JPS6226365A - Intake manifold - Google Patents

Abstract

PURPOSE:To equalize amount of fuel distributed to each cylinder by providing a balance tube with an orifice as a flow rate control member opened or closed by a solenoid actuator operated by an accelerator pedal. CONSTITUTION:When an accelerator pedal 25 is depressed, a contact point 26 is closed, a circuit of a solenoid valve 24 is energized, and an orifice 19 in a balance tube 18 is closed. As a result, injected fuel is uniformly distributed because there is no variance in mixture from cylinder to cylinder. Then when a foot 27 is removed from the accelerator pedal 25 to produce a partially loaded condition, the contact point 26 is opened, the solenoid valve 24 becomes inoperative, and the orifice 19 is opened. As a result, fuel distribution to each cylinder becomes equal. In this way, fuel can be distributed uniformly to each cylinder and driveability can be improved regardless of driving conditions whether with wide open throttle or partial loading.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an intake manifold for an internal combustion engine, and more particularly to an intake manifold with multiple air throttle valves for a multi-cylinder gasoline internal combustion engine.

[Background of the invention]

In an intake manifold equipped with a multiple air throttle valve installed in a multi-cylinder gasoline internal combustion engine, the air pulsation generated in the intake manifold in accordance with the intake timing is transmitted to the carburetor part, which prevents the variable venturi from flapping. need to be suppressed.

Ideally, as a means to suppress this pulsation, the pulsations in each cylinder would interfere with each other using the pressure phase difference that occurs at the intake timing, and the peaks and troughs of pressure fluctuations would work to cancel each other out. For this purpose, a structure in which the intake passages of each cylinder are communicated with each other through a balun tube is disclosed in Japanese Patent Laid-Open No. 60-8457.

A conventional intake manifold as disclosed by this proposal was constructed as shown in FIG.

The branch part 5.6 of the pair of intake manifolds 1 and 2
Nearby is the first balance tube 1 that connects each
3 is provided, and this first balance tube 13
is connected to an Ivjiest gas recycling device (hereinafter referred to as EGR device) 15. Further, a second balance tube 18 having an orifice 19 provided therein is connected to the intake manifolds 1 and 2 near the inlet ports 3 and 4 thereof.

According to the conventional intake manifold configured as described above, as shown in FIG. 6, cylinders A of the engine are connected to each branch end of the intake manifold.

B, C, and D are when the throttle valves (not shown) are fully open.

Assuming that the cylinders take air in the order of B, A, C, and D, when cylinders A and B are in the intake stroke, air flows in the direction of the arrow 20 shown by the broken line in the second balance tube 18. Similarly, when cylinder C2D is in the intake stroke, air flows in the direction of arrow 21. In either case, a large amount of air flows into the outer cylinder A or D due to the inertial effect of the air, so the mixture of air and fuel introduced from the inlet ports 3 and 4 is as shown by the solid line arrows 22 and 23, respectively. Since the flow becomes a biased flow, the air-fuel mixture in cylinders A and D will become richer if the balance tube 18 is in communication. However, if the orifice 19 in the balance tube 18 is fully opened to stop the flow of air, the fluctuation in the air-fuel mixture between cylinders is eliminated and a stable output is achieved.

However, when the engine is under partial load, that is, when the opening of the throttle valve (not shown) is small, when the balance tube is closed and the four-cylinder engines are arranged in series, the fuel distribution will not be uniform and between the cylinders. The A and D mixture tends to be richer and opening the balance tube 18 will result in an even distribution between the cylinders.

As mentioned above, in the conventional intake manifold equipped with multiple air throttle valves, the function of the balance tube 18 is completely opposite in operation with the throttle valve fully open and operation with partial load, and in fully open operation, the balance tube 18 Orifice 1 inside
9 and open the orifice 19 during partial loads.

However, since the diameter of the conventional orifice 19 was fixed,
There was a limit to the improvement in the performance of distributing fuel to each cylinder.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned points, and its purpose is to make it possible to equalize the amount of fuel distributed to each cylinder under all operating conditions, thereby improving drivability and reducing fuel consumption. An object of the present invention is to provide an intake manifold equipped with multiple air throttle valves for a multi-cylinder gasoline internal combustion engine, which can realize reduction in air intake.

[Summary of the invention]

According to the experimental results of the inventors, when the engine is fully loaded, as shown in Figure 7, when the orifice 19 is fully opened, the mixture in cylinders A and D becomes richer, and when the orifice 19 is fully opened, the mixture concentration between the cylinders increases. There will be no fluctuation. However, when the engine is under partial load, as shown in FIG. 8, when the orifice 19 is fully closed, the air-fuel mixture in cylinders A and D becomes richer, and when it is fully opened, there is no variation in air-fuel mixture concentration between the cylinders.

The present invention has been made based on the above findings, and includes a branch pipe disposed between each of at least a pair of air throttle valves linked to an accelerator pedal and a plurality of cylinders, and branched on the cylinder side; In an intake manifold that has a communication hole provided on the side of a branch pipe, and a balance tube that connects each branch pipe to each other by viewing these communication holes, by providing a flow rate regulating member in the balance tube, the desired effect can be achieved. This was done to achieve the objectives of the period.

[Embodiments of the invention]

An embodiment of the intake manifold according to the present invention will be described below with reference to the drawings.

An embodiment of the present invention is shown in FIG.
Components that are the same or equivalent to those of the conventional example shown in the figures are designated by the same reference numerals. The pair of intake manifolds 1.2 are each formed with air inlet ports 3 and 4.
．． 4 are each branched into two directions at a branching portion 5.6,
The respective tip portions 7, 8 and 9, 10 are communicated with each cylinder boat of an engine (not shown). Discharge ports 11.12 are formed in the upstream side walls of the intake manifolds 1 and 2 near the branch portions 5 and 6, respectively, and each of these discharge ports 11.12 has a first inlet branched in two directions. One end of the first balance tube 13 is connected to the first balance tube 13, and the other end of the first balance tube 13 is connected to the E
It is communicated with the GR device 15.

Further, in the immediate vicinity of the inlet ports 3 and 4 of the intake manifold 1.2, communication ports 16.17 are formed in the side walls connected to the tip portions 7, 8 and 9.10, respectively. A straight second balance tube 18 is connected to the balance tube 17 . An orifice 19 is provided inside the second balance tube 18, and a solenoid valve 24 for opening and closing the orifice 19 is provided on the outer wall of the second balance tube 18. This electromagnetic valve 24 is operated by opening and closing a contact 26 provided on an accelerator pedal 25.

The operation of the above-mentioned embodiment will be explained below.

When the accelerator pedal 25 is depressed with the foot 27, the contact point 26 closes and the circuit of the solenoid valve 24 operates, and the balance tube 18
The orifice 19 inside is shut off. As a result, as shown in Fig. 7, the injected fuel has no fluctuations in the air-fuel mixture between the cylinders, and the fuel/fuel mixture is evenly distributed. When this happens, the contact point 26 is open, and as a result, the solenoid valve 24 is not operated and the orifice 19 is open, so that the fuel is evenly distributed between the cylinders as shown in FIG. In this case, the diameter of the orifice 19 varies depending on the engine displacement, but is best between 10 and 18++n.

In this embodiment, a case has been described in which the solenoid valve 24 is opened and closed in accordance with the opening degree of the throttle valve by the accelerator pedal 25. may be set in advance, and the solenoid valve 24 may be opened or closed via a control circuit according to these amounts.

FIG. 2 shows an example of an engine fuel system using this embodiment. Intake manifolds 1 and 2 each having a pair of multiple throttle valves 29 and 30 fixed to the engine block 28 instantly receive fuel injected from fuel injection valves 31 and 32 and these injection valves 31 and 32, respectively. Atomization device equipped with an ultrasonic vibrator capable of atomization 33.34
are provided downstream of the throttle valves 29 and 30, respectively. These throttle valves 29, 30 each have a link 35
The throttle valves 29 and 30 are linked to the accelerator pedal 25 via the throttle valves 29 and 30, and a collector box 3
6 is installed to stabilize the air flow, and further upstream of this collector box 36,
A movable vane type or hot wire type flow meter (not shown) is provided to measure the amount of air sucked into the engine block 28, and is configured to send a signal of the air flow rate to the control circuit 37.

As described above, if this embodiment is used as an intake system of an engine fuel system, as shown in FIG. 3, fluctuations in shaft torque due to fluctuations in engine speed can be reduced, and shaft output can be improved. Can be done. The improvement effect is particularly remarkable in the low engine speed range. Further, as shown in FIG. 4, the time t when the accelerator pedal 25 is pressed to open the throttle valve and the engine speed begins to increase, that is, the response becomes faster, thereby improving drivability and reducing fuel consumption.

In the example of application of this embodiment to the engine fuel system described above, the throttle valve 29,
30, the pressure inside the intake manifolds 1 and 2 is detected by a pressure transducer (not shown), and is stored in a storage device in the control circuit 37 along with the engine rotation speed. Compared with the parameters, the injection valve 3
1°32 may be controlled. Further, the number of cylinders is not limited to four.

〔Effect of the invention〕

As described above, according to the present invention, two balance tubes are provided that communicate with the intake manifold, one of them is provided with an exhaust gas discharge port, and the other one is provided with an exhaust gas discharge port in the middle, and the amount of communication is determined depending on the engine operating conditions. Since an adjustment member is provided to adjust the amount of fuel, fuel can be evenly distributed to each cylinder regardless of operating conditions, and drivability can be improved.

[Brief explanation of the drawing]

゛- Fig. 1 is a sectional view showing one embodiment of the intake manifold according to the present invention, Fig. 2 is a system diagram of the engine fuel system using this embodiment, and Figs. 3 and 4 are diagrams showing the system according to this embodiment. Graph showing the effect, Figure 5 is a sectional view showing the conventional intake manifold, Figure 6 is a schematic diagram showing the airflow in the conventional example shown in Figure 5, Figures 7 and 8 are shown in Figure 5. It is a graph showing the fuel chamber ratio in each cylinder of a conventional example. 1.2... Intake manifold, 5, 6... Branch part, 1
1゜12...Discharge port, 13...First balance tube. 18... Second balance tube, 19... Orifice, 24... Solenoid valve, 25... Accelerator pedal,
29°30... Throttle valve, 37... Control circuit.

Claims (1)

[Scope of Claims] 1. Branch pipes arranged between each of at least one pair of air throttle valves linked to an accelerator pedal and a plurality of cylinders and branched on the cylinder side, and side portions of each of these branch pipes. What is claimed is: 1. An intake manifold having a communication hole provided in the air and a balance tube that communicates each branch pipe through each of the communication holes, the intake manifold comprising a flow rate adjusting member provided in the balance tube. 2. The intake manifold according to claim 1, wherein the flow rate adjusting member is an orifice that is opened and closed by an electromagnetic actuator. 3. The intake manifold according to claim 1 or 2, wherein the electromagnetic actuator is actuated by the accelerator pedal. 4. The intake manifold according to claim 1 or 2, wherein the electromagnetic actuator is operated by a control circuit that sets operating conditions.