counter 31 (communication start determination means) monitors the power source / clock signal line L5 and determines that communication is started when a predetermined number of clock signals are sent. There are three wires between the control device 5 and the non-pump-equipped control device 5: a ground line L2, a data communication line L3, and a power / clock signal line L5. .
[0067]
Further, there is an advantage that the wire harness of the power source can be deleted compared to the second embodiment.
As an application example of the present embodiment, as shown in FIG. 11, a comparison circuit 32 as communication start determination means is connected to the output side (point b) of the filter circuit 8 instead of the pulse counter 31, and b is compared by the comparator 32a. The potential at the point may be compared with the comparison voltage value Vref, and when the potential at the point b exceeds the comparison voltage value Vref (when predetermined power is sent), it may be determined that communication is started.
(Fourth embodiment)
Next, the fourth embodiment will be described focusing on the differences from the first to third embodiments.
[0068]
This embodiment has a self-diagnosis function shown in FIG. The process of FIG. 12 is activated every predetermined time.
First, the CPU 13 serving as the abnormality determination means determines whether or not a data communication request has been made in step 401, and when a data communication request is made, starts a time measuring operation in step 402. That is, in FIG. 2, the timing operation is started after the transistor 16 of the step 104 is turned on, in FIG. 6, the timing operation is started after the transmission of the clock signal of the step 204, and in FIG. The clocking operation starts after sending the data.
[0069]
Then, the CPU 13 determines whether or not a predetermined time has elapsed in step 403, and determines whether or not there is response data in the tap 404 when the predetermined time has elapsed. If there is no response data, the CPU 13 performs control using standard data in step 405 and performs warning processing. The warning process specifically refers to a warning lamp lighting or a warning by a buzzer.
[0070]
In this way, in this embodiment, the CPU 13 (abnormality determination means) determines that there is a communication abnormality when no data is received within a predetermined time after instructing the start of communication. When a failure occurs or a communication wire is disconnected, control using a standard value or warning can be performed.
[0071]
In the first to fourth embodiments, an OTPROM may be used instead of the EEPROM 6 as the storage element.
[0072]
【The invention's effect】
  As described above in detail, according to the first aspect of the present invention, it is easy to use a simple configuration.And surelyIt exhibits an excellent effect that can determine the start of communication.
[0073]
  Claim2According to the invention described in claim1In addition to the effects of the described invention, it is possible to detect communication abnormality and take various countermeasures.
[Brief description of the drawings]
FIG. 1 is an overall view of a control apparatus for a diesel engine fuel injection pump according to a first embodiment;
FIG. 2 is a flowchart of correction data communication processing.
FIG. 3 is a timing chart.
FIG. 4 is a data flowchart showing processing up to calculation of a fuel injection amount.
FIG. 5 is an overall view of a control device for a fuel injection pump for a diesel engine according to a second embodiment.
FIG. 6 is a flowchart of correction data communication processing.
FIG. 7 is a timing chart.
FIG. 8 is an overall view of a control device for a fuel injection pump for a diesel engine according to a third embodiment.
FIG. 9 is a flowchart of correction data communication processing.
FIG. 10 is a timing chart.
FIG. 11 is an overall view of a control device for a diesel engine fuel injection pump according to an application example of the third embodiment.
FIG. 12 is a flowchart of the fourth embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Diesel fuel injection pump, 4 ... Pump mounting side control apparatus, 5 ... Pump non-mounting side control apparatus, 6 ... EEPROM as memory element, 7 ... Serial communication interface as communication means, 10 ... As communication start judgment means 13... Control circuit, voltage level changing means, clock signal output means, CPU as abnormality determination means, 29... Edge detection circuit as communication start determination means, 31... Pulse counter as communication start determination means, 32 ... Comparison circuit as communication start determination means, L1 ... power supply line, L4 ... clock signal line, L5 ... power supply / clock signal line

Claims (2)

A pump-mounted device that is mounted on a fuel injection pump that supplies fuel to a diesel engine, and that has a storage element that stores data on the difference between the fuel injection pumps and a communication means for transferring the data stored in the storage element; ,
The engine operation state is output using the data of the storage element that is not mounted on the fuel injection pump and outputs a communication start command of data stored in the storage element and transferred by the communication means in response to the communication start command. A fuel injection pump control device comprising a non-pump-equipped device having a control means for driving the fuel injection pump according to
A power supply / clock signal line that sends a clock signal as a power source from the non-pump-equipped device to the pump-equipped device;
A clock signal output stage that is provided in a non-pump mounted device and outputs a clock signal as a power source to the power supply / clock signal line;
Provided on the pump-mounted device, monitor the power / clock signal line, convert the clock signal sent to power by the signal-power conversion circuit, and the power obtained by the conversion has reached a predetermined value And a communication start determining means for determining data communication when a communication start command is output when it is determined that predetermined power has been transmitted. Control device. Provided non-pump side device, the control device of the fuel injection pump according to claim 1 provided with the abnormality determination means determines that a communication abnormality when there is no reception of data within a predetermined time after instructing the start of communication .

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