JPH02291469A - Suction system of internal combustion engine - Google Patents

Abstract

PURPOSE:To measure the suction amount with accuracy allowing an engine main body to move by fixing a rigid suction introduction pipe that is connected to an air flow meter to the engine main body, and by connecting an elastic suction introduction pipe between the rigid suction introduction pipe and an air cleaner. CONSTITUTION:To an air flow meter 16 connected to a throttle body 14 on the upper side of a suction manifold 8 of an engine main body 6, one end of a rigid first suction introduction pipe 20 made of metal, etc., is connected, which is fixed to the engine main body 6 with a fixture 24. The other end of the first suction introduction pipe 20 is connected to one end of an elastic second suction introduction pipe 22 made of rubber hose, etc. The other end of the second suction introduction pipe 22 is connected to a connection 26 of an air cleaner fixed to the engine main body 6. Even when the engine main body 6 moves, reciprocal locational relationship between the air flow meter 16 and the first suction introduction pipe 20 is maintained constant, whereby the flow of the suction air is made homogeneous, and the suction amount can thus be measured with accuracy.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an intake system for an internal combustion engine, and in particular, the present invention relates to an intake system for an internal combustion engine, and in particular, a device that changes the relative positional relationship between an air flow meter and an intake introduction pipe connected immediately upstream of the air flow meter. The present invention relates to an intake system for an internal combustion engine that can prevent

[Conventional technology]

In the intake system of an internal combustion engine, an intake air introduction pipe is provided that forms an intake passage that guides intake air from an air cleaner to the internal combustion engine. This intake pipe is made of a metal pipe, a resin pipe, or the like. An example of such an intake system structure is shown in FIG. 2. That is, as shown in FIG.
A throttle body 108 having an intake throttle valve 106 is connected to the upstream side of the intake manifold 104 attached to the intake manifold 104, and an air flow meter 110 for measuring the amount of intake air is provided upstream of the throttle body 108.
One end of a flexible intermediate intake hose 12 made of rubber or the like is provided on the upstream side of the internal combustion engine 102 to absorb vibrations and movement of the internal combustion engine 102, and a metal hose is connected between the other end of the intermediate intake hose 112 and the air cleaner 114. An air cleaner side intake hose 116, which is a rigid intake introduction pipe made of aluminum or resin, is interposed. Further, as shown in FIG. 3, the air cleaner side intake hose 116, which communicates the intermediate intake hose 112 with the inside of the air cleaner 114, is connected to the vehicle body 120 by means of fixing devices 11B.
Some have a fixed configuration.

Furthermore, as for the configuration of the intake system, for example, Japanese Patent Laid-Open No. 57-19
It is disclosed in Japanese Patent No. 3755. The device described in this publication has a configuration in which an intake duct is interposed between an air flow meter connected to an air cleaner and a throttle body.

Since air flow meters attached to the intake system are susceptible to vibration, they are generally not attached directly to the internal combustion engine, but rather to the vehicle body. However, in recent years, air flow meters are sometimes attached directly to internal combustion engines for reasons such as wanting to increase the response speed of intake air flow measurement or wanting to mount auxiliary parts of the internal combustion engine in a compact manner.

By the way, in an air flow meter, in order to accurately measure the amount of intake air, it is necessary for the flow of intake air to pass through the measuring section without drifting. That is, as shown in FIG. 4, when the intake air flows uniformly through the measuring section of the air flow meter A, the amount of intake air can be accurately measured. but,
If the flow of intake air concentrates at the center of air flow meter A as shown in Figure 5, or if the intake air flows unevenly to air flow meter A as shown in Figure 6, an error will occur in the measurement of the amount of intake air. It is what it is.

[Problem that the invention seeks to solve]

However, in the configuration shown in FIG. 2, since the rubber intermediate intake hose 112 is connected immediately upstream of the air flow meter 110, there is an inconvenience that an error occurs on the plus side or minus side depending on the direction of movement of the internal combustion engine 102. was there.

In addition, in the configuration shown in FIG. 2, the relative position between the internal combustion engine 102 and the vehicle body 120 does not change while constant speed operation continues, but if the internal combustion engine 102 tilts backward during sudden acceleration, the air flow meter The intermediate intake hose 112 connected immediately upstream of the intake hose 110 is twisted, causing the intake air to flow unevenly, making it impossible to accurately measure the amount of intake air.
If the air-fuel mixture necessary for acceleration cannot be obtained and the internal combustion engine 102 tilts forward during deceleration, the intermediate intake hose 112 will be twisted in the opposite direction to that during acceleration, and the intake air will also be biased in the opposite direction. Therefore, there was a problem that accurate measurement of the amount of intake air could not be performed.

Furthermore, the system described in the above-mentioned publication has the disadvantage that the intake duct may be unnecessarily deformed, and since the air flow meter is connected to the air cleaner, the auxiliary parts of the internal combustion engine may become disorganized. .

[Purpose of the invention]

Therefore, the purpose of this invention is to eliminate the above-mentioned disadvantages.
By fixing a rigid intake introduction pipe directly upstream of the air flow meter to the internal combustion engine body, and providing a visible intake introduction pipe between the rigid intake introduction pipe and the air cleaner, it is possible to However, since the air flow meter and the rigid intake pipe move integrally in the same way as the internal combustion engine body, the relative positional relationship between the air flow meter and the rigid intake pipe does not change, and the flow of intake air is made uniform. An object of the present invention is to realize an intake system for an internal combustion engine that can accurately measure the air-fuel ratio, prevent unnecessary fluctuations in the air-fuel ratio, improve drivability, and improve exhaust gas purification performance. [Means for solving the problem] In order to achieve this object, the present invention provides a method in which a rigid intake inlet pipe is fixedly connected to the internal combustion engine body immediately upstream of an air flow meter that measures the amount of intake air into the internal combustion engine. However, a flexible intake air introduction pipe is provided between the rigid air intake introduction pipe and the air cleaner. [Operation] According to the configuration of the present invention, when the internal combustion engine moves, the rigid intake introduction pipe and the air flow meter fixed to the internal combustion engine move in the same manner as the internal combustion engine. Therefore, the relative positional relationship between the air flow meter and the rigid intake air introduction pipe does not change, and as a result, the flow of intake air to the air flow meter is uniform, and the amount of intake air can be accurately measured.

〔Example〕

Embodiments of the present invention will be described in detail and specifically below based on the drawings.

FIG. 1 shows an embodiment of the invention.

In the figure, 2 is the vehicle body, 4 is the internal combustion engine, and 6 is the internal combustion engine 4.
body, 8 is an intake manifold, 10 is an exhaust manifold,
12 is an air cleaner fixed to the zero body 6. A throttle body l4 is connected to the upstream side of the intake manifold 8, and an air flow meter 16 is connected to the throttle body 14.

An intake throttle valve 18 is disposed within the throttle body 14.

The air flow meter 16 is connected to one end of a first rigid intake pipe 20 made of a metal pipe, a resin pipe, or the like.

This first intake introduction pipe 20 is located on the side surface of the zero body 6 and extends upstream, and the other end is connected to one end of a second intake introduction pipe 22 made of a rubber hose or the like, which is a flexible intake introduction pipe. are doing.

The first intake air introduction pipe 20 is fixed to the zero body 6 with fixtures 24, 24.

The other end of the second intake inlet pipe 22 is connected to a connecting portion 26 of the air cleaner 12.

That is, the first intake pipe 2 on the upstream side of the air flow meter 16
0 is installed so that it moves in the same way as the zero body 6 of the internal combustion engine 4, and a second intake introduction pipe is attached to the first intake introduction pipe 20 to absorb the vibration and movement of the zero body 6 of the internal combustion engine 4. 22 is installed.

Next, the operation of this embodiment will be explained.

The air purified by the air cleaner 12 is drawn into the air flow meter 16 side as intake air through the second intake air introduction pipe 22 and the first intake air introduction pipe 20.

The airflow meter 16 measures the amount of intake air, and the intake air is supplied to the internal combustion engine 4 through the throttle body 14 .

At this time, when the internal combustion engine 4 moves during sudden acceleration or deceleration of the vehicle, the rigid first intake introduction hose 20 is fixed to the zero body 6 of the internal combustion engine 4, so that the first 1. The intake pipe 20 and the air flow meter 16 integrally move in the same manner as the zero body 6 of the internal combustion engine 4. That is, even if the zero body 6 of the internal combustion engine 4 moves, the relative positional relationship between the air flow meter 16 and the first intake air introduction hose 20 does not change.

Therefore, the flow of the intake air flowing into the air flow meter 16 side is maintained uniformly in the measuring section (not shown) of the air flow meter 16 as shown in FIG. 4, and the air flow meter 16 accurately measures the amount of intake air. be able to.

In this way, by accurately measuring the amount of intake air, it is possible to prevent the air-fuel ratio from fluctuating unnecessarily, that is, to prevent the air-fuel ratio from becoming richer or leaner, thereby improving drivability. , exhaust gas purification performance can also be improved.

Further, the vibration of the zero body 6 of the internal combustion engine 4 is caused by the vibration of the second intake introduction pipe 2.
2, so it is not transmitted to the vehicle body 2 side. Thereby, the riding feeling can be improved.

Furthermore, since the air flow meter 16 is attached to the zero body 6 side of the internal combustion engine 4, the response speed for measuring the intake air amount can be increased, and the auxiliary parts of the internal combustion engine 4 can be made compact.

〔Effect of the invention〕

As is clear from the above detailed description, according to the present invention,
By fixing a rigid intake introduction pipe directly upstream of the air flow meter to the internal combustion engine body, and installing a flexible intake introduction pipe between the rigid intake introduction pipe and the air cleaner, it is possible to prevent the internal combustion engine from moving. Since the air flow meter and the rigid intake pipe work together in the same way as an internal combustion engine, the flow of intake air is uniform, the amount of intake air can be accurately measured, and unnecessary fluctuations in the air-fuel ratio are prevented. This can improve drivability and improve exhaust gas purification.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention, and is a schematic diagram of an intake system for an internal combustion engine. FIGS. 2 and 3 are schematic diagrams of conventional intake devices. 4 to 6 are explanatory diagrams of the flow state of intake air flowing into the air flow meter. In the figure, 2 is the vehicle body, 4 is the internal combustion engine, 6 is the main body, l6
is an air flow meter, 20 is a rigid first intake introduction pipe, and 22 is a flexible second intake introduction pipe. Patent Applicant Suzuki Motor Co., Ltd. Representative Patent Attorney Yoshimi Saigo Figure 1 Figure 2 Figure 3 Figure 4 A Junior high school 11th place

Claims (1)

[Claims] 1. A rigid intake introduction pipe connected directly upstream of an air flow meter that measures the amount of intake air into the internal combustion engine is fixed to the internal combustion engine body, and a flexible intake introduction pipe is installed between the rigid intake introduction pipe and the air cleaner. An intake device for an internal combustion engine characterized by being provided with a pipe.