JPH0981207A - Electronic device - Google Patents

Abstract

It is possible to optimize data transfer when data is transferred between both devices by including a storage element in one device and a control means in the other device. A pump mounting side control device 4 is mounted on a fuel injection pump 1 for supplying fuel to a diesel engine,
The OTPROM 6 stores the data of the machine difference for each fuel injection pump. The communication interface 8 continuously sends the data of the OTPROM 6 from the pump-equipped side control device 4 to the non-pump-mounted side control device 5 with the head identification data added. The CPU 14 reads the correction data after confirming the reception of the head identification data. The CPU 14 uses this data to control the actuators 2 and 3 in accordance with the engine operating state to drive the fuel injection pump 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device that transfers data stored in a storage element by serial communication and performs control based on the data. For example, fuel in a fuel injection pump that supplies fuel to a diesel engine. It is suitable for a control device that controls the injection amount, the fuel injection timing, and the like.

[0002]

2. Description of the Related Art There is a technique of mounting a control device including a memory element on a fuel injection pump in order to correct the characteristic variation of a fuel injection pump for a diesel engine (for example, Japanese Patent Laid-Open No. 61-1832). This technique will be described in more detail. As shown in FIG. 15, a control device 51 is mounted on the fuel injection pump 50, and the control device 51 includes a CPU 52.
A communication buffer 53, an interface signal input / output buffer 54, a power supply circuit 55, an input signal buffer 56, a characteristic variation storage element 57, and an actuator drive circuit 58. The power supply circuit 55 receives power from the battery 59 and supplies a predetermined voltage to each device. Also, CP
The U52 takes in various sensor signals via the input signal buffer 56 and performs data communication with the external control device 60 via the communication buffer 53. Further, the CPU 52
Exchanges interface signals (flag data such as an abnormality flag and a start start flag) with an external control device 60 via the interface signal input / output buffer 54. The CPU 52 outputs a drive signal to the injection amount control actuator 61 via the actuator drive circuit 58 using the data stored in the characteristic variation storage element 57 to control the injection amount, and at the same time, the actuator drive circuit 58.
A drive signal is output to the injection timing control actuator 62 via the to control the injection timing.

That is, in the diesel fuel injection pump, mechanical factors such as component processing accuracy and assembly accuracy of constituent parts, or injection amount control actuators 61 and injection timing control actuators mounted on individual pumps are used. 62
There are variations in performance among individuals due to electrical and magnetic factors such as the responsiveness of the above, or the output characteristics of various sensors mounted on each pump. Therefore, in the characteristic variation storage element 57 mounted on the injection pump, the actual fuel injection amount or the fuel injection timing with respect to the control command value of the fuel injection amount or the fuel injection timing is kept within an appropriate target tolerance to improve the control accuracy. Therefore, the correction data unique to each injection pump is stored based on the characteristic difference from the diesel fuel injection pump having the standard characteristics, and this is reflected in the control.

[0004]

However, as shown in FIG. 15, both devices 51 and 60 must be provided with CPUs, respectively, which complicates the structure. Therefore, it is conceivable that a CPU is provided only in the control device 60, the data of the storage element 57 is transferred to the CPU of the control device 60, and the CPU controls the actuators 61 and 62 based on this data. However, various problems remain in the transfer of data between the control device 51 and the control device 60. For example, a specific method has been established for establishing a technique for reliably transferring data, saving power, and synchronizing (more specifically, giving a clock signal). Absent.

Therefore, an object of the present invention is to provide an electronic device capable of optimizing data transfer when data is transferred between both devices by providing a storage element in one device and a control means in the other device. To provide.

[0006]

According to a first aspect of the present invention, there is provided a first device having a storage element storing data,
A second device having control means for driving the actuator using the data stored in the storage element; and a communication line for transferring the data stored in the storage element to the second device by serial communication. Data sending means for continuously sending the data of the storage element from the first device to the second device in the form of giving a head identifier, and storing the data after confirming the reception of the head identifier in the second device. The gist is an electronic device provided with a data reading means for reading data of an element.

According to a second aspect of the present invention, there is provided a first device having a storage element storing data, and a second device having a control means for driving the actuator using the data stored in the storage element. A communication line for transferring the data stored in the storage element to the second device by serial communication; a power supply line for supplying electric power from the second device to the first device; And a power supply control means for supplying power from the second device to the first device using the power supply line prior to the data transfer and ending the power supply at the end of the data transfer. The electronic device provided is the gist.

According to a third aspect of the invention, there is provided a first device having a storage element storing data, and a second device having a control means for driving the actuator using the data stored in the storage element. A communication line for transferring the data stored in the storage element to the second device by synchronous serial communication; and a clock signal line for supplying a clock signal from the second device to the first device. A clock that is provided in the second device and supplies a clock signal from the second device to the first device using the clock signal line at the start of the data transfer and ends the supply of the clock signal at the end of the data transfer The gist is an electronic device provided with a signal supply control means.

According to a fourth aspect of the present invention, the electronic device according to any one of the first to third aspects is a device for controlling a fuel injection pump that supplies fuel to an engine. The device of No. 1 is mounted on the fuel injection pump, the device of the second is not mounted on the fuel injection pump, data of the machine difference for each fuel injection pump is stored in the storage element, and the control unit Uses the data stored in the storage element to drive the fuel injection pump according to the engine operating state. (Operation) According to the invention described in claim 1, data is stored in the storage element of the first device. This data is transferred to the second device by serial communication using a communication line,
In the second device, the control means drives the actuator using the data.

At the time of the above-mentioned communication, the data sending means continuously sends the data of the storage element to the second equipment from the first equipment in the form of giving the head identifier, and the data reading means is the second equipment.
The device reads the data in the storage element after confirming the reception of the head identifier. At this time, even if the head identifier cannot be received for some reason, the data is fetched again based on the data sent next, and the data in the storage element is reliably fetched in this way. Be seen.

According to the invention described in claim 2, data is stored in the storage element of the first device. This data is transferred to the second device by serial communication using the communication line, and the actuator is driven using the data by the control means in the second device.

In the above-mentioned communication, the power supply control means supplies the power from the second device to the first device by using the power supply line prior to the data transfer and ends the power supply when the data transfer ends. To do. As a result, the power consumption is minimal.

According to the third aspect of the invention, data is stored in the storage element of the first device. This data is transferred to the second device by synchronous serial communication using the communication line, and the actuator is driven using the data by the control means in the second device.

In the above communication, the clock signal supply control means supplies the clock signal from the second device to the first device using the clock signal line at the start of data transfer, and at the end of the data transfer, the clock signal supply control means supplies the clock signal to the first device. Supply is terminated.
As a result, the clock signal is minimal.

According to the invention described in claim 4, according to claim 1 of the present invention,
In the invention according to any one of items 1 to 3, the first device is mounted on the fuel injection pump, the second device is not mounted on the fuel injection pump, and the storage element is a device for each fuel injection pump. The difference data is stored, and the control means drives the fuel injection pump according to the engine operating state by using the data stored in the storage element. At this time, it is possible to optimize the technique for reliably transferring data, saving the amount of electric power, and giving a clock signal.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) A first embodiment of the present invention will be described below with reference to the drawings.

In the present embodiment, the present invention is embodied as 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.

A diesel fuel injection pump 1 (control object) for supplying fuel to a diesel engine has an injection amount control actuator 2 and an injection timing control actuator 3 for electronically controlling the fuel injection amount and the fuel injection timing. Is provided. 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. Consists of The non-pump mounted control device 5 is packaged as an electronic control unit (ECU).

The pump-mounted control device 4 and the non-pump-mounted control device 5 are capable of clock-synchronous serial communication.
The correction data stored in the ROM 6 is transferred to the pump non-installation side control device 5, stored in the backup memory 7 of the pump non-installation side control device 5, and the actuators 2 and 3 are drive-controlled using the correction data. It has become.

Hereinafter, the details will be described. The pump-mounted control device 4 includes an OTPROM (characteristic variation storage element) 6 as a storage element, a serial communication interface 8 as a data transmission unit, a communication buffer 9,
It comprises an input filter (noise filter) 10, a power supply capacitor 11, and backflow prevention diodes 12 and 13. The OTPROM 6 is a writable non-volatile storage element, and the OTPROM 6 stores information on the machine difference for each fuel injection pump. This data is obtained by actually injecting fuel at the time of the shipping inspection process from the factory of the fuel injection pump 1 to check the injection characteristic, and the data corresponding to the deviation from the standard injection characteristic of the pump is stored as correction data. It was what I had. The OTPROM 6 is an element that does not require a power supply for holding data but needs a power supply for access.

FIG. 2 shows the data stored in the OTPROM 6. In the head identification data storage area A1, 1-byte head identification data 1, 1-byte head identification data 2,
... 1-byte head identification data M (M; predetermined integer) is stored. Further, in the correction data storage area A2, 1-byte correction data 1, 1-byte correction data 2,
... 1-byte correction data N (N; predetermined integer) is stored. Further, the checksum storage area A3 stores a 1-byte checksum for the above-mentioned correction data.

The communication buffer 9 in FIG. 1 is for performing signal level conversion or impedance conversion. As described above, the control device 4 is mounted on the diesel fuel injection pump 1, and even if the diesel fuel injection pump 1 is replaced, it is not necessary to readjust the control unit.
It is managed integrally with the diesel fuel injection pump 1.

Incidentally, instead of the OTPROM 6, EPRO
Other non-volatile storage elements such as M and EEPROM may be used. The non-pump side control device 5 performs various calculations regarding control of the diesel fuel injection pump 1, and includes a CPU 14, an input signal buffer 15, an analog / digital converter (ADC) 16, a power supply circuit 17, and a PN.
It includes a P-transistor 18, a resistor 19, a communication buffer 20, an actuator drive circuit 21, a ROM 22, and a backup memory 7. The power supply circuit 17 is supplied with power from the battery 25 via the ignition key switch (engine start switch) 24 and supplies a predetermined voltage to each device (circuit) of the pump non-installed side control device 5. The CPU 14 takes in various sensor signals via the input signal buffer 15. When the sensor signal is an analog signal, the ADC 16 converts it into a digital value and fetches it. 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 temperature signal from an intake temperature sensor, It is a water temperature signal or the like from an engine cooling water temperature sensor.

The ROM 22 stores the matching data for each engine model (control data when there is no pump difference). That is, the ROM 22 functions as a storage element for storing the central value control data. ROM22 is CP
Although it is an external ROM of U14, it may be a ROM with a built-in CPU.

The backup memory 7 is a writable storage element in which data is retained by the power supply from the battery 25 even when the ignition key switch 24 is turned off, and the OTPROM 6 of the pump-side control device 4 is stored.
Is stored. This is because the correction data once received by communication is supplied with power only to the backup memory 7 when the ignition key switch 24 is turned off as well as when the power is supplied while the engine is operating. This is to save the correction data and minimize the frequency of communication. That is,
The backup memory 7 functions as a storage element for storing correction data. Although the backup memory 7 is an external memory of the CPU 14, it may be a memory built in the CPU.

The non-pump mounted control device 5 and the pump mounted control device 4 are connected by three signal lines L1 to L3 for communication. PNP of non-pump side controller 5
The power supply voltage V _cc (5
Volt) and PNP transistor 18
The base terminal of is connected to the CPU 14. further,
The collector terminal of the PNP transistor 18 is connected to the capacitor 11 via the input filter 10 and the diode 12 of the pump-mounted control device 4 through the resistor 19 through the power supply / clock signal line L1. At the same time, the power supply / clock signal line L1 is branched on the upstream side of the diode 12 inside the pump-mounted control device 4 and connected to the serial communication interface 8. In the pump-mounted control device 4, the power supply capacitor 11 is connected to the OTPROM 6 via the diode 13, and
It is connected to the serial communication interface 8. Then, the CPU 14 turns on / off the transistor 18 to send a pulse signal of L level (ground potential) and H level (V _cc potential; 5 V) to the pump mounting side control device 4 through the power supply / clock signal line L1. To do. This pulse signal is sent to the serial communication interface 8 after removing noise through the input filter 10. The signal is a clock signal for the serial communication interface 8. The pulse signal from the power supply / clock signal line L1 serves as a power source for the OTPROM 6 and the serial communication interface 8. That is, power is stored by the power supply capacitor 11, and the OTPROM 6
Then, power is supplied to the serial communication interface 8.

The serial communication interface 8 of the pump-equipped control device 4 includes a communication buffer 9, a serial communication line L2, and a communication buffer 2 in the non-pump-mounted control device 5.
It is connected to the CPU 14 via 0. Further, the ground line L3 directly connects the ground potential of the non-pump side control device 5 side and the ground potential of the pump side control device 4 and uses them as operation reference potentials. If the fluctuation of the ground potential is not a problem, the pump-side control device 4 may be indirectly connected to the ground potential common to the non-pump-side control device 5 via the fuel injection pump 1.

At the time of data communication during normal control, by connecting only these three lines L1, L2, L3, a writable OTP in the pump-mounted control device 4 is connected.
The correction data previously written in the ROM 6 can be transmitted to the pump non-mounting side control device 5. Further, the write voltage supply line L4 is provided as a terminal of the pump-mounted side control device 4, and this terminal is stored in the writable OTPROM 6 in the pump-mounted side control device 4 at the time of shipment from the factory or after shipment. Used only when writing or rewriting. That is, the data input tool 26 shown by the alternate long and short dash line in FIG. 1 is connected to L1 to L4, and a write voltage is applied to the write voltage supply line L4 to input data. In this example, the serial communication line L2 is used as the input signal line for write data, but an input signal line used only during writing may be separately provided.

At the time of communication, the non-pump mounted control device 5
In synchronization with the clock signal output from the so-called clock, correction data is sequentially output from the OTPROM 6 in the pump-side control device 4 to the serial communication line L2 via the serial communication interface 8 and the communication buffer 9 bit by bit. Synchronous communication is performed. At this time, the serial communication interface 8 repeatedly sends the data of the OTPROM 6 as long as the power supply and the clock signal are supplied. That is, the head identification data is added before the correction data, and a checksum is added after the correction data so that the correction data is repeatedly and continuously sent.

The actuator drive circuit 21 of the non-pump side control device 5 and the injection amount control actuator 2 of the diesel fuel injection pump 1 are connected by a drive line 35, and the actuator drive circuit 21 and injection timing control The actuator 3 is connected by a drive line 36.

The CPU 14 of the non-pump side control device 5 performs an operation using the compatible data for each engine model stored in the ROM 22 (data assuming that there is no pump difference) based on various sensor signals, and the operation is performed. Based on the result, the injection amount control actuator drive signal SG1 and the injection timing control actuator drive signal SG2 are output through the actuator drive circuit 21 so that the fuel injection amount and fuel injection timing required according to the engine operating state are obtained. To do. The drive signals SG1 and SG2 drive the injection amount control actuator 2 and the injection timing control actuator 3.

At this time, because the diesel fuel injection pump 1 has characteristic variations among individuals due to machining accuracy and assembly accuracy, even if the same drive signal is output in the same engine operating state, The actual fuel injection amount and the fuel injection timing vary depending on the difference between the fuel injection pumps. Therefore, the OTP stored in the backup memory 7
The correction data is stored in the ROM 6 so that the characteristic variations are finely corrected, and the performance of the engine is improved by setting the fuel injection amount and the fuel injection timing as close to the required values as possible.

As described above, the CPU 14 has the OTPROM 6
The actuators 2 and 3 of the diesel fuel injection pump 1 are drive-controlled using the information on the machine difference for each fuel injection pump. The details of the operation of the control device for the fuel injection pump will be described below with reference to the flowcharts of FIGS. 3, 4 and 5 and the time chart of FIG.

3 and 4 show a processing routine for reading communication data sent from the pump-mounted control device 4 after the ignition key switch 24 is turned on. Further, FIG. 5 shows a processing routine for controlling the drive of the transistor 18. These processes are started only once after the ignition key switch 24 is turned on.

When the ignition key switch 24 is turned on (timing t1 in FIG. 6), power is supplied from the battery 25 to the power supply circuit 17, and when a predetermined time T1 has elapsed (timing t2 in FIG. 6), the power supply is turned on. A reset signal is output from the circuit 17 to the CPU 14. This reset signal activates the CPU 14 to start the processing of FIGS. In FIG. 5, the CPU 14 immediately turns on the transistor 18 by the input of the reset signal in step 151, and passes through the resistor 19, the power supply / clock signal line L1, the input filter 10 and the diode 12, and the capacitor 11
To start charging. In step 152, the CPU 14 determines whether or not the predetermined time T2 has elapsed, and if not, returns to step 151. This predetermined time T2 is
This is the time required from the start of power supply to the completion of capacitor charging, during which initialization of communication such as flags and counters is performed. Then, when the predetermined time T2 has elapsed in step 152 (timing t3 in FIG. 6), the CPU 14 in step 153 sets the transistor 18 at a predetermined frequency based on the oscillation signal from the oscillator 23 in FIG.
Is controlled to be turned on / off and a clock signal is transmitted. After that,
This clock signal sending operation is continuously performed.

The capacitor 11 is repeatedly charged and discharged due to the voltage change of the clock signal, but the fluctuation of the voltage level is set so as not to fall below the minimum operating voltage of the pump-mounted control device 4. This will be described with reference to FIG. Figure 7
Shows a relationship between a clock signal line operation waveform supplied to the pump mounting side control device 4 by the power supply / clock signal line L1 and a charge / discharge waveform of the power supply capacitor 11 as a conceptual diagram. Operating power supply voltage of control device 4 on the pump side (V _cc
= 5 V) Allowable voltage fluctuation range ΔV (for example,
0.5 volt, communication clock cycle T (for example, 20 μ
s) is shown in the figure.

The charging / discharging waveform of the power supply capacitor is synchronized with the operation waveform of the clock signal line, and is charged at the H level and discharged at the L level, and this is repeated. At this time, the H level means the supply of the operating power supply voltage, and the current supply capacity thereof is larger than the current consumption of the pump-mounted control device 4. or,
The L level is the ground level of the communication system, but the voltage drop due to the discharge at that time does not fall below the minimum operating voltage during the L level period. The power supply capacitor 11 is charged in the communication idle state, and charging and discharging are repeated in synchronization with the change of the clock signal during communication.

In the serial communication interface 8, the data stored in the OTPROM 6 is continuously and repeatedly sent through the serial communication line L2 in the order of the head identification data, the correction data and the checksum in response to this clock signal.

On the other hand, the CPU 14 in FIG.
The data reading is started at the timing of 4. CP
In step 101, U14 checks whether the check code of the backup memory 7 (correction data storage storage element) is normal. This check code is for checking whether the data stored in the backup memory 7 is valid, and is performed by a sum check or the like. Note that this check may be performed by a mirror check. If the CPU 14 is normal, the processing ends without any processing in order to minimize the communication frequency. If the check code is abnormal, the CPU 14 proceeds to step 102 and permits reception. CPU 14 sets 1 in step 103
Receives bytes of data. At this time, an error check such as parity, framing, or overrun may be performed on 1-byte data. In step 104, the CPU 14 determines whether the head identification completion flag F1 is "1". Initially, F1 = 0 due to initialization, so CPU1
In step 4, the process proceeds to step 105, and it is determined whether the received data of 1 byte is the head identification data. If it is the head identification data (timing of t5 in FIG. 6), step 106
The head identification data counter C1 is incremented by "1". Then, in step 107, it is judged whether or not the count value by the head identification data counter C1 is "M" (the number of bytes of the head identification data), and the count value is "M".
If not, the process returns to step 103.

In this way, steps 103 → 104 → 1
Repeat step 05 → 106 → 107 → 103 and step 1
When the count value of the head identification data counter C1 reaches "M" in 07 (timing t6 in FIG. 6), the process proceeds to step 108, the head identification completion flag F1 is set to "1", and the process returns to step 103.

In this way, the leading identification data is identified by the processing of steps 105 to 108. If an error occurs during the reception of the head identification data, step 105
To step 109, the flags F1, F2, F
3. Clear all counters C1, C2 and sum value (=
0) and shifts to step 103. As a result, the data read operation is performed again by the same procedure as described above.

Since the head identification completion flag F1 is "1" in the next step 104 after the reception of the head identification data is completed, the process proceeds to step 110 of FIG. 4 and the correction data reception completion flag F2 is set to "1". It is determined whether it is "1". Initially, F2 = 0 due to initialization, so
The CPU 14 proceeds to step 111, stores the received data of 1 byte in the backup memory 7, and stores it in step 11
In step 2, the sum value is added to the received data to update the sum value.
At this time, in order to limit the number of digits, only the lower 8 bits are enabled and the other upper digits are disabled. Initially, the sum value is "0" due to initialization. Furthermore, CP
The U14 increments the correction data counter C2 by "1" in step 113. Initially, the count value of the correction data counter C2 is "0" due to initialization.
Then, the CPU 14 determines in step 114 whether the count value of the correction data counter C2 is "N" (the number of bytes of the correction data), and if the count value is not "N", the CPU 14 proceeds to step 103 of FIG. Return.

Thus, steps 103 → 104 → 1
10 → 111 → 112 → 113 → 114 → 103 is repeated, and in step 114, the correction data counter C2
Becomes "N" (timing of t7 in FIG. 6), the CPU
14 shifts to step 115 to set the correction data reception completion flag F2 to "1" and returns to step 103.

In the next step 110, since the correction data reception completion flag F2 is "1", CP
The U14 proceeds to step 116 and determines whether or not the sum value as the data sent and the sum value at step 112 match, and if they match, the check sum value sent at step 117 is stored in the backup memory 7. Then, the data reception completion flag F3 is set to "1" at step 118 (timing t8 in FIG. 6). Then step 1
Reception is prohibited at 19.

As described above, until the data reception completion flag F3 becomes "1", the CPU 14 has no data to be reflected in the correction, so that the R of the pump non-mounting side control device 5 is R.
The control based on the central value control data stored in the OM 22 is continuously executed.

On the other hand, if the checksum value sent in step 116 and the sum value in step 112 do not match, the CPU 14 determines that an error has occurred due to noise or the like during the transmission of the correction data, and the step of FIG. In step 109, the flags F1, F2, F3, the counters C1, C2 and the sum value are all cleared (= 0),
Control goes to step 103. As a result, the data read operation is performed again by the same procedure as described above (data read at t8 to t9 indicated by the alternate long and short dash line in FIG. 6).

FIG. 8 is a data flow chart showing the process up to calculation of the fuel injection amount in the CPU 14 of the non-pump side control device 5 (control device main body). First, the basic injection amount calculation unit 27 calculates the basic injection amount Qa from the accelerator opening and the engine speed. On the other hand, the basic maximum injection amount calculation unit 28 calculates the basic maximum injection amount Qb from the engine speed and the intake pressure, and the correction calculation unit 29 further uses the correction coefficient K1 based on the intake air temperature and the correction coefficient K2 based on the water temperature. After correcting the amount Qb, the corrected basic maximum injection amount Qb '
(= Qb · K1 · K2) is calculated. Then, the selector 30 selects the smaller one of the basic injection amount Qa and the corrected basic maximum injection amount Qb ', and the addition unit 31 performs acceleration correction based on the accelerator opening degree on the minimum value.

On the other hand, the machine difference correction calculation unit 32 receives the correction data received as serial communication data by the pump-mounted control device 4, the engine speed, and the basic injection amount calculation unit 27.
Is calculated from the basic injection amount Qa. Then, the adder / subtractor 33 compares the output value of the adder 31 with the machine difference variation correction amount Δ from the machine difference correction calculator 32.
By adding or subtracting Q, a correction is made in accordance with the machine difference for each injection pump. Further, the addition / subtraction unit 34 adds / subtracts various correction values to / from the output value of the addition / subtraction unit 33, and then outputs the calculation result as the final injection amount.

As described above, the pump-mounted control device 4 corrects the characteristic variation correction data received as the serial communication data according to the variation in the machine difference between the injection pumps, and reflects it in the final injection amount.

Here, as a correction method using the correction data, in the example of FIG. 8, the basic injection amount is used as a parameter when calculating the fuel injection correction amount (machine difference variation correction value ΔQ) corresponding to each engine speed. As a result, fine correction control can be performed for various engine operating conditions, and performance can be improved.

With respect to the fuel injection timing, the method is not particularly limited, but the same correction can be performed. Also, based on the respective calculation results, the 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. It is also possible to correct characteristics such as a few responsiveness.

As described above, in the present embodiment, the pump mounting side control device 4 as the first device and the pump non-mounting side control device 5 as the second device are provided with the power supply / clock signal line L1 and the serial communication. In the system connected by the line L2, the serial communication interface 8 as the data sending means transfers the data of the OTPROM 6 (storage element) from the pump-mounted side control device 4 to the pump-unmounted side by adding the head identification data as the head identifier. Control equipment 5
The CPU 14 as the control means and the data reading means reads the data of the OTPROM 6 after confirming the reception of the head identification data. Therefore, when the data is taken in, even if the head identification data cannot be received for some reason (for example, a momentary power interruption occurs at the time of transmitting the head identification data), the process proceeds from step 105 to step 109 in FIG. Then, the flag, counter, etc. are cleared, and the process proceeds to step 103 to fetch the data again based on the data sent next. In this way, the data in the OTPROM 6 is surely fetched.

Further, although it is necessary to identify the head identification data, no special measures are taken on the pump-non-installed side control device 5 side,
Data can be received. That is, it is possible to eliminate the need for processing such as synchronizing with the control line and outputting a request command. (Second Embodiment) Next, a second embodiment will be described focusing on differences from the first embodiment.

FIG. 9 shows the OTPR in this embodiment.
The data stored in OM6 is shown. There is no head identification data storage area A1, but a correction data storage area A2 and a checksum storage area A3 are prepared. Also, when communicating, the data output after power supply is always the first (correction data 1)
It is supposed to be done from. In other words, it is not necessary for the other side (reception side) to synchronize with the head identification data.

Then, the processing shown in FIGS. 10 and 11 is executed. FIG. 10 shows a data reading processing routine, and FIG.
Reference numeral 1 is a processing routine for controlling the driving of the transistor 18. Further, FIG. 12 shows a time chart.

When the ignition key switch 24 is turned on (timing t11 in FIG. 12), the power supply circuit 17
Is supplied with power from the battery 25 for a predetermined time T11.
When (time t12 in FIG. 12) has elapsed, the power supply circuit 17 outputs a reset signal to the CPU 14. The CPU 14 is started by the input of the reset signal and executes the processing of FIGS.

In FIG. 11, the CPU 14 executes step 25.
At 1, system initialization processing including flags and counters is performed. In this example, T12 indicates the processing time. T
When 12 has passed (timing of t13 in FIG. 12), C
In step 252, the PU 14 turns on the transistor 18 to supply the capacitor 1 through the power supply / clock signal line L1.
1 is started. Then, the CPU 14 executes step 2
At 53, it is determined whether the predetermined time T13 has elapsed, and if not, the process returns to step 252. The predetermined time T13 is the time required from the start of power supply to the completion of capacitor charging. When the predetermined time T13 has elapsed (t in FIG.
14 timing), the CPU 14 turns on / off the transistor 18 in step 254 to send out a clock signal. After that, the operation of transmitting the clock signal is continuously performed.

In the serial communication interface 8, the data stored in the OTPROM 6 is sent out through the serial communication line L2 in the order of correction data and checksum in response to this clock signal.

On the other hand, the CPU 14 in FIG.
Data reading is started at the timing of t14 (start of transmission of clock signal). In step 201, the CPU 14 checks in advance whether the check code of the backup memory 7 (correction data storage storage element) is normal. If the CPU 14 is normal, the processing ends without any processing in order to minimize the communication frequency. Therefore, in this case, the processing for reading data after the timing t13 in FIG. 12 is not performed. If the check code is abnormal, the CPU 14 proceeds to step 202 and permits reception.

The CPU 14 receives one byte of data in step 203, determines in step 210 whether the correction data reception completion flag F2 is "1",
If it is not "1", the process proceeds to step 211, the received data is stored in the backup memory 7, and step 21
In step 2, the sum value is added to the received data to update the sum value.
Further, in step 213, the correction data counter C2 is incremented by "1". Then, the CPU 14 determines in step 214 whether the count value of the correction data counter C2 is "N" (the number of bytes of the correction data), and if the count value is not "N", the step 2
Return to 03.

In this way, steps 203 → 210 → 2
11 → 212 → 213 → 214 → 203 is repeated, and the correction data counter C2 is “N” in step 214.
When (time t15 in FIG. 12) comes, the CPU 14
Shifts to step 215, sets the correction data reception completion flag F2 to "1", and returns to step 203.

In the next step 210, since the correction data reception completion flag F2 is "1", the sum value sent in step 216 and step 2
It is determined whether or not the sum value of 12 matches the sum value. If they match, the sum value sent in step 217 is stored in the backup memory 7, and the data reception completion flag F3 is set to "1" in step 218 (see FIG. 12). timing of t16). Further, reception is prohibited in step 219.

If the sum value sent in step 216 and the sum value in step 212 do not match, the CPU 14 bypasses steps 217 to 218 and sets the retransmission request flag F4 to "1" in step 220 to set step 219. After the reception is prohibited by, the processing ends. At the same time, also in step 255 of FIG. 11, the process is forcibly moved to step 256 to turn off the transistor. Also, if any abnormality occurs during communication, step 20
If F3 = 0 remains in spite of a lapse of a predetermined time from the start of communication due to the failure of reception at 3
The transistor is turned off by forcibly shifting to step 256 in FIG. Due to the occurrence of abnormality in this way, F3 =
Since it remains 0, and there is no data to be reflected in the correction, the CPU 14 performs control using the central value control data stored in the ROM 22 of the non-pump side control device 5. However, although not shown in the figure, when the flag F4 is "1", communication is tried again by the same procedure after a certain time has elapsed.

The CPU 14 monitors the data reception completion flag F3 in step 255 of FIG. 11, and when the data communication is normally completed, F3 = 1, so that step 2
Moving to 56, the transistor 18 is turned off. As a result, the supply of the clock signal and the power supply are terminated.

As described above, according to the present embodiment, the CPU 14 as the control means and the power supply control means uses the power supply / clock signal line L1 to pump electric power from the non-pump side control device 5 prior to data transfer. It is supplied to the mounting side control device 4 (steps 251, 2 in FIG. 11).
52, 253, 254) and the power supply is terminated at the end of the data transfer (steps 255, 256 in FIG. 11). As a result, the power consumption is minimal. Further, the CPU 14 as the control means and the clock signal supply control means supplies a clock signal from the pump non-mounting side control equipment 5 to the pump mounting side control equipment 4 by using the power supply and clock signal line L1 at the start of data transfer ( Step 25 of FIG.
3, 254), the supply of the clock signal is terminated when the data transfer is completed (steps 255, 256 in FIG. 11). Therefore, the clock signal is minimized. In this way, the output of the clock signal is also minimized, so that it is possible to prevent the clock signal from radiating from the wire to cause noise and adversely affect other electronic devices.

In the present embodiment as well, in order to improve reliability by considering various kinds of errors, the same head identifier as in the first embodiment may be added. (Third Embodiment) Next, a third embodiment will be described focusing on differences from the second embodiment.

The data stored in the OTPROM 6 in this embodiment is the same as that shown in FIG.
In this example, the process shown in FIG. 13 is executed instead of the process shown in FIG. The processing shown in FIG. 10 is the same. Furthermore, FIG. 14 shows a time chart.

In this embodiment, the CPU 14 turns on the transistor in step 351 of FIG. 13 prior to the system initialization processing. After that, in step 354, on / off control of the transistor is performed. The data reception completion flag F3 is monitored in step 355, and when F3 = 1 (timing at t26 in FIG. 14), the process proceeds to step 356 to turn on the transistor 18. As a result, the output of the clock signal is terminated and the power supply is continued.

In the above description, the system for supplying the power and the clock signal through the line L1 which also serves as the power supply line and the clock signal line has been described, but the system may be provided with the power supply line and the clock signal line separately. Good.
In this case, (a) power is supplied prior to data transfer, and power supply is terminated at the end of data transfer;
(B) At least one of supplying the clock signal at the start of data transfer and ending the supply of the clock signal at the end of data transfer may be performed.

Further, if the clock oscillation source can be mounted in the pump mounting side control device 4, the sending of the clock signal from the pump non-mounting side control device 5 may be abolished and asynchronous serial communication may be performed. In that case, L1 will be used as a dedicated line for power supply.

Further, although the checksum is used as the block check character BCC for checking the correction data, horizontal parity may be used.

[0072]

As described in detail above, according to the invention described in claim 1, data can be surely taken in.

According to the second aspect of the invention, it is possible to transfer data with the minimum power. According to the invention described in claim 3, data can be transferred with a minimum amount of clock signals.

According to the invention of claim 4, claim 1
In addition to the effect of the invention described in any one of items 1 to 3, the data transfer can be optimized in the fuel injection pump control device.

[Brief description of drawings]

FIG. 1 is an overall view of a control device for a diesel fuel injection pump.

FIG. 2 is an explanatory diagram showing data storage contents according to the first embodiment.

FIG. 3 is a flowchart showing a data reading process according to the first embodiment.

FIG. 4 is a flowchart showing a data reading process according to the first embodiment.

FIG. 5 is a flowchart showing a driving process of a transistor according to the first embodiment.

FIG. 6 is a time chart showing various kinds of processing in the first embodiment.

FIG. 7 is a relationship diagram between a clock signal line operation waveform and a charge / discharge waveform.

FIG. 8 is a data flow chart showing a process up to calculation of a fuel injection amount.

FIG. 9 is an explanatory diagram showing data storage contents in the second and third embodiments.

FIG. 10 is a flowchart showing a data reading process in the second and third embodiments.

FIG. 11 is a flowchart showing a transistor driving process according to the second embodiment.

FIG. 12 is a time chart showing various kinds of processing in the second embodiment.

FIG. 13 is a flowchart showing a transistor driving process according to the third embodiment.

FIG. 14 is a time chart showing various processes in the third embodiment.

FIG. 15 is an overall view of a conventional control device for a fuel injection pump.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Diesel fuel injection pump, 2 ... Injection amount control actuator, 3 ... Injection timing control actuator, 4
... Pump-mounted control device as first device, 5 ... Second
No pump-side control equipment as equipment, 6 ... OTPROM as storage element, 8 ... Serial communication interface as data sending means, 14 ... Control means, data reading means, power supply control means, clock signal supply control means CPU, L1 ... Power supply and clock signal line,
L2 ... Serial communication line.

Claims (4)

[Claims] 1. A first device having a storage element for storing data
And a second device having control means for driving the actuator by using the data stored in the storage element, and the data stored in the storage element by the second serial communication.
And a communication line for transferring the data to the other device, and the first data of the storage element in the form of giving a head identifier.
And a data reading means for reading the data of the storage element after confirming the reception of the leading identifier in the second device. Electronic device to do. 2. A first device having a storage element for storing data
And a second device having control means for driving the actuator by using the data stored in the storage element, and the data stored in the storage element by the second serial communication.
Communication line for transferring the power to the device, a power supply line for supplying power from the second device to the first device, and a power supply line provided in the second device for connecting the power supply line prior to the data transfer. An electronic device, comprising: power supply from the second device to the first device by using the power supply control means for terminating the power supply at the end of the data transfer. 3. A first device having a storage element for storing data
And a second device having control means for driving an actuator using the data stored in the storage element, and transferring the data stored in the storage device to the second device by synchronous serial communication. And a clock signal line for supplying a clock signal from the second device to the first device, and a clock provided by the second device for using the clock signal line at the start of the data transfer. An electronic device comprising: a clock signal supply control means for supplying a signal from the second device to the first device and ending the supply of the clock signal at the end of the data transfer. 4. A device for controlling a fuel injection pump that supplies fuel to an engine, wherein the first device is mounted on the fuel injection pump, and the second device is the fuel injection pump. Data of the machine difference for each fuel injection pump is stored in the storage element, and the control means drives the fuel injection pump according to the engine operating state by using the data stored in the storage element. The electronic device according to claim 1.