JPS6345976B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a control device for an internal combustion engine used in an automobile. As a conventional internal combustion engine control device, the
As disclosed in Japanese Patent No. 33225, a proper half-clutch state is created by adjusting the throttle valve opening to move the clutch using fluid pressure. However, in this method, the engine operation control means that adjusts the operating state of the internal combustion engine and the transmission mechanism operation control means that adjusts the operation of the transmission mechanism are not controlled in relation to each other, resulting in insufficient compatibility and low output. The problem was that fuel consumption, harmful exhaust components, and noise increased. An object of the present invention is to improve driving performance by optimally matching the output characteristics of an internal combustion engine and the transmission characteristics of a transmission mechanism. A feature of the present invention is that the internal combustion engine control device (a) couples the internal combustion engine and the driven wheels of the automobile in order to mutually control the control amount of the engine operation control means and the transmission mechanism operation control means. a transmission mechanism; (b) at least one engine operation control means for controlling operation of the internal combustion engine; (c) at least one transmission mechanism operation control means for controlling operation of the transmission mechanism; (d) operation of the internal combustion engine. (e) transmission mechanism operation detection means for detecting the operation state of the transmission mechanism; (f) an engine operation control signal for the engine operation control means based on information from the engine operation detection means; and a shared control signal generating means for generating a transmission mechanism operation control signal for the transmission mechanism operation control means based on the engine operation control signal and information from the transmission mechanism operation detection means. FIG. 1 is a system diagram of a control device for an internal combustion engine, which is an embodiment of the present invention. The internal combustion engine 29 and the driven wheels 30 are connected to a torque converter 20, which is a transmission mechanism.
Clutch 17, brake 18 and planetary gear mechanism 1
They are mechanically coupled via 9. On the other hand, engine operation control means (hereinafter referred to as a first control device group) consisting of a fuel control device 26 , an ignition timing control device 27 , and an exhaust gas recirculation control device 28 is also connected to the internal combustion engine 29 . Further, this first control device group is connected to a microprocessor 24, which is an electrical logic operation device with storage capability. The plurality of terminals 25 of the microprocessor 24 are
Internal combustion engine rotation speed pickup, temperature sensors installed in various parts, load (intake pipe pressure, fuel injection amount) sensors, intake air amount sensor, throttle valve opening sensor, crank angle sensor, exhaust recirculation control valve position sensor,
It is connected to necessary sensors such as an atmospheric pressure sensor and an exhaust composition concentration sensor, and is connected to the control devices 27 and 2.
Microprocessor 2 supplies information to 8 and 29.
Enter 4. The structure and operation of these devices are shown in, for example, Japanese Patent Application No. 52-45795. On the other hand, a transmission mechanism operation control means (hereinafter referred to as a second control device group) that controls a second parameter group that influences the transmission characteristics and performance of the transmission mechanism is configured as follows. That is, a plurality of servos 16 for turning on and off a clutch 17 and a brake 18 for speed reduction ratio control, a 2nd-3rd speed control valve 11, a low speed adjustment valve 12, a speed change valve 13, a low speed suppression valve 14 and These are the transition valve 15 and the like.
These valves use electromechanical conversion elements such as electromagnetic solenoids, and control the hydraulic pressure transmitted from the pump 2 to the servo 16 using electrical output signals from the microprocessor 24 to turn on the clutch 17 and the plurality of brakes 18. -Turn it off. In order to control the oil pressure of each of the above-mentioned valves 11 to 15 and the torque converter 20, a check valve 5, a control pressure regulating valve 3, a converter pressure regulating valve 4, a modulator valve 6, a throttle valve 7, a downshift valve 8, a modulator valve 9 and A compensating stator valve 10 is provided. Among these valves, the throttle valve 7 and downshift valve 8 for correction may not be installed. The control device of this embodiment uses electromechanical conversion solenoid valves as means for connecting the microprocessor 24, which is a logic operation means, and the second control device group (various valves 11 to 15). Further, as the fuel control device 26, a carburetor, an electronically controlled fuel injection device, or the like is used. For diesel engines, refer to 14 of the Mechanical Engineering Handbook (Japan Society of Mechanical Engineers, published in 1970).
- A fuel injection system as described on pages 58 et seq. is used. In this case, the first parameter group (air-fuel ratio, ignition timing,
A group of sensors that input information regarding fuel injection timing, etc.) will be newly connected to the fuel control device 26. As the pump 2, an internal gear pump, a vane type pump, or the like is used, and the discharge pressure is about 5 to 15 kg/cm ² . Further, the hydraulic oil that transmits pressure is oil with relatively low viscosity, and the planetary gear mechanism 19 may be a manual three-shaft type or two-shaft type gear mechanism or various types of synchronization devices. One of the functions of the second control device group (various valves 11-15) is to control the reduction ratio of the transmission element. That is, the output of the microprocessor 24 operates the control valves 11-14 to connect or disconnect the clutches _C1 - _C4 , and by combining them as shown in Table 1, the reduction ratio can be controlled. In addition,
Generally, the ratio between the rotational speed Ne of the internal combustion engine and the rotational speed of the final drive unit on the load side is determined by the gear ratio of the transmission and the reduction ratio of the final drive unit, but here both are collectively referred to as the reduction ratio. .

[Table] Although the torque converter 20 is shown as an example of the main clutch of the transmission element in FIG. 1, a fluid coupling, a hydraulic clutch, a magnetic powder clutch, a manual friction clutch, etc. may also be used. Further, as the clutch 17 for switching the planetary gear mechanism 19, a wet multi-plate clutch,
Coupling elements such as conical clutches, band brakes and one-way clutches are used. The friction materials of these clutches include sawn lumber made of asbestos and cellulose fibers, quasi-metallic materials made of inorganic powder, and sintered metal materials. The microprocessor 24 performs the following calculations and judgments. When the rotational speed of the internal combustion engine is Ne and the vehicle speed is Nv, the reduction ratio x is expressed by the following equation. x=Ne/Nv (1) FIG. 2 is a diagram showing the relationship between vehicle speed and reduction ratio. That is, as the speed changes from 1st to 3rd speed, the reduction ratio x decreases and the vehicle speed increases, and as the rotational speed of the internal combustion engine increases, the vehicle speed also increases. Also, if V is the rotational speed of the axle and R is the radius of the tire, Nv = 60/2πRV... (2) Now, if the required running resistance on the load side is F, the torque T of the internal combustion engine is expressed by the following formula. It will be done. T=1/xF・R...(3) If x is too large relative to V and F, Ne will increase, which will increase internal combustion engine friction and pumping loss, leading to increased noise and fuel consumption. Become. On the other hand, if x is too small, the mixture ratio will fall within the range of the output mixture ratio of an internal combustion engine and a large amount of fuel will be consumed. Figure 3 is a diagram showing the relationship between shaft torque and fuel consumption rate, and the horizontal axis shows the internal combustion engine's rotating shaft torque in kg.
The fuel consumption rate on the vertical axis is shown in g/psh. For example, if the reduction ratio x is 1 and Ne is 2000 rpm, the shaft torque is 10 kg・m at point A.
When x=1.4 and Ne is 2800 rpm, the shaft torque is 7.2 Kg・m
Move to point B. This means that the fuel consumption rate is 220
This shows an increase of approximately 20% from 260g/psh to 260g/psh. Also, x = 0.6 and the shaft torque is 16.7
At point B, where Kg・m and Ne are 1200 rpm, the fuel consumption rate increases by about 7% to 235 g/psh. In this embodiment, information related to running resistance, that is, information such as intake negative pressure of the internal combustion engine, throttle valve opening, shaft torque, etc., and information on vehicle speed V are input from a sensor group, (1),
The logical operations of equations (2) and (3) are performed by the microprocessor 24. The microprocessor 24 outputs information related to the second parameter group, such as the reduction ratio, and operates the second control device group so that the reduction ratio becomes a small value within a range that does not enter the output range. It saves money. Figure 4 is a diagram showing the relationship between the rotational speed Ne of the internal combustion engine and the intake pipe pressure.Curve C is the intake pipe pressure when driving at low altitude and the reduction ratio x = 1, and curve C' is the curve when x = 2.
C″ shows the change in intake pipe pressure when x=0.5. Also, D-D′ shows the low limit of the engine rotation speed Ne at which the internal combustion engine can rotate stably, and the area A
is the range where the intake pipe pressure is close to atmospheric pressure, and region B
indicates a high range of rotational speed Ne. In addition, in region B, the air-fuel ratio is reduced and the engine is cooled with fuel,
This prevents the engine from burning out. Therefore, a group of information regarding the first group of parameters directly related to the internal combustion engine is sent to the microprocessor 2.
4, thereby allowing the second information group, vehicle speed, running resistance, etc., to be determined and output. That is, it is possible to control the optimum operating state by outputting the reduction ratio so that the engine is operated along the line a'→a→b→c in FIG. Note that C' is a state of direct connection, and C'' is a state of overtop. Figure 5 is a diagram showing the relationship between vehicle speed V and the second information group, and the curve α-α' represents the running resistance. F, curve a-e is
This is the reduction ratio x when Ne=400 rpm. As the vehicle speed V increases, x becomes smaller and the torque T increases.
The microprocessor 24 determines that V cannot be increased any further because T is saturated at the point _V0 .
will judge. That is, since the following holds true from equation (3): x=F/T ₀ R (4), the microprocessor 24 determines that x needs to be increased when F increases. In the next process, as x increases, Ne also increases, moving from point A to point B on the curve when Ne=6000 rpm, and the vehicle speed V becomes Vmax. Here, as F becomes larger, x becomes larger, so when Ne=6000 rpm, Nv, that is, the vehicle speed becomes smaller. In the above process, information regarding x is constantly outputted from the microprocessor 24, and the reduction ratio of the transmission element is controlled via the aforementioned connection means. As the transmission element, in addition to the gear reduction mechanism 19, it is also possible to use a continuously variable transmission consisting of various belts, chains, etc. As can be seen from equation (4), when F is small, x becomes small, and as seen from FIG. 2, the engine rotational speed Ne relative to the vehicle speed becomes small.
Therefore, when Ne is less than or equal to the minimum stable rotational speed Nemin, x increases and the engine operates in the region of T<T ₀ . Furthermore, when F is large, x becomes large, and Ne with respect to vehicle speed V increases. If ne is greater than the maximum allowable rotation speed Nemax, reduce x,
Operate in the region of T > T ₀ . The above judgment, logic,
Arithmetic operations are performed by microprocessor 24. Therefore, the first key points of this control device are: (a) The running resistance F of the second information group, the vehicle speed V, allowable torque T ₀ , and minimum stable rotation speed of the first information group
When Nemin and the allowable maximum rotational speed Nemax are given, the microprocessor 24 is used to adjust the speed change means so that FR/T ₀ + ε>x≧FR/T ₀ within the range of Nemin<Ne<Nemax. It's about controlling.
That is, by adjusting ε. Conventionally, technologies to achieve the above (a) using various electrical or mechanical control devices have been proposed, but the response is slow and it is difficult to calculate T ₀ , so it is still difficult to achieve a sufficient effect. has not been reached. This control device solves this problem as follows. (b) To calculate T ₀ using a first information group related to the first group of parameters of the internal combustion engine, and thereby control the reduction ratio x accurately and quickly. Conventionally, intake pipe pressure has been used to calculate T ₀ , and a negative pressure diaphragm switch or the like has been used to detect this. This negative pressure diaphragm switch is installed separately from the negative pressure sensor that is involved in the parameters of the first group, and deviations in their operating points cause errors and reduce controllability. In contrast, in the control device of this embodiment, both are controlled simultaneously using the same negative pressure signal, the same load signal, or the same air amount/rotation speed signal, so the above-mentioned error does not occur at all. . Furthermore, this allows the number of sensors to be reduced and responsiveness to be increased, resulting in improved controllability. Particularly when inputting information from a large number of sensors to the microprocessor 24, it is difficult to capture the signals from each sensor at the same time, so sharing the sensors in this way is an extremely effective means. In practice, changing the reduction ratio x continuously would be mechanically complicated, so the planetary gear mechanism 19 is used to change x in steps such as 1st speed, 2nd speed, 3rd speed, and overtop. In Figure 5,
a-a', b-b', c-c', d-d', d'-e', f-
g
By switching x according to the vehicle speed V, as shown in FIG. Here, d−d′,
The region d'-e' is an overtop region. Note that the overtop region refers to a region where the rotation speed of the internal combustion engine is lower than the rotation speed of the propeller shaft. In general, in a spark ignition engine, the first parameter group, ignition timing, exhaust recirculation rate, air-fuel ratio, etc., is controlled using signals that correspond to the engine load and rotation speed, such as intake pipe pressure, throttle valve opening, and intake air amount. It controls the parameters that affect it. For example, the shaft torque increases in accordance with the intake pipe pressure, and the shaft torque is controlled to be maximum in a region where the intake pipe pressure is high when the throttle valve is fully open. FIG. 6 is a diagram showing the relationship between intake pipe pressure and shaft torque T. In a region where the intake pipe pressure is higher than point A, it is common practice to reduce the air-fuel ratio and increase the shaft torque T to ensure the output of the internal combustion engine.
This area is already shown in areas A and B in FIG. Now, if the maximum shaft torque in the economical driving range where the intake pipe pressure is lower than A is T ₀ ', then the shaft torque is saturated at the vehicle speed V ₀ ' in Figure 5, and the overtop region d-e' becomes d-e. narrows to ₁ ′. Furthermore, since the operating range of the third speed is reduced to the range of V'max, at vehicle speeds higher than this, it is necessary to change from T ₀ ' to T ₀ and from Z to Z' as F increases. The third point of the control device of this embodiment is as follows: (c) The operating parameters of the internal combustion engine shown in FIG. The ignition time control device 27, fuel control device 26, and exhaust recirculation control device 28 that control the dotted chain line U) are linked to control the reduction ratio x. FIG. 7 is a flowchart for controlling the reduction ratio x. In block 101, vehicle speed V and running resistance F are given and supplied to block 102. Block 102 temporarily gives x and blocks 1
Calculate the torque T in step 03. In this case, T may be calculated by measuring the intake pipe pressure from the relationship shown in FIG. Next, the rotational speed Ne of the engine is determined from the torque T using a block 104. In this case, the rotational speed Ne of the engine may be directly measured. Block 105 compares T with T ₀ ' to determine. At this time, the intake pipe pressure and the amount of intake air may be determined. If T is smaller than the set value T ₀ ', or if the intake pipe pressure or intake air amount is smaller than the value corresponding to T ₀ ', x is reduced in block 106. If the above quantities are larger than the set value T ₀ ', x is increased in block 107. In block 108, the magnitude of the rotational speed Ne is determined. That is, when Ne is smaller than the set value Nemax, x is decreased in block 109. if,
If Ne>Nemax, x is increased in block 110. Such logical operations are performed by the microprocessor 24.
is executed. Therefore, the fourth point of the control device of this embodiment is as follows: (d) The microprocessor 24 inputs the reduction ratio x, torque T, running resistance F, intake pipe pressure, and engine speed.
Ne, vehicle speed V, torque set value T ₀ ', and rotation speed set value Nemax are input or calculated by calculating the above quantities, and the appropriate reduction ratio x is determined by determining the magnitude of the above quantities. The purpose is to output information regarding. As an example of such control, if the weight of the car is 1000Kg
Let us consider the case where a car with a speed of 20 km/h is accelerated at an acceleration of 0.8 m/s ² . Reduction ratio x is 4.1, 5.6, 8.6,
15, and the tire diameter R is 0.33m. From the above equation (2), Ne=x・60/2π×0.33×11.1=x・310 When x=4.1, the speed is 1310 rpm. Also, from equation (3), T = 1/xF・0.33 In this case, F = 100Kg, and in the case of x = 4.1, T = 8
Kg・m. Furthermore, during steady running with F=20Kg and x=4.1, T=1.6Kg・m. Here, T ₀ ′=8.1
When set to Kg·m, T<T ₀ ', so it is necessary to use an overtop during steady running. If x at overtop is 3, Ne=910rpm, T=
It becomes 2.2Kg・m. When accelerating from this state at F=100Kg, T=11Kg, so T>T ₀ '.
Therefore, increase x to 4.1 and accelerate to T=8Kg・m. When accelerating to 80km/h in this way, Ne=2620rpm. If F=80Kg・m during steady running at 80Kg/h, then T=6.4Kg・m when x=4.1. Here, if x=3,
Since T=8.7Kg・m and T>T ₀ ', x=
Return to 4.1. The 8th diagram shows the above as a diagram.
It is a diagram. FIG. 8 is a diagram showing an example of control by the present control device, in which the vertical axis shows vehicle speed V, running resistance F, reduction ratio x, engine rotational speed Ne, and torque T, respectively.
Here, in order for the reduction ratio x to be switched appropriately, if T < T ₀ ' and x ₁ = x - Δx, T ₁ = 1/x ₁ F・R, T = 1/xF・R. Therefore, T ₁ = x/x ₁ T, and if T ₁ < T ₀ ', then x ₁ = x - Δx
prevent it from happening. Alternatively, if T<x/x ₁ T ₀ ', it is necessary to add a measure to prevent x-Δx. In addition, in the above, Ne when x ₁ = x - Δx becomes Ne ₁ = x ₁ · Ne / x from equation (1), and if Ne ₁ becomes too small, the engine will become unstable, so Ne ₁ > Nemin, that is, , x-Δx will not be used if the minimum rotational speed at which the engine can rotate stably is not satisfied.
Figure 9 summarizes the above. FIG. 9 is another flowchart for controlling the reduction ratio x. Instructions in blocks 120-124 are executed by microprocessor 24. This reduces the switching rotation of x and prevents the increase in torque T shown in FIG. 8, making it possible to reduce fuel consumption. Furthermore, in order to prevent the increase in T at the initial stage of acceleration shown in FIG. 8, it is necessary to increase x before acceleration. Since F during acceleration corresponds to the angle or angular velocity of the throttle valve, input the throttle valve angle signal to the microprocessor 24 from the terminal 25 in _FIG . In this case, x ₁ =x+Δx. In this way, x
Select the minimum x that satisfies >F・R/T ₀ '. Furthermore, if Ne ₁ =x′/xNe>Nemax, the engine will burn out, so x ₁ =x−Δx. The foregoing is controlled by microprocessor 24 executing instructions in blocks 125-130. Now, if F = 400Kg during acceleration,
When x=4.1, T=32Kg・m, When x=5.6, T=23.4, When x=8.6, T=15.3Kg・m, x=
In the case of 15, T=8.7Kg・m. Also, x=15
Ne ₁ 15/4.1×1310=4800rpm. In this state, as V increases, Ne ₁ increases to 6000 rpm, so when Nemax reaches 6000 rpm, it is necessary to return x from 15 to 8.6 in blocks 131 and 132, regardless of the value of T. In this case, if x = 8.6 in advance, Ne = 2740 rpm, and T = 15.3
Kg・m. This is illustrated in FIG. 10. FIG. 10 is a diagram showing another example of control by the present control device, and each vertical axis is the same as in FIG. 8. As you will see, if x is large, ne will immediately become Nemax, so make x small from the beginning.
It is desirable to keep Ne small. In this case x=5.6
If it is made small, F is limited and acceleration performance is reduced. This is controlled by the microprocessor 24 executing the flowchart shown in FIG. FIG. 11 is still another flowchart for controlling the reduction ratio x. The reference point Neo is set at a location lower than the rotational speed that provides the maximum torque, and x is lowered so that Ne<Neo, regardless of T. By this, by entering the A region of small Ne without entering the B region in Fig. 4,
Prevent increase in fuel consumption rate. That is, block 1
40 to 142 are executed by the microprocessor 24, thereby preventing entry into the B region beyond Neo'. However, if x is small and F is large, then
It is allowed that Ne increases until Ne<Nemax. Therefore, the fifth point of the control device of this embodiment is to (e) input engine speed and throttle valve angle signals;
The microprocessor 24 calculates in advance changes in shaft torque and rotational speed when x is changed, and outputs information regarding x that makes the shaft torque appropriate. When V is constant and F is increasing, such as when climbing a hill, press the accelerator to increase T. Here T＞
In the case of T ₀ ', blocks 126 and 12 in FIG.
Increase x by 7. Here, if Ne<Neo′, x can be increased, but Ne>
In the case of Neo', the increase in x is suppressed and T is
Increase to T ₀ . In the case of a steep slope, V will be small if T ₀ is the same. T ₀ x/R=F=W・μ+f(V) ...(5) However, W is the weight of the car, μ is the coefficient of friction, f(V)
is the resistance force. Therefore, by increasing x and F, a decrease in V can be prevented. However, since it is not possible to increase the engine speed beyond Neo, the maximum value of vehicle speed V with respect to x is determined from the relationship shown in FIG. Conversely, when going downhill, F becomes smaller and the car accelerates. Therefore, it is necessary to reduce x in accordance with the vehicle speed V, and in this case, if x is made too small, engine braking becomes difficult, so the degree to which x can be reduced is limited. Therefore, the greater the slope of the slope, x
Therefore, the maximum value of vehicle speed V is restricted. Generally, the amount of work required for air suction during engine braking is expressed by the following equation. However, p ₁ is atmospheric pressure, p ₂ is vacuum pressure, k is polytropic index, m is mass, and mv ₁ is suction capacity m ³ . Therefore, if the suction capacity is constant,
The smaller p ₂ is, that is, the higher the engine rotational speed and the smaller the throttle valve opening, the larger W increases. By using the above-mentioned means, it is possible to control the reduction ratio to an optimum speed according to the load and speed of the vehicle, so that fuel consumption can be significantly reduced. In addition, the frequency of entering the output range shown in Figure 4 decreases, and even when the air-fuel ratio is set low, the
It does not increase the amount of CO and HC. As described above, the control device of this embodiment can improve the control product of the transmission element that transmits the movement of the internal combustion engine to the load and improve the compatibility between the engine and the load, thereby improving fuel economy, output, and drivability. This has the effect of reducing harmful gas emissions and noise. The internal combustion engine control device of the present invention automatically adjusts the reduction ratio to improve drivability, purify exhaust gas, and reduce noise.

[Brief explanation of drawings]

Fig. 1 is a system diagram of a control device for an internal combustion engine that is an embodiment of the present invention, Fig. 2 is a diagram showing the relationship between vehicle speed and reduction ratio, and Fig. 3 is a diagram showing the relationship between shaft torque and fuel consumption rate. Figure 4 shows the rotational speed of the internal combustion engine.
Figure 5 is a diagram showing the relationship between Ne and intake pipe pressure; Figure 5 is a diagram showing the relationship between vehicle speed V and the second information group;
The figure is a diagram showing the relationship between intake pipe pressure and shaft torque T, Figure 7 is a flowchart for controlling the reduction ratio x, Figure 8 is a diagram showing an example of control by this control device, and Figure 9 is another flowchart for controlling the reduction ratio x, FIG. 10 is a diagram showing another example of control by the present control device, and FIG. 11 is still another flowchart for controlling the reduction ratio x. . 11...2-3 speed control valve, 12...low speed regulating valve, 1
3... Speed change valve, 14... Low speed suppression valve, 15... Transition valve, 16... Servo, 17... Clutch, 18
...Brake, 19...Planetary gear mechanism, 20...Torque converter, 24...Microprocessor, 25...
Terminal, 26...Fuel control device, 27...Ignition timing control device, 28...Exhaust recirculation control device, 29...Internal combustion engine, 30...Load, 31...Display device, 32...Direct coupling clutch, 101-110, 120-132...Block .

Claims (1)

[Claims] 1. (a) A transmission mechanism that connects an internal combustion engine to driven wheels of an automobile; (b) At least one engine operation control means that controls the operation of the internal combustion engine; (c) The transmission mechanism at least one transmission mechanism operation control means for controlling the operation of the internal combustion engine; (d) engine operation detection means for detecting the operation state of the internal combustion engine; (e) transmission mechanism operation detection means for detecting the operation state of the transmission mechanism; ( f) generating an engine operation control signal for the engine operation control means based on information from the engine operation detection means, and generating an engine operation control signal for the transmission mechanism operation control means based on the engine operation control signal and information from the transmission mechanism operation detection means; A control device for an internal combustion engine, comprising a shared control signal generating means for generating a transmission mechanism operation control signal.