JPS595773B2 - turbocharged spark ignition engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a turbocharged spark ignition engine that uses an electronically controlled fuel injection computer to control the pitch of the stator vanes of a turbocharger turbine and compressor.

In general, turbo superchargers have a problem in that the responsiveness of the turbo supercharger's rotational speed to throttle operation is low, and therefore the responsiveness of engine output is also low.One specific example is low-speed, low-load operation. There was a problem in that even if the throttle was suddenly opened, the supercharger rotation speed would not increase until the exhaust energy increased, and the engine output would not increase rapidly either.

In order to solve the above problems, the present invention uses an electronically controlled fuel injection computer to control the pitch of the variable stator blades of the turbocharger turbine and compressor, and is configured as follows. There is.

That is, the present invention provides a turbocharged spark ignition engine in which the amount of fuel injection is controlled by a computer, in which variable stator vanes are provided in the turbine and compressor of the turbocharger, and the servo motor that changes the pitch of the variable stator vanes is controlled by the electronic system. It is electrically connected to the control fuel injection computer, and the computer controls the above pitch so that the intake air flow rate increases in response to an increase in accelerator opening, and when the accelerator opening rapidly increases, the variable stator blade of the turbine It is characterized by decreasing the pitch to rapidly increase the rotational speed of the compressor, and increasing the pitch of the variable stator vanes of the compressor to prevent surge fern.

Next, embodiments will be described with reference to the drawings. In FIG. 1, which is a schematic diagram, E is a spark ignition engine, specifically one of gasoline engines, alcohol engines, LPG engines, etc. The air outlet is connected, and the exhaust inlet of the turbine T of the supercharger 2 is connected to the exhaust outlet 3 of the engine E.

4 is a turbine shaft.

In FIG. 2, the frame 5 of the diffuser of the compressor C (shown schematically in the direction of the arrows ■-■ in FIG. It is rotatably supported via a pin T parallel to 4.

The ends of the variable stator vanes 6 on the air outlet 8 side are connected via pins 10, for example, by a ring (not shown), and a drive section 11 of a servo motor CM is connected to the ring. A variable stator blade 16 is similarly supported on the frame 15 of the nozzle of the turbine T via a pin 17.
Similarly, a drive section 21 of a servo motor TM is connected. 18 is an exhaust gas population, and 20 is a connecting pin.

The positions of the drive parts 11 and 21 of both servo motors CM and TM change depending on the magnitude of an electric human power signal, for example. The output terminals are electrically connected. The computer 25 has conventionally been generally used in electronically controlled fuel injection type engines, and as in the past, various sensors are connected to the human power terminal of the computer 25, specifically an air flow meter 30, an accelerator opening sensor, etc. 31, an intake pressure sensor 32, an intake air temperature sensor 33, an engine speed sensor 34, a cooling water temperature sensor 35, an exhaust pressure sensor 36, an exhaust temperature sensor 37, a knock sensor 38, etc. are connected.

Further, an injector nozzle 39 and a distributor 40 are connected to another output terminal of the computer 25, so that the computer 25 can control the fuel injection amount and ignition timing. In Figure 2, the accelerator opening is small;
The state when the engine output is also small is shown, and in this state, the variable stator blade 16 of the turbine T assumes a posture in which the pitch P1 becomes large, as shown by the solid line.

When the accelerator opening rapidly increases in this state, the computer 25 detects this as a signal from the accelerator opening sensor 31 and sends a signal to the servo motor TM, and the drive unit 21
moves and pulls the end of the variable stator blade 16 in the direction of arrow F,
The variable stator vane 16 rotates around the pin 1r to the position indicated by the two-dot chain line 16', and 3°2 inches Pl decreases to P1'.
On the other hand, when the accelerator opening is rapidly increased, the engine output remains low and the exhaust energy sent to the turbine T is small, but the pitch P1 of the stationary blades 16 decreases, so the turbine population and the gap between the exits are reduced. The expansion ratio increases, and the rotational speeds of the turbine shaft 4 and compressor C rapidly increase. Therefore, the amount of air sent out from the compressor C increases rapidly, and the engine output also increases rapidly. However, in this case, as shown in FIG. 3, there is a risk that the compressor operating point A may suddenly move into the surge region B. The servo motor CM is activated by the output signal,
By changing the pitch of the variable stillness 6 from P to P5 and moving the operating point to point C outside the surge range, surging of the combustor is prevented. } In Figure 3, line N
1, N2, and N3 each indicate a constant number of rotations of the compressor. Furthermore, during high-speed, high-load operation with excessive exhaust energy, it is also possible to increase the pitch P of the stationary blades and reduce the turbine inlet pressure. Furthermore, computer 25
is always activated by the signals from each sensor, both servo motors CM,
The pitches P, P, of the stator vanes 6, 16 are changed via the TM, and the combustor rotation speed and air flow pressure ratio are controlled so as to obtain the desired and optimal operating conditions.

As explained above, according to the present invention, the variable stator vanes 6 and 16 are provided in the turbocharger 2 of the spark ignition engine E, and the variable stator vanes 6 and 16 are provided.
, 16 are controlled by the computer 25 according to the operating conditions, so that the engine output can be quickly adjusted as follows in response to a sudden increase in the accelerator opening.

That is, in the present invention, when the accelerator opening rapidly increases, the pitch P of the variable stator blades 16 of the turbine T is decreased to rapidly increase the rotational speed of the combustor C, and the pitch P of the variable stator blades 6 of the combustor C is increased. Since this is designed to prevent surging, the amount of air sent out from the combustor C can be rapidly increased in accordance with the accelerator opening, and the engine output can be rapidly increased. Furthermore, the optimum amount of air can always be supplied to the engine E even when the accelerator opening is rapidly increasing.

Moreover, since the computer 25 is for electronically controlled fuel injection, unlike the case where a computer dedicated to the turbocharger 2 is provided, there is no significant cost increase.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an engine with a turbocharger, FIG. 2 is a partial schematic diagram of a supercharger and a control device, and FIG. 3 is a schematic diagram of a compressor map. 1...Turbo supercharger, 6,16...Variable stator vane, 25...Computer, C...
・Compressor, CM, TM... Servo motor, E... Engine, P, Pl... Pitch, T pin.

Claims (1)

[Claims] 1. In a turbocharged spark ignition engine in which the amount of fuel injection is controlled by a computer, variable stator vanes are provided in the turbine and compressor of the turbocharger, and a servo motor that changes the pitch of the variable stator vanes is used to control the above-mentioned electronically controlled fuel injection. electrically connected to the computer for use by the computer,
The pitch is controlled so that the intake air flow rate increases in response to an increase in the accelerator opening, and when the accelerator opening rapidly increases, the pitch of the variable stator vanes of the turbine is decreased to rapidly increase the rotation speed of the compressor. A turbocharged spark-ignition engine characterized by increasing the pitch of variable stator vanes to prevent surging.