JPS5999029A - Air supercharging apparatus for engine with turbocharger - Google Patents

Abstract

PURPOSE:To prevent lack of intake air at the time of rapid acceleration of an engine in a reliable manner, by detecting rapid acceleration of the engine from the variation speed of the output of a load sensor, and injecting high-pressure air into an intake pipe when said variation speed is higher than a prescribed value. CONSTITUTION:When an engine is fully accelerated from its idling operation by depressing an accelerator pedal rapidly at a time (t1), the level of the output of a first comparator 11 in a control means 5 receiving the output voltage of a load sensor 1 interconnected to the accelerator pedal is changed immediately from ''H'' (high) to ''L'' (low). At the same time, the level of the output of a second comparator 12 is changed from ''L'' to ''H'' at the time (t2), for instance, 0.2sec later from the time (t1) and kept at the level ''H'' for a time period T1 when the engine is fully accelerated. Further, at the time (t2), the second comparator 12 produces a short pulse having a time width T2. Accordingly, an AND-circuit 14 is kept at an ''H'' level only for a time period T2 and an FF circuit 15 produces an output signal for a prescribed time period T3 to open a solenoid valve 6 in a high-pressure air passage and to thereby inject high-pressure air into an intake pipe only for the time period T3.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to an air supercharging device for a turbo engine.

In particular, it relates to an air supercharging device that operates when an engine suddenly accelerates.

[Description of prior art]

When an engine with a turbo is attempted to accelerate at full speed suddenly, the rotational speed of the turbine cannot be obtained sufficiently from the start of full acceleration, and the intake air amount of the engine tends to be insufficient due to a delay in the rising speed of the turbine rotation.

For this reason, turbocharged engines currently use air supercharging devices that forcefully blow air into the engine from the outside.

Conventionally, this type of air supercharging device, as shown in Fig. 1,
The outputs of the load sensor 1 that detects the engine load, the position sensor 2 that detects the gear position of the transmission, the rotation sensor 3 that detects the engine rotation speed, and the detection output of the amount of M in the air tank 4 are used as control inputs. The opening timing and degree of opening of the electromagnetic valve 6 of the air tank 4 were controlled by the output of the control device 5, and air was blown into the ejector 7 connected to the intake manifold.

The present inventor conducted various tests regarding the timing of air injection during full acceleration of the engine, and found that if air injection is performed immediately after the start of full acceleration, that is, during sudden acceleration,
The present invention has been completed by focusing on the fact that optimum acceleration response can be obtained.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an air supercharging device for a turbocharged engine with a simple device configuration, which improves the starting performance and transient response of the turbocharged engine, and prevents insufficient air intake during sudden acceleration.

[Features of the invention]

The present invention includes a load sensor for detecting the load of a turbo engine, a blowing means for forcibly blowing air into an intake pipe of the engine, and controlling the blowing means based on a detection output of the load sensor. In the air supercharging system for a turbo engine, the control device detects a rate of change in the output of the load sensor during acceleration, and when this rate of change is equal to or higher than a predetermined value, the control device controls the blowing means. It is characterized in that it is configured to send output to.

[Explanation based on examples]

Embodiments of the present invention will be described in detail based on the drawings.

FIG. 2 is a diagram showing the main parts of an air supercharging device according to an embodiment of the present invention. In this example, the load sensor 1 is a potentiometer that is linked to an accelerator pedal (not shown), and is configured so that its output voltage changes depending on the load of the engine.

The output of this load sensor 1 is connected to each comparison power of the first comparator 11 and the second comparator 12 of the control device 5. A reference voltage (ESll) corresponding to 80% of the engine load factor is applied to the reference input of the first comparator 11.A reference voltage (ESll) corresponding to 80% of the engine load factor is applied to the reference input of the second comparator 12. A reference voltage (E!!2) corresponding to an idling state of 0% is applied.

A delay circuit 13 is connected to the output of the second comparator 12 to delay the output timing of the comparator 12 by a predetermined time (0.2 seconds in this example). The outputs of this delay circuit 13 and the first comparator 110 are connected to an input of an AND circuit 140. The output of this AND circuit 14 is connected to the set input of flip-flop circuit 150. The output of this flip-flop circuit 15 is connected to the electromagnetic valve 6 shown in FIG.

The operation of the air supercharging device having such a configuration will be explained with reference to an operation time chart shown in FIG. In Figure 3,
Each symbol represents the electrical signal waveform at the location indicated by the x mark in FIG. First, if the accelerator pedal is suddenly depressed from an idling state at time t1, and the accelerator pedal is brought into a full acceleration state at time t2, 0.2 seconds after the engine is depressed, the second comparator 12
The output changes from high level to low level at the instant (FIG. 3(b)). Also, the output of the second comparator 12 is at time t2.
The level becomes high only during the time T1 during which the vehicle accelerates from low level to full speed ((a)). The delay circuit 13 outputs the output of the second comparator 12 at time t2, which is 0.2 seconds after the above-mentioned time t1.
A short pulse is generated for a time T2 (time t2 to time h) ((C)). As a result, the AND circuit I4 becomes high level only during time T2 from time t2 to time t3 (
Same (d)). When the high level signal of this AND circuit 14 is given to the set input of the flip-flop circuit 15,
The flip-flop circuit 15 sends out an output signal for a predetermined time T3 and opens the electromagnetic valve 6 shown in FIG.

With the above operation, sudden acceleration of the engine can be detected without the need for input from a rotation sensor that detects the engine rotation speed. Only during sudden acceleration, high pressure air is blown into the ejector from the air tank, can compensate for insufficient intake air volume.

In the above example, the second comparator 12 is used as a means for detecting the idling state of the engine, but instead of the second comparator 12, it is possible to detect the output when the gear position of the transmission is in neutral. A transmitting position sensor may also be used.

Further, the engine load factor applied to the reference input of the first comparator 11 is not limited to 80%, but is 90% or 100%.
It may be %.

Furthermore, the delay time of the delay circuit 13 is not limited to 0.2 seconds.

Further, in the above example, the rate of change in the load sensor output is detected using a delay circuit, but the load sensor output can be detected by various electric circuits that differentiate the load sensor output with respect to time. The present invention can be implemented using these devices as well.

〔Effect of the invention〕

As described above, according to the present invention, sudden acceleration of a turbo engine is detected by the rate of change in the output of the load sensor during acceleration, without using the conventional engine rotation sensor, and this rate of change is determined by a predetermined value. By configuring the engine to blow high-pressure air into the intake pipe of the engine when the value is greater than or equal to the value, the intake air amount will not be insufficient during sudden acceleration.
The starting performance and transient response of a turbo engine can be improved.

Further, since no rotation sensor is required, the control input system is simplified, and an excellent air supercharging device for a turbo engine with a simple configuration can be obtained.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a conventional air supercharging device. FIG. 2 is a configuration diagram of main parts of an air supercharging device according to an embodiment of the present invention. FIG. 3 is an operation time chart of FIG. 2. ■...Load sensor, 2...Position sensor, 3...
Rotation sensor, 4... Air tank, 5... Control device,
6... Solenoid valve, 7... Ejector, 11...
First comparator, 12... Second comparator, 13... Delay circuit, 14... AND circuit, 15... Flip-flop circuit. Patent Applicant Hino Motors Co., Ltd. Agent Nao Takashi Ide

Claims (1)

[Claims] (1) A load sensor that detects the load of the turbo engine, a blowing means for forcibly blowing air into the intake pipe of the engine, and a control that controls the blowing means based on the detection output of the load sensor. In the air supercharging device for a turbo engine, the control device detects a rate of change in the output of the load sensor during acceleration, and when this rate of change is equal to or higher than a predetermined value, the control device controls the blowing means to An air supercharging device for a turbo engine, characterized in that it is configured to deliver output.