JPS5954938A - Knocking detector for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve knocking detecting property, by controlling a current, which is supplied to the exciting coil of a knocking detector in response to the operating state. CONSTITUTION:A DC voltage Vin, which is proportional to the number of rotation, from an engine state detector 7 is connected to an inverted input terminal 35a of a differential amplifier circuit 35. A voltage Vref, which is sufficiently higher than the voltage Vin, is applied to a positive input terminal 35b as a constant reference voltage with respect to the number of rotation. The output of the differential amplifier circuit 35 becomes an output Vout, which is proportional to Vref - Vin. The voltage Vout is converted into a current by a voltage-current converter 36, and the current is supplied to an exciting coil 22 of a knocking detector 2. When the number of rotation is increased, the exciting current is decreased. Therefore, the noise level of the output of the knocking detector is kept approximately constant. The judgment of the knocking is made as follows: the output of a detecting coil 25 is integrated by an integrating circuit 32 through a filter circuit 31, and the result is compared with the direct output of the filter circuit 31 in a comparator circuit 33.

Description

[Detailed Description of the Invention] The present invention has a function of detecting the 8-king signal flitz-king generated in the cylinder due to the internal combustion engine pressure and adjusting the ignition timing to a certain level. Used in ignition timing control devices for internal combustion engines.

In conventional internal combustion engines, the focus is on the ignition timing, which is closely related to the onset of knocking η1, and the ignition timing is advanced in response to the knocking condition while detecting the engine's jig condition. An internal combustion engine timing control device that aims to improve output and reduce costs by retarding the engine and causing the engine to run in a weak state called trace knock. are employed□. □Figure '1' shows the presence or absence of □occurrence of ignition timing in such an ignition timing control device.
6 shows a conventional example of a knocking i-claw device that determines l+
'(2) In other words, 2: Knocking with the King detector.

If the device detects high frequency signals generated by
Knocking is detected from □ knocking (91), for example, blow, da vibration: movement, sound, or cooling 2-ton pressure vibration.

4c' When the knocking Sayama is installed, the ignition timing is advanced or retarded by which output j, /, ν1. So, detector 2 (7)
13 power is increased by the amplifier circuit 41 to a predetermined important level.

Generally, high-frequency components of knocking appear in the cylinder internal pressure near the maximum value of the cylinder internal pressure only during knocking, but knocking detectors have resonance, resonant, □ non-resonant, non-resonant, □ Vibration noise (for example, valve seating noise or ignition noise) appears outside of the vicinity of the maximum value of the cylinder internal pressure. Furthermore, this vibration noise is
, Awakening, #'h Banaru Godai Death Hand...S/N
The town's Hibiki is *medium* especially for 60 high revolutions and high loads. : An example is shown in FIG. Figure 2 shows the side mold 6
2. Change the rotation speed of the cylinder engine at full load. ? ,,
If you look at the vibration acceleration of a professional machine when the Y-King is not running, you can see that the noise component (3) changes greatly.

' □ Conventionally, the presence or absence of knocking was determined using the amplifier circuit 4.
, ::::11: The Φ output is integrated by the integrator circuit 42 and set as a background noise level.
- I was making judgments based on the results. 44 is a bank circuit; 1. For example, when there is knocking, a logic level "1" is output, and when there is no knocking, a logic level "0" is output.

It is desirable that the noise level does not change depending on the engine conditions, and the above-mentioned fluctuation in the noise level causes deterioration in the detectability of knocking.

Therefore, the present invention aims to control the current supplied to the excitation coil of the knocking detector according to the driving experience, while keeping the noise and level approximately constant.
It is an object of the present invention to provide a backing detection device that maintains good detection performance for opening, opening, and opening.

The present invention will be explained below with reference to the examples shown in the drawings.

Figure 3 shows 1□1 using the knocking detection device of the present invention. (4) FIG. 2 is a configuration diagram of an isokufinidobasok ignition system.

In the figure, 1 is a 4-cylinder in-line type QPP 7 seated engine, and a knocking intermediate unit 2 is attached to the cylinder pro-coupling section of the engine 1 by means of screws or the like. 3 is a non-king width circuit that detects engine hike from the output signal of the knocking detector 2;
The ignition timing control device controls the ignition timing control device according to the output of the small circuit 3. The ignition timing control device controls the optimum ignition timing. Kihi Koi'
It is attached to the engine 1 through an ignition device w6 such as a striper repeater, and the air-fuel mixture is ignited by a spark plug. , stiff,
Details Qj of the ignition timing control device 5 and the ignition device, 6,
Since the configuration is well known, the explanation will be omitted. ,,,.

Next, the above haki, <g detector 21.4? I'll give more details soon. Figure 4 is its cross-sectional configuration diagram! , ! 1. ,,,,2
1 is the knocking frequency of 5 to 1. (Plate-shaped lead piece '21a with a resonance point at lKIiz and this glue piece 21a,
The jig-shaped holding part, ♀1b, to be held is made of a magnetic material (e.g., iron, iron-nickel alloy, gold, or S,..., LT S
, 43, 0), and one end of the lead piece 21a is held by a holding part 21b. 22 is an excitation coil serving as a magnetic flux generating means;
23. , is a cylindrical rod-shaped magnetic body made of iron, iron-nickel alloy, etc., extending in the ψ-axis direction, with its lower end tail 23a facing the lead piece 21a, and a gear knob Gt7 formed between the lead piece 21a. It constitutes the central magnetic path section of the magnetic path. ,.

25 is a resin bobbin 25 attached to the rod-shaped magnetic body 23. The magnetic flux detector is wound through a, the detection coil is arranged in stages, and
The excitation coil 22 also connects the rod-shaped magnetic body 23 via the bobbin 25a.
It is wrapped around. Furthermore, the holding portion 21 of the vibrating body 21 . b is attached to the inner bottom surface of the cup-shaped housing 27.

29 is a non-magnetic material, e.g. +4' aluminum, ram, copper alloy,
Non-magnetic stainless steel.

It is a ring-shaped spacer consisting of the Sakai moving body 2.1. The intermediate portion supports the collar 23a of the rod-shaped magnetic body 23, and the upper end holds the bobbin 25a together with the collar 23a. Since the spacer 129 is made of a non-magnetic material, its magnetic resistance is isometrically designed to be an optimum value close to the air gap (6) and sufficiently large. The housing 27 has a substantially cylindrical side wall and is made of a magnetic material such as iron or iron-Nisodal alloy. This housing 27 has a screw part 2 for mounting the opening and shifter in 1.
t, a, and a hexagonal part 27d for a wrench for tightening the housing 27 using the threaded part 27a.

28 is a sealing plate that seals one detector from the outside;
It is used to protect the outside air from moisture, dirt, etc. and forms part of the magnetic path. It is made of a magnetic material and is stamped into the seal part of the housing 27. It is an O-ring for the Mi-seal. 26a to the opening end of the 6-jing 27.
Fix by caulking B. On this plate 2, there is fixed an 8-mesh rail 2sa in which a terminal 28b for taking out a signal is embedded and fixed. :Which honeymetically sealed coil 2 is each part of each coil 22.25?
8.a:, and is connected to an external signal line 31 from this terminal 28b. 32 is a rubber bushing that covers the connecting portion between the signal line 31 and the terminal 2□8b, and (7) 26b is an 01i7 ring interposed between the plate 28 and the bobbin 25'a. □ 1 Here, the plate □ plate 2 [the lower end of which is in close contact with the rod-shaped magnetic body 23, and the housing 2 except for the periphery of the vibrating body 21 as necessary.
When the molding resin is filled in 7, the space between each coil 22, 25 and the rod-shaped magnetic body 23 is secured to prevent changes in the interlinkage magnetic flux due to dynamic positional changes 25.
1mm' 252 is a square-shaped groove provided in the bobbin 25'a in order to draw out each narrow width of each coil 22, 25 to the outside; This is a slit-like groove that was created on the 2nd day of the blend in order to draw out each end of the 25 to the outside. This detector smells like excitation coil 2□
A magnetic path of a bundle generated in 2 is as follows: rod-shaped magnetic body 2'3-' gear knob G → vibrating body 21 → housing 27 - plate 28
- It is composed of a rod-shaped magnetic body 23.

Next, the output of the knocking detector 2 is measured to detect knocking, and then the engine speed is detected as the engine state, and the knocking detection circuit 3 is implemented to control the current supplied to the excitation coil described above. □The male side is shown in Figure 5 (8). Reference numeral 7 denotes an engine state detector which detects the engine speed in this embodiment, and may have any configuration as long as it generates a predetermined number of pulses in synchronization with the engine speed. . 34 is a frequency-voltage conversion circuit that measures the pulses generated by the engine condition detector 7 and converts them into a voltage proportional to the rotation of the engine. 315□ has a differential amplifier circuit 7 including a reference voltage generating circuit, and its output decreases in response to an increase in the number of engine rotations of 2 and 1 and 0. 36 is a voltage-current conversion circuit that supplies current to the exciting coil 22 of the knocking detector 2. □ 31 is a filter circuit that removes valve seating noise and ignition noise from the output of the detection coil 25 of the knocking detector 2, and extracts only the knocking component. 32 is an integrating circuit that outputs the background noise level. Reference numeral 33 compares the noise level with the direct output of the filter circuit 31 in a comparison circuit to determine whether or not there is knocking.
.

Next, the operation of each part will be explained using FIG.・First, let's explain the case where the excitation current is not controlled.

(9) Generally, as the rotational speed increases, the output of the knocking detector 2 increases in nozzle level. Therefore, according to the conventional method shown in FIG. An explanation will be given of the control of the excitation current, which gradually increases in response to the increase in the number of revolutions.The engine condition detector 7 generates a pulse i signal of 360 pulses per revolution as a frequency-voltage signal. The conversion circuit converts it into a DC voltage proportional to the rotation speed.This DC voltage is connected to the inverting input terminal 35a of the differential amplifier circuit 35. That is, as shown in FIG. A voltage Vin is applied to the rotation speed.A voltage V ref that is sufficiently higher than the DC voltage Vin is applied to the normal input terminal 35b of the differential amplifier circuit 35 as a constant reference voltage with respect to the rotation speed. As a result, the output of the differential amplifier circuit 35 is
The difference between the two voltages mentioned above, i.e. (V ref - V t
The output Vout is proportional to n). Therefore, it has a characteristic of decreasing as the number of rotations increases. This voltage is then the voltage −
The current is converted into a current output by the current conversion circuit, and the current is supplied to the excitation coil 22 (10) of the knocking detector 2. Therefore, in FIG. 6, as the rotational speed increases, the excitation current decreases, so that the output of the knocking detector is kept at a substantially constant nozzle level. ,, ・.

The presence or absence of knocking is determined by removing components other than knocking from the output of the detection coil 25 of the non-king detector 2 using a filter circuit 31, and then 1. Integrate in the integrating circuit 32 and use the ratio of the comparing circuit 33 as the voltage.1. This is done by comparing the direct output of filter circuit 3.1. For example, the comparison circuit 33 outputs a logic level "-1" when there is knocking, and outputs a logic level "0" when there is no knocking.
.

However, in this case, as mentioned above, the current supplied to the exciting coil is controlled to decrease as the rotational speed increases, so the output of the integral main circuit 32 is kept approximately constant even if the rotational speed changes. ,ru.

In the two consecutive embodiments, the current supplied to the excitation coil of the no-king extractor was controlled with respect to the rotational speed, which has the greatest influence on the noise level of the no-king detector. Needless to say, it is effective to control the current.

As described above, the knocking detection device according to the present invention controls the current supplied to the excitation coil of the knocking detector in an engine-like manner, and maintains the noise level generated in the detection coil at a constant level, thereby improving engine operation. This has the excellent effect of maintaining good knocking detectability even when conditions change.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing a conventional knock/doking detection device, Fig. 2 is a graph showing an increase in vibration acceleration when the engine speed is changed, and Fig. 3 is a graph showing an increase in vibration acceleration when the engine speed is changed. A block diagram of a knock feedback ignition system, FIG. 4 is a vertical sectional view showing an embodiment of a knocking detector used in the device of the present invention, and FIG. 5 is a diagram showing an embodiment of a knocking detection circuit used in the device of the present invention. FIG. 6 is a block diagram showing the output waveforms of various parts of the knocking detection circuit with and without excitation current control, and FIG. 7 is a characteristic diagram showing voltages of various parts of the differential amplifier circuit of the knocking detection circuit. 1... Internal combustion engine, 2... Knocking detector, 22.
・・Excitation bump, 25 River detection coil, 3・Knocking detection circuit, 7・Engine condition detector, 31・
...filter circuit, 32. ...integration, circuit 1.33.
... Comparison circuit, 34 ... Frequency-voltage conversion circuit, 35
・:・Differential amplifier circuit, 36・;・Voltage-current conversion circuit,
:Representative patent attorney Takashi Okabe (13) Figure 1 Figure 2

Claims (1)

[Claims] +i+ A non-king detector that detects a knocking state of the internal combustion engine, an operating state detector that detects the operating state of the internal combustion engine, and □ a non-king detector that detects the knocking state of the internal combustion engine; In a non-king detector for an internal combustion engine having a knocking detection circuit for detecting the presence or absence of knocking, the non-king detector has an excitation coil, and the knocking ridge outgoing path is set in accordance with the output of the operating state detector. A knocking detection device for an internal combustion engine, characterized in that the current supplied to the excitation coil is changed so that the level of vibration noise remains approximately constant. ′□ “
(2) The knocking detection device for an internal combustion engine according to claim 1, wherein the operating state detector is an engine speed detector that detects the degree of rotation of the engine.
□(3) The operating state detector is characterized by an engine speed detector that detects the speed of the engine, and a load group indicator that detects the load state of the engine. A knocking detection device for an internal combustion engine according to patent iu search range 1i.
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