JPS6172844A - Control device of engine - Google Patents

Abstract

PURPOSE:To high accurately suppress a vibration, by reducing the vibration of an engine to be suppressed on the basis of an output from a torque sensor only in a low speed and a low load operational range excepting an idle operational range while on the basis of an output from a roughness sensor of vibration sensor or the like in the other operational range. CONSTITUTION:A control device, comparing in a comparison discriminating device 43 an output from a roughness sensor A with a preset reference value, corrects in accordance with the compared result by a control circuit 46 a control value in a memory device 44 storing the control value of a fuel injection quantity or the like preset in accordance with the operational condition of an engine. The above roughness sensor A is constituted by a torque sensor 33 and the other roughness sensor 34. And on the basis of an output from an operational condition detecting means 50, a torque signal from a torque sensor 34, high accurately detecting a roughness condition, is selected by a sensor selecting means 51 and output to the comparison discriminating means 43.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in an engine control device that reduces and suppresses engine vibration (roughness) caused by engine torque fluctuations.

(Prior Art) In recent years, there has been a trend in heavy-duty automatic engines to set the air-fuel ratio of the air-fuel mixture supplied to the combustion chamber of the engine on the lean side in order to improve the fuel efficiency. However,
When the air-fuel ratio of the air-fuel mixture is set to the lean side, the fuel efficiency improves, but on the other hand, engine torque fluctuations gradually increase, the roughness of the engine becomes significant, and ride comfort deteriorates. Therefore, it is necessary to improve fuel efficiency while suppressing engine torque fluctuations.

Therefore, conventionally, for example, in the system disclosed in Japanese Patent Publication No. 56-33571, a rotation speed sensor is provided to detect the engine rotation speed, and when the engine rotation speed is above a predetermined value and the torque fluctuation is small, air is supplied to the engine. On the other hand, when the engine speed is less than a predetermined value, that is, when the torque fluctuation is about to increase due to engine misfire, the amount of air supplied to the engine is reduced and the air-fuel ratio is reduced. Make the fuel ratio rich and reduce torque fluctuations. Set the air-fuel ratio as lean as possible while suppressing engine torque fluctuations to ensure good ride comfort and improve fuel efficiency. It is designed to be compatible with both. As sensors for detecting engine vibrations (so-called roughness sensors), in addition to the rotational speed sensor described above, it is known that a torque sensor for detecting engine torque and a vibration sensor for detecting engine vibrations themselves are used. It is being

(Problems to be Solved by the Invention) By the way, as for which of the plurality of roughness sensors mentioned above to adopt, it is important to consider whether a torque sensor should be used for the original purpose of reducing and suppressing engine vibrations caused by engine torque fluctuations. It is considered desirable to select

However, when a torque sensor is selected in this way, if we look closely at its detection accuracy, we find that although high accuracy is obtained in low rotation/low load operating ranges excluding the idling operating range, the torque is small in the idling operating range. As a result, the detection accuracy is lowered and is worse than that of other vibration sensors. Additionally, in high-speed, high-load operating ranges, increased fuel consumption slows down combustion and reduces torque fluctuations, increases inertia, makes it difficult to detect torque fluctuations, and makes tires more likely to spin. Due to inaccurate detection of torque fluctuations, the detection accuracy is lowered and other vibrations are worse than with sensors or the like. Therefore, if the torque sensor is used in all operating ranges, it will not be able to stably and fully demonstrate the effect of reducing engine vibration and improving fuel efficiency during idling, driving, and high-speed/high-load operation. The problem is that it disappears.

The present invention has been made in view of the above, and its purpose is to reduce and suppress engine vibration based on the detection signal of the torque sensor in the engine operating range where the detection accuracy is high (i.e., low rotation speeds excluding the idling operating range). In other operating ranges, engine vibration is reduced and suppressed based on detection signals from high vibration sensors such as torque sensors. The objective is to stably reduce engine vibration and improve fuel efficiency in the driving range.

(Means for Solving the Problems) In order to achieve the above object, Kazuaki's solution is based on the engine control device that suppresses engine vibrations, that is, the engine operating state. 11) A memory wave @ 44 that stores control values for engine control such as the fuel injection Q determined in advance, a roughness sensor 8 that detects the roughness state of the engine, and the roughness sensor A.
a comparison/discrimination device 43 that compares the output of tII'(11'I) with a preset base tII'(11'I); and a control circuit 46 that receives the output of the comparison/discrimination device 43 and corrects the control value of the storage device 44.
In the engine control device, the roughness sensor A is composed of a plurality of sensors 33 and 34 including at least a torque sensor 34, and an operating state detection means 50 for detecting the operating state of the engine; Upon receiving the output of the operating state detecting means 50, the torque signal of the torque sensor 34 of the roughness sensor A is selected in the low rotation/low load operating range excluding the idling operating range, and the comparison/discrimination means 4 selects the torque signal of the torque sensor 34 of the roughness sensor A.
3) j sensor selection means 51 is provided.

(Function) Based on the above configuration, in the present invention, a torque sensor is used to detect the engine vibration (roughness state) with high accuracy in the low rotation/low load operating range excluding the idling operating range, Based on the detection signal, engine vibration is reduced and suppressed, and in other idle operating ranges and high rotation/high load operating ranges, other roughness sensors such as vibration sensors are used in place of the torque sensor, which has poor detection accuracy. By reducing and suppressing engine vibration based on the detection signal, the roughness state of the engine can be detected with high accuracy over the entire operating range of the engine, thereby reducing and suppressing engine vibration and improving fuel efficiency. The improvement can be stably obtained over the entire operating range.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings from FIG. 2 onwards.

In FIG. 2, 1 is an engine, 2 is a combustion chamber formed by a piston 4 that is slidably inserted into a cylinder 3 of the engine 1, and 5 is a combustion chamber 2 with one end communicating with the atmosphere and the other end. An intake passage opens to supply intake air, and in the middle of the intake passage 5 there is a throttle valve 6 for controlling the amount of intake air, and on the downstream side of the throttle valve 6 there is a fuel injection valve for injecting and supplying fuel. 7 is arranged, and the combustion chamber 2
An intake valve 8 is arranged at the frontage of the engine. Reference numeral 9 denotes an exhaust passage with one end opening into the combustion chamber 2 and the other end opening to the atmosphere for discharging exhaust gas, and an exhaust valve 10 is provided at the opening of the exhaust passage 9 to the combustion chamber 2. A catalyst device 11 for purifying exhaust gas is interposed in the middle of the exhaust passage 9. Reference numeral 15 denotes a bypass valve which is interposed in a bypass passage 16 that bypasses the throttle valve 6 of the intake passage 5 and increases the amount of intake air during idle operation, and 17 supplies a part of the exhaust gas from the exhaust passage 9 to the intake passage 5. The recirculation control valve 19 is interposed in the exhaust recirculation passage 18 for recirculating the exhaust gas to the downstream side of the throttle valve 6;
7 is a solenoid valve that controls the operation; 20 is a distributor;
21 is an ignition coil, 22 is a battery, 23 is a key switch, and 24 is a starter.

In addition, 30 is an air flow sensor that measures the amount of intake air;
31 is a boost sensor that detects the intake negative pressure on the downstream side of the throttle valve 6 in the intake passage 5; 32 is a throttle opening sensor that detects the openness of the throttle valve 6; and 33 is a first roughness sensor that detects vibrations of the engine 1. A vibration sensor 34 is a second roughness sensor disposed on the output shaft of the engine 1 and detects the torque of the engine 1. 35 is a water temperature sensor that detects the engine cooling water temperature. A rotation speed sensor detects the engine speed by detecting the crank angle, 37 is a catalyst sensor that detects the catalyst temperature, 38 is an 02 sensor that detects the air-fuel ratio based on the oxygen concentration component in the exhaust gas, and 39 is)! It is a position sensor that detects the opening degree of the flow control valve 17, and constitutes an operating state detection means 50 that can detect the operating state of the engine 1 using the boost sensor 31 and the rotation speed sensor 36. Each detection signal from each of the sensors 30 to 39 is input to a control unit 40 including a CPU.

As shown in FIG. 3, the control unit 40 has a built-in book that selects one of the detection signals from the vibration sensor 33 and the torque sensor 34 according to the engine operating state signal from the operating state detecting means 50. Sensor selection means 51 which is important in the structure of the invention, and the sensor selection means 51
an integrator 41 that integrates and A/D converts a roughness signal selected from the integrator 41, and a comparison/discrimination means that compares the roughness signal from the integrator 41 with a reference value set by a reference value setting device 42; In addition, the basic fuel injection ff1T (control value for engine control) is mapped in advance according to the engine operating state determined by the engine speed and the intake air amount. A RAM 44 as a storage device in which data is stored;
Basic fuel injection tJ that reads out the basic fuel injection amount T corresponding to the current engine operating state from the RAM 44 in response to the signals from the rotation speed sensor 36 and the air 70-sensor 30.
J amount calculating device 45; a control circuit 46 that corrects the basic fuel injection amount T of the calculating device 45 based on the output signal from the differential amplifier 43 and the output signals from the water temperature sensor 35 and the O2 sensor 38; The fuel injection valve 7 is provided with an output means 47 for controlling the operation of the fuel injection valve 7 so as to inject and supply the corrected fuel injection IT' corrected by the control circuit 46.

The sensor selection means 51 previously classifies the engine operating states into four categories as shown in FIG. Idle operating range, low rotation/low load operating range excluding the idle operating range,
The fuel cut range and high rotation/high load operation range are stored internally.

Next, the basic operation of the control unit 40 will be explained based on the flowchart shown in FIG. First, after initialization in step S1, in step S2, the engine vibration signal R from the vibration sensor 33 and the torque signal @q from the torque sensor 34 are read, as well as the engine rotational speed and intake air amount signals. In step S3, the basic fuel injection tJJfflTeRA corresponding to the current engine operating state is determined.
Cannot read from M44.

Thereafter, in order to correct the basic fuel amount tJJ amount T according to the engine operating state, it is determined in step $4 whether the current engine operating state is in the pre-stored idle operating range, and the engine is adjusted to the idle operating range. In a certain case of YES, the engine vibration signal R from the vibration sensor 33 is selected as a roughness signal in step S5, and this is selected as the roughness signal by the reference value setting device 4.
The deviation X (=R-r+) is calculated by comparing the magnitude with the reference value "Electricity" (see Figure 6 (a)) in the idle operating range in step S6. Then, in step S6, it is determined whether the deviation If x<Q is No, it is determined that the engine vibration is small and good, and step S is performed.
7, the fuel reduction m
I ・Calculate with 6 guns (8 T is correction factor) and get fuel = 11
- After increasing the size reduction amount, in step So, the corrected fuel injection amount T' is calculated by the following formula T-T-X+ and reduced. On the other hand, in the case of YES (×≧O), it is determined that the engine vibration is large, and in order to correct the fuel injection amount tA in the direction of increase, the fuel reduction I
- After correcting the fuel reduction amount by calculating with ΔT, it is further determined in step S9 whether the fuel reduction Jet It is judged that the correction is on the increasing side up to T, and the correction fuel injection jitT' is increased from the previous time in step S++, while if X+<0 is No, the increase correction exceeds the basic fuel injection In. After making a judgment, the fuel reduction I
Correct fuel injection with +! ) Set T' to the actual fuel injection amount T.

After that, in step 812, fuel reduction IIXz in a low rotation/low load operating range and a high rotation/high load operating range, which will be described later, is performed.
After clearing Xs to "0", the fuel injection timing is determined in step S13, and in step 814, the fuel injection valve 7 is outputted so as to inject and supply the corrected fuel injection cN amount T', and the process returns to step s2.

Further, if NO in step S4, which is not in the idle operation range, it is determined in step S+s whether or not the engine is in the fuel cut range, and if NO, in the case of NO, which is not in the fuel cut range, further proceeds to step 816, where the engine is running at low speed and low speed. Determine whether it is in the load operating range (excluding the idle operating range), and if it is in the operating range YES
In this case, in step 817, the torque signal q from the torque sensor 34 is selected as the roughness signal, and then the deviation Q' (=Q (n) - Q
(n −+ ) is calculated. And step S
The reference ll1Q is +6 and the deviation q' corresponds to the occurrence of large engine vibration.

(Refer to Figure 6 (B)) It is determined whether or not the above is satisfied, and if 1q'-〇〇I<O, it is determined that the engine vibration is small and good, and the fuel reduction amount X2 is determined in step 81B. The following formula X2-X; r + I t I・ΔT(t-1q'
-qo l) and increase the fuel reduction amount, in step 823, the corrected fuel injection amount T' is calculated using the following formula: T'=T-
Calculate with X2 to reduce the amount.

On the other hand, in the above step S +e, Y of lq'-qol≧O
In the case of ES, it is determined that the engine vibration is large, and in order to correct the fuel injection amount in the direction of increasing it, in step 820, the fuel reduction Mk After the reduction correction, it is further determined in step 821 whether or not this fuel reduction amount x 2 is greater than "0", and if x 2 ≧ 0 (YES), it is determined that the correction is on the increase side up to the basic fuel injection amount T. Then, in step 823, the corrected fuel injection amount is increased from the previous time, and if X2 < O, it is determined that the increased correction exceeds the basic fuel injection IT, and in step 822, the fuel injection amount is increased by 2. is re-corrected to rOJ, and in step 823, the corrected fuel injection IT' is set to the basic fuel injection amount T. Thereafter, in step S24, the fuel reduction amounts X+ and Xa in the idle operating range and high rotation/high load operating range are reset to rOJ, and then the process returns to steps S+s and S+< to inject and supply fuel at a predetermined fuel injection timing. Then, the process returns to step S2.

Similarly, in the case of No in step 816, which is not in the low rotation/low load operating range, it is determined that the engine is in the high rotation/high load operating range, and in step 825, the engine vibration signal R from the vibration sensor 33 is detected. After selecting it as a roughness signal,
This is compared in size with the reference value r2 (r, , >rl, see FIG. 6 (c)) in the high rotation/high load operating range in the reference value setter 42, and the deviation X (-Rr2) is calculated. . Thereafter, in step 82+1, it is determined whether the deviation x is equal to or greater than rOJ. If the answer is NO, it is determined that the engine vibration is small and the engine is good, and in step S27, the fuel consumption reduction IA After increasing the fuel reduction amount by calculating with the following formula ×3-×3+1×1·8T, in step S3+, calculate the corrected fuel injection amount T' with the following formula T' = T-×3 to obtain 8i Measure. On the other hand, in the above step S prisoner, YE with ×≧0
In the case of S, it is determined that the engine vibration is large, and in order to correct the fuel injection amount in the direction of increasing it, in step 828, the fuel reduction fl X 3 is calculated using the following formula: After the reduction correction, it is further determined in step 829 whether the fuel reduction JIX3 is equal to or greater than rOJ, and ×
If 3≧O, YES, it is determined that the correction is to increase up to the basic fuel injection IT, and in step S31, the corrected fuel injection tA amount T' is increased from the previous time, and if X3<O, NO, then is determined to be an increase correction that exceeds the basic fuel injection amount T, and in step S31+, the fuel reduction amount x 3 is corrected again to "0", and in step S3+, the corrected fuel injection amount T' is changed to the basic fuel injection amount. Set to king. After that, in step 832, the fuel reduction amounts X+ and X2 in the idle operating range and low rotation/low load operating range are reset to rOJ, and then the process returns to step SI3.8I4 to inject and supply fuel at a predetermined fuel injection timing. Return to S2.

On the other hand, YE in the fuel cut region in step S+s above
In the case of S, in step 833 all fuel reduction amounts X+
, X2, and X3 to "0", the process immediately returns to step S2.

Therefore, when it is determined in step 816 that the engine operating state is in the low rotation/low load operating range (excluding the idling operating range), the torque sensor 34 is activated in step Say.
The sensor selection means 51 is configured to select the torque signal q from , and compare the deviation q' between the previous time and the current time with the reference 1flqo in step Sza.

Therefore, in the above embodiment, FIGS.
As shown in c), since the engine vibration is controlled to converge to the reference value 'I+Qo+r2 according to each engine operating range,
The fuel injection amounts T+, T2 correspond to the basic fuel injection amount T to the reference value rl+QO+r2 for each engine operating range while engine vibration is suppressed to a small level.
, maximum T-T+ up to Ta, T-T2, T-Ts
This results in an improvement in fuel efficiency.

At that time, during low rotation/low load operation (excluding idling operation) shown in Fig. 6 (b), the engine vibration is at the reference value based on the torque signal from the torque sensor 34, which has high detection accuracy in the operating range. qO, and engine vibration is detected based on the engine vibration signal from the vibration sensor 33, which has a higher detection accuracy than the torque sensor 34, which has a lower detection accuracy during idling operation and high rotation/high load operation. are reduced to the corresponding reference values rl, r2, so engine vibrations are always reduced to the reference values r1.r2, regardless of the engine operating state. It is possible to accurately reduce the amount of fuel injection to qo and rz, and accordingly reduce the fuel injection amount to the reference value r l +
Lean side values T+, T corresponding to q o + r 2
2, T3 can be accurately controlled, and therefore it is possible to stably achieve both reduction and suppression of engine vibration and improvement of fuel efficiency.

In the above embodiment, the engine vibration during idling is suppressed to be reduced based on the engine vibration signal R from the vibration sensor 33. signal).

However, since the rotational speed of the engine 1 is calculated from the reception period of the engine rotational speed signal from the rotational speed sensor 36, it is necessary to interrupt the control flowchart of FIG. 5 to perform this. Therefore, during high-speed, high-load operation, the number of interruptions increases, causing a delay in major performance such as the corrected fuel injection amount tA, so it is preferable to use the vibration sensor 33.

□In addition, in the above embodiment, the fuel efficiency was improved by correcting and controlling the amount of fuel injected to the engine, but in addition, the engine ignition timing was selected as a control value for engine control, and this Shin-Germany or a firestorm Dj f
Of course, it is also possible to improve fuel efficiency by performing correction control together with l.

(Effects of the Invention) As explained above, according to the engine 1lilJ control device of the present invention, based on the detection signal from the torque sensor only in the low rotation/low load operating range excluding the idling operating range, Since engine vibration is reduced and suppressed based on detection signals from other roughness sensors such as vibration sensors, engine vibration can be reduced and suppressed with high precision in all engine operating ranges. Therefore, it is possible to stably achieve both suppression of reduction in fuel consumption and improvement of fuel efficiency.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing the configuration of the present invention, Figures 2 to 6
The figures show an embodiment of the present invention, and Fig. 2 is an overall configuration diagram, and Fig. 3 is an overall configuration diagram.
Figure 4 is a block diagram showing the internal configuration of the control unit, Figure 4 is a diagram showing the memory contents of the sensor selection means, Figure 5 is a flowchart diagram showing the operation of the controller, and Figures 6 (a) to (c) are operations. It is an explanatory diagram. 1... Engine, 33... Vibration sensor (roughness sensor), 34... Torque sensor (roughness sensor),
43...Differential amplifier (comparison/discrimination device), 44...R
AM (memory device), 46... control circuit, 50... operating state detection means, 51... sensor selection means. Unexamined Japanese Patent Publication Showa G1-72844 (8) 1 clI (K-cho guard distance)

Claims (1)

[Claims] (1) A storage device that stores control values for engine control that are preset according to the operating state of the engine; a roughness sensor that detects the roughness state of the engine; An engine control device comprising a comparison/discrimination device for comparing with a reference value and a control circuit for correcting a control value of the storage device in response to an output of the comparison/discrimination device, wherein the roughness sensor includes at least a torque sensor. Operating state detection means configured with a plurality of sensors and detecting the operating state of the engine;
Sensor selection means is provided which receives the output of the operating state detection means, selects a torque signal from a torque sensor among the roughness sensors in a low rotation/low load operating range excluding an idling operating range, and outputs the selected torque signal to the comparison/discrimination means. An engine control device characterized by: