JP2000320383A - Hunting detection device for governor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hunting detection device that can reliably and automatically detect hunting of governors and contribute to efficient, power-saving engine operations. SOLUTION: A rack sensor 3 detects the rack position of the fuel pump of a diesel engine 1 controlled by a governor 2. A computer 5 samples the detection signals of the rack sensor 3 to obtain discrete amplitudes of the signal waveform and determines whether they exceed a threshold amplitude. Once the threshold amplitude is exceeded, a timer 6 is actuated to measure a decision time, during which such amplitude-exceeded determinations are counted up. A count value, in excess of a fixed value, causes an output of a signal indicative of hunting of the governor 2 to an output terminal 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed control for detecting a hunting of a speed governor for controlling a rotational speed of a prime mover by changing a fuel supply amount in accordance with a load variation of a prime mover such as an internal combustion engine. The present invention relates to a hunting detection device for a machine.

[0002]

2. Description of the Related Art Conventionally, for example, a governor for a diesel engine
As a (governor), a centrifugal weight is pivotally attached to a rotating shaft connected to the engine output shaft, and the displacement of the centrifugal weight that rotates radially outward according to the rotation speed is transferred to the fuel pump rack via a link mechanism. Known to be conveyed. The rack moves to increase the fuel supply when the rotation speed of the weight decreases due to the increase in the engine load, and decreases when the rotation speed of the weight increases due to the decrease in the engine load. At this time, the engine speed at the time of stop is controlled to be constant.

[0003]

If the governor is improperly adjusted or malfunctions, the drive system of the fuel rack by the governor becomes unstable, the governor hunts, and the fuel rack frequently becomes large in amplitude and short in period. May vibrate. If the governor causes hunting, stable engine speed cannot be maintained, and normal engine output cannot be obtained.
In a generator driven by a diesel engine, the frequency fluctuates and normal power supply cannot be performed. In addition, if hunting is left for a long time, there is a risk of causing serious failure or damage to various parts of the engine. However, the conventional governor of a diesel engine is not provided with any means for detecting hunting, and a skilled driver is required to visually check the rotation of the tachometer of the governor rotating shaft and the output state of the engine. The fact is that governor hunting is determined based on years of experience and intuition. Therefore, it is necessary to arrange a skilled person at all times to monitor the hunting of the governor, so that labor saving and labor saving of the engine operation cannot be achieved, and erroneous recognition and oversight cannot be avoided by visual observation, so that reliable and reliable hunting judgment cannot be performed. There is.

Accordingly, an object of the present invention is to make it possible to reliably and automatically determine the hunting of the governor by comparing the time-dependent change in the position of the fuel rack driven by the governor with that during normal operation. It is an object of the present invention to provide a hunting detection device for a governor that can contribute to labor saving and efficiency of engine operation.

[0005]

To achieve the above object, a hunting detecting device for a governor according to the present invention comprises a rack sensor for detecting a rack position of a fuel pump controlled by the governor, and the rack sensor. Amplitude detection means for sampling individual detection signals from the signal waveform to obtain individual amplitudes from the signal waveform, amplitude determination means for determining whether the amplitude calculated by the amplitude calculation means exceeds a predetermined value, and When it is determined that the time counting means to start time counting for a predetermined time and the number of times the amplitude determining means determines positive in a predetermined time counted by the time counting means, and when the counted value exceeds a predetermined value And a determining means for determining that the governor is hunting.

The amplitude calculating means of the hunting detecting device receives a detection signal of a rack sensor which has detected a rack position of a fuel pump controlled by a governor, samples the signal, and obtains individual amplitudes from a signal waveform. The amplitude judging means judges whether the obtained amplitude exceeds a predetermined value. When the amplitude determining means determines positive, the timing means starts timing for a predetermined time, and during the time counting for the predetermined time, the determining means counts the number of times the amplitude determining means determines positive, and the counted value is a predetermined value. Exceeds the threshold, the determining means determines that the governor is hunting. That is, if the amplitude exceeding the predetermined value appears in the signal waveform of the detection signal of the rack sensor at the number of times exceeding the predetermined value during the predetermined time, the fuel rack frequently vibrates with a large amplitude and a short cycle. , It is determined that the governor is hunting. The driver of the prime mover can know the hunting of the governor based on the discrimination of the discriminating means even if he is not skilled, and can stop the prime mover to repair or readjust the governor. Normal motor output without any damage or damage,
Labor saving and efficiency of prime mover operation are achieved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. Fig. 1 shows the governor of the present invention (governor)
FIG. 1 is a schematic diagram of a diesel engine provided with a hunting detection device of 1), 1 is a diesel engine, 2 is a rack of a fuel pump displaced according to a load change of the diesel engine 1, and a fuel injection amount is changed to change the engine speed. A governor for constant control, 3 is a rack sensor for detecting the amount of displacement (rack position) of the rack, 4 is a rack scale indicator for receiving a detection signal from the rack sensor 3 and displaying the rack position with a pointer, and 5 is described later. A computer that performs a predetermined calculation based on the detection signal and a signal from a timer (time measuring unit) 6 as an amplitude calculating unit, an amplitude determining unit, and a determining unit. The computer 5 and the timer 6 are provided together with a contact 7 that is turned on when the diesel engine 1 is operating at or above the minimum speed, and an output terminal 8 that outputs an alarm signal when the computer 5 detects hunting of the governor. The hunting detection unit 9 is integrated with the hunting detection unit 9, and the rack scale indicator 4 is attached to the alarm panel 10. The hunting detection unit 9
And the rack sensor 3 constitute a hunting detection device.

The computer 5 samples the signal waveform of the detection signal at regular time intervals (for example, 0.1 seconds) as shown by a circle in FIG. The adjacent maximum R from the relationship
_{1, (S13~S20} in Figure 4) the minimum value R ₂ of the calculated and then calculates the individual amplitude R from the difference therebetween (R ₁ -R ₂₎
(S5 in FIG. 3), the amplitude determination means determines whether the calculated amplitude R exceeds the limit amplitude _RH (S6 in FIG. 3).
When the computer 5 determines that the amplitude R exceeds the limit amplitude R _H , the computer 5 causes the timer 6 to start measuring a certain determination time t _c (for example, 10 seconds) (S in FIG. 3).
8), when the amplitude R during counting of the determination time t _c exceeds a by counting the number of times exceeding the R _H (S9 in FIG. 3), the count value n ₂ is a constant value n _c (e.g. 20) (S10 in FIG. 3), governor 2
Is determined to be hunting, and an alarm signal is output to the output terminal 8 (S26 in FIG. 3).

FIG. 2 schematically shows the arithmetic processing by the computer 5 together with the waveform of a detection signal. FIG.
As shown in (B), when the first and second sampling values are r ₁ and r ₂ , in the portion where the signal waveform monotonically increases, the second sampling is performed as long as r ₁ ≦ r ₂ continues. Value r
Replace ₂ to r _1, but the sampling values of the third process of the r ₂ are repeated at a sampling sandwiching the maximum value is stored as the maximum value R ₁ a r ₁ when a r _1> r ₂ On the other hand, in the portion where the signal waveform monotonically decreases, r ₁
> As long as r ₂ continues similarly replace th sampled value r ₂ 2 times r _1, but the sampling values of the third process of the r ₂ are repeated at a sampling sandwiching the minimum value, r
R ₁ when ₁ ≦ r ₂ is stored as the minimum value R ₂ .
Then, when a pair of the maximum value R ₁ and the minimum value R ₂ are obtained, the amplitude R is calculated from the difference between them. Further, as shown in FIG. 2 (A), when the calculated amplitude R exceeds the limit amplitude R _H, the timer 6 starts counting the determination time t _c, the determination time t _c
If the amplitude exceeding the limit amplitude R _H within appears beyond a certain number n _c, is the alarm signal of hunting it is output. Note that R _c and R _m in FIG.
2 shows the rack scale of the fuel pump corresponding to the minimum and maximum output operation, respectively.

The operation of the governor hunting detecting device having the above configuration will be described below with reference to FIGS. In step S1 of FIG. 3, the computer 5 determines the determination time t _c , the limit amplitude R _H , the constant value n _c , and the minimum rack scale R _c which are constants.
And reset the counters C1 and C2 storing the wave numbers exceeding the limit amplitude and the counters storing the maximum value R ₁ , the minimum value R ₂ and the amplitude R to zero, and reset the timer 6 to perform initialization. . Next, in step S2, it is determined whether or not the diesel engine 1 is operating by turning on and off the contacts 7, and when it is determined that the engine is operating, the process proceeds to step S3, where the detection signal r from the rack sensor 3 is set to the minimum rack scale. It is determined whether or not _Rc is exceeded. If not, the process proceeds to step S25, and an alarm signal indicating that the rack detection signal is abnormal is output from the output terminal 8, while if affirmative, the process proceeds to step S4.

In step S4, the stored value n ₁ of the counter C1 is set.
Is greater than or equal to 2 to determine whether or not a pair of local maxima and minima has appeared in the detection signal r. If not, step S13 in FIG.
On the other hand, if it is affirmative, the process proceeds to step S5, where the amplitude R is obtained from the difference (R ₁ −R ₂ ) between the extreme values. Then, in step S6, it is determined whether or not this amplitude R exceeds the limit amplitude _RH . If not, there is no problem, so the process proceeds to the process of finding the extremum in FIG.
Proceed to determine whether the timer 6 is either in counting, after through the step S8 if not to start counting the determination time t _c by the timer 6, the process proceeds directly if affirmative respective step S9.

In step S9, since it is determined that an amplitude exceeding the limit amplitude R _H has already appeared in step S6, the stored value n ₂ of the counter C2 is incremented to (n ₂ +1). stored value n ₂ to determine whether more than a predetermined value n _c. Then, in the case of affirmation, the signal waveform of the detection signal from the rack sensor 3, the amplitude exceeding the limit amplitude R _H in decision time t _c appears above a certain number n _c, the process proceeds to step S26, Governor 2
Causes a hunting and outputs an alarm signal indicating that it is abnormal. On the other hand, in the case of No, since the large amplitude has not yet appeared in the signal waveform exceeding n _c , step S1
It proceeds to 1 and determines whether or not the timer 6 has finished measuring time.
Since affirmative if the determination time t _c large amplitude in the signal waveform in is that no frequently appear, to begin hunting determination newly, counter C1, C2 and maximum value R ₁ at step S12, the minimum value R _2, After resetting the counter for storing the amplitude R to zero, if not, the process directly returns to the process of obtaining the extremum in FIG. 4 to continue the hunting determination.

In the process of obtaining the extremum in FIG. 4, the computer 5 determines in step S13 that the first sampling value r
Was the r _1, at step S14, the second sampling value r and r _2, in step S15, it is determined whether r _1> r _2. For affirmation, the signal waveform is monotonously decreased, in step S16, replace the second sampling value r ₂ to r _1, at step S17, the third sampling value r and r _2, in step S18 , R ₁ > r ₂ are determined. Since monotonically decreasing if affirmative is continuing while repeating the same sampling returns to step S16, since turned to monotonically increase beyond whether if the minimum value, the process proceeds to step S20, the previous sampling value r ₁ stored as the minimum value R _2, step S2
1, after incrementing the stored value n ₁ of the counter C1 for counting the number of occurrences of extrema (n ₁ +1), returns to step S4 of FIG. 3. On the other hand, if the determination of r ₁ > r ₂ in step S15 is negative, since the signal waveform is monotonically increasing, the same processing as described in steps S16 and S17 is performed in steps S22 and S23, and in step S24, r _1> r _2, it is determined whether or not turned in the affirmative. If not, the process returns to step S22 and the same sampling is repeated since the monotonous increase is continued.
Proceeds to step S20, the previous sampling value r ₁ is stored as the maximum value R _1, the following step S21, the stored value n ₁ of the counter C1 for counting the number of occurrences of extreme (n ₁ +
After incrementing to 1), the process returns to step S4 in FIG.

As described above, the hunting detecting device includes:
A rack sensor 3 detects a rack position of a fuel pump driven by a governor 2 that keeps the rotational speed of the diesel engine 1 constant irrespective of load fluctuations. _{If the} amplitude exceeding the limit amplitude _RH appears more than the fixed value nc during _c , it is determined that the governor 2 is hunting, assuming that the rack is frequently vibrating with a large amplitude and a short cycle. Is determined. Therefore, the driver of the diesel engine 1 can know the hunting of the governor 2 by the alarm signal output from the computer 5 even if he is not skilled, and can stop or stop the diesel engine 1 to repair or readjust the governor 2. A normal engine output can be obtained without causing any serious failure or damage to the diesel engine 1, and labor and efficiency of the engine operation can be reduced.

In the above embodiment, the computer 5
It is determined whether or not the diesel engine 1 is operating at the minimum speed and whether or not the rack position of the fuel pump exceeds the minimum rack scale. If both determinations are positive, the hunting detection process is started. Therefore, unnecessary detection processing can be eliminated, and not only hunting detection but also clues to know the malfunction of the engine speed sensor and the rack sensor 3 itself can be obtained. It is needless to say that the hunting detection device of the present invention can be widely applied not only to the diesel engine of the above-described embodiment but also to a prime mover that controls a fuel supply amount by a governor.

[0016]

As is apparent from the above description, in the hunting detecting device for the speed governor of the present invention, the amplitude calculating means detects the rack sensor detecting the rack position of the fuel pump controlled by the speed governor. The signal is sampled and sampled to determine individual amplitudes from the signal waveform.On the other hand, the amplitude determining means determines whether or not the determined amplitude exceeds a predetermined value. The time counting is started, and the discriminating means counts the number of times the amplitude judging means judges positive during the counting of the predetermined time, and when the counted value exceeds a predetermined value, the governor is hunted by the judging means. The driver of the prime mover can quickly and reliably know the hunting of the governor by the above-mentioned discrimination even if he is not skilled, and repair or readjust the governor By doing so, Normal engine output is obtained without causing a large fault or damage, labor saving and efficiency of the prime mover driving can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a diesel engine provided with a hunting detection device for a governor of the present invention.

FIG. 2 is a diagram for explaining arithmetic processing by the computer in FIG. 1 together with a waveform of a detection signal.

FIG. 3 is a flowchart showing a flow of a calculation process of the computer.

FIG. 4 is a flowchart showing a flow of a calculation process of the computer.

[Explanation of symbols]

Reference Signs List 1 diesel engine 2 governor (governor) 3 rack sensor 4 rack scale indicator 5 computer 6 timer 7 contact 8 output terminal 9 hunting detection unit 10 alarm board R ₁ maximum value R ₂ minimum value R amplitude _RH limit amplitude t _c Judgment time

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masato Kaihara 2-4-1-4 Tokui-cho, Chuo-ku, Osaka City, Osaka Prefecture F-term in Daihatsu Diesel Co., Ltd. (reference) 3G084 AA01 DA27 EA05 EA07 EA11 EB24 FA13 3G301 HA02 JA06 JB09 NA08 NB03 NC08 NE23 PB04B PB04Z

Claims (1)

[Claims] 1. A hunting detection device for a governor that changes a supply amount of fuel in accordance with a load fluctuation of a prime mover and controls a rotation speed of the prime mover to a constant value, wherein the fuel pump is controlled by the governor. A rack sensor for detecting a rack position of the rack sensor; an amplitude calculating means for sampling a detection signal of the rack sensor to obtain an individual amplitude from a signal waveform; and whether or not the amplitude obtained by the amplitude calculating means exceeds a predetermined value. Amplitude determining means for determining, when the amplitude determining means determines affirmative, timing means for starting clocking of a predetermined time, and the number of times the amplitude determining means determines affirmative within a predetermined time counted by the timing means. A hunting detecting device for a governor, comprising: a determining means for counting and determining that the governor is hunting when the counted value exceeds a predetermined value.