JPH04370320A - Engine tuning structure - Google Patents

Abstract

PURPOSE:To improve the acceleration performance of an automatic transmission car by specifying the volume of the air-intake system so that a resonance condition may be generated in the stall condition during acceleration. CONSTITUTION:A resonator 6 connected to an air-intake pipe 3 constituting an air-intake system is capable of changing the volume by moving a partitioning plate 7. Here, in an engine 1 of an automatic transmission car, the volume of the air-intake system is specified so that the resonance condition may be generated in the stall condition during acceleration. This specification allows the resonance supercharging to be realized in the stall condition during acceleration, and the stagnation of the engine speed is eliminated due to the torque rise, leading to improvement of the acceleration performance.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to an intake system of an automatic transmission vehicle (hereinafter referred to as an A/T vehicle).
This invention relates to an engine tuning structure that actively utilizes resonance supercharging to improve acceleration performance.

0002

2. Description of the Related Art In the intake system of an automobile, resonance supercharging is performed by utilizing intake pulsation between an intake valve of an engine and a throttle valve. In other words, resonance generates large positive pressure waves, supercharging the engine, and improving output.

0003

However, as shown in FIG. 3, this resonance supercharging is effective at a certain engine speed, that is, when the engine is in a steady state. This means that the engine condition in which the resonance effect can be used is within a certain limited range (a certain engine rotational speed ±100 rpm).
m).

Therefore, as shown in FIG. 4, the resonant supercharging effect (the part indicated by the broken line in the figure is the resonant supercharging effect part) is hardly utilized in an excessive state such as during acceleration. In particular, A/T vehicles have a stall region where the engine rotational speed is constant during acceleration, but the resonance supercharging effect has not been effectively utilized.

[0005]

[Means for Solving the Problems] In order to solve the above problems, in the present invention, in an A/T vehicle, the volume of the intake system is determined so that a resonance state occurs during a stall state during acceleration.

[0006]

[Operation] Since resonance supercharging is performed in the stall state during acceleration, the engine rotational speed does not stagnate due to the rise of torque, improving acceleration performance.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 schematically shows a tuning structure according to an embodiment of the present invention. 1 is an engine, 2 is an intake manifold connected to each intake port of the engine 1, 3 is an intake pipe connecting an air cleaner 4 and the intake manifold 2, and a throttle valve 5 is provided in the middle thereof.

A resonator 6 is connected to the intake pipe 3 constituting the intake system. The capacity of the resonator 6 can be changed by moving the partition plate 7.

[0009] Therefore, when manufacturing a vehicle, the volume of the intake system is set so that it will be in a resonant state in a stalled state. If the pipe length is L, the pipe cross-sectional area is A, and the volume of the resonator 6 is V, then the resonance engine rotation speed (natural frequency) of this intake system is
Ne is expressed by the following formula by approximating the intake system to a Helmholtz resonance box.

0010

[Math 1]

That is, by adjusting the resonator partition plate 7 and changing the volume V, it is possible to cause resonance at the engine rotational speed in the stalled state. Note that it is desirable that the length of the intake pipe (distance from the engine 1 to the resonator 6) and the cross-sectional system of the intake pipe be the same for all cylinders. Further, the throttle valve 5 is in a fully open state.

In this embodiment, the resonator 6 is provided to tune the volume of the intake system, but this can also be achieved by not providing the resonator 6 and by setting the length of the intake pipe 3 fixedly. Can be done.

As described above, by setting the volume of the intake system, the intake pipe pressure in the stall region increases as shown in FIG. 2, and resonance supercharging is performed, so that the engine speed does not stagnate during acceleration. , acceleration performance is improved.

[0014]

[Effects of the Invention] According to the engine tuning structure of the present invention, since resonance supercharging is adjusted to the stall region, torque can be improved in this region, and the engine rotational speed does not stagnate during acceleration, resulting in acceleration. Improves sex. Along with this, the acceleration feeling also improves.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a tuning structure according to an embodiment of the present invention.

FIG. 2 is a diagram showing acceleration performance in the example.

FIG. 3 is a diagram showing the effect of conventional resonance supercharging.

FIG. 4 is a diagram showing the effect of conventional resonance supercharging during acceleration.

[Explanation of symbols]

1 Engine 2 Intake manifold 3 Intake pipe 4 Air cleaner 5 Throttle valve 6 Resonator 7 Partition plate

Claims (1)

[Claims] 1. An engine tuning structure for an automatic transmission vehicle, characterized in that the volume of the intake system is determined so that a resonance state occurs in a stall state during acceleration.