JPH10331651A - Turbo charger controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set a nozzle vane opening with high accuracy by detecting the actual operating position of the actuator of a nozzle vane which controls exhaust speed flowing into an exhaust turbine, and controlling driving of the actuator by a deviation to a targeted operating position set according to an engine condition. SOLUTION: At the time of running an engine, a control unit 25 refers to a stroke map 26 based on engine load 32 and engine speed 33 to select the targeted operating position of the actuator 10. The operation of respective solenoid valves 22-24 is controlled to drive the actuator 10 and control the opening of a nozzle vane which controls exhaust speed flowing into the exhaust turbine of a turbo unit. The actual operating position of the actuator is detected by a position sensor 18, and it is discriminated whether or not the actual operating position is within a prescribed tolerance to the targeted operating position. If it is discriminated as not acceptable, opening control is conducted again so as to be convergent within the tolerance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention optimizes the opening of a nozzle vane in a turbocharger having a nozzle vane for controlling the speed of exhaust gas flowing into an exhaust turbine according to the engine speed and load. The present invention relates to a turbocharger control device having a simple configuration that can be used.

[0002]

[Related background art] One of the engine power-up technologies
One has a turbocharger. This type of turbocharger uses an exhaust gas from an engine to drive a supercharger to compress the intake air, thereby increasing the efficiency of charging the engine with the intake air. Incidentally, a variable nozzle vane type turbocharger (so-called VG turbo), for example, as shown in FIG. 1, changes the angle (opening) of nozzle vanes 2 arranged at equal intervals around the turbine blades 1 of an exhaust turbine. The rotational speed is adjusted by adjusting the rotational position of the annular ring 3 provided, thereby controlling the speed (flow rate) of the exhaust gas from the engine flowing into the exhaust turbine. The rotation position of the annular ring 3 is adjusted by driving an actuator 5 including a rod 4 connected to the annular ring 3 and formed of, for example, an air cylinder.

[0003]

As means for controlling the opening degree of the nozzle vane 2 in this type of turbocharger, specifically, the actuator 5 for driving the annular ring 3 is, for example, an operating position of the rod 4 (advancing / retracting position). )
Is used in a multi-stage manner. That is, an actuator 5 having a plurality of pressure chambers and capable of variably setting the operating position of the rod 4 stepwise by selectively controlling the introduction of a control pressure (compressed air) into each of the pressure chambers is used. .

However, this type of multi-stage actuator has a complicated structure and is expensive. Moreover, since the operating position of the rod 4 can be controlled only stepwise (stepwise), the opening degree of the nozzle vane 2 can be set only stepwise naturally. In other words, the speed (flow rate) of the exhaust gas flowing into the exhaust turbine can be adjusted only stepwise. For this reason, there is a problem that the engine state and the operating state of the exhaust turbine are not always finely matched.

On the other hand, a diaphragm type negative pressure actuator is used as the actuator 4, and the operation of the negative pressure actuator is feedback-controlled according to the boost pressure by the turbocharger, whereby the nozzle vane 2 is controlled.
A method of adjusting the opening degree of the vehicle has been proposed. According to such a method, the opening degree of the nozzle vanes 2 can be adjusted continuously (steplessly) according to the state of the engine.

However, since the opening degree of the nozzle vane 2 is adjusted by driving the negative pressure actuator in accordance with the engine state, specifically, the fluctuation of the boost pressure in the intake manifold, the negative pressure actuator itself and the adjustment of the negative pressure are adjusted. It is undeniable that the valve operates frequently. Because of this,
There is concern about the durability of the negative pressure actuator and the negative pressure adjusting valve. Moreover, as the operating pressure of the negative pressure actuator (control negative pressure), generally, a large negative pressure cannot be expected, so that the diameter of the diaphragm cannot be denied.
There is a problem that the actuator becomes large and complicated.

The present invention has been made in view of such circumstances, and has as its object to adjust the opening of a variable nozzle vane optimally according to the state of the engine. An object of the present invention is to provide a turbocharger control device suitable for reducing the size and weight of a turbocharger assembly.

[0008]

In order to achieve the above-mentioned object, a turbocharger control device according to the present invention provides a turbocharger having a nozzle vane capable of controlling the speed of exhaust gas flowing into an exhaust turbine. An actuator that receives the control pressure in the pressure chamber and operates to move the nozzle vane, a solenoid valve that adjusts the control pressure applied to the pressure chamber of the actuator, and a position sensor that detects an actual operating position of the actuator. A target position setting means for setting a target operation position of the actuator according to an engine speed and a load; and a tolerance between the actual operation position of the actuator detected by the position sensor and the target operation position is within a predetermined range. Feed the solenoid valve so that it is It is characterized by comprising a control means for back control.

That is, according to the present invention, the actual operation position of the actuator is detected by the position sensor, and the tolerance between the target operation position of the actuator set according to the state of the engine and the actual operation position is set to a predetermined value. By performing feedback control of the solenoid valve so as to fall within the range, the operation position of the actuator that defines the opening degree of the nozzle vane can be set with high accuracy. In other words, actuator assembly accuracy,
Even if there is an error in the control pressure introduced into the pressure chamber of the actuator, the operation position of the actuator can be accurately controlled in accordance with the engine state so that the nozzle vane opening can be optimally set. Is simplified.

[0010] Further, the present invention provides,
The control means further includes a boost pressure detecting means for detecting a boost pressure of the engine, wherein a tolerance between an actual operation position of the actuator and a target operation position is within a predetermined range, and the boost pressure is a target boost pressure. When the pressure is within a predetermined tolerance range, the target operating position of the actuator is fixed. In other words, when the boost pressure indicating the operating state of the engine deviates from the tolerance with respect to the target boost pressure, the above condition is satisfied by correcting the operating position of the actuator (target operating position). It is characterized in that the operating position is optimized.

Further, according to the present invention, the actuator is realized as a diaphragm type actuator which operates by inputting a positive pressure, which can easily obtain a large pressure as compared with a negative pressure, into a pressure chamber. By configuring the actuator to supply a positive pressure from an air tank mounted on the vehicle, the diameter of the diaphragm in the actuator can be reduced, and the actuator can be reduced in size, and the turbocharger assembly can be reduced in size and weight. Features.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a turbocharger control device according to an embodiment of the present invention will be described with reference to the drawings. The control device for a turbocharger according to this embodiment basically has a configuration in which variable nozzle vanes 2 are arranged around a turbine blade 1 of an exhaust turbine at equal intervals as shown in FIG. In the turbocharger configured to vary the angle (opening) of the nozzle ring 2 by driving the annular ring 3, an actuator that drives the annular ring 3 to adjust the opening of the nozzle vanes 2 is shown in, for example, FIG. It is characterized by using the positive pressure diaphragm type actuator 10 configured as described above.

The structure of the positive pressure diaphragm type actuator 10 will be briefly described. In the figure, reference numeral 11 denotes a rod having a distal end connected to the annular ring 3, which can move freely through a bearing 13 in a casing 12. Is provided. A diaphragm 14 is provided at an intermediate portion of the rod 12 so as to airtightly divide the internal space of the casing 12 into two parts, and a positive control pressure consisting of compressed air is applied to the space on the left side of the diaphragm 14 in the drawing. The pressure chamber 15 and the right space in the figure are configured as an atmospheric pressure chamber 16.

A compression spring 17 for biasing the rod 11 to the left in the drawing is mounted in the atmospheric pressure chamber 16. The control pressure introduced into the pressure chamber 15 drives the rod 11 forward and backward by sliding the diaphragm 14 rightward in the drawing against the compression spring 17. The pressure chamber 15
Is mounted with an electromagnetic coil type position sensor 18 surrounding one end of the rod 11. The position sensor 18 linearly detects the sliding position of the rod 11, that is, the actual operating position of the rod 11 slid by receiving the control pressure (positive pressure) introduced into the pressure chamber 15. .

The turbocharger control device according to this embodiment is characterized in that it operates by receiving a positive pressure as a control pressure and incorporates a position sensor 18 for detecting the actual operating position of the rod 11. Not only can the opening degree of the nozzle vane 2 be variably set using the positive pressure diaphragm type actuator 10 having the above configuration, but also the positive pressure diaphragm type actuator 10 can be controlled under a control system configured as shown in FIG. The point is that the operation is controlled.

The control system introduces a control pressure consisting of compressed air of, for example, 3.0 kgf / cm ² from an air tank 21 mounted on a vehicle into a pressure chamber 15 of the actuator 10 to drive the actuator 10. The solenoid valve 22, a solenoid valve 23 for venting which gradually releases the control pressure introduced into the pressure chamber 15 to the atmosphere side at a pressure of about 0.1 kgf / cm ² , for example, is introduced into the pressure chamber 15. And a solenoid valve 24 for rapidly turning off the control pressure to the atmosphere at once.

These solenoid valves 22, 23, 24
Are driven and controlled under a control unit 25 mainly constituted by a microprocessor, and operate by the solenoid valves 22, 23,
24 actuates the pressure chamber 1 of the actuator 10
The control pressure applied to 5 is adjusted, and the displacement amount (moving stroke) of the rod 11 is varied. The opening of the nozzle vane 2 is variably set in accordance with the position where the rod 11 is displaced.

The control unit 25 includes:
Not only the engine temperature information such as the water temperature 31, the engine load 32, the engine speed 33, and the boost pressure 34 detected by various sensors incorporated in the engine, but also the power tard switches 35 and 36 and the cold start switch 3
7, a position sensor 18 incorporated in the actuator 10
The operation of each of the solenoid valves 22, 23, 24 is controlled in accordance with the information on the actual operating position of the rod 11 detected by the control unit. In particular, by referring to the stroke map 26 of the actuator according to the engine state, an optimum stroke (control position of the rod 11) according to the engine state is obtained, and the operation of each of the solenoid valves 22, 23, 24 is feedback-controlled. I have.

The stroke map 26 is composed of data indicating the optimum position (stroke from the reference position) of the rod 11 of the actuator 10 determined according to the engine speed and the load condition, for example, as shown in FIG. ,
It is given as ROMized data. The data shown in such a map 26 is, of course, determined in accordance with the specifications of the engine and the like, and it is of course possible to variably set the map data in accordance with the state of the power tard and the like.

The operation control of the solenoid valves 22, 23, 24 by the control unit 25 is executed as follows. FIG. 5 shows the flow of the control procedure. Basically, the procedure is started by first detecting the engine load 32 and the engine speed 33 as the state of the engine [step S1]. Then, based on the information, a target operation position of the actuator 10 with respect to the rod 11 is selected with reference to the stroke map 26 [Step S2]. That is, the moving position of the rod 11 (the target operating position of the actuator 10) for defining the opening degree of the nozzle vane 2 that can optimize the flow rate (speed) of the exhaust gas flowing into the exhaust turbo according to the engine state at that time. Ask for.

Thereafter, each of the solenoid valves 22,
The operation of the actuators 23 and 24 is controlled [Step S3], whereby the actuator 10 is activated [Step S3].
4]. The operation of these solenoid valves 22, 23, 24 is basically controlled by introducing compressed air (control pressure) having a pressure capable of positioning the rod 11 at a target operating position into the pressure chamber 15 of the actuator 10. Will be

The control pressure is introduced into the pressure chamber 15 by driving the boost solenoid valve 22 to supply the compressed air stored in the air tank 21 to the actuator 10. At this time, when the overstroke of the rod 11 occurs, the control pressure is reduced by driving the venting solenoid valve 23 to gradually discharge the compressed air introduced into the pressure chamber 15 to the atmosphere side. The adjustment is made in. Conversely, when the rod 11 has an understroke, the pressure chamber 15 is driven by the operation of the solenoid valve 22.
Is adjusted by refilling with compressed air and increasing the control pressure.

As described above, the solenoid valve 22,
If the actuator 10 is driven under the operation control of 23 and 24, the moving position of the rod 11 is detected by the position sensor 18 [Step S5].
That is, the position sensor 18 detects the actual operating position of the rod 11 in the actuator 10 that actually operates under the control pressure.

Thereafter, it is determined whether or not the actual operating position of the rod 11 detected as described above is within a predetermined tolerance range with respect to the target operating position described above [Step S].
6]. When the actual operating position of the rod 11 deviates from the tolerance of the target operating position, the operation control of the solenoid valves 22, 23, and 24 is performed again depending on whether the stroke is overstroke or understroke with respect to the target operating position. Is performed [Step S3]. That is, the solenoid valve 2 is set so that the tolerance between the actual operating position of the rod 11 and the target operating position falls within a predetermined range, in other words, the actual operating position falls within the tolerance range with respect to the target operating position.
2, 23 and 24 are feedback controlled.

In this way, the actual operating position of the rod 11 detected by the position sensor 18 is set within the tolerance range of the target operating position by feedback control of the solenoid valves 22, 23, 24, so that the engine state can be changed. The rod 11 can be simply and accurately positioned at the target operating position determined accordingly, and the opening of the nozzle vane 2 defined by the target operating position can be set with high accuracy.

Once the actual operating position of the rod 11 has been determined as described above, a determination is then made on the boost pressure 34 of the intake air supercharged by the turbocharger. The determination of the boost pressure is started by first checking whether the boost pressure is over-boost (step S7). That is, it is checked whether the boost pressure has exceeded the allowable value Pb-LIM required for the supercharger. If it is overboost, the nozzle vane 2 is promptly fully opened in order to eliminate this [Step S8]. Specifically, the quick-off solenoid valve 24 is driven to rapidly release the control pressure applied to the pressure chamber 15, thereby promptly returning the rod 11 of the actuator 10 to the original position. To stop the supercharging operation by the turbocharger.

On the other hand, when it is not over-boost, that is, when the supercharging action by the turbocharger is operating in a normal operating range, the boost pressure is then set within the target boost pressure tolerance range. It is determined whether or not there is [Step S9]. The target boost pressure is determined according to the engine state, and the opening of the nozzle vane 2 is set to obtain the target boost pressure. Further, the target operating position of the rod 11 is set to obtain the opening degree of the nozzle vane 2 according to the target boost pressure.

If the actual operating position of the rod 11 is determined by the feedback control of the solenoid valves 22, 23 and 24 as described above, the boost pressure obtained in that state is compared with the target boost pressure [step]. S9]. When the boost pressure is less than the lower limit value Pb-min indicated by the tolerance, it means that the opening degree (throttle amount) of the nozzle vane 2 is insufficient and the inflow amount (speed) of the exhaust gas is smaller than the target. Therefore, for example, the stroke (operation position) of the rod 11 is stepwise increased and corrected by a predetermined amount [Step S10]. Specifically, the target operating position with respect to the rod 11 is, for example, (+0.1 m
m), and the processing procedure from step S3 described above is repeatedly executed.

On the other hand, if the boost pressure exceeds the upper limit value Pb-max indicated by the tolerance, it is indicated that the nozzle vanes 2 are too narrowed, so that the stroke of the rod 11, for example, is reduced by a predetermined amount. [Step S11]. Specifically, the target operation position with respect to the rod 11 is corrected by, for example, (-0.1 mm), and the processing procedure from step S3 described above is repeatedly executed.

In this way, the target operating position of the rod 11 is finely adjusted in a feedback manner as described above in accordance with the boost pressure. When the position of the rod 11 is adjusted based on the boost pressure, that is, when the target operating position of the rod 11 is corrected by feedback control based on the boost pressure, if the boost pressure is set within a tolerance range of the target boost pressure, the state is determined. To fix the operating position of the rod 11 [Step S12].

The position of the rod 11 fixed in this manner depends on the nozzle vane 2 defined by the rod 11.
Means that the boost pressure obtained under the opening degree is set to the target boost pressure. In other words, the opening degree of the nozzle vane 2 is set to an optimal position according to the engine state,
The desired boost pressure is obtained by the turbocharger.

Thus, according to the present control device functioning as described above, the amount of exhaust gas corresponding to the engine state can be simply and effectively flown into the exhaust turbine, and the boost pressure thereof can be optimized. . Moreover, while detecting the position of the rod 11 in the actuator 10 by the position sensor 18, the solenoid valves 22, 23, 2
4 is feedback-controlled to set the actual position of the rod 11 within the tolerance range of the target operation position, so that the position of the rod 11 is steplessly controlled only by setting the target operation position according to the engine state. can do. That is,
The operating position of the rod 11 is not defined stepwise by the structure of the actuator as in the prior art.
The operating position can be arbitrarily set in one movable range according to the engine state.

Further, according to the present apparatus, after setting the actual operating position of the rod 11 to the target operating position, the target operating position is corrected in a feedback manner according to the boost pressure, and the boost pressure is adjusted to the target boost pressure tolerance. Since the control is performed so as to be within the range, it is possible to easily obtain the optimum boost pressure according to the engine state, which is the final target of the operation position control of the rod 11 described above. In particular, since the target operating position of the rod 11 is corrected according to the boost pressure, the opening of the nozzle vane 2 can be optimized with high accuracy without depending on a mechanical error or the like in the actuator 10.

Further, according to the above-described embodiment, a positive pressure diaphragm type actuator is used, and high pressure compressed air is supplied from an air tank 21 mounted on a vehicle to operate the actuator 10. The diameter of the diaphragm can be significantly reduced as compared with the diaphragm type actuator. Therefore, not only can the size and weight of the actuator 10 be reduced, but also the size and weight of the turbocharger assembly including the actuator 10 can be reduced.

Unlike the conventional method of feedback-controlling the control pressure (negative pressure) applied to the negative pressure actuator according to the boost pressure, the boost pressure is controlled by correcting the target operating position of the rod 11 in the actuator 10. The actuator 10 and the solenoid valves 22, 23, and 24 do not frequently operate with the change of the boost pressure, and the operation frequency can be reduced. As a result, effects such as the problem of durability of the actuator 10 and the solenoid valves 22, 23, 24 can be effectively solved. Moreover, a vacuum pump for generating a negative pressure is not required, and the compressed air obtained from the air tank 21 mounted on the vehicle can be used as it is, so that the overall configuration can be simplified.

The present invention is not limited to the above embodiment. For example, the target operating position of the actuator 10 according to the engine state may be determined by real-time calculation according to information such as the engine speed instead of using the stroke map 26 described above. In addition, the tolerance of the target operating position when controlling the actual operating position of the rod 11 may be determined according to the specifications of the engine, and the correction amount of the target operating position according to the boost pressure is also specified. It should just be determined according to. In short, the present invention can be variously modified and implemented without departing from the scope of the invention.

[0037]

As described above, according to the present invention, in a turbocharger having a nozzle vane capable of controlling the speed of exhaust gas flowing into an exhaust turbine, the turbocharger operates by receiving a control pressure from an air tank in a pressure chamber. The control pressure applied to the pressure chamber of the actuator that moves the nozzle vane is adjusted by a solenoid valve, and the actual operating position of the actuator is detected by a position sensor, and the target of the actuator is adjusted according to the engine speed and load. After setting the operating position,
Since the solenoid valve is feedback-controlled so that the actual operation position of the actuator detected by the position sensor is within the tolerance range of the target operation position, the actuator for simply and effectively defining the opening degree of the nozzle vane is The operating position can be set with high accuracy. Moreover, since the operating position of the actuator is controlled in accordance with the target operating position set in accordance with the state of the engine, the operating position can be set to an arbitrary position within the operating range of the actuator according to the state of the engine.

According to a second aspect of the present invention, the boost pressure of the engine is detected, the tolerance between the actual operation position of the actuator and the target operation position is within a predetermined range, and the boost pressure is equal to the target boost pressure. While correcting the target operating position so as to be within a predetermined tolerance range, the target operating position of the actuator is fixed when the above conditions are satisfied. Even if there is an error, it can be effectively corrected to optimize the operating position of the actuator, and the boost pressure can be optimized according to the engine state.

Furthermore, as described in claim 3, since a diaphragm type actuator which operates by inputting a positive pressure which can easily obtain a large pressure as compared with a negative pressure into the pressure chamber is used, the diaphragm in the actuator is used. In this case, the size of the actuator can be reduced, and the size of the actuator can be reduced, and further, the size and weight of the turbocharger assembly can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a variable nozzle vane type turbocharger.

FIG. 2 is a partial cross-sectional view showing a schematic configuration of a positive-pressure diaphragm type actuator used in a turbocharger control device according to an embodiment of the present invention.

FIG. 3 is a schematic diagram showing a system configuration of a turbocharger control device according to an embodiment of the present invention.

FIG. 4 is a diagram showing an example of an actuator stroke map used in an embodiment of the present invention.

FIG. 5 is a diagram showing an example of a control processing procedure in the turbocharger control device according to one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Turbine blade 2 Nozzle vane 3 Annular ring 10 Positive pressure diaphragm type actuator 11 Rod 14 Diaphragm 15 Pressure chamber 16 Atmospheric chamber 18 Position sensor 21 Air tank 22 Solenoid valve for boost 23 Solenoid valve for vent 24 Solenoid valve for quick off 25 Control unit 26 Actuator・ Stroke map 32 Engine load 33 Engine speed 34 Boost pressure

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Noritaka Yamaguchi 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation

Claims (3)

[Claims] 1. A turbocharger having a nozzle vane capable of controlling the speed of exhaust gas flowing into an exhaust turbine, an actuator that receives a control pressure from an air tank to a pressure chamber and operates to move the nozzle vane, and an actuator of the actuator. A solenoid valve for adjusting the control pressure applied to the pressure chamber, target position setting means for setting a target operation position of the actuator according to a rotation speed and a load of the engine, and a position sensor for detecting an actual operation position of the actuator And a control means for performing feedback control of the solenoid valve so that a tolerance between the actual operation position of the actuator and the target operation position detected by the position sensor is within a predetermined range. Charger control device. 2. The turbocharger control device according to claim 1, further comprising: a boost pressure detection unit that detects a boost pressure of the engine, wherein the control unit determines a difference between an actual operation position and a target operation position of the actuator. A turbocharger having a means for fixing a target operating position of the actuator when a tolerance is within a predetermined range and the boost pressure is within a predetermined tolerance range with respect to a target boost pressure. Control device. 3. The actuator according to claim 1, wherein the actuator comprises a diaphragm-type actuator that operates by inputting a positive pressure into a pressure chamber, and the positive pressure is supplied from an air tank mounted on a vehicle. 3. The control device for a turbocharger according to 2.