JPH029181B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel injection advance angle measurement device for a fuel injection device for an internal combustion engine, and more specifically, the present invention relates to a fuel injection advance angle measuring device for a fuel injection device for an internal combustion engine, and more specifically, it is a device for automatically correcting installation errors of each sensor for detecting the fuel injection advance angle. The present invention relates to a fuel injection advance angle measuring device that can be used to measure the advance angle of fuel.

Conventional fuel injection advance angle measuring devices of this type include, for example, a top dead center sensor installed on the crankshaft of a mechanism to detect the timing when the piston of an internal combustion engine reaches the top dead center position, and a top dead center sensor installed on the crankshaft of the mechanism to detect the timing when the piston of the internal combustion engine reaches the top dead center position, and a top dead center sensor installed in the mechanism to detect the timing when the piston of the internal combustion engine reaches the top dead center position An injection timing sensor is provided on the rotating shaft of the injection pump to detect timing, and each of these sensors is mounted so as to obtain an electrical signal that accurately indicates the required timing. These sensors are installed using, for example, dowel marks engraved on the casing of the injection pump, but installation errors occur when connecting the engine and injection pump, and installation errors of each sensor occur. The walls are difficult to break, and therefore, it is necessary to make certain installation adjustments after installing the sensor.

For this installation adjustment, in the past, after each sensor was fixed at a predetermined position, the engine was driven at a predetermined rotational speed, and in this driving state, the injection timing of the injection pump and the injection timing detected by the timing sensor were determined. Based on this measurement result, the error lead angle data corresponding to the detected sensor installation error is set in the computer's storage device by operating the rotary switch, and the lead angle data due to the sensor installation error is stored. A method for obtaining data without measurement errors has been proposed (Japanese Unexamined Patent Publication No. 18529/1983). However, this conventional method requires a strobe light to detect sensor installation errors and requires manual adjustment, which requires a lot of man-hours and increases adjustment costs. There are some problems such as:

Therefore, an object of the present invention is to provide a fuel injection device for an internal combustion engine, which is capable of automatically correcting mechanical installation errors of a sensor at a desired timing, and facilitates sensor installation work. An object of the present invention is to provide a fuel injection advance angle measuring device.

The present invention includes a first signal generating means for outputting a first signal indicating the timing at which a piston of an internal combustion engine reaches a predetermined reference position, and a fuel injection device for injecting and supplying fuel to the internal combustion engine. a second signal generating means for outputting a second signal indicating injection start timing; and calculating a fuel injection advance value adjusted by a timer connected to the fuel injection device based on the first and second signals. a first means for controlling the timer so that the advance adjustment value by the timer becomes the most retarded value; a second means for obtaining injection advance value data output from the calculation means when the retard value control state is set; and comparing the injection advance value data obtained by the second means with predetermined reference data. and a third means for obtaining correction data by
The present invention is characterized in that an error in the injection advance value due to an installation error of the first and/or second signal generating means is corrected based on the correction data.

The most retarded angle value control by the first means may be configured, for example, to be performed when the engine speed is within a predetermined rotation range after the engine has started, and the designed maximum retarded angle value obtained in this way may be The value is a predetermined constant value determined by the type of fuel injection device and timer.
This predetermined constant value is given in advance as reference data, and by comparing the lead angle value data actually obtained during the most retarded angle control with the reference data, the The amount of error in the lead angle value that occurs can be obtained. By using the correction data indicating this error, it is possible to obtain data indicating an accurate advance angle value in which the error in the advance angle value caused by the installation error of each signal generating means has been corrected. Correction can be automatically performed at desired timing by electrical means.

Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

FIG. 1 shows a block diagram of an embodiment of a fuel injection advance angle measuring device according to the present invention. This fuel injection advance angle measuring device 1 is a diesel engine 2.
This is a device for measuring the fuel injection advance value in the fuel injection device 3 for injecting and supplying fuel to the fuel injection device 3. It has an injection timing sensor 7 provided on the driven shaft 6. These sensors 5 and 7 are both known sensors consisting of a combination of a timing plate and an electromagnetic pitch up coil, and the top dead center sensor 5 detects that the piston (not shown) of the diesel engine 2 is at top dead center. A pulse train signal consisting of pulses output every time the position is reached is output as a top dead center pulse signal _P1 , while a pulse train signal consisting of pulses output every time fuel is injected from the fuel injection device 3 is output from the injection timing sensor 7. A pulse train signal consisting of is output as an injection timing pulse signal _P2 .

The crankshaft 4 is connected to a driven shaft 6 via a transmission 8 and a hydraulic timer 9. By adjusting the hydraulic pressure supplied to the timer 9 by a timer control device 10, the crankshaft 4 and the driven shaft 6 can be arbitrarily set, and the fuel injection timing (advance angle) in the fuel injection device 3 can be adjusted. Since the fuel injection advance angle set as described above is calculated based on the top dead center pulse signal _P1 and the injection timing pulse signal _P2 , each pulse signal _P1 , _P2 is After being waveform-shaped by provided waveform shaping circuits 11 and 12, the signal is input to an arithmetic circuit 13. The arithmetic circuit 13
The output data D indicating the result of the injection advance angle calculated in is the output data D generated based on the installation error of the top dead center sensor 5 and the injection timing sensor 7.
is corrected in a correction circuit 14 for correcting the error, and the correction circuit 14 outputs advance value data Do that does not include any errors and accurately indicates the actual injection advance value at that time.

Next, a circuit for obtaining correction data Dc indicating an error in the injection advance angle due to a mounting error of each sensor 5, 7, which is necessary for performing a correction calculation in the above-mentioned correction circuit 14, will be described.

In order to detect the advance angle amount to be corrected, this device 1
is the most retarded angle that controls the advance angle adjustment value by timer 9 to be the slowest advance angle value in the advance angle adjustment range when the rotation speed of the diesel engine is within a predetermined speed range after the diesel engine has started. A control device 15 is provided. The most retarded angle control device 15 outputs a control signal S for most retarded angle control according to a predetermined condition, and the timer control device 10 adjusts the advance angle adjustment value by the timer 9 in accordance with this control signal S. Use the minimum advance angle value. The control signal S is also input to the comparison circuit 16 to which the output data D is input, and the control signal S
Output data D when is output, that is, output data D when the injection advance angle of the fuel injection device 3 is set to the slowest (smallest) advance value by the timer 9,
It is compared with the reference data Dr from the reference data generator 17, and data corresponding to the difference is sent to the comparison circuit 16.
After that, the control signal S is latched within, and thereafter is output as correction data Dc until the next control signal S is output.

The reference data Dr is data indicating the designed advance angle value θr that is to be adjusted when the timer 9 is in the most retarded angle control state, and is the output data D when the control signal S is output. Data indicating the difference θd (=θa−θr) between the advance angle value θa and the advance angle value θr indicated by is outputted as the correction data D _C. Therefore, the correction data D _C indicates the error in the output data D caused by the installation error of the sensors 5 and 7, and by calculating D - D _C in the correction circuit 14, the actual advance angle at that time can be determined. Lead angle value data D _p indicating the value will be obtained.

According to the above configuration, the correction data is obtained when the diesel engine is under predetermined operating conditions, and the data output from the arithmetic circuit is corrected using this data, so automatic calibration of the advance angle data is possible. It becomes possible. Therefore, mechanical adjustment after installation of each sensor 5, 7 is not required, so the adjustment process can be omitted, and assembly costs can be significantly reduced. In addition, changes over time in each part can be automatically adjusted. It can be calibrated and the injection advance angle can always be measured with high accuracy.

FIG. 2 shows a block diagram of an embodiment of an electronically controlled timer to which the present invention is applied. This electronically controlled timer 20 controls the timer 9 so that the injection advance value of the fuel injection device 3 for injecting and supplying fuel to the diesel engine 2 becomes an optimal value according to the operating state of the diesel engine 2. This is done electronically, and the same parts in FIG. 2 as those in FIG. 1 are given the same reference numerals and their explanations will be omitted.

Reference numeral 21 indicates a control calculation circuit including a microcomputer, and the control calculation circuit 21 receives the top dead center pulse signal P ₁ whose waveform has been shaped by the waveform shaping circuits 11 and 12, respectively, and the injection timing. While the pulse signal _P2 is input,
Data Dop indicating the operating state of the diesel engine 2 outputted from the operating state detector 22 is also input, and based on these input signals and data, the measurement of the fuel injection advance angle and the control of the fuel injection advance angle are performed. Calculations are performed for this purpose. The control data Dout from the control calculation circuit 21 is input to the timer control device 10, and optimal control of the injection advance angle by the timer 9 is performed in accordance with the control data Dout. Required control calculations in the control calculation circuit 21 are executed according to a predetermined program stored in a microcomputer (not shown) provided in the control calculation circuit 21.

FIG. 3 shows a flowchart of this control calculation program. The control operation of the electronically controlled timer 20 will be explained based on this flowchart. After the program is started, initialization is performed in step a, and then data is read (step b). Next, it is determined whether a detection completion flag EF indicating whether detection of the advance angle offset amount has been completed is "1" (step c).

If the lead angle offset amount has been detected and therefore the flag EF is "1", step d is executed.
The lead angle value is calculated by taking into account the offset amount detected in advance, and based on this result, the optimum lead angle value is calculated according to the engine operating condition at the time. Step e). Thereafter, control data _Dput for controlling the timer 9 so as to obtain the calculated optimum lead angle value is output (step f), and then the process returns to step b.

On the other hand, if the detection of the advance angle offset amount has not been completed and the flag EF is "0", the process advances to step g and checks whether or not the engine is rotating based on the data indicating the engine rotation speed. Only when the rotation of the engine is detected, the process proceeds to step h, and the timer 9 is most retarded. This most retarded angle control is executed by activating the most retarded angle control device 15 in response to the most retarded angle control signal Y output from the control calculation circuit 21.
The injection advance value of the fuel injection device 3 is set to the slowest advance value by the timer 9. Thereafter, it is determined whether the engine rotational speed N is between a predetermined rotational speed _N1 and _N2 (step i), and only if the determination result at step i is YES, The injection advance value θist at that time is calculated. This calculation is performed using the top dead center pulse signal _P1 and the injection timing pulse signal _P2.
It is carried out based on.

Therefore, the value of θist is the data of the advance angle value when the advance angle value of the fuel injection device 3 has reached the minimum value that can be adjusted by the timer 9, and the value of θist is the advance angle value θ. A determination is made in step k as to whether the value is between ₁ and θ ₂ .
The lead angle value range defined by θ ₁ and θ ₂ is determined by taking into consideration the variation in the value of θist caused by normal assembly errors of the sensors 5 and 7, and the value of θist is within the lead angle value range mentioned above. If it deviates from the data error, proceed to step p. If it is determined that the data deviation state continues to occur for t ₂ seconds (step p), a failure is displayed in step q. After performing the necessary backup processing, proceed to step d.

On the other hand, if the determination result in step k is YES, it is further determined in step l whether or not the determined state continues for t ₁ seconds, and only when the determination result in step l is YES, step Proceed to m.

In step m, it is determined whether the value of the variation Δθist of θist sampled for t ₁ second is less than a predetermined value k, and only if Δθist≦k,
The offset amount of the advance angle is detected (step n). Detection of the advance angle offset amount is the same as the operation of the comparison circuit 16 of the device shown in FIG. The reference data indicating the value and the data indicating the value of θist are compared, and the advance angle value according to the difference is detected as the offset amount.

When the offset amount detection is completed in step n, the detection completion flag EF is set to "1".
(Step o).

If the determination result in step m is NO, it is further determined whether the number M of times the determination result in step m is NO exceeds a predetermined number N (step r), and the determination result is If is YES, it is assumed that some abnormality has occurred, and step q is executed. If the determination result in step r is NO, no failure is displayed and the process proceeds to step d. Therefore, due to the influence of noise etc.
In the case where a state of Δθist>k temporarily occurs, if the cause is removed, the advance angle offset amount will be detected.

According to such a configuration, as in the case of the device shown in FIG. 1, errors in advance angle data caused by mounting errors of the sensors 5 and 7 are detected under predetermined operating conditions, and the advance angle control is controlled. Since the advance angle data for the fuel injection system is automatically corrected, the actual injection timing can be detected with high precision without the need for sensor installation adjustment, and the advance angle control of the fuel injection device can be performed with high precision. Can be done.

In each of the above embodiments, the injection timing sensor 7 is provided on the driven shaft 6 of the fuel injection device 3.
However, instead of the timing sensor 7 as described above, a needle valve lift sensor provided on the fuel injection valve is used to obtain a signal indicating the actual injection start timing. Similar excellent effects can be obtained by applying the present invention to the fuel injection advance angle measuring device constructed as described above. In this case, the top dead center sensor 5
The measurement error in the injection advance value caused by the installation error will be corrected.

According to the present invention, as described above, there is no need to electrically install and adjust the sensor to obtain the signal necessary to measure the fuel injection advance angle, so it is possible to expect a reduction in adjustment costs. An automatic correction function that can automatically correct installation errors due to installation adjustment defects at a desired timing makes it possible to measure the fuel injection advance angle with high accuracy without human intervention.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of an injection advance angle measuring device according to the present invention, FIG. 2 is a block diagram showing an embodiment of an electronically controlled timer to which the present invention is applied, and FIG. 3 is a flowchart of an arithmetic control program stored in the control arithmetic circuit of the electronically controlled timer shown in FIG. DESCRIPTION OF SYMBOLS 1... Fuel injection advance angle measuring device, 2... Diesel engine, 3... Fuel injection device, 4... Crankshaft, 5... Top dead center sensor, 6... Driven shaft, 7...
...Injection timing sensor, 9...Timer, 10...
...Timer control device, 13... Arithmetic circuit, 14...
Correction circuit, 15... Most retarded angle control device, 16... Comparator, 17... Reference data generator, 20... Electronically controlled timer, 21... Control calculation circuit, P ₁ ...
Top dead center pulse signal, P ₂ ... Injection timing pulse signal, D ... Output data, Dc ... Correction data,
Dr...Reference data, Do...Data, Dout...Control data, S...Control signal.

Claims (1)

[Claims] 1. A first signal generating means for outputting a first signal indicating the timing at which the piston of the internal combustion engine reaches a predetermined reference position, and a first signal generating means indicating the timing for starting fuel injection of a fuel injection device for injecting and supplying fuel to the internal combustion engine. a second signal generating means for outputting a second signal;
a calculation means for calculating a fuel injection advance value adjusted by a timer connected to the fuel injection device based on the first and second signals; a first means for controlling the timer so that the advance angle adjustment value becomes the most retarded value; and an injection output from the calculation means when the timer is brought into the most retarded value control state by the first means. a second means for obtaining advance angle value data; and a third means for obtaining correction data by comparing the injection advance value data obtained by the second means with predetermined reference data, and based on the correction data. 2. A fuel injection advance angle measuring device, wherein an error in the injection advance value due to an installation error of the first and/or second signal generating means is corrected.