JPS61152923A - Intake-air control device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To enable the intake pressure in each intake pipe at the time of low loads to be standardized without a sacrifice of the merit of individual intake at the time of high loads by permitting a communicating pipe communicated with each intake pipe to be changed either into a communicating state or into a non-communicating state depending on the operating conditions of an internal-combustion engine. CONSTITUTION:In an internal-combustion engine comprising a number of independent intake systems, a communicating pipe 8 is mounted for communicating intake pipes 4a-4d on the downstream side of throttle valves 5a-5d. The communicating pipe 8 is permitted to have a volume being large enough to standardize the intake pressure in each intake pipe, and also is provided with an air control valve 7 involving a valve 9 which is used for changing each of the intake pipes 4a-4d into a communicating state or a non-communicating state. The valve 9 is turned through a lever 16 by an actuator 17 controlled with an operating condition detecting means, so that two kinds of state, such as communicating state at the time of low loads, and non- communicating state at the time of high loads, can be presented depending on the locational relation between the connecting opening for the communicating pipe 8 and the ports 15a-15d for connection.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention provides an internal combustion engine in which the intake pipes from the surge tank or air cleaner to the cylinders are independent for each cylinder, and each independent intake pipe is provided with a throttle valve. The present invention relates to an electric control device for communicating or not communicating a communicating pipe provided for an independent intake system of an internal combustion engine.

[Background Art] In an independent intake system for an internal combustion engine, intake pipes that guide intake air from a surge tank or an air cleaner to each cylinder are independent from each other, but there are systems in which the intake pipes are connected to each other.

For example, because the length of the intake passage to each cylinder is different,
Since the amount of air to each cylinder is different, balance tubes are provided to balance the intake air amount of each cylinder especially during idling (for example, Japanese Patent Application Laid-Open No. 54-137516, Japanese Patent Laid-Open No. 58-57066), In order to obtain the original pressure of the brake booster, the communication pipe is used to average the intake pressure to obtain the intake average pressure, and the 7? is used to increase rotation during cold starting. - Air introduction pipes for idlers (for example, Japanese Utility Model Application No. 57-117721).

[Problems to be Solved by the Invention]However, each of these cannot satisfy a single required function of the intake system; for example, in the example of a balance tube, the amount of intake air at idle in each intake pipe cannot be It can only be balanced against the cylinder,
It is not possible to satisfy multiple required functions of the intake system, which vary depending on the operating state of the internal combustion engine. For this reason, it is not possible to combine these intake systems with electronic control to control them in accordance with the various operating conditions of the internal combustion engine, and even if control is provided, it is mechanical and it is not possible to apply electronic control. not suitable for doing.

Furthermore, if the capacity of the balance tube is made small, sufficient intake pressure will not be produced, and if it is made large, it will be difficult to obtain the transient response and improvement in engine output performance that are the original characteristics of independent intake.

Furthermore, in the classic independent intake system under load, the intake pressure is repeatedly applied to the throttle valves of each cylinder every cycle, so consideration must be given to the durability of the throttle shaft and bearings.

In order to solve the above-mentioned problems, the present invention provides an air control valve that enables electronic control in the communication pipe in an internal combustion engine equipped with an independent intake system, thereby improving the response characteristic of an independent intake system. Without sacrificing performance improvement, we aim to: ■improve the accuracy of flow calculation at light loads, ■secure negative pressure for the brake booster, secure negative pressure sources for other control systems, and ■improve the reliability of the throttle shaft. purpose.

[Means for Solving the Problems] An intake control device for an internal combustion engine according to the present invention that meets this objective communicates the intake pipe of each cylinder with the intake pipe downstream of the throttle valve of an internal combustion engine having an independent intake mechanism. A communicating pipe is provided, and the communicating pipe has a volume sufficient to average the intake pressure of each cylinder, and the communicating pipe is capable of switching between a communicating state and a non-communicating state, and the switching is made in accordance with the operating state of the internal combustion engine. It consists of an intake control device for an internal combustion engine with a correspondingly electrically controlled air control valve.

Here, an electronic control device may be provided as a means for determining the operating state of the internal combustion engine, and the inputs of the electronic control device may be the engine rotational speed and the intake pressure.

Further, an electronic control device may be provided as a means for determining the operating state of the internal combustion engine, and the input of the electronic control RI device may be the throttle opening.

Further, an electronic control device may be provided as a means for determining the operating state of the internal combustion engine, and the input of the electronic control may be used as a signal from an air flow meter.

Further, as a means for determining the operating state of the internal combustion engine, an electronic control device may be provided, and the input of the electronic control device may be an injection pulse width.

Furthermore, it is preferable that the air control valve is set in a communicating state on the low air amount side and in a non-communicating state on the high air amount side.

[Operation] In the intake control device for an internal combustion engine having the above configuration, the air control valve is controlled by electrical control instead of conventional mechanical control, so that control accuracy is improved.

Then, when the load is light, the operating state determining means sets the communication pipe to a communicating state, and the intake pressure of each intake pipe is averaged.
At light loads, the accuracy of flow rate calculation is improved, negative pressure is secured for the brake booster, negative pressure source is secured for other control systems, and the load on the throttle shaft and bearings is reduced by reducing pressure pulsation, and their reliability is improved. Improves sexual performance.

In addition, the operating state determination means makes the communicating pipes non-communicating at high loads, and the intake pipes of each cylinder become independent, which improves transient response performance at high speeds, which is the original advantage of an independent intake system for each cylinder. The output performance is ensured.

[Example] Below, intake control l of an internal combustion engine according to an example of the present invention will be explained.
The apparatus will be described with reference to the drawings.

First, FIGS. 1 and 2 show a case where the present invention is applied to a four-cylinder engine. In the figure, each cylinder 2 of an internal combustion engine 1 is connected to a surge tank or air cleaner 3 by an independent intake pipe 4. Code 4a, 4b
, 4C, and 4d indicate independent intake pipes. Each intake pipe 4
Throttle valves 5 are provided at each of a, 4b, 4c, and 4d, and are simultaneously opened and closed by a rod 6. Reference numerals 5a, 5b, 5c, and 5d indicate throttle valves provided in each intake pipe 4a, 4b, 4c, and 4d. The independent intake pipes 4 and the throttle valves 5 provided in each intake pipe constitute an independent intake system. The independent intake pipes 4a, 4b, 4c, and 4d are communicated with each other downstream of the throttle valve 5 by a communication pipe 8 so as to be able to communicate or not communicate with each other. The volume of the communication pipe 8 is set to such a volume that the intake pressure of each cylinder is averaged when the communication pipe 8 is in a communicating state.

Reference numeral 7 indicates an air control pulp, and as shown in FIGS. 3 to 5, the air control valve 7 includes a cylindrical communication pipe 8 extending over each intake pipe 4a, 4b, 4c, and 4d, and It has a valve 9 rotatably mounted within the communication pipe 8.

The valve 9 is closed at both ends by blinding means 10.11. The communication pipe 8 has a connection port 12 that communicates with the intake pipe 4 of each cylinder. Code 12a.

12b, 120.12d are intake pipes 4a, respectively.

4b, 4c, and 4d are shown. The valve 9 connects both ends of the cylindrical body to the blind means 10.11.
It is made up of a closed body and has a communication space 13 inside. Furthermore, the valve 9 is connected to the connection port 12 of the communication pipe 8.
It has a connecting boat 15 extending long in the circumferential direction at a position corresponding to .

Reference numerals 15a, 15b, 15c and 15d indicate bows 1- corresponding to the connecting ports 12a, 112b, 12c and 12d, respectively. valve 9 boat 1
5, the air control valve 7 is provided at a position where it can exhibit the following two states depending on the positional relationship of the communication pipe 8 with respect to the connection port 12. That is, in FIG. 4, by rotating the valve 9 into the communication pipe 8, the connecting ports 12a, 12b, 12c are opened.

12d is brought into emergency communication by the wall 9a of the valve 9 i'
gi, and each intake pipe 4a, 4h, 4c, 4d operates as an independent intake. FIG. 5 shows that by rotating the valve 9 into the communication pipe 8, each connection port 12a, 12b, 12c, 12d is connected to each connection boat 1.
5a, 115b, and 150.15d are opened to communicate with each other.

One end of the valve 9 extends outside the communication pipe 8, and a lever 16 is fixed thereto with a nut 14. The lever 16 pivots the valve 9 into the communication tube 8, which is actuated by an actuator 17, as shown in FIG. The actuator 17 is an electronic control device t (ECtJ) 1
8, and its rotation is electrically controlled by the ECU 18. EC (J18 includes an engine speed sensor and an intake pressure sensor 21, or a throttle opening sensor 22, or an air 70 meter 23, or an injection pulse width sensor 24 as a detection means 19 for engine operating conditions (see Fig. 1). is electrically connected to
The operating state of the engine is determined based on the signals from these, and a rotation signal corresponding to the operating state is sent to the actuator 17.

As shown in FIG. 6, the ECU 18 includes, for example, an A/D converter 18 that converts an analog signal from the engine operating condition detection means 19 into a digital signal, a ROM 18c that stores conversion conditions, and a ROM 18c that stores conversion conditions. A RAM 18d that temporarily stores the values of , and a CPU that compares predetermined operating conditions and actual operating condition signals from various sensors to optimally calculate the opening and closing of the air control valve 7 according to the operating conditions. 18e, CLOCK 18r that determines the operating period of the CPU 18, an output boat 18 that outputs output signals from the CPU 18e6s, etc.;
It has an output circuit 18h that converts the signal from () into an Iζ output signal suitable for the actuator 17 and outputs it.

7 and 8 show the flow of control in the ECU 18. FIG. FIG. 7 shows the case where the throttle opening is the input signal, and C determines whether the actual throttle opening TA is larger or smaller than the predetermined throttle opening TB stored in the ROM 18c.
It is calculated by the PU 18e, and if rA>TB, the actuator 17 is turned on, t, that is, the ports 15a, 15b, 15
c, 15d are closed to create a non-communicating state.

Figure 8 shows the case where both engine speed and intake pressure are input signals, and the actual engine speed NE is stored in ROM18C.
The CPU 18e calculates whether the actual intake pressure PM is larger or smaller than the predetermined engine speed NEB stored in
It is calculated by the PU 18e, and if PM>PMB, the actuator 17 is turned on, that is, the boats 15a, 15b, 1
5c and 15d are closed and the non-communication state is calculated.

Next, the operation of the intake control device for an internal combustion engine configured as described above will be explained.

The ECU 18 receives the signal from the operating condition detection means 19, determines the operating condition of the internal combustion engine, such as the load condition, rotation speed, @machine condition, etc., and satisfies the required functions of the air control valve 7 necessary for each operating condition. A signal is sent to the actuator 17 to change the position of the pulse 19 of the air control valve 7 by operating the actuator 17.

First, under high load operating conditions, the valve 9 is in the position shown in Figure 4, and each intake pipe 4a, 4b, 4c, 4d is operated as an independent intake, and at this time the pressure in each cylinder is as shown in Figure 9. The cylinder is in a state where it is in M shift without being affected by other cylinders. This provides good output performance and response performance.

Next, during light load including idling, the valve 9 is in the position shown in FIG. 5, and the intake pipes 4a, 4b, 4c, and 4d are in a communicating state and are not in a state of independent intake. When the load is light, the amount of intake air into the cylinder 2 is small, and the amount of intake air in each cylinder tends to vary.
, 4d are in communication, each intake pipe 4a
, 4b, 4c, and 4d are averaged as shown in Fig. 10 to improve the accuracy of flow calculation during light loads, secure negative pressure for the brake booster, and improve negative pressure in other control systems. The load on the throttle shaft and bearings is reduced and their reliability is improved through the reduction of pressure pulsations and the reduction of pressure pulsations.

[Effects of the Invention] When the internal combustion engine intake control device of the present invention is used, it is possible to improve the inter-cylinder pressure balance at low loads without sacrificing the response and output performance at high loads, which are the advantages of independent intake. Modification, securing intake negative pressure with brake booster,
In addition to improving the accuracy of the air flow meter in the low rotation range when detecting intake pressure in one cylinder, it also reduces repeated stress changes on the throttle shaft due to changes in intake negative pressure, increasing the reliability of the throttle shaft and bearing. You can improve your sexual performance.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of an internal combustion air intake control device according to an embodiment of the present invention, Fig. 2 is a plan view of the device shown in Fig. 1, and Fig. 3 is a cross-sectional view of an air control valve provided in a communicating pipe. 4 is a cross-sectional view when the air control valve shown in FIG. 3 is in a non-communicating state; FIG. 5 is a cross-sectional view when the air control valve shown in FIG. 3 is in a communicating state; The figure shows E used to control the air control valve.
A block diagram of CLl, Figure 7 is a flow diagram showing an example of the operational flow of the ECU, Figure 8 is a flow diagram showing the other side of the operational flow of the ECU, and Figure 9 is a diagram showing the inside of each intake pipe in a non-communicating state. Pressure change diagram, No. 10
The figure is a diagram showing changes in the pressure inside each intake pipe in a communicating state. 1...Internal combustion engine 2...Cylinder 4.4a, 4b, 40, 4d...Intake pipe 5.5a, 5b. 5c, 5d... Throttle valve 7...
...Air control valve 8...Communication pipe 9...Valve 9a...Valve! 12.12a, 12b. 120.12d...Connection port 13...Communication space 14.15.15a1 15b, 15c 115d...Boat 17.
...Actuator 18...ECU Fig. 2

Claims (6)

[Claims] (1) A communication pipe that communicates the intake pipes of each cylinder is provided in the intake pipe downstream of the throttle valve of an internal combustion engine that has an independent intake mechanism, and the communication pipe has a volume large enough to average the intake pressure of each cylinder. Intake control for an internal combustion engine, characterized in that the communicating pipe is provided with an air control valve that can switch between a communicating state and a non-communicating state and electrically performs the switching according to the operating state of the internal combustion engine. Device. (2) An air intake control device for an internal combustion engine according to claim 1, wherein an electronic control device is provided as means for determining the operating state of the internal combustion engine, and the inputs of the electronic control device are engine rotation speed and intake pressure. . (3) An intake control device for an internal combustion engine according to claim 1, wherein an electronic control device is provided as a means for determining the operating state of the internal combustion engine, and the input of the electronic control device is a throttle opening. (4) An intake air control device for an internal combustion engine according to claim 1, wherein an electronic control device is provided as means for determining the operating state of the internal combustion engine, and the input of the electronic control device is an air flow meter signal. (5) An intake control device for an internal combustion engine according to claim 1, wherein an electronic control device is provided as means for determining the operating state of the internal combustion engine, and the input of the electronic control device is an injection pulse width. (6) The air intake control device for an internal combustion engine according to claim 1, wherein the air control valve is set in a communicating state on the low air amount side and in a non-communicating state on the high air amount side.