JPS61123717A - Variable nozzle controller for turbosupercharger - Google Patents

Abstract

PURPOSE:To improve a degree of start-accelerating performance or the like, by keeping an opening area of an exhaust gas intake port in a turbine in a minimal state irrespective of an engine speed when boost pressure is below the specified value and exhaust gas pressure also is below the specified value, in the case where engine load is more than the specified value. CONSTITUTION:When engine load to be detected by a load sensor 31 additionally installed in an accelerator pedal 30 is below the specified value, a driving mechanism 7 is controlled by a controller 40, and adjustable vanes 4 are kept in a normal state of maximum in opening. On the other hand, when engine load in more than the specified value, output Pb of a boost pressure sensor 41 is compared with maximum boost pressure Pbmax. And, when Pb>=Pbmax is the case, output Ne of an engine speed sensor 32 is compared with the specified value Ne2, and when Ne W Ne2 is the case, these adjustable vanes 4 are set to their intermediate opening but when Ne>=Ne2, these vanes are controlled to be set to the maximum opening. And, when Pb<Pbmax is the case, exhaust gas pressure by an exhaust gas pressure sensor 42 is compared with maximum exhaust gas pressure Pitmax, and when Pit<Pitmax is the case, these adjustable vanes 4 are kept up to the minimum opening.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a variable nozzle control device for a nine-term supercharger in which an on-off valve mechanism is provided at an inlet for introducing exhaust gas to a turbine.

<Prior Art> A turbocharger includes a turbine disposed in a passage for exhaust gas from an engine, and a compressor connected to the turbine and disposed in a passage for intake air to the engine. As the turbine is rotationally driven by the exhaust gas discharged from the engine, the compressor is rotationally driven to supply a large amount of intake air to the combustion chamber of the engine.

By the way, in the conventional turbocharger as mentioned above,
When the engine speed is low, that is, when the flow rate of exhaust gas is low, the rotational speed of the turbine decreases.
There was a problem in that the function of sufficiently increasing the amount of intake air could not be fully utilized.

Therefore, with the aim of solving the above problem, the applicant of the present application has already developed a variable nozzle type target supercharging system 1! as shown in FIG. ! I developed it.

As shown in Fig. 4, the Tarza supercharger is formed of a turbine 1 disposed in the exhaust passage of the engine's exhaust gas and a compressor disposed in the intake passage of the engine. A turbine 1 is rotationally driven by the exhaust gas, and as the turbine 1 is driven, a compressor installed coaxially with the turbine 1 is rotationally driven, thereby increasing the filling efficiency of intake air supplied into the combustion chamber of the engine. ing. Furthermore, an on-off valve mechanism 2 is disposed at the exhaust gas inlet of the turbine 1 . This on-off valve mechanism 2
is formed by a movable ring 3, a plurality of movable vanes 4, and a plurality of connecting rods 5 that connect each movable vane 4 to the movable ring 3. Each of the movable vanes 4 is rotatably provided around a pin 6, and as the movable ring 3 rotates clockwise in FIG. 4... is rotated clockwise around pin 6..., and
As the movable ring 3 rotates counterclockwise, each movable vane 4 is rotated counterclockwise about the pin 6. This on-off valve mechanism 2
is adapted to be driven by a drive mechanism 7. This drive mechanism 7 includes a cylinder 8, which is an actuator, and a first cylinder 8, which is an actuator.
1 and 2 are formed by the respective electromagnetic switching valves 9 and 10 and the air tank 11. Inside the cylinder 8 is a first
．． Second respective pistons 12,13 are arranged, as well as first and second respective pistons/414, 15, respectively. The first stop nog 14 is attached to the middle part inside the cylinder 8, and the first stop nog 414 connects the first stop nog 14 to the inside of the cylinder 8. Each second pressure chamber 16.
17 are formed respectively.

The second stopper 15 is provided protruding from the end face on the second pressure chamber 17 side. A first piston 12 is disposed inside the first pressure chamber 16, and a second piston 13 is disposed inside the second pressure chamber 17. The piston rod 12a of the first piston 12 is inserted into an insertion hole 18 provided at the center of the first piston/4'14, and in a state where the piston rod 12a is guided by the insertion hole 18, the first The piston 12 reciprocates within the first pressure chamber 17. The piston rod 13a of the second piston 13 is protruded to the outside through an insertion hole 19't provided in the end face of the cylinder 8 on the second pressure chamber 17 side. It is connected to 3. Piston rod 13a of this second piston 13
A coil spring 21 is wound around. The second piston 13 is capable of reciprocating movement within the second pressure chamber 17 and is normally held pressed against the first stop horn 414 by the biasing force of the coil spring 21. . A first vent hole 22 is formed in the end surface of the cylinder 8 on the first pressure chamber 16 side, and a second vent hole 23 is formed in the circumferential tube surface on the second pressure chamber 17 side. One end of a first air pipe 24 is connected to the first ventilation hole 22, and one end of a second air pipe 25 is connected to the second ventilation hole 23, respectively. The other end of the first air pipe 24 is connected to a first electromagnetic switching valve 9, and the other end of the second air pipe 25 is connected to a second electromagnetic switching valve 10.

The first electromagnetic switching valve 9 has an exhaust pipe 26 and a third air supply pipe 27, and the second electromagnetic switching valve 10 has an exhaust pipe 28 and a fourth air pipe 27.
The air supply pipes 29 are connected to each other. And the first
The first air supply pipe 24 and the exhaust pipe 26 are controlled by the electromagnetic switching valve 9.
or the first air pipe 24 and the third air pipe 27 are connected to each other, and the second electromagnetic switching valve 10 connects the second air pipe 25 and the exhaust gas. The pipe 28 is connected to the next state or the second air pipe 25 and the fourth air pipe 29 are connected to each other. The third and fourth air supply pipes 27 and 29 are in communication with each other, and are supplied with air from the air tank 11, respectively. Then, each of the first and second electromagnetic switching valves 9
, 10 is the first. Each second air pipe 24,25 and each exhaust pipe 2
6.28, the second piston 13 is held at the reference position pressed against the first stopper 14 by the biasing force of the coil spring 21. There is. Also, the first solenoid valve 9
is operated to connect the first air pipe 24 and the third air pipe 27 to the next state, and the second electromagnetic switching valve 10 connects the second air pipe 25 and the exhaust pipe 28. When the switching operation is performed, the air supplied from the air tank 11 into the first pressure chamber 16 through the first air pipes 27 and 24t causes the first piston 12 to move to the first stop horn 414. At the same time, the second piston 13 is moved by the piston rod 12a of the first piston 12 against the biasing force of the coil spring 21, and the second piston 13 is moved against the first piston 13. Second double stopper 14.15
It is adapted to be held at a first displacement position between. 1st. Each second electromagnetic switching valve 9°10 is connected to the first solenoid switching valve 9°10. If the air tank 11 is switched so that the second air pipes 24,25 and the third air pipes 27,29 are in communication with each other, the air tank 11 is switched to the third air pipe 27,29. Air is supplied into the first pressure chamber 16 via the first respective air supply pipes 27, 24', and the fourth. Since air is also supplied into the second pressure chamber 17 through each second air supply pipe 29.25t, the second piston 13
is held at the second displacement position pressed against the stopper 15 at tIX2. Therefore,
2 piste/13 is the 1st piste. Each second solenoid switching valve 9.10
Based on the switching operation, the second piston 13 is moved to three stages: a reference position, a first displacement position, and a second displacement position, and when the second piston 13 is held at the reference position, Movable link 3 and each movable vane 4...
The opening degree is maximized, and the opening area of the exhaust gas inlet of the turbine 1 is maintained in a normal state with a wide open area, and
When the second piston 13 is operated to move to the second displacement position, the moving operation of the second piston 13 causes the movable ring 3 to rotate clockwise at - in FIG. 4 are rotated clockwise around the bins 6, respectively, and their opening degrees are minimized, and the opening area of the exhaust gas inlet of the turbine 1 is held in a constricted state, and When the second piston 13 is operated to move to the first displacement position, the moving operation of the second piston 13 causes the movable ring 3 and each movable vane 4 to move to an intermediate state, respectively. The opening area of the exhaust gas inlet of the turbine 1, which is between the maximum and minimum opening degrees, is maintained in an intermediate throttle state, which is narrowed down to a state between the normal state and the throttle state.

On the other hand, 30 is an accelerator pedal of the automatic main body, 31 is a load sensor that detects the engine load from the accelerator opening degree of this accelerator pedal 30, and 32 is a rotation speed sensor that detects the engine rotation speed Ne. The output signals from these load sensors 31 and rotation speed sensors 32 are sent to the controller 3.
3 is set to be input. This controller 3
Reference numeral 3 controls the drive mechanism 7 according to the engine speed and engine load. That is, the engine load is detected and the engine load is set to a predetermined value (for example, 65%).
), the drive mechanism 7t-controls the movable base/4.
... is maintained in the normal state. This is because the intake air excess ratio is sufficiently large in the low load region and good combustion is performed. This is because if the opening area of the engine is narrowed, the pumping loss of intake and exhaust air will increase, which will worsen the fuel efficiency.

On the other hand, when the engine load is equal to or higher than the predetermined value, the engine rotation speed Ne is detected and the predetermined value Net INew is detected.
, (However, Ne1) Nez, for example, Net =
1350 rpmNe, = 175Orpm). Then, when Ne<Net, that is, when the engine speed is extremely low, the movable vanes 4 are held in the throttled state.

As a result, as shown by the solid line in Figure 5, the intake air pressure (
Pb (hereinafter referred to as boost pressure) increases at a large rate of increase, and a sufficient function of increasing the amount of intake air can be achieved. Moreover, Nel≦Ne<Net.

When Ne≧Nc4, all the movable vanes 4 are held in the intermediate aperture state 9 and the normal state. As a result, the fifth
As shown by the solid line in the figure, the boost pressure pb is increased at an increase rate suitable for each engine speed, and the intake air ii is increased with a sufficient increase function.

<Problems to be Solved by the Invention> The variable nozzle type turbocharger described above exhibits the characteristics shown by the solid line in Fig. 5 in a steady state, and achieves a sufficient function of increasing the amount of intake air. However, during transient situations where the accelerator pedal is pressed all at once from a state where the engine load is small and the boost pressure is low, such as when accelerating to start or passing in wind and rain, the following problems may occur. hand. That is, as shown by the dotted line in Fig. 5, the opening degree of the movable vane expands to the maximum side as the engine speed Ne increases, even though the boost pressure pb has not increased sufficiently. Unfortunately, I was unable to obtain the desired acceleration performance with the turbo supercharger.

The present invention was developed in view of the above-mentioned conventional circumstances, and provides a variable nozzle control device for a turbocharger that achieves performance improvement during transitions such as starting acceleration performance and overtaking acceleration performance without deteriorating overall fuel efficiency. What you do is for money.

<Means for solving the problem> The variable nozzle control imu of the turbocharger according to the present invention guides the exhaust gas from the engine to the turbine of the turbocharger driven by the exhaust gas from the engine. an on-off valve mechanism provided, a drive mechanism that drives the on-off valve mechanism to vary the area of the inlet, a rotation speed sensor that detects engine rotation speed, and a load sensor that detects engine load;
a boost pressure sensor that detects intake air pressure supplied from the turbo supercharger to the engine; an exhaust pressure sensor that detects exhaust gas pressure between the engine and the turbine; the rotation speed sensor; and the load. When output signals from the sensor, the Punist King sensor, and the exhaust pressure sensor are input, and the engine load is a predetermined value or more, the intake air pressure is a predetermined value or more, or the intake air pressure is less than a predetermined value and the exhaust gas pressure is a predetermined value. In this case, the drive mechanism is controlled to increase the area of the inlet in response to the increase in engine speed, while when the engine load is above a predetermined value, the intake air pressure is less than the predetermined value and the exhaust gas pressure is The present invention is characterized in that it includes a controller that controls the drive mechanism to maintain the area of the inlet in a minimum state regardless of the engine speed when the value is less than a predetermined value.

When the engine load is above a predetermined value, when the intake air pressure (boost pressure) is less than the predetermined value and the exhaust gas pressure is less than the predetermined value, the opening area of the exhaust gas inlet of the turbine is increased regardless of the engine speed. is maintained at a minimum, and the increase rate of boost pressure is increased to achieve improvements in starting acceleration performance, etc. In addition, this control is performed to prevent the exhaust gas pressure from exceeding a predetermined value by narrowing the opening area of the exhaust gas inlet to the minimum when the exhaust gas pressure is less than a predetermined value. This also prevents deterioration in fuel efficiency caused by high exhaust gas pressure.

Embodiment> Hereinafter, an embodiment of the present invention will be described based on the drawings. It should be noted that the same parts as those in the prior art are given the same reference numerals and redundant explanations will be omitted.

As shown in FIG. 1, which schematically shows the configuration of a variable nozzle control device for a turbocharger according to this embodiment, compared to the conventional one, a boost pressure sensor 41 that detects boost pressure pb;
An exhaust pressure sensor 42 is provided to detect the exhaust gas pressure between the exhaust air port of the engine and the exhaust gas inlet to the turbine 1. The gust pressure sensor 41 detects the boost pressure pb from within the intake manifold of the engine, and the exhaust pressure sensor 42 detects the boost pressure PB from within the exhaust manifold.
For example, the exhaust gas pressure P at the exhaust gas inlet to the turbine 1
itt-detect.

Further, the controller 40 is configured to receive the output signal from each of the gust pressure sensor 41 and the exhaust pressure sensor 42. Therefore, compared to the conventional controller 33, this controller 40 has a higher controllability of boost pressure pb and exhaust gas. A control function based on pressure Pit is added. still,
The other functions of the controller 40 are those of the controller 3.
Same as 3.

The operation of the variable nozzle control device configured as described above is performed according to the flowchart shown in FIG.

mass, engine load is detected, and if this engine load is less than a predetermined value (for example, 65%), the drive mechanism 7'f,
The movable pane 4 is controlled to be held in the maximum opening state (normal state). On the other hand, when the engine load is greater than or equal to a predetermined value, boost pressure Pb is detected and compared with maximum boost pressure Pbmax. Here, the maximum boost pressure Pb
The max is based on the conditions such as the upper limit of the cylinder pressure of the engine.
Although it is determined for each engine model, it may be determined as appropriate depending on other conditions. As a result of this comparison, Pb≧Pb
max, the engine rotation speed Ne' is detected and compared with a predetermined value Ne, and the drive mechanism 7 is controlled so that Ne<
When Ne, the movable vane /4... is at the upper intermediate opening (intermediate drawing shape B), and when Ne is on Ne, the movable vane 4 is
...Keep at the maximum opening. As a result, as shown by the solid rock in Figure 3, the boost pressure Pb increases at a large rate of increase as the engine speed Ne increases in the range below the maximum boost pressure Pbmax, and the intake air amount becomes sufficient. The increasing function is performed.

Furthermore, as a result of the above comparison, if Pb<Pbmax, the exhaust gas pressure Pitt- is detected and the maximum exhaust gas pressure PIt
Compare with max. Here K, maximum exhaust gas pressure Pi t
max is the maximum value within the range that does not cause deterioration of fuel efficiency,
It is determined for each engine model. As a result of this comparison, if Pit < Pitmax, the drive mechanism 7
by controlling the movable base 1/4... to the engine rotation speed N.
It is maintained at the minimum opening (throttled state) regardless of the As a result, the deadest Tamashima increases at an extremely large rate as the engine speed increases. Therefore, even during transitions such as starting acceleration or overtaking acceleration, where the accelerator pedal is pressed all at once from a low boost pressure state, the boost pressure formula continues to increase as shown by the dotted line in Figure 3. , it is possible to obtain the desired acceleration performance by the target supercharger without causing any deterioration in fuel efficiency.

Further, as a result of the above comparison, if Pit≧Pitmax, the engine rotation speed Ne is detected and the opening degree of the movable vanes 4 is maintained at an intermediate or maximum value under the same conditions as described above. That is, even though the exhaust gas pressure Pit is in a high pressure state, the opening degree of the movable vanes 4 is not minimized, and a further increase in the exhaust gas pressure Pit can be completely avoided. As a result, as shown by the dashed line in FIG. 3, the exhaust gas pressure Pit is suppressed within a range below Pitmax, and deterioration of fuel efficiency due to an increase in exhaust resistance is prevented.

Note that the predetermined value for the engine load and the predetermined value for the engine rotation speed are not limited to the above embodiments.
These are set for each engine and target supercharger model. Further, the number of switching stages of the movable vane opening may be two or more stages, and the movable vane opening ft may be variable steplessly. In addition, although a comparator or microcomputer control is used as a controller and a trap is used, it is also possible to apply a known child actor such as an electronic controller. Further, the drive mechanism 7 may be of a hydraulic type, for example, other than a pneumatic type.

<Effects of the Invention> According to the present invention, the entire opening area of the exhaust gas inlet of the turbine is adjusted to the extent that the exhaust gas pressure does not decrease and become back pressure even when the boost pressure is in a relatively low state. j'j
Therefore, it is possible to obtain acceleration performance that fully utilizes the function of the tarp supercharger during transitions such as starting acceleration and overtaking acceleration, without deteriorating fuel efficiency.

[Brief explanation of the drawing]

Figures 1 to 3 relate to one embodiment of the present invention; Figure WJ1 is a schematic configuration diagram of the Kaga nozzle control device of the Tarza turbocharger;
Figure 3 is a flowchart, Figure 3 is a characteristic diagram of boost pressure and exhaust gas pressure, Figure 4 is a schematic configuration diagram of a conventional variable nozzle control device for a turbocharger, Figure 5 is a characteristic diagram of its boost pressure,
It is a sex diagram. In the drawings, 1 is a turbine, 2 is an on-off valve mechanism, 7 is a drive mechanism, 31 is a load sensor, 32 is a rotation speed sensor 40 is a controller, 41 is a boost pressure sensor, and 42 is an exhaust pressure sensor. %+7'f Applicant Sanshime Dosha Kogyo Koshiki Company Agent

Claims (1)

[Claims] An on-off valve mechanism is provided at an inlet that guides exhaust gas from the engine to a turbine of a turbocharger driven by the exhaust gas, and the on-off valve mechanism is driven to reduce the area of the inlet. a variable drive mechanism; a rotational speed sensor that detects engine rotational speed; a load sensor that detects engine load; a boost pressure sensor that detects intake air pressure supplied from the turbocharger to the engine; An exhaust pressure sensor detects the exhaust gas pressure between the engine and the turbine, and output signals from the rotation speed sensor, the load sensor, the boost pressure sensor, and the exhaust pressure sensor are input, and the engine load is adjusted to a predetermined level. If the intake air pressure is above a predetermined value, or when the intake air pressure is less than a predetermined value and the exhaust gas pressure is above a predetermined value, the drive mechanism is controlled to increase the area of the inlet in response to an increase in engine speed. On the other hand, when the engine load is above a predetermined value and the intake air pressure is less than the predetermined value and the exhaust gas pressure is less than the predetermined value, the drive mechanism is controlled to increase the area of the inlet regardless of the engine speed. A variable nozzle control device for a turbo supercharger, comprising: a controller for maintaining the nozzle in a minimum state.