JPS60216030A - Internal-combustion engine equipped with turbochargers - Google Patents

Abstract

PURPOSE:To improve the engine performance in all the operation range by installing two turbochargers and installing the opening and closing valves having different operation range into exhaust pipes which lead from the respective turbines from the engine exhaust system of the turbochargers. CONSTITUTION:In the low-speed range of an engine, the both opening and closing valves V1 and V2 are closed, and the all amount of exhaust gas is introduced into the turbine T1 of one turbocharger A, passing through one exhaust pipe 17. Only one turbocharger A operates, and the other turbocharger B is in stop. A check valve V3 prevents the reverse flow of the fresh gas pressure-increased on the turbocharger A side to the turbocharger B side. In the high- speed range of the engine, the opening and closing valve V1 is opened, and the exhaust gas is introduced into the both turbochargers A and B. When the pressure becomes over a certain pressure, the opening and closing valve V2 is opened, and a portion of the exhaust gas which flows in the exhaust pipe is discharged, passing through a bypass pipe, not through the turbocharger A.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in turbocharged internal combustion engines.

As is well known, a turbocharger uses high-temperature, high-pressure exhaust gas discharged from an engine to turn a turbine and drive a compressor placed coaxially with the turbine to compress the gas, thereby increasing the output direction of the engine. be.

By the way, such a turbocharger cannot fully demonstrate its original performance since sufficient rotation cannot be obtained in the low speed range of the engine.For this reason, internal combustion engines equipped with this type of turbocharger cannot be used for the first time in the high speed range. There are drawbacks that come with the benefits of turbocharging.

The present invention has been made to effectively eliminate the above-mentioned disadvantages, and its purpose is to provide a turbocharged internal combustion engine that can exhibit high performance over the entire operating range.

In order to achieve such an object, the present invention provides a turbocharger in parallel to each exhaust pipe that communicates with the exhaust manifold and muffler, and a bypass pipe that communicates the turbine of one turbocharger with the high output of the engine. The on-off valve that opens when
The exhaust pipe that communicates with the exhaust manifold and the turbine of the other turbocharger has an on-off valve that opens when the engine is at medium output, and the intake pipe that communicates with the compressor of the negative turbocharger has an on-off valve that opens when the other turbocharger is activated. Their feature is that they each have a check valve that opens.

A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a side view of a motorcycle equipped with a turbocharged internal combustion engine according to the present invention, FIG. 2 is a circuit diagram of the same turbocharged internal combustion engine, and FIG. 3 is a pressure characteristic diagram of the turbocharger. FIG. 4 is a perspective view of the same turbocharged engine.

In the motorcycle shown in Fig. 1, the body frame (2)
A stem shaft (not shown) is rotatably inserted into the head pipe (3) fixed to the front of the head pipe, and a top bridge (4) and a bottom bridge (5) are fixed to the upper and lower ends of the stem shaft, respectively. has been done. As shown in the figure, a front wheel (7) is rotatably supported at the lower end of a front fork (6) on both the top and bottom bridges (4) and (5).

A handle (8) is fixedly attached to the top bridge (4).

Also, behind the head pipe (3) is a fuel tank (9).
and a seat (10), and an engine (11) is mounted below the fuel tank (8).

On the other hand, the front end of a rear fork (12) is pivotally attached to the lower central part of the vehicle body via a pivot shaft (13) so as to be able to swing up and down, and the rear end of the rear fork (12) is attached to the rear wheel as shown in the figure. (14) is rotatably supported.

By the way, two turbochargers (A) and (B) shown in FIG. 2 are arranged at the front lower part of the engine (11). Turbochargers (A) and (B) are respectively cocompressor (Ct), (C9), and turbine (TI).
(T2). In Figure 2, (15-1), (
+5-2) is a turbine blade, (1B-1), (16-2
) is a compressor impeller arranged coaxially with the turbine blades (15-1) and (15-2).

In addition, the turbocharger (B) may be a small one for auxiliary use, one of the same type as the turbocharger (A) for cost reasons, or a large one for emphasis on output. The turbocharger (B) was designed to be large enough to provide a large amount of supercharging at high speeds. Furthermore, in this embodiment, a one-car turbocharger (A) is used as shown in FIG.
, (B) is installed in front of and below the engine, and the turbine (
I made the axes of TI) and (T2) intersect, but
This is because if the exhaust ports of both turbochargers (A) and (B) are made to face each other, the exhaust gases will interfere with each other, which is not desirable in terms of increasing output.

As shown in Fig. 2, exhaust pipes (+7) and He) led out from the engine (11) are connected to the inlet side of each turbine (tl) and (72), respectively, and the outlet side An exhaust muffler (19) is connected to the exhaust muffler (19). A bypass pipe (20) is branched from one exhaust pipe (17), and this bypass pipe (20) is connected to the exhaust muffler (19).
are merging with. - On-off valves (Vl) with different operating ranges are provided in the exhaust pipe (18) and the bypass pipe (20), respectively.
(Vll) is provided.

On the other hand, intake pipes (22) and (23) led out from an air cleaner (21) disposed at the rear of the engine (11) are connected to the intake side of each of the compressors (II,) and (C2). Also compressor (C1), (02
Charge pipes (24) and (25) are led out from the discharge side of the air pump 2, and these charge pipes (24) and (25) are connected to an intake chamber (26). and,
The intake chamber (26) is connected to a carburetor (27) as shown in FIG. 1, and the carburetor (27) is connected to the intake side of the engine (11). In addition, a reed valve type check valve (v3) that allows flow only from the compressor (C1) side to the compressor (C2) side is interposed in the middle of one of the charge pipes (25).

Therefore, the pressure P2 in the intake chamber (26) becomes the set pressure Pq shown in FIG. 3, and the set pressure P2-! shown in FIG. In the low speed range below, both on-off valves (Vθ, (V2) are closed, and the entire amount of high-temperature, high-pressure exhaust gas generated by the combustion of the air-fuel mixture in the engine (11) is transferred to one exhaust pipe (
17) into the turbine (T1) of one turbocharger (^), where the turbine blades (15-1
) is rotated and then exhausted into the atmosphere from the exhaust muffler (18). Therefore, in this low speed range, only one turbocharger (A) is in operation, and the other turbocharger (CB) is stopped. In FIG. 3, the horizontal axis indicates the engine rotational speed.

The rotation of the L turbine blade (+5-1) rotates the compressor impeller (1B-1) arranged coaxially with the turbine blade (+5-1), and the air cleaner (21) and the intake pipe (
Fresh air introduced into the compressor ((:1) through the compressor (22) is compressed and pressurized by the impeller (1B-1), and then discharged from the discharge side of the compressor (C1).

This compressed fresh air is introduced into the carburetor (27) via the charge pipe (24) and the intake chamber (2B), where it mixes with the atomized fuel to form an air-fuel mixture. The air-fuel mixture formed in the carburetor (27) is filled into the cylinder of the engine (11), compressed by the piston, and then ignited and combusted, and part of the heat generated by the combustion of this air-fuel mixture is It can be effectively converted into mechanical energy.

In this low speed range, as the engine speed increases, the pressure of fresh air, that is, the pressure P in the chamber (26) increases.
2 increases along the curve (C1) in FIG. Here, in FIG. 3, a shows the dynamic characteristics of the high-speed side turbocharger, and b shows the dynamic characteristics of the low-speed side turbocharger. Then, when the engine speed ■ reaches 1, the pressure P2 becomes the set pressure P2.
It does not rise above -1. Note that the check valve (v3) serves to prevent fresh air pressurized on the turbocharger (A) side from flowing back to the turbocharger (B) side. Further, a check valve (v4) may be provided in the intake pipe. In this way, pressurized oil is guided to the turbine shaft, so if the compressor is brought to a high pressure state, there is a risk that the oil will leak into the intake air, but this can be suppressed.

Next, in a high-speed range where the engine speed increases beyond the NEI shown in the figure, the on-off valve (vl) opens and the exhaust gas passes through both exhaust pipes (17) and (18) to both turbochargers (A). , (B) into the turbines (T1) and (T2), and the operation of the turbocharger (B) is started.

In the high-speed range where the engine speed exceeds ground 2, both turbochargers (A) and (B) operate sufficiently, so the pressure P2 is as high as A above the engine speed range.
In FIG. 3, it rises along the curve (C2). Here, if the valve (vl) is gradually opened in the rotation range (1) before and after the boost pressure of the turbocharger (A) increases, the connection between the turbochargers (A) and (B) will be smooth. can be done.

When the pressure P2 reaches the set value P2-2, the on-off valve (v2) is opened and a part of the exhaust gas flowing through the exhaust pipe (17) is routed through the bypass pipe (without passing through the turbocharger (A)).
20) and directly flows to the exhaust muffler (18) side.

The opening degree of this on-off valve (v2) is controlled so that the pressure P7 does not exceed the setting P2-2.

Hereinafter, the operation of the turbochargers (A) and (B) is controlled according to the operating speed range of the engine (11), and especially in the low speed range, only one turbocharger (A) is operated to perform necessary operations. Since supercharging pressure is obtained, the engine (11) can exhibit high performance over the entire operating speed range.

As is clear from the above description, according to the present invention, there are two turbochargers, and the exhaust pipes from the engine exhaust system of these turbochargers to each turbine are provided with on-off valves with different operating ranges. Performance can be improved.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a side view of a motorcycle equipped with a turbocharged internal combustion engine according to the present invention, and FIG. 2 is a circuit diagram of the turbocharged internal combustion engine. FIG. 3 is a pressure characteristic diagram of the turbocharger, and FIG. 4 is a perspective view of the turbocharged engine. In the drawings, (1) is a motorcycle, (11) is an engine,
(17) and (1B) are exhaust pipes, (20) is a bypass pipe (21) is an air cleaner, (22) and (23) are intake pipes, and (24). (25) is a charge pipe, (26) is an intake prechamber, (27) is a carburetor, (A), (B) are turbochargers, (CI), (C2) are compressors, (
Tl), (T2) are turbines, (Vz), (V2
) is an on-off valve, and (v3) is a check valve. Fig. 2 9a → Enshi's rotary clothes N+: Fig. 4

Claims (1)

[Claims] It is a horizontal multi-cylinder engine, and a turbocharger is installed in parallel in each exhaust pipe that communicates with the exhaust manifold and the muffler, and a bypass pipe that communicates with the downstream side of the turbine of one turbocharger has a turbocharger connected to the engine. The on-off valve that opens when output is
The exhaust pipe that communicates with the exhaust manifold and the turbine of the other turbocharger is equipped with an on-off valve that opens when the engine is at medium output, and the intake pipe that communicates with the compressor of the other turbocharger is equipped with an on-off valve that opens when the other turbocharger operates. An internal combustion engine with a turbocharger, which is characterized by being equipped with a reverse single-turn valve.