JPH0128326B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a measuring device suitable for use in measuring the angle of a rotating body device (so-called timer) that advances the injection timing of a fuel injection pump for a diesel engine.

[Conventional technology]

The timer has an advance function as the engine speed increases, and has an important characteristic that determines the timing of fuel injection.In recent years, timers have become more accurate in order to prevent exhaust gases, and the adjustment and inspection process It became necessary to improve the accuracy of advance angle measurement in However, the fuel injection pump, which rotates via the timer, injects fuel at high pressure, so it requires a large torque during fuel injection, and the advance axis of the timer is affected by this.
Angular fluctuations appear during rotation. For this reason, the timer angle can be measured by measuring the angular fluctuation of the advance axis with respect to the timer's drive shaft, or by measuring the value at which the average value of the angular fluctuation changes as the rotation speed increases, that is, by continuously measuring the advance angle with high precision. It became necessary to do so.

[Problem to be solved by the invention]

Conventionally, a strobe device has been used as one method for this type of measurement. For example, as shown in FIG. 1, for a timer 1, discs 2 and 4 having scales are made to correspond to an advance shaft 7 connected to a drive shaft 6 and a camshaft of a fuel injection pump, and are separately controlled for rotation. By lighting the strobe lamp with a synchronized signal, the scales appear stationary, and the angle scale 4
The angle is measured by visually observing and reading the change in the advance angle scale 5 relative to the angle. However, in this measurement method, there is a limit to the size of the disk on which the angle scale is carved, and the resolution of the angle scale is low (0.5°/
(approx. 1mm) Measurement accuracy is poor. In addition, it has drawbacks such as the fact that automatic measurement is not possible because it is a visual measurement.

Furthermore, as another measurement method, there is a method of obtaining a measured value by measuring the phase difference of timing signals detected by an optical sensor or the like on the drive axis and advance axis of the timer, respectively, and calculating the angle of the measured data. However, even with this method, torque fluctuations during fuel injection by the fuel injection pump are large;
Therefore, it has been difficult to accurately measure the advance angle of the timer during fuel injection due to the influence of rotational fluctuations.

In order to eliminate the drawbacks of the above-mentioned conventional methods, the first invention provides an advance angle characteristic of a device having a rotating body having a drive shaft and an advance shaft, such as a fuel injection pump of a diesel engine, that is, a predetermined rotation angle. It is an object of the present invention to provide a device that can automatically measure the distribution or average value of advance angle values with high precision.

Further, an object of the second invention is to detect the actual actuation timing of the actuating body defined by the advance angle characteristic of the rotating body, and to make the advance angle characteristic of the rotating body more accurate in accordance with the operation of the actuating body. The objective is to provide a device that can be evaluated.

〔Example〕

Hereinafter, the first and second inventions will be explained in detail with reference to the embodiments shown in the figures. FIG. 2 shows a first embodiment to which the first and second inventions are applied. FIG. 3 shows the waveforms of each part of FIG. 2 with the rotation angle as the horizontal axis. Reference numeral 15 indicates a motor serving as a rotational drive source, and a desired rotation speed can be obtained by a known adjustment device. The rotational torque of this motor 15 is transmitted to a reference rotating shaft 17 via a timing belt 16, and is further transmitted to a timer 11, which is an angle measuring object to which a drive shaft 11a is connected via this rotating shaft 17, and The diesel engine fuel injection pump 12 connected to the advance shaft 11b is rotationally driven. The first and second angle signal generators 14 and 13 are connected to the reference rotation shaft 17 and the pump 12, respectively.
The rotation angle of the drive shaft 11a and the advance shaft 11b of the timer 11 is detected. These angle signal generators use a known rotary encoder, which generates 3600 pulses per revolution, that is, 1
It has a resolution of 0.1 degree per pulse, basically
Pulses with an on-off ratio of 1:1 are generated continuously in synchronization with the rotation for every 0.1 degrees of rotation angle. That is, the second angle signal generator 13 on the advance angle axis 11b side generates an angle timing signal (so-called reference angle signal A-
3600P/R) (b), and the first angle signal generator 14 on the drive shaft 11a side outputs a reference timing signal (so-called advance angle signal S-3600P/R) (d). In addition to this, the first and second angle signal generators 14 and 13 generate a one-rotation signal A- of one pulse per one rotation.
Output 1P/R(a) and S-1P/R(c), respectively.

Counting circuit 21, frequency dividing circuit 22, latch circuit 2
3 and the digital computer 24 constitute a data processing means, and by integrating the angle timing signal (b) and the reference timing signal (d), the timer drive shaft 11a and the advance angle shaft are determined. 11b
Create angle fluctuation data that continuously shows the rotational phase with respect to the rotational phase.

Here, the counting circuit 21 receives the angle timing signal (b)
However, in this embodiment, the angle timing signal (b) is used to increase the detection accuracy by four times.
It also has a built-in quadruple multiplier circuit that multiplies the
Count the frequency signal multiplied by 4. Then, the count value is reset for each rotation signal (a) of the advance angle shaft 11b. By using this quadrupled angle timing signal (b), the counting circuit has a resolution of approximately 0.025 degrees. If this counted integrated value θ _A is shown continuously, it will be as shown in FIG. 3 i.

Note that if a rotary encoder (known) that generates a two-pulse 1/4 phase difference signal (two signal lines) as the angle timing signal (b) is used as the second angle signal generator 13, the two-pulse A circuit that generates a pulse signal in response to both rising and falling edges can be used as a quadrupling circuit.

On the other hand, the frequency dividing circuit 22 receives the reference timing signal (d).
As a result, a reference timing pulse (g) is generated by dividing the frequency of the reference timing signal (d) by 144 every time the timer drive shaft 11a rotates by 2.5 degrees. A command circuit 26 attached to this frequency dividing circuit 22 outputs a one-rotation signal (c) on the drive shaft 11a side when a control signal (e) applied to the start terminal ST from, for example, a manually operated external switch reaches 1 level. The command signal (f) is set to level 1 in synchronization with the frequency division function, thereby enabling frequency division. Also, the control signal
When (e) becomes 0 level, the measurement command signal (f) from the command circuit 26 becomes 0 level, and the frequency dividing circuit 22 is reset.

Every time the latch circuit 23 receives the reference timing pulse (g) whose frequency is divided by 144 and which is output from the frequency divider circuit 22, the latch circuit 23 calculates the count value of the angle timing signal (b) which is multiplied by 4 and which is output from the counter circuit 21. Latch.
The digital computer 24 also receives the reference timing pulse (g) whose frequency is divided by 144, and in response, stores the count value immediately after being latched by the latch circuit 23 in the internal storage device (RAM). . When the latch data for one rotation, that is, 144 pieces, is received, digital calculation is executed to obtain angle variation data θ, which will be described in detail later.

The calculation results by the digital computer 24 are then displayed on a numerical display 25-1 and a recorder (for example, X-Y
The angle variation data including the plotter 25-2 is displayed by the display device 25, which serves as an evaluation means for evaluating the angle variation data.

The fuel injection pump 12 includes injection steel pipes 41, 4.
2, 43, 44 through injection nozzles 51, 52,
53 and 54 (actuating bodies) are connected. In order to detect the injection operation timing of the injection nozzles 51, 52, 53, 54, timing detectors 61, 62, 63, 64 (detection means) are formed by combining a piezoelectric conversion element, a signal amplification, and a waveform shaping circuit. attached to each nozzle. Timing pulses obtained from the timing detectors 61 to 64 corresponding to the operation of each nozzle are applied to the shift latch circuit 73 as a series timing pulse train (h) by an OR gate 71 (detection means).

The counting circuit 72 has the same configuration as the counting circuit 21,
The reference timing signal (d) is counted and reset every one rotation signal (c) on the drive shaft 11a side. And shift latch circuit 73
latches the count value of the counting circuit 72 every time it receives a timing pulse (h) (not shown in FIG. 3), that is, every injection timing, and holds the latched value a predetermined number of times. . However, this value indicates the rotation angle (reference rotation angle) of the drive shaft 11a at the actual injection timing advanced by the timer 11. In this embodiment, since the engine is a four-cylinder engine, the number of rotation angle data items latched during one rotation of the engine is four. The latched value is sent to the digital computer 24 in response to a command signal from the digital computer 24, and is used in its digital calculation.

The operation of the above device will be explained below. In addition, the third
In the figure, the solid line indicates the case where the number of rotations is N ₀ , and the broken line indicates the case where the number of rotations is N _x (>N ₀ ).

Now, when the motor 15 rotates at a rotational speed N ₀ at which the timer 11 does not advance, the timer 11 and the fuel injection pump 12 connected to the timer 11 through the timing belt 16 rotate. The second angle signal generator 13 is connected to the timer 11 via the advance shaft 11b that is integrated with the pump shaft 18 of the fuel injection pump.
An angle timing signal (b) corresponding to the rotation of the advance angle shaft 11b is obtained. The frequency signal obtained by multiplying this angle timing signal (b) by four is integrated and counted by the counting circuit 21, and the one revolution signal (a) (A-1P/
R signal), the integrated count value which is the output of the counting circuit 21 is as shown in Figure 3 i.
It is reset to zero every time the timer 11 rotates, as shown in _FIG . Note that this wave-like angle variation is due to the advance axis 11b due to the shock during fuel injection.
due to torque fluctuations.

On the other hand, a first rotation signal (c) (S-1P/R signal) of the drive shaft 11a and a reference timing signal (d) are obtained from the first angle signal generator 14 connected to the drive shaft 11a of the timer 11. It will be done. Then, the frequency of the reference timing signal (d) is divided by 144 by the frequency dividing circuit 22. In this case, the start and stop of frequency division are determined by the command signal (e) applied to the terminal ST of the command circuit 26 and the measurement command signal (c) synchronized with the one-rotation signal from the reference side (c). f) is obtained, and the frequency dividing circuit 22 is controlled by this measurement command signal (f). As mentioned above, in this frequency dividing circuit 22, 3600
Since the frequency of the pulse-generated angle signal is divided by 144, the output of the frequency dividing circuit 22 is a reference timing pulse (g) with each pulse having an interval of 2.5 degrees, which is divided by 144 over one rotation.
You can get one. And this reference timing pulse
At the timing of (g), the integrated value θ _A of the counting circuit 21
are sequentially latched by the latch circuit 23. Data θ _A
The digital computer 24 is immediately activated each time it is latched.
The data is transferred to the computer 24 and stored in each address 1 to 144 in the memory built into the computer 24 in order.

When the digital computer 24 stores 144 pieces of data θ _A , it executes the next digital calculation according to a predetermined control program. (This is achieved by counting and determining the results by the computer itself).

First, in order to obtain angle fluctuation data of the advance angle axis 11b with respect to the drive shaft 11a, 2.5 of the advance angle axis 11b is
From the above 144 pieces of data θ _A corresponding to rotation angles in degrees, one rotation signal S- of the reference timing signal (d)
The integrated value θ _S is sequentially subtracted from 1P/R(c). In addition,
The integrated value θ _S of the reference timing signal (d) every 2.5 degrees is θ _S
= 4 x 2.5n (n = 1, 2,...144), which is calculated simultaneously during subtraction. The coefficient 4 in the above equation is due to the reference timing signal (d) being multiplied by 4. Then, the 144 consecutive θ _S is the third one.
This is Figure J. Normally, the drive shaft 11a is rarely subject to torque fluctuations due to the influence of injection, so the count integrated value θ _S of the rotation angle on the drive shaft side can be accurately determined only by calculation in this way. Next, drive shaft 1 of timer 11
Angle fluctuation data θ ₀ of advance angle axis 11b with respect to 1a,
In other words, by calculating the angle fluctuation value when the timer 11 is not advancing, θ ₀ = θ _A − θ _S ,
Continuously calculate 144 pieces for one rotation of a.
In this way, at every 2.5 degrees on the drive shaft side, the angle variation with respect to the drive shaft on the advance axis side is calculated by θ _A
It can be calculated by subtracting θ and θ _S. The angle variation data θ ₀ finally obtained by subtraction is illustrated as shown by the solid line in FIG. 3k. In addition, in this subtraction, when θ _A −θ _S <0, 3600×4+
Correct angle fluctuation data θ ₀ is obtained by complement calculation of (θ _A −θ _S ).

In this embodiment, the drive shaft rotation angle of the timer 11, that is, θ _S =4×2.5n, is plotted on the X axis of the recorder 25-2.
The values of angle fluctuation data θ ₀ of the advance axis with respect to the drive axis shown in FIG. 3k are displayed on the Y axis using an XY plotter. Also, the drive shaft 1 obtained over one rotation of the timer 11 at this time
The average value (average phase angle) of 144 angle fluctuation data θ ₀ of advance angle axis 11b with respect to 1a _{is 0 =} 1/n _o 〓 ⁱ⁼¹ (θ _Ai - θ _Si ), (n = 144) It is calculated by calculation and displayed on the numerical display 25-1.

Now, increase the rotation of motor 15 until the rotation speed is _N
The rotation starts, and along with this, the timer 11 changes the rotation speed.
When the angle is advanced from the time of N ₀ , the second signal generator 13
One rotation signal A-1P/R becomes A'-1P/R,
Accordingly, the integrated value of the counting circuit 21 that counts the angle timing signal (b) becomes θ _A ', and the angle fluctuation data θ _X at that time can be obtained in the same manner as when the rotation speed N ₀ . Furthermore, the average phase angle at this time is _X = 1/n _o 〓 ⁱ⁼¹ (θ' _Ai - θ _Si ).

Therefore, the lead angle value (average phase difference) of the timer 11 when the rotational speed is _NX can be measured by the difference (= _X - ₀ ) between the average phase angles after and before the lead angle.

Further, the digital computer 24 operates to display the angle variation data θ such as θ _A and θ _X described above in relation to the actual injection timing of the fuel injection pump 12 . That is, in addition to calculating 144 pieces of angle variation data θ as described above, several pieces of data representing the rotation angle (reference rotation angle) of the drive shaft 11a at each injection operation timing latched in the shift latch circuit 73 as described above are calculated. The counted values (in this example, 4 in the case of 4 cylinders) are re-stored in the built-in memory. Then, in order to plot the angle fluctuation data θ, the position of the rotation angle corresponding to the injection timing stored in correspondence with the rotation angle (reference rotation angle) of the timer drive shaft 11a shown on the X axis of the recorder 25-2. , a mark 25-2a indicating the actual injection timing
Record. Furthermore, the reference rotation angle indicating the injection timing is also displayed on the numerical display 25-1.

Thus, in the apparatus of the first embodiment, the 144 consecutive angle fluctuation data θ shown in FIG. −
2a is also shown.

Further, the average phase angle (advanced angle value) of the advance angle axis 11b with respect to the timer drive shaft 11a is displayed on the numerical display 25-1.

Note that, if necessary, only one of the angle fluctuation data θ and the average phase difference may be displayed.
Furthermore, instead of using data display, it may be possible to compare whether or not these data θ satisfy a predetermined reference value, and to display only the results. Furthermore, in addition to recording and displaying the data, the data may be punched out onto a paper tape or the like that can be processed by a large-sized computer.

Further, the number of angle variation data θ is not limited to 144, but may be several. For example, only data regarding the injection timing may be used.

Further, the injection timing mark 25-2a does not necessarily have to be printed.

Note that the configuration of the first embodiment described above may be slightly modified and implemented, for example, the angle signal generator 1
The structures and mounting positions of 3 and 14 are sufficient as long as they can accurately respond to the rotation angles of the drive shaft and advance shaft of the rotating body (timer). Further, in this case, the second angle signal generator 13 may be provided between the timer 11 and the pump 12 to eliminate the influence of twisting of the pump rotation shaft. In addition, a measuring means for measuring the rotational speed of the drive shaft 11a (for example, one that temporally measures the generation interval of the one rotation signal (c)) is provided, and the rotational speed value and advance angle value ( For example, the relationship with the average phase difference) may be displayed in XY using a recorder.

4 and 5 show a second embodiment to which the first and second inventions are applied, and this is a fuel injection pump 12.
This system uses a simple circuit configuration to measure the relationship between angular fluctuations caused by load fluctuations during fuel injection that affect the advance axis of the timer and fuel injection timing. FIG. 4 shows its configuration, and FIG. 5 shows its operation. Note that the same configurations and signal waveforms as in FIGS. 2 and 3 are given the same reference numerals.

31 is a phase adjustment circuit that receives two angle signals from independent second and first angle signal generators 13 and 14;
When (b) and (d) are applied to the 32 up and down inputs of the up-down counter, the up and down inputs are synchronized with a clock signal CK that is sufficiently higher than the frequency of each angle signal to prevent counting errors. This is to shift the timing of the up-down counter 32 (data processing means) by at least one clock to maintain consistency in the input logic of the up-down counter 32 (data processing means). 33 is the output of the up-down counter (k)
34 is a two-phenomenon recorder (evaluation means), and 35 is a gate circuit for obtaining an initial reset signal for the up-down counter 32.

The angle signals (b) and (d) detected by the angle signal generators 13 and 14 are passed through a phase adjustment circuit 31 (data processing means) to an up-down counter 3.
2 is applied to the up input as an angle timing signal (b) on the advance shaft 11b side, and to the down input as a reference timing signal (d) on the drive shaft 11a side. on the other hand,
When the timer 11 is rotating at a predetermined rotation speed N ₀ without advancing, the gate circuit 35 synchronizes with the 1 rotation signal (c) at the 1 level of the control signal (e) applied to the start terminal ST. Obtain the command signal (f), add this command signal (f) as an initial reset of the up-down counter 32, and calculate the integrated value θ _A of the angle timing signal (b') and the reference timing from the time when this is canceled. Up-down counting of both integrated values θ _S of the signal (d') is started, and the output (k) of the up-down counter is the subtracted value of θ _A - θ _S , that is, the angle fluctuation value θ ₀ of the timer 11.
are obtained continuously.

When the rotation speed increases and the timer advances at _N
The value of the output value θ of No. 2 increases, and the changed value becomes the advance angle value (angle fluctuation data) θ _X. The output of the up-down counter 32 is converted into an analog signal by the digital-to-analog conversion circuit 33, and the angular fluctuation of the timer 11 is recorded and displayed in addition to the recorder 34.

On the other hand, the injection timing signal of the fuel pumped by the fuel injection pump 12 is obtained as a pulse train (h) to the OR gate 72, which is added to the other input terminal of the recorder 34 and recorded simultaneously with the angle fluctuation. , the relationship between the angle fluctuation of the timer 11 and the fuel injection timing can be recorded simultaneously and continuously.

〔Effect of the invention〕

As described above, according to the present invention, there is an excellent effect that the distribution or average value of advance angle values at a predetermined rotation angle can be automatically measured with high precision. This has the excellent effect of being able to evaluate the relevance in correspondence with the above, and the practical effects are significantly improved.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the principle of angle measurement to explain the conventional measurement method, Fig. 2 is a block diagram showing the configuration of a first embodiment to which the first and second inventions are applied, and Fig. 3 shows its operation. The time chart shown in Figure 4 is the first one.
A block diagram showing the configuration of a second embodiment to which the second invention is applied, and FIGS. 5 1 to 7 are time charts showing its operation. 11...Timer forming a rotating body, 11a...Drive shaft, 11b...Advance shaft, 12...Fuel injection pump, 13...Second angle signal generator, 14...First angle signal generator , 15...Rotation drive motor, 21, 22, 23, 24...A counting circuit, a frequency dividing circuit, a latch circuit, and a digital computer which constitute an example of a data processing means, 25, 34...A display device which constitutes an evaluation means. 2. Phenomenon recorder, 31, 32...Phase adjustment circuit and up/down counter, which are other examples of data processing means, 51, 52, 53, 54...Injection nozzle, which is an operating body, 61, 62, 63, 64 ，
71...Timing detector 61~ serving as a detection means
64 and orgate.

Claims (1)

[Scope of Claims] 1. A device for measuring the advance angle characteristic of the advance angle shaft with respect to the drive shaft in a rotating body having a drive shaft and an advance angle axis that advances the drive shaft with respect to the drive shaft, the device comprising: a power source that rotates and drives the drive shaft;
and a second angle signal generating means for generating an angle timing signal corresponding to the rotation angle with a predetermined resolution in synchronization with the rotation of the advance angle shaft.
By integrating the two timing signals from the angle signal generating means and the first and second angle signal generating means and sequentially comparing them, the rotational phase of the drive shaft and the advance angle shaft can be continuously adjusted. What is claimed is: 1. An angle measuring device comprising: a data processing means for creating angle variation data shown; and an evaluation means for evaluating the angle variation data obtained from the data processing means. 2. The data processing means is configured to sequentially store the integrated value of the angular timing signal at the generation timing of the reference timing signal, and to subtract the stored value by the integrated value of the reference timing signal. An angle measuring device according to claim 1. 3. The data processing means is configured to add the angular timing signal and the reference timing signal to another input terminal of an up-down counter to obtain an integrated addition/subtraction value. The angle measuring device according to item 1. 4. A device for measuring the advance angle characteristic of the advance angle axis with respect to the drive shaft in a rotating body having a drive shaft and an advance angle axis that advances the angle relative to the drive shaft, the device comprising: a power source that rotationally drives the drive shaft; , a first timing signal that synchronizes with the rotation of the drive shaft and generates a reference timing signal corresponding to the rotation angle with a predetermined resolution;
and a second angle signal generating means for generating an angle timing signal corresponding to the rotation angle with a predetermined resolution in synchronization with the rotation of the advance angle shaft.
By integrating the two timing signals from the angle signal generating means and the first and second angle signal generating means and sequentially comparing them, the rotational phase of the drive shaft and the advance angle shaft can be continuously adjusted. a data processing means for producing angle variation data shown in the table; a detection means for generating a timing sequence signal in response to the actual actuation timing of the actuating body that operates in accordance with the advance angle characteristic of the rotary body; An angle measuring device comprising evaluation means for evaluating angle variation data in relation to a timing sequence signal from the detection means.