JPH04183952A - Engine control device - Google Patents

Abstract

PURPOSE:To obtain inertial effect of air intake created by pulsation of the air intake and increase charging efficiency by arranging an air intake passage constituted so that the length can be changed, changing the length of the air intake passage according to engine revolution speed, and controlling so that characteristic frequency in an air intake system can synchronize with the engine revolution speed. CONSTITUTION:An air intake pipe 8 connected to a cylinder head 10 through a flange 12a is constituted of a fixing part 12 being a downstream part and a moving part 13 housed in this fixing part 12 in a telescopic shape so as to slide freely, and the moving part 13 is moved in the shaft direction through a wire 20 winding round a pulley 19 on a shaft 18 rotated by means of an actuator 5, and thereby, the length of an air intake passage can be made variable. Furthermore, the actuator 5 is controlled by means of a control unit according to deviation between the length of a target intake air passage having characteristic frequency in synchronism with engine revolution speed and the length of an actual air intake passage obtained by means of a potentiometer, and according to this deviation, control volume of an engine operation control factor is also corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine intake system, and more particularly to an engine control system that changes the length of an intake passage depending on the engine operating condition.

(Prior technology) In the engine intake system, the length of the intake passage is changed according to the engine speed, and the natural frequency of the intake system follows the engine speed, thereby suppressing the intake inertia effect over a wide range of engine speeds. Engines that improve intake air filling efficiency are known.

Japanese Utility Model Application Publication No. Hei 1-i11136 discloses a device that controls the length of an intake passage in accordance with the engine speed.

(Problem to be solved) In such an intake system with variable intake passage length, a part of the intake system is movable, and this movable part is controlled by a predetermined drive source in response to changes in engine speed. The structure is configured such that the length of the intake passage is controlled 1111 by the power from the engine.

In this case, the operation of the movable part inevitably causes a response delay due to its openness. Second, in the conventional intake device with variable intake passage length, the length of the intake passage cannot be controlled.
It is difficult for wholesalers to follow changes in engine speed in a responsive manner, making it impossible to obtain a sufficient intake air permeability effect and making it impossible to achieve the set target charging amount. Even if the engine is operated with the engine control amount corresponding to the filling amount, the actual filling amount of intake air is less than that, so the engine O control cannot be properly controlled. Because the output is low (), fuel efficiency also deteriorates.

In order to deal with this problem, it is conceivable to increase the power of the drive system of the variable intake passage length mechanism, but if this increases the size of the device, problems will arise.

Therefore, the object of the present invention is to provide an intake passage length that can properly compensate for the inevitable response delay caused by intake passage length variable control without increasing the size of the device. An object of the present invention is to provide a variable intake device.

(Means for Solving the Problems) In order to achieve the above object, the apparatus of the present invention has the following configuration. That is, the engine control device according to the present invention includes a 3-m intake passage configured to be able to change its length, a passage length setting means for setting a target intake passage length in accordance with the engine speed, passage length variable control means for changing the intake passage length so as to achieve the target intake passage length;
An engine rotation speed detection means for detecting the engine rotation speed, a load detection means for detecting the engine load, and a control amount setting means for setting a control amount for controlling the engine operating state based on the engine rotation speed or the engine load; The present invention is characterized by comprising passage length detection means for detecting an actual intake passage length, and correction means for correcting the control amount based on a deviation between the target intake passage length and the actual intake passage length. .

Preferably, the correction means determines a correction amount for the control amount (based on the deviation and the engine speed).In a preferred embodiment, the control amount is ignition timing. .

Furthermore, in a preferred embodiment (j), the control @j is the fuel injection amount.

(Function) According to the present invention, the length of the intake passage is changed according to the engine speed, so that the natural frequency of the intake system is tuned to the engine speed! In this way, the intake inertia effect due to the pulsation of intake air is obtained, and the filling efficiency is increased. In this case, according to the present invention, the length of the intake passage that provides the natural frequency at which the intake air per unit life effect can be obtained with maximum efficiency at the engine speed is set as the target intake passage length, and this passage length is set as the target intake passage length. The path length control means operate to achieve this. However, as described above, due to the penetrating force of the movable portion of the intake passage, there is a certain response delay in the passage length variable operation. In the present invention, in response to the reduction in charging efficiency caused by this response delay, a fuel injection amount correction is applied to control variables that affect the engine operating state (for example, ignition timing).

Therefore, it is possible to provide a control amount corresponding to the actual intake air amount.

(Description of Embodiments) Hereinafter, embodiments of the present invention will be explained with reference to the drawings.

1st Embodiment of the Invention J Referring to FIG. 1 in the form of a front diagram corresponding to the claims for the basic configuration of an intake system, an engine I is provided with an intake passage 2 whose passage length is variable. . The length of the intake passage is detected by a potentiometer/yometer 3 serving as a passage length detection means, and the rotational speed of the engine is detected by any known means. Further, the engine load is also detected by any detection means, for example, by detecting a change in throttle opening.

The engine speed, engine load, and intake passage length (words) are preferably manually input to a control unit 4 that includes a microcomputer. , through the actuator 5, the operating state: ko 51
The length of the 3-meter intake path is controlled so that the inertia effect of the intake air can be obtained, that is, the intake system has a natural frequency that is synchronized with the engine speed. In this case, the control unit 4 sets a target intake passage length of the natural vibration synchronized with the engine speed j, and includes target passage length setting means 6. The control unit 4) is designed to detect the difference between the target passage length setting means and the actual intake passage length obtained by the stop button yometer 3j. And the control unit 4 further corrects this deviation! (2), a control amount setting means 7 for providing a control amount of an operation control factor that affects the output state of the engine, and a correction means 8 for correcting the control amount based on the above-mentioned 1-in difference. have

Referring to FIGS. 2, 3, and 4, the variable intake passage length mechanism of this example is shown. A flange 1 is provided at the downstream end of the intake pipe 9 that constitutes a part of the intake passage 2 shown in FIG.
2a is formed, and the intake pipe 8 is connected via this flange 12a to the cylinder head 10 via a hole 11. The intake pipe 9 has a fixed portion 12, which is a downstream portion provided with a flange 12a, and a movable portion 13 that is slidably accommodated in the fixed portion 12 in a nested manner.

Guide members 14 , 15 and 16 are provided at the tip of the fixed part 12 to support the sliding movement of the movable part 13 , and the tip of the movable part 13 slides through a bearing 17 on the kite part side 15 . Captured while being able to move freely. Figures 2 and 4 (
The movable part 13 is substantially housed inside the fixed part 12, and the intake passage is shown in a shortened state. Further, FIG. 3 shows a state in which the movable portion 13 is in a protruding position and the intake passage is lengthened. The intake pipe 8 is configured to be able to continuously take positions between the two. The actuator 5 serves as a power source for variable operation of the intake pipe 8.
(an electric motor in this example) is attached to the fixed part 12 . Shaft 1 rotated by actuator 5
A pulley 19 is attached to 8. Pulley 19
A wire 20 is wound around the wire 20, and one end of the wire 20 is attached to the distal end of the movable part 13 via the guide tube 21 and the attached hook 22j along the sliding direction of the movable part 13. The end is connected to the distal end of the movable part 13 via the guide tube 23 (to the hook 24 which is smoothed) in a direction along the sliding direction 2 of the movable part 13 and to the above-mentioned one end side. : Well, they are connected in the opposite direction.

When the pulley 19 rotates, this rotation continues to the wire 2.
0 is reached. , , - 1. Therefore, the movable part 13 slides along the guide members 14, 15 and 16, and the intake pipe 9
change in length.

Although not shown, a potentiometer 3 for detecting the rotational position of the pulley 19, i.e., the length of the intake pipe 9, is installed inside the actuator 5, and a wire 20. Intake pipe 9 obtained through rotation of Boo IJ 19
It is designed to detect the length of .

Note that near the flange 12a at the lower end of the fixed portion 12 (or worse, the fuel injection valve 25 is provided, and a throttle half 26 is provided slightly upstream thereof).

The details of the intake passage length variable control and the correction of the ennon control amount in this example will be explained below in '5).

FIG. 5 shows a flowchart of the intake pipe length variable control of this example.

The control unit 4 first outputs various single words (engine speed (RP i = I), throttle opening (T ~
10) And the length of the intake pipe! Corresponding intake pipe position (P
(e.g. IN:1) (step 1).

Next: The control unit 4 determines the target intake pipe position C, l I N > from the engine rotation speed (RP) and throttle opening (TVO) (step 2).
Also, the current intake pipe position (PIN) and target intake pipe position! (!, IIN) Calculate the deviation ΔL from (!, IIN) (step 3).

In step 2 above, the target intake pipe position (1, 11N
) can be obtained by referring to a map that provides the output voltage (V) to the actuator 5 from the relationship between the throttle opening (%) and the engine rotation speed (RPM) as shown in FIG. Therefore, the deviation ΔL is also expressed in voltage (V). As is clear from Figure 7, the larger the throttle opening and the higher the engine speed,
Is the output of the target intake pipe position (M[N) 1 shift small? Koru.

Come on, control unit 4 j-! , deviation △L
is within a predetermined range (step 4)
). If this determination is Yes, that is, the deviation ΔL is within the predetermined range: second, the control unit 4 does not output a position change instruction to the actuator 5j.

If the deviation △L is within a predetermined range, and if the deviation △L is larger than the target intake pipe position <+, ++\1) by more than the predetermined range, the control unit 4 controls the actuator. 5j outputs a signal to rotate the pulley 19 in the normal direction (steps 5 and 6).

Also, if the deviation △L is within a predetermined range,
If the deviation △L is smaller than the target intake pipe position (I; In by more than a predetermined range '9), j-: Well, the control unit 4 outputs a signal to the actuator 5 to reverse the pulley 19 (step 5). and 7).

Referring to FIG. 7, the relationship between the output value to the actuator 5 and the boolean rotation angle is shown. In this example, when the intake pipe length is 150 mm, the output value to the actuator 5 is 5 (V).
This output value corresponds to a rotation angle of 250° of the pulley 19.
corresponds to

Referring to FIG. 8, there is shown a flowchart for the correction of the control amount in step '7).

This control is executed by interrupting the fifth control described above at a predetermined timing.

Control unit 4! t, tl' engine speed (
Read the RP:・4) and the opening degree (TVII) (Step 1).

Next, the control unit 4 controls the engine speed <
RPrt>, the basic fuel injection amount (TB:l) is determined from the throttle opening (TtlO), and the basic ignition advance amount (AD) is determined (step 2).

In this case, the basic fuel injection amount (TB>) increases as the engine speed and engine load increase, and the basic ignition advance amount (TB) increases as the engine speed increases. It increases as the load increases.

The control unit 4 is provided with respective maps from which one shift can be obtained from the engine speed and the engine load in order to provide the basic fuel injection amount <TB) and the basic ignition advance amount (AD).

Tsukini, control 22) 4 j ma, fi difference △L
and engine speed, natural injection correction ff1 (TB1
), gives the ignition timing correction amount (Seki I) (Step 3:)
.

In this case, a map is prepared that provides the correction amount based on the deviation △L and the engine speed, and this map is prepared as a common map that provides the fuel injection correction amount (TBI) and the ignition timing correction amount (light 11). ).

Since the correction amounts (TBI> and (ADI)) can both be considered to represent the degree of deviation from the target value, they can be calculated using a common map.

This correction amount increases as the deviation ΔL increases.

Moreover, if the engine speed increases, it becomes smaller. This is done in consideration of the fact that as the engine speed increases, the intake speed increases and the effect becomes smaller.

Next (this, the control unit 4 controls the basic fuel injection amount (
TB) and fuel injection correction amount (TBI), final fuel injection M(T+) is calculated from basic ignition advance amount (A D ) and ignition timing correction amount (1・\DI), final ignition timing < l
g) Determine (Step 4) c. Then, when a predetermined injection timing comes, an injection command is output to the natural fuel injection valve 25 (Step 5). Further, a spark plug (not shown) ignition command is output at the predetermined timing determined above (step 6).

In addition, the final fuel injection amount (T1) and the final ignition timing (Ig
), the amount of correction (
For example, intake air temperature correction, engine temperature correction, high altitude correction) can also be added.

(Effect of engine control) According to the present invention, the control amount of the engine is determined by taking into consideration the deviation of the intake air amount from the target value due to the response delay in controlling the intake pipe length, so that the fuel consumption is reduced. Appropriate engine control can be performed in terms of speed and output.

[Brief explanation of drawings]

Fig. 1 is a schematic system diagram of an engine to which the present invention can be applied, Fig. 2 is a partial cross section when the variable intake pipe length mechanism is in a contracted state, Fig. 3: Well, the variable intake pipe length mechanism is in an expanded state. Figure 4 shows a contracted state of the intake pipe variable mechanism. Figure 5 shows a flowchart of intake pipe length control according to an embodiment of the present invention, similar to Figure 3. 1., 6th
Figure: shows a map showing the relationship between throttle opening, engine speed, and intake pipe position. Figure 8 is a flowchart of control for correcting the engine control amount. DESCRIPTION OF SYMBOLS 1... Engine, 2... Intake passage, 3... Potenometer, 4... Control unit, 5... Actuator, 6... Target passage length setting means, 7... ... Controlled amount setting means, 8 ... Correction means, 9 Intake pipe, 12 - Fixed part, 13 - Movable part, 20 - Wire. □□→ SE; Ω Q OOOo ○ O■I'-1nCXJ Vero Ushiku Eizai I Mei 11th Ward Coffee Tsui E

Claims (4)

[Claims] (1) An intake passage configured so that its length can be changed; a passage length setting means for setting a target intake passage length according to the engine speed; a passage length variable control means for changing the passage length;
An engine rotation speed detection means for detecting the engine rotation speed, a load detection means for detecting the engine load, and a control amount setting means for setting a control amount for controlling the engine operating state based on the engine rotation speed or the engine load; Engine control characterized by comprising passage length detection means for detecting an actual intake passage length, and correction means for correcting the control amount based on a deviation between the target intake passage length and the actual intake passage length. Device. (2) Claim (1), wherein the correction means determines a correction amount for the control amount based on the deviation and the engine rotation speed.
Control device for the engine described. (3) The engine control device according to claim (1), wherein the control amount is ignition timing. (4) The engine control device according to claim (1), wherein the control amount is a fuel injection amount.