JPH01219315A - Variable air intake device for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve the air intake efficiency by providing an external cylinder outside an inlet pipe to open and close opening/closing valves connected to the external cylinder in accordance with the engine speed. CONSTITUTION:An external cylinder 4 is provided outside an inlet pipe 3 between a carburetor 1 and an air cylinder 2. Opening/closing valves 7, 8 connected to the inside of the external cylinder 4 are provided in front and rear of the inlet pipe 3. The opening/closing valves 7, 8 are opened and closed in accordance with the engine speed to make the inside of the external cylinder an auxiliary inlet passage or a resonance chamber. Thus, the air intake efficiency can be enhanced over a wider range of rotation of the engine.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a variable intake system for an internal combustion engine.

[Conventional technology and its problems]

The intake air of an internal combustion engine is made by heating air purified by an air cleaner and fuel in a carburetor to form intake gas, which is sucked into the combustion chamber when the i intake valve opens. Since the intake valve opens intermittently in accordance with the intake stroke of the engine, intake is performed rapidly intermittently, and pulsating waves are generated within the intake pipe. In order to increase the intake efficiency and engine output by increasing the intake air volume, the pulsation of the intake air is effectively used to increase the charging efficiency, and the length of the intake pipe is adjusted to match the engine's high output required rotation range. It is set.

However, the intake pulsation frequency changes with engine rotation, so while it is possible to set the intake pipe length to increase intake efficiency in a specific rotation range, this intake pipe length will not be effective in other rotation ranges. I can't. Therefore, there are some engines that move the intake pipe forward and backward depending on the engine speed, making it possible to utilize the intake pulsation over a wider rotation range and obtain high output. For example, see Japanese Unexamined Patent Publication No. 50-20126 and Utility Model Application No. 58-181930@. However,
Machine I! Due to the number of chambers, it is not possible to freely set the length of the intake pipe to move forward and backward, and there is a limit, so there is a problem that the intake efficiency cannot be set to increase the intake efficiency over the entire rotation range.

[Purpose of the invention]

This invention provides an outer cylinder on the outside of the intake pipe, and provides communication parts at the front and rear of the intake pipe connected to the outer cylinder to provide an on-off valve.
The aim of the present invention is to obtain a variable intake system for an internal combustion engine that can increase intake efficiency and achieve high output over a wide rotation range by opening and closing a valve in relation to the rotational speed of the am and creating an auxiliary intake passage or a resonance chamber. purpose.

[Structure of the invention]

Embodiments of the present invention shown in the drawings will be described below.

An inlet of a carburetor 1 for internal combustion and an outlet of an air cleaner 2 are connected by an intake pipe 3. An outward direction 4 having a volume of 1 is provided on the outer periphery of the intake pipe 3. An opening 5.6 communicating with the outside and inside 4 is provided at the rear of the intake pipe 3. Each opening 5.6 is provided with a cylindrical sliding gap valve 7.8. The on-off valve 7.8, which is slidable, is biased so as to be closed by a spring 9.10, and the i'lla solenoid region is moved by a vacuum movable body 11.12, via a link, to the spring 9. ．．
It is designed to open against 10. The vacuum movable body 11.12 in the electromagnetic solenoid area is actuated by a switch 13.14, which is operated by a rotation sensor 15 of the engine. That is, the switches 13 and 14 respond to the input pulse signal of the rotation sensor 15. The opening area of the opening 5.6 is as follows: If the moving distance of the on-off valve 7.8 is h, and the diameter of the intake pipe 3 is d, then the opening area of the opening 5.6 is slightly Even if there is a gap, it will hardly affect the performance, so a simple oil seal will suffice.

[Action of the invention]

Figure 3 does not show the four types of cases A to A. Intake pipe 3 capacity! Iv, Volume inside outer cylinder 4 ■1, Intake pipe n
, intake pipe length 1 when one side of the titz valve 7.8 is opened
Indicated by 1. In the case of A, the on-off valves 7 and 8 are both closed, the outer cylinder 4 is completely unrelated, and the intake air is as follows. It flows. In case B, only the open valve 7 on the inlet side of the intake pipe 3 is open, and the resonance chamber (1) is connected to the inlet of the intake pipe 3. In the case of C, the on-off valve 8 on the outlet side of the intake pipe 3
This means that the resonance chamber of Vl is connected to the outlet side of the intake pipe 3. In the case of D, r on both sides of the intake pipe 3
JIarJl valves 7 and 8 are both open, and the intake pipe 3 has no meaning and V. Intake passage j having a volume of 10V1. become. ■1, ■It depends on the selection of o and jo settings, but B is a low speed type and C1D is a high speed type, which can utilize the pulsation of the intake air to increase the filling efficiency of the intake air, and has a wide rotation range. This can improve intake efficiency and increase output.

Furthermore, four types of changes can be made within the short length of the intake pipe 3.

〔Effect of the invention〕

As explained above, the present invention connects a carburetor and an air cleaner with an intake pipe, provides an outer cylinder having a predetermined volume on the outside of the intake pipe, and has an opening leading into the outer cylinder before and after the intake pipe. Since the m valve is provided and the rMr11 valve is opened and closed in relation to the engine speed, by opening and closing the on-off valve,
It can be changed to four types of intake systems, and can be varied to achieve a pulsating effect according to the pulsating frequency of the intake air, which varies depending on the rotation speed, increasing the filling efficiency of the intake air over a wide rotation range. It is possible to increase the output of the engine. Furthermore, since a wide range of changes can be obtained with a short intake pipe length, installation is easy.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a longitudinal side view, Fig. 2 is a side view of the outer cylinder longitudinally showing the operating section, and Fig. 3 is
-D is a schematic diagram showing four types of operating conditions. 1... Carburetor, 2... Air cleaner, 3...
Intake pipe, 4...Outer cylinder, 7...Opening/closing valve, 8...I?
1l (1 valve. Applicant's agent Hiroshi Fujimoto Figure 3)

Claims (1)

[Claims] The carburetor and the air cleaner are connected by an intake pipe, an outer cylinder having a predetermined volume is provided outside the intake pipe, on-off valves communicating with the outer cylinder are provided before and after the intake pipe, and the on-off valves are connected to the engine. A variable intake device for an internal combustion engine, characterized in that it opens and closes in relation to the rotational speed.