JPS6075721A - Control device for internal-combustion engine with supercharger - Google Patents

Abstract

PURPOSE:To obtain good charging efficiency over an entire rotational area of an engine, by providing a first supercharger, inertia supercharging device, and second supercharger operable accoding to high, medium and low rotational speed areas of the engine, and selectively operating these according to the rotational speed of the engine. CONSTITUTION:An intake manifold 2 is divided into two groups, and each of resonance pipes 3 having a length determined by a synchronous rotational speed in inertia supercharging is provided in each of the groups. The resonance pipes 3 are cummunicated with each other through a bypass passage 4 including an openable valve 5, and inertia supercharging is carried out by the resonance pipes 3 upon closing of the valve 5. Both the resonance pipes 3 are collected at an upstream side thereof, and a selector valve 7 is provided upstream of a collective portion 6 to allow first and second superchargers 8 and 9 to be selectively used. The supercharger 8 only is used at a low engine speed under a medium and high load. At a medium engine speed, the valve 5 is closed to effect inertia supercharging. Further, at a high engine speed, the supercharger 9 only is used to obtain a predetermined charging efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for an internal combustion engine that switches between at least seven or three supercharging devices.

Internal combustion engines are equipped with a supercharging device to achieve smaller size and higher output.

Among supercharging devices, turbochargers are very effective because they have a high filling rate, but on the other hand, they have drawbacks in terms of cost, maintenance, etc. On the other hand, inertia and supercharging only use the inertia of air supply. , cost is low, and maintenance is free. However, there is also a drawback that the air supply passage must be made longer. In particular, in engines that have a relatively wide rotational speed range and are frequently used at low rotational speeds, such as diesel engines for vehicle width, it is necessary to match the inertia supercharging in the low speed range C. The disadvantage is that the passage is long and the volume of the air supply passage becomes large.

The present invention aims to effectively combine the advantages of each supercharging system, thereby providing a low-cost and highly efficient internal combustion engine. 3. 1 will be explained below with the help of figures. First, inertia 1@feed will be explained.

Inertial supercharging uses the inertia of the air to force the air into the cylinder, and i4 is calculated so that the maximum filling rate is reached at the engine speed.

Diesel engine H, generally 2200-2400r,
Only m, the maximum rotation speed is 1000r, p
, m.

If the tuning point of inertial supercharging is set nearby, the air supply passage will become extremely long.

On the other hand, in a diesel engine, 1000 r, p, m,
to 240 Or, pm, and a supercharging device using one turbocharger is insufficient to achieve a good filling rate over the entire rotation range, so a supercharging device using two or more turbochargers is required. A supercharger jN must be provided and used selectively.

The greatest feature of this invention is to synchronize the turbocharger with high rotation to obtain a high filling rate, to completely reduce the length of the air supply passage as inertia supercharging in the mid-speed range, and to synchronize the turbocharger in the low-speed range. Figure 1 is a schematic system diagram showing an embodiment of the present invention. Air supply is supplied to the engine 1 via an air supply manifold 2. The supply air manifold is divided into two groups, and a resonance pipe 3 is provided for each group.The length of the resonance pipe 3 is determined by the tuned rotation speed of the inertial supercharging. However, in this embodiment, the tuning time ka is set in the middle rotation range of the engine (for example, 1600 rpm, etc.), so it is relatively short.

The resonance pipe 3 is provided with a bypass passage S, and the bypass passage 4 is provided with an on-off valve 5.

The on-off valve 5 stops the resonance and the inertial supercharging by the C-ive 3 by opening the valve.

The two resonant vibrators 3 are gathered into one upstream, and the gathering part 6
A switching valve 7 is provided in the V-stream so that the first turbocharger 8 and the second turbocharger V-jar 9 can be selectively employed.

A switching valve 11 is located downstream of the exhaust manifold 10 of the engine 1.
is provided to the first turbo bench.

- The 1° switching valves 7.11 with which the turbocharger 8 and the second turbocharger 9 are selectively employed are each provided with an actuator 12.13, and the actuator 12.13 receives an activation signal from the controller 14. is given. The controller 14 detects the engine's overload rotation/change and controls the actuator 1.
2. Give a signal for 1;7J conversion operation to 13.

An actuator 15 is also provided on the opening/closing valve 5, and the actuator 15 is opened/closed by a signal from the controller 14.

The operation of the control device of the present invention configured as described above will be explained with reference to the following table.

In the following table, 8 is the first DVD charger.

9 is the second turbocharger, 5 is the on-off valve 1. First, only the small IC starter + 45 charger 8 is used at low speeds under medium and high loads. , th triter, 1 (Charger 8 ID tuned to low rotation - C5 The maximum filling rate is achieved in this rotation range.

Next, 7, which is in the middle rotation range, open/close jP 5 is closed. When the on-off valve 5 is closed, inertial supercharging is performed. Inertial supercharging is achieved by resonance
This tuning point is set in the middle rotation range, and then when the rotation speed reaches the high rotation range, the second turbocharger 9
only used. Since the second turbocharger gear 9 is tuned to high rotation, the filling rate is maximum in this rotation range.

In all of the above operations, the engine rotation and engine load are increased by the controller 14, and as a result, the controller 14 outputs the engine speed and the engine load to the controller 14.
This is done by applying a signal to the valve 5 and activating it, thereby causing the switching valve 7.11 and the on-off valve 5 to operate.

In the above-mentioned reference, "one opening or closing of the on-off valve 5" means that it may be open or closed at any time. Moreover, each turbocharger 8,
90 Half-operation operation means that both turbochargers are used in a non-operating manner, and that both use the supply air and use half of both turbochargers (stopping the switching valves '7 and 11 halfway). It's easy to read.

If the above action is plotted in a diagram, it will look like Figure 2.

Fig. 2 Q- is plotted with the vertical axis 1!11I representing the filling rate (volume ratio) ηV and the horizontal axis representing the rotational speed. Line A in the figure is ηV obtained by the 10th turbocharger 8, The moat is ην obtained by inertia supercharging. The C line in the diagram is ην obtained by the second turbocharger 9.

As can be seen from Section 24, according to the present invention, a stable ηW can be obtained over the entire rotation range. is due to the following reason.

At light loads, not so much output is required.

On the other hand, if the filling rate is increased, pumping + bus (pressure, work approximately during stroke) increases, which is undesirable.

Therefore, when the load is light, the filling rate is lowered to reduce the pumping loss.

In addition, in the above, the term "filling rate" refers to filling effect, volumetric efficiency, etc. 1. As explained above, according to the r= of the present invention, good performance is achieved over the entire rotation range. It is possible to obtain a high filling rate and shorten the length of the resonant pipe.

Furthermore, when the load is light, each optimal supercharging position is not used and the pumping S rice is reduced. a p control X1111
ζIt is also desirable that the drawings (θ1) 1. Agent: Patent Attorney Tsuji Mibe; °・1 Figure 2, ) 2 Figure

Claims (1)

[Claims] The engine rotation range is divided into three stages: high rotation, medium rotation, and low rotation, and a first turbocharger, an inertial supercharging device, and a second turbocharger are provided to synchronize the engine rotation speed with each rotation speed. A control device for an internal combustion engine equipped with a supercharging device, characterized in that the detection [2] operates means for selecting the first turbocharger, the inertial supercharging device, and the second turbocharger.