JPS59158320A - Engine suction system - Google Patents

Abstract

PURPOSE:To improve acceleration characteristic by improving inertia supercharging effect in random rotary area of engine. CONSTITUTION:When transferring from low speed to quick acceleration, an exchange valve 13 is exchanged from solid line to dashed line. Rotation of engine 1 is detected by a rotation sensor 16 while quick stepping of accelerator pedal is detected by an accelerator sensor 17. Upon detection, a controller 15 will feed a control signal to an actuator 14 which will cause exchanging of the exchange valve 13 to choke an inertia supercharging pipe 11 while to open a branch pipe 12.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine intake system, and relates to an engine intake system that performs inertial supercharging of intake air by setting the shape of the intake pipe to a predetermined length. Regarding.

In an internal combustion engine, external air is introduced through an intake pipe, and by listening to an intake valve, this intake air is supplied into a cylinder to cause a combustion explosion. The intake air (composed of highly compressible fluid, and because the end side of the intake pipe is opened and closed by an intake valve, a pressure wave force of the intake air is generated in the intake pipe. By appropriately selecting the shape of the intake pipe, the quality of the intake pipe, or the directness of the intake pipe, the above pressure waves can be synchronized with the opening and closing of the intake valve at a certain engine speed. In other words, by setting the length of the intake pipe to appropriate values, it is possible to introduce intake air into the cylinder in a certain rotational range of the engine even if the engine reaches the bottom dead center. This greatly improves the volumetric efficiency of the intake air. Therefore, such inertial supercharging makes it possible to improve the engine output by increasing the filling efficiency of the intake air.

In a conventional engine that performs such inertial supercharging, the synchronized rotational speed is set to a value considerably higher than the rotational speed of the eye 1 to the ring, so that b'=t=.

For example, in a diesel engine, 100
The culm degree was set at 0 to 1500 rpm. Therefore, in such conventional diesel engines, the effect of iQ supercharging cannot be obtained at low speeds, for example, at 600 rpm.
m (When increasing the amount of fuel supplied to rapidly increase output near q, the ratio of i% between intake air and fuel in the cylinder is appropriate. There was a drawback that the occurrence was 1.
``J-type supercharging engines had a defect in that the J: jjj of black smoke in the exhaust gas was high < 4 at the time of starting or when accelerating suddenly from low speed. Therefore, in order to improve this inconvenience, we were looking for countermeasures such as suppressing the suspension of J5 fuel oil on the low-speed rotation ΦΔ side of the engine.

Therefore, such a single engine has the problem of deteriorating the acceleration characteristics at low speeds.

The present invention was made in view of the 2fU point between 4r and
) It is an object of the present invention to provide a one-engine intake system that improves the acceleration characteristics [1] by increasing the effect of H-type supercharging.

The present invention will be explained below with reference to an illustrated embodiment.

- Fig. 1 shows a six-cylinder diesel engine 1 according to this embodiment, and this engine 1 has an intake manifold iJ.
It includes a route 2 and an exhaust manifold 3. The intake manifold 2 is connected to an intercooler 5 via an intake pipe 4, and the intercooler 5 is further connected to a compression tree 7 of a turbocharger 6. This compressor 7 is connected to an air cleaner 8. On the other hand, the exhaust manifold 3 is connected to the exhaust pipe 9 via the turbine 1o of the turbocharger 6.

The intake pipe 4 that supplies intake air from the intercooler 5 to the intake manifold 2 is divided into two parts every three cylinders from the middle, and the part from this part to the manifold 1 to 2 is an inertial supercharging vibe 11. It consists of The part () up to A-8 in the figure is the part that contributes to inertial supercharging. A branch pipe 12 is provided in parallel to each of these pair of inertial supercharging vibes 11. Therefore, the inertial supercharging vibe 11 constitutes a branch pipe that branches to the branch pipe 12. A switching valve 1 is provided at the branch part between this branch pipe 12 and the vibrator 11.
3 are provided. The switching valve 13 is provided with 41 so that its opening/closing is controlled by the actuator 14.

Control signals are then supplied to the pair of actuators 14 from the controller 1 to the roller 15.The controller 15 is composed of, for example, a microphone controller. This con 1-[1-la 15
A rotation detection sensor 16 detects the rotation speed of the engine 1.
The detection output of the accelerator sensor 17 that detects the accelerator pedal jjll (included 1) is manually input.
Suction 5 'iff' I (7) The angle between A and intercooler 5 to C is abnormal (J is longer, but the actual system 1 has a pair of branch vibes 11J3 and branch pipe 1 for inertial supercharging.
2 are arranged three-dimensionally, Δ
The length of the intake pipe 4 from the point to the intercooler 5 is shortened.

In the above configuration, the intake air that has passed through the air cleaner 8 is compressed by the intake air of the turbocharger 6, cooled by the intercooler 55, and then passed through the intake pipe 4 and intake manifold 2 to each cylinder of the engine 1. Ill' will be supplied primary. The length of the portion of the intake pipe 4 that contributes to inertial supercharging is the length from point CA to point B in FIG. When the branch pipe 12 is switched to be closed as shown by the solid line J, the length of the portion of the intake pipe 4 that contributes to inertial supercharging is shortened.

If we spell this old length as [1, then engine 1 at this time
The efficiency of the air body Mi due to inertial supercharging with respect to the rotational speed of is as shown in Fig. 2 by jj, and the characteristic is that it is synchronized at the engine rotational speed, for example, 11000pp. There is. Therefore, under normal running conditions, the engine output can be improved by increasing the volumetric efficiency of air at such rotational speed a5.

Next, when starting a vehicle equipped with this engine, or when performing a sudden 10-speed maneuver from low speed, change the switching valve 13 from the state shown by the solid line (J3) in Figure 1 to the state shown by the chain line. Switch. That is, the rotation speed of the engine 1 is detected by the rotation detection sensor () 16, and
The accelerator sensor 17 detects rapid depression of the accelerator pedal. Then, in order for the controller 15 to supply a control signal to the actuator 14 in response to such detection, the actuator 14 is connected to the switching valve 1.
3 to close the inertial supercharging vibe 11,
Pull the branch pipe 12 open.

The branch pipe 12 is bent J5 compared to the vibrator 11, and its effective length is longer, so the distance from point A to point B changes from Ll to 12. Therefore, the air volume efficiency with respect to the engine speed at this time changes as shown by the chain line in Fig. 2. For example, when the engine speed is 60
Becomes in sync with Orpm. Therefore, when the engine 1 is rotating at a low speed, even if the amount of fuel injection is increased by rapidly depressing the accelerator pedal, more intake air will be mixed with this fuel, resulting in more intake air being mixed with the fuel, resulting in less gas being added to the exhaust gas. (This makes it possible to improve the acceleration characteristics at low speed rotation without increasing the tower of black smoke.) This shows the black smoke temperature, and as is clear from this result, the concentration of black smoke does not become very high even when the engine speed is low.The characteristics shown by the dotted line in the figure are the conventional characteristics. .Therefore, as is clear from this comparison, especially at 600 rpm
It is possible to effectively reduce the concentration of black smoke in the exhaust gas that flows during low-speed front and rear rotation.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made based on the technical idea of the present invention. For example, the above embodiment relates to an intake system for a diesel engine, but the present invention is also applicable to an intake system for a gasoline engine. In addition, in this embodiment, 1 of the intake pipe is 85.
The part that contributes to manual supercharging is made up of two types of branch pipes with different tuned rotation speeds, and more than 31,000 branch pipes are designed to match each of the three or more types of tuned rotation speeds. Branch pipe h + r et al.
By avoiding a change in the effective length of J:, the tuning rotational speed is made to differ, but it is also possible to make the tuning rotational speed different by keeping the effective length the same and changing the diameter.

As mentioned above), the present invention provides the following advantages:
At least a part of the part contributing to supercharging is made up of a plurality of branch pipes 474 having mutually different synchronized rotational speeds, and intake air is selectively supplied by one of these branch pipes. J: This relates to a high-speed air intake system equipped with a sea urchin switching valve. Therefore, according to the present invention, since matching of inertia supercharging is achieved in at least two rotation ranges, intake air can be more effectively supplied into the cylinder, and the inertia supercharging can be matched over a wide rotation range. This not only improves the output of the engine, but also reduces the concentration of black smoke in the exhaust residue.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing an intake system of an engine according to an embodiment of the present invention, Fig. 2 is a graph showing changes in air volume efficiency with respect to the engine speed, and Fig. 3 is a graph of this engine. It is a graph showing the change in black Xi i11 degree in the exhaust gas depending on the rotation speed. In the symbols used in Figure A5, 4...Intake pipe 11...Inertia supercharging vibe 12...Branch pipe 13...Switching valve. Applicant Hino Motors Co., Ltd.

Claims (1)

[Claims] In a device that performs inertial supercharging of intake air by setting the shape such as the length of the intake pipe to a predetermined value, at least a part of the portion of the intake pipe that covers the inertial supercharging of the odd LJ is synchronized with each other. 1. An intake system for an engine, comprising a small number of branch pipes having different rotational speeds, and comprising a switching valve so that intake air is selectively supplied by one of the branch pipes.