JPH045185A - Suction device of engine for vehicle - Google Patents

Abstract

PURPOSE:To obtain high output in the whole rotational frequency area by providing plural suction chambers corresponding to the number of cylinders of an engine, providing a communication path for communicating the above suction chambers with each other, and controlling the communicating path to be opened and closed. CONSTITUTION:A radiator 21 and a suction box 22 are disposed above a V-type two-cylinder engine of a motorcycle, and two conduit pipes 25a, 25b and two suction pipes 26a, 26b are connected to the suction box 22. The conduit pipes 25a, 25b are extended forward and opened forward in front of a front fork 14. In this case, the suction box 22 is constructed so that the interior of the main body 22a is divided into two suction chambers 27a, 27b by a partition wall 22b and the conduit pipes 25a, 25b are opened to the respective suction chambers 27a, 27b. A hole (communicating path) 28 for communicating the suction chambers 27a, 27b with each other is formed on the partition wall 22b, and a valve 29 for opening and closing the hole 28 is provided there. The valve 29 is controlled to be opened and closed according to the rotating speed.

Description

Detailed Description of the Invention (Field of Industrial Application) This invention relates to an intake system for a vehicle engine, and in particular, an intake system that introduces running wind into an intake chamber and supplies intake air from the intake chamber to the cylinders of the engine. Regarding equipment.

(Prior Art) As an intake system for this type of vehicle engine, for example,
The one described in Japanese Unexamined Patent Publication No. 1-223090 is known. This intake device introduces running air into an air cleaner, detects the pressure inside the air cleaner, and corrects the intake air amount.

(Problem to be solved by the invention) However, in the conventional intake device described above, pulsations occur in the intake air in the air cleaner in response to the engine speed, so the frequency range specified by the volume of the near cleaner, etc. There is a problem in that resonance behavior occurs in the engine, making it impossible to supply sufficient intake air to the engine, resulting in a reduction in engine output.

This invention was made in view of the above problems, and aims to provide an intake device that can supply sufficient intake air to the engine over the entire engine speed range, and to prevent a decrease in engine output in a specific speed range. shall be.

(Means for Solving the Problems) The present invention provides an intake system for a vehicle engine that introduces running wind into an intake chamber and supplies intake air from the intake chamber to the cylinders of the engine. The gist is to provide a plurality of intake chambers, to individually communicate these intake chambers to their corresponding cylinders, to provide communication passages that communicate these intake chambers with each other, and to control the opening and closing of these communication passages.

(Function) The intake system for a vehicle engine according to the present invention prevents resonance of intake air from occurring in the intake chambers because the communication path that communicates between the intake chambers is controlled to open and close depending on the engine speed and the volume changes. This allows sufficient intake air to be supplied to the engine.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show an intake system for a vehicle engine according to an embodiment of the present invention, with FIG. 1 being a side view of the motorcycle and FIG. 2 being a sectional view of the main parts.

In FIG. 1, reference numeral 1 indicates a main frame, and a head tube 12 is fixed to the front portion of the main frame 11, and a swing arm 13 is swingably supported at the rear portion of the main frame 11. A front wheel 15 is supported on the head tube 12 so as to be steerable by a front fork 14, and a swing arm 1 is attached to the head tube 12.
3 has a rear wheel 16 supported at the rear. In addition, 17 is a fuel tank, and 19 is a seat mounted on the seat frame 18.

Further, a V-type two-cylinder two-stroke engine 20 is suspended on the main frame 11, and above the engine 20, a radiator 21 and a suction box 22 are arranged in front and behind.

The engine 20 is assembled integrally with the transmission and connected to the rear wheel 16 via a chain 23 so as to be able to transmit power, and exhaust pipes 24 and 24 extend rearward from each cylinder of the engine 20. The suction box 22 has two introduction pipes 2.
5a, 25b and two intake pipes 26a, 26b are connected, the introduction pipes 25a, 25b extend forward and open forward on the front side of the front fork 14, and the intake pipes 26a, 28b are connected. 20 engines each
It is connected to the crankcase and opens into the crank chamber. Although not shown, these intake pipes 26a.

26b is provided with a fuel injection valve and a riet valve.

As shown in FIG. 2, the suction box 22 has two suction chambers 27a separated by a partition wall 22b within the main body 22a.

27b is defined. These intake chambers 27a, 27b
The aforementioned introduction pipes 25a and 25b are opened and exposed to the atmosphere through the introduction pipes 25a and 25b, respectively, and the intake pipes 26a and 26b are opened and communicated with the crank chamber through the intake pipes 28a and 26b. There is. A hole (communication path) 28 is formed in the partition wall 22b to communicate between the intake chambers 27a and 27b, and a valve 29 for opening and closing the hole 28 is provided. The valve 29 is driven by an actuator such as a solenoid (not shown), and this actuator is connected to a controller (not shown). The controller is connected to a rotational speed sensor that detects the rotational speed NE (r, p, m) of the engine 20, and drives an actuator based on a detection signal output from this sensor. In addition, the first
In the figure, 32 is a funnel.

Such an intake device introduces running air through a pipe 25a.

25b into the intake chambers 27a, 27b to obtain a pressure corresponding to the traveling speed, and send the intake air from these intake chambers 27a, 27b to the respective intake pipes 26a, 26b. Fuel is injected by the injection valve, and intake air (air mixture) mixed with the fuel is supplied into the crank chamber of the engine 20. Therefore, in the engine 20, when the amount of intake air sent from the intake chambers 27a and 27b changes, the air-fuel ratio changes and the output is greatly affected. In addition, since the intake air generates pulsations according to the rotational speed N of the engine 20, When the intake air causes resonance in the intake chambers 27a and 27b, the amount of intake air also changes and the engine 20
output is also affected.

Here, in the intake device of this embodiment, the intake chamber 27
a and 27b are communicated through a hole 28, and the hole 28 is connected to the valve 2.
9, the speed is controlled according to the rotation speed of the engine 20, and the air intake chamber 27a is
, 27b. And engine 20
exhibits the output characteristics with respect to engine speed shown by the solid line in Figure 4 with the hole 28 closed and the broken line in Figure 344 with the hole 28 open, so the hole 28 is opened to communicate between the intake chambers 27a and 27b, and the predetermined rotation speed N is greater than the predetermined rotation speed NEI. The hole 28 is closed to isolate the intake chambers 27a and 27b in the middle rotation speed range smaller than NE2, and the intake chamber 27a is closed in the high rotation speed range above the predetermined rotation speed NE2.
, 27b. therefore,'! As is clear from diagram J4, the engine 20 has smooth output characteristics relative to the rotation speed, and can obtain a large output over the entire rotation speed range.

It goes without saying that the characteristics shown in FIG. 4 described above (the same applies to FIG. 5 described later) are merely examples, and
, 27b changes and the resonant frequency of the intake chambers 27a, 27b changes, the above-mentioned characteristics also change, and the control characteristics are changed in accordance with this change.

Furthermore, although the valve 29 and the like are schematically shown in the above-described embodiments, it goes without saying that various types of valves 29 can be used.

FIG. 4 shows an intake device according to another embodiment of the invention.

In this embodiment, the introduction pipe 25a is located near the suction box 22.

25b are provided with a communication pipe (communication path) 30 that communicates with each other,
This communication pipe 30 is provided with a valve 31 for opening and closing the communication pipe 30. This valve 31 is also controlled by the controller in accordance with the rotational speed NE of the engine 20, similarly to the embodiment described above.

In this embodiment as well, as shown in FIG.
The open state of the valve 31 is shown as a solid line, and the closed state of the valve 31 is similarly shown as a broken line. Therefore, in the low rotation speed range where the rotation speed of the engine 20 is below the predetermined rotation speed NEI, the introduction pipe 25a,
25b is in communication, the introduction pipes 25a and 25b are disconnected in the middle rotation speed range that is higher than the predetermined rotation speed NEI, and the predetermined rotation speed Nゎ is smaller than the predetermined rotation speed NEI, and the introduction pipe 25 is connected in the high rotation speed range of the predetermined rotation speed NE2 or higher.
a and 25b are connected to improve the output of the engine 20 over the entire rotation speed range.

In addition, in each of the above-mentioned embodiments, a fuel injection type two-stroke engine that injects fuel by a fuel injection valve is exemplified, but
It goes without saying that the present invention is also applicable to general two-stroke engines that use a carburetor.

In addition, in each of the above-mentioned embodiments, the opening and closing of the valves is controlled according to the engine speed, but in cases where the intake air flowing into the intake chamber via the introduction pipe has pulsations depending on the running speed, the running speed is further taken into account. It is also possible to perform similar control.

(Effects of the Invention) As explained above, according to the intake device for a vehicle engine according to the present invention, a plurality of intake chambers are provided for supplying running air to each cylinder corresponding to the cylinders of the engine, and these intake Since the chambers are communicated and disconnected depending on the engine speed, the engine can obtain high output over the entire speed range.

[Brief explanation of the drawing]

1 to 3 show an intake system for a vehicle engine according to an embodiment of the present invention, in which FIG. 1 is a side view of a motorcycle, FIG. 2 is a schematic plan cross-sectional view of the main parts, and FIG. is a graph showing the output characteristics of the engine. 4 and 5 show an intake system for a vehicle engine according to another embodiment of the present invention, FIG. 4 is a plan view schematically showing the main parts thereof, and FIG. 5 shows the output characteristics of the engine. This is a graph representing 20...Engine 22...Suction box 22a...
・Main body 22b...Partition walls 25a, 25b
- Inlet pipes 26a, 26b - Intake pipes 27a, 2
7b... Intake chamber 28... Hole (communication path) 29...
・Valve 30...Communication pipe (communication path) 31...
·valve

Claims (1)

[Scope of Claims] An intake system for a vehicle engine that introduces running wind into an intake chamber and supplies intake air from the intake chamber to the cylinders of the engine, wherein a plurality of intake chambers are provided corresponding to the number of cylinders of the engine, These intake chambers are individually connected to their corresponding cylinders, and a communication path is provided to communicate these intake chambers with each other,
An intake device for a vehicle engine characterized by controlling the opening and closing of this communication passage.