JPH11264331A - Automated idling stopping device for turbo supercharger engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent surging which is generated in a turbo supercharger when an engine is stopped, by closing an intake shutter in an automated idling stopping device for a turbe supercharger engine. SOLUTION: An intake shutter 9 is arranged near an inlet of an intake manifold 5 in an intake system of an engine 1. A solenoid valve 10 is arranged on a second intake pipe 12 on a discharging side of a compressor 2C of a turbo supercharger 2. The solenoid valve 10 is opened to atmosphere based on the command from a control unit 18 when the intake shutter 9 is closed during idling stoppage. The boosted air is released to atmosphere by opening the solenoid valve 10. The discharge pressure of the compressor 2C is reduced to prevent surging. It is thus possible to prevent occurrence of vibration, deterioration of durability of the compressor 2C, and generation of surging noises.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic idling stop device for a turbocharged engine, and more particularly to a technique for preventing surging of a turbocharger when idling is stopped.

[0002]

2. Description of the Related Art FIG. 3 is a diagram showing a pipeline and a control system including a conventional automatic idling stop device for a turbocharged engine. In the intake and exhaust systems, new air that has passed through the air cleaner 3 is boosted by the compressor 2C of the turbocharger 2,
The air is guided to the intake manifold 5 via the first intake pipe P1, the intercooler 4, and the second intake pipe P2. In some cases, the intercooler 4 is not provided.

The boosted air guided to the intake manifold 5 becomes combustion gas via the engine 1 and is guided to the exhaust muffler 7 via the exhaust manifold 6 and the turbine 2T of the turbocharger 2. In the above intake and exhaust systems, the automatic idling stop device 8Q includes the electromagnetic intake shutter 9 provided on the second intake pipe P2 or the second intake pipe 2 side of the intake manifold 5, and the control unit 8. It is configured.

The automatic idling device 8Q stops the engine when waiting for a traffic light, parks, etc., to stop emission of exhaust gas, save fuel, stop engine noise, and the like. In this case, the vehicle is in a stopped state and the engine rotation satisfies an automatic stop condition such as a low speed within a predetermined range. The control unit 8 is configured to judge by the signal S that the gear position is within an allowable condition for automatic start of the engine necessary for starting by depressing a clutch pedal such as neutral, and to give an instruction.

For such an automatic idling stop device, there is disclosed a technique for preventing black smoke accumulated at the time of an exhaust brake from being discharged at the time of an automatic start (Japanese Patent Application Laid-Open No. 9-1990).
-60538). Further, in order to prevent a decrease in rotation of the compressor due to the operation of an exhaust brake in an engine equipped with a supercharger and to prevent surging, a technique is disclosed in which an air bypass circuit is provided to bypass the compressor when the intake shutter is closed. I have. (JP-A-6-69
332).

[0006]

In the conventional automatic idling stop device as described above, when the intake shutter is closed, the front-rear pressure ratio, that is, the pressure ratio of the supercharger compressor increases, causing surging and generating vibration noise. ,
This leads to reduced durability of the compressor blade. Such a phenomenon cannot prevent surging even if the intake shutter is provided in front of the compressor.

In addition, of the above-mentioned techniques, the provision of an air bypass for preventing the occurrence of surging has a drawback in arrangement. It is an object of the present invention to provide an automatic idling stop device for a turbocharged engine that can stop an engine by closing an intake shutter without generating surging.

[0008]

According to the present invention, there is provided an automatic idling stop device for a turbocharged engine which stops idling during stopping by closing an intake shutter provided in an intake system. The intake shutter is provided between a turbocharger of a turbocharged engine and an intake manifold, and an opening / closing means for releasing pressurized air to the atmosphere is provided between the intake shutter and the turbocharger. Features.

Thus, when the intake shutter is closed, new air boosted by the turbocharger is released to the atmosphere from the opening / closing means in the open state, thereby preventing occurrence of surging. The invention according to claim 2 is an automatic idling stop device for a turbocharged engine that stops idling rotation when the vehicle is stopped by closing an intake shutter provided in an intake system, wherein the intake shutter is a turbocharged engine of a turbocharged engine. A return pipe is provided between the turbocharger and the intake manifold, and a return pipe is provided between the intake shutter and the turbocharger for returning boosted air to the suction side of the turbocharger and returning the return air. It is characterized by having means interposed.

Thus, when the intake shutter is closed, the air pressurized by the turbocharger is returned to the suction side of the turbocharger through the opening / closing means which is opened, thereby forming one kind of closed circuit. . Therefore, the ratio of the suction pressure to the discharge pressure of the turbocharger compressor is reduced, and the occurrence of surging is prevented.

[0011]

An embodiment of the present invention will be described below with reference to the drawings. The same components as those described in the related art are denoted by the same reference numerals. In FIG. 1, an intake system includes an air cleaner 3 that sucks and filters new air, a compressor 2C of a turbocharger 2, an intercooler 4 that cools air that has been pressurized and heated by a compressor 2T, An intake manifold 5 for supplying to the
A first intake pipe 11 that guides clean air from the air cleaner 3 to the compressor 2C; a second intake pipe 12 that guides the clean air from the compressor 2T to the intercooler 4; A main device relating to the flow of the intake air is constituted by the pipe 13.

Further, the intake system is provided with an intake shutter 9 near the entrance of the intake manifold 5 for shutting off air supply, and a second intake pipe 12 is provided with a solenoid valve 10 as opening / closing means. A control unit 8 that operates according to conditions is connected. The automatic idling stop device 10Q that controls the flow of the above intake air and stops idling when the vehicle is stopped,
A control unit 8 for operating the intake shutter 9 and the electromagnetic valve 10 according to various signals of the vehicle and the engine 1;
It is comprised including.

The control unit 8 has a vehicle speed signal S
1. The system includes a computer for determining an engine automatic stop condition for determining using the engine rotation signal S2, the shift position signal S3, and the clutch pedal depression position signal S4 as inputs. Further, the control unit 8 determines the limit of automatic stop, which is determined by inputting the engine water temperature, the brake air pressure, the normal operation of the electronic governor and the like (not shown), and operates the intake shutter 9 and the solenoid valve 10. Engine control unit EC
The stop of the fuel supply is instructed via the command. Reference numeral IP connected to the engine control unit EC indicates a fuel supply device.

Further, the control unit 8 is configured to judge the condition of the automatic start and perform the start. The exhaust system includes an exhaust manifold 6 for collecting combustion air from the engine 1, a turbine 2T of the turbocharger 2 using combustion air from the exhaust manifold 6, and a muffler 7 for silencing exhaust from the turbine 2T. A main device is constituted by a pipeline connecting these devices.

Next, the operation will be described. In FIG. 1, when the vehicle is running, the automatic idling stop device 10Q is in an inactive state except for receiving various signals. That is, the intake shutter 9 is in the open state, and the solenoid valve 10 is closed. Next, when waiting for a traffic light or the like, the vehicle speed signal S1 is set to zero vehicle speed, the engine speed signal S2 is set to an idling state, for example, 300 to 700 rpm, the transmission shift position signal S3 is shifted to neutral, and the clutch pedal depression position signal S4 is depressed. When zero is received by the control unit 8, the automatic idling stop device 10 operates as follows.

First, the intake shutter 9 is closed.
Thus, the supply of air to the engine 1 is stopped. During the time until the engine 1 is completely stopped, the intake air from the air cleaner 3 is boosted by the compressor 2C. Second, the electromagnetic valve 10 is opened almost simultaneously by an instruction from the control unit 8. With this opening, the air pressurized by the compressor 2C is released to the atmosphere, and the internal pressure of the first and second intake pipes 12, 13 and the intercooler 4 is reduced to substantially the atmospheric pressure.

Third, also at the same time as the first and second, the engine controller EC from the control unit 8
, The fuel supply device IP is controlled and the fuel supply is stopped. Then, the engine 1 is completely stopped, and emission of exhaust gas is stopped. As described above, the first and second intake pipes 12 and 13 by closing the intake shutter 9 are provided.
In addition, surging in the compressor 2C caused by an increase in air pressure in the intercooler 4 is prevented.

The operation of the solenoid valve for closing the intake shutter 9 is the same in the intake system without the intercooler 4. In another embodiment shown in FIG. 2, the intake system includes an air cleaner 3 that sucks and filters new air, a compressor 2C of the turbocharger 2, and an intercooler 4 that cools the air pressurized and heated by the compressor 2C. And an intake manifold 5 for supplying air to the engine 1;
A first intake pipe 11 that guides clean air from the air cleaner 3 to the compressor 2C; a second intake pipe 12 that guides the clean air from the compressor 2T to the intercooler 4; A main device relating to the flow of the intake air is constituted by the pipe 13.

Further, the intake system is provided with an intake shutter 9 near the entrance of the intake manifold 5 for shutting off air supply, and a return pipe 12a for connecting the second intake pipe 12 and the first intake pipe 11 is provided. An electromagnetic valve 10 as an opening / closing means is interposed in the return pipe 12a. The automatic idling stop device 20Q that controls the flow of the above-mentioned intake air and stops idling when the vehicle is stopped,
The intake shutter 9, the solenoid valve 10, and the intake shutter 9 according to various signals of the vehicle and the engine 1.
And control unit 18 for operating solenoid valve 10
And is configured.

The operation is performed as follows when the vehicle satisfies the automatic stop condition and the intake shutter 9 is closed by an instruction from the control unit 18 of the automatic idling stop device 20Q. Air supply to the engine 1 is stopped by closing the intake shutter 9. Then, almost simultaneously, the solenoid valve 10 is opened, and the return pipe 12a is connected.

Then, the pressurized air in the second intake pipe 12 is returned to the first intake pipe 11 through the return pipe 12a, enters the compressor 2C, and is compressed by the compressor 2C to the second intake pipe 12 to the return pipe. 12a to form a circulation circuit of the compressor 2C. Therefore, the pressure ratio of the compressor 2C does not increase, and the occurrence of surging is prevented. Next, the fuel supply is stopped almost simultaneously with the above operation. Then, the engine 1 is completely stopped, and emission of exhaust gas is also stopped.

[0022]

As described above, according to the first and second aspects of the present invention, it is possible to prevent an increase in the compressor pressure ratio due to the closing of the intake shutter and a vibration caused by surging caused by this, thereby reducing the durability of the compressor. Generation of surging noise can be prevented.

[Brief description of the drawings]

FIG. 1 is a diagram of a pipeline and a control system illustrating an embodiment of an automatic idling stop device for a turbocharged engine of the present invention.

FIG. 2 is a diagram of a pipeline and a control system illustrating an automatic idling stop device for a turbocharged engine according to another embodiment.

FIG. 3 is a pipeline and control system diagram illustrating a conventional automatic idling stop device for a turbocharged engine.

[Explanation of symbols]

 EC engine controller IP fuel supply device S1 vehicle speed signal S2 engine rotation signal S3 shift position signal S4 clutch pedal depression position signal 1 engine 2 turbocharger 2C compressor 2T turbine 3 air cleaner 4 intercooler 5 intake manifold 6 exhaust manifold 7 exhaust muffler 9 intake Shutter 10Q Automatic idling stop device 10 Solenoid valve 11 First intake pipe 12 Second intake pipe 12a Return pipe 13 Third intake pipe 18 Control unit

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02D 29/02 321 F02B 37/00 303H

Claims (2)

[Claims] 1. An automatic idling stop device for a turbocharged engine for stopping an idling rotation when the vehicle is stopped by closing an intake shutter provided in an intake system, wherein the intake shutter is provided with a turbocharger of a turbocharged engine. An automatic idling stop device for a turbocharged engine, comprising: an opening / closing means provided between the intake shutter and the turbocharger for releasing pressurized air to the atmosphere. 2. An automatic idling stop device for a turbocharged engine for stopping idling at the time of stopping by closing an intake shutter provided in an intake system, wherein the intake shutter is provided with a turbocharger of a turbocharged engine. A return pipe provided between the intake shutter and the turbocharger for returning pressurized air to the suction side of the turbocharger and returning the same, and the return pipe is provided with opening / closing means. An automatic idling stop device for a turbocharged engine, wherein the device is mounted.