JP2000054899A - Method and device for controlling exhaust brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the safety in braking by judging the circuit failure of an exhaust brake system, when the pressure value within an intake manifold is a prescribed value or less in the operation of an exhaust brake, and the deceleration of engine rotation is a prescribed value or less, and stopping the exhaust brake control to increase the engine braking force. SOLUTION: A turbo supercharger 2 and a muffler 3 are interposed in the exhaust pipe 1 of an engine E, and an exhaust shutter 4 is provided between the supercharger 2 and the muffler 3 in the exhaust pipe 1. The exhaust shutter 4 is closed, and an intake bypass valve 16 is opened to operate an exhaust brake. At this time, when the pressure value within an intake manifold or within an exhaust manifold is a prescribed value or less, and the deceleration of rotation of the engine E is a prescribed value or less, the circuit failure of the exhaust brake system is judged, the exhaust brake control is stopped, and the intake bypass valve 16 and an idling speed control valve is closed to increase the engine braking force by intake resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an exhaust brake for an engine in which an exhaust pipe is provided with an exhaust shutter, an intake pipe is provided with a bypass passage bypassing a throttle valve, and the bypass passage is provided with an intake bypass valve. The present invention relates to a control method and an apparatus.

[0002]

2. Description of the Related Art In order to improve deceleration performance in the same manner as a large vehicle equipped with a diesel engine, an exhaust shutter is provided in an exhaust pipe of a premixed engine that sucks a mixture of fuel and air, for example, an exhaust pipe of a gas engine. Exhaust brake devices are known (see, for example, JP-A-6-40326, JP-A-7-310563).

[0003]

However, in the above-mentioned technology, when an abnormality such as disconnection of an electric circuit or leakage of an air pipe occurs in the operation system of the exhaust shutter, the braking force of the engine cannot be obtained, and As a result, the braking force of the entire vehicle is reduced, and there is a risk of collision due to insufficient deceleration or a rollover without being able to turn completely.

Accordingly, the present invention performs abnormality determination of the exhaust brake operation system and performs a backup process when an abnormality occurs,
It is an object of the present invention to provide an exhaust brake control method and device that improve safety during braking.

[0005]

According to the present invention, an exhaust pipe is provided with an exhaust shutter, an intake pipe is provided with a bypass passage bypassing a throttle valve, and the bypass passage is provided with an intake bypass valve. In the exhaust brake control method for an engine, when the exhaust shutter is closed and the intake bypass valve is opened to operate the exhaust brake, the pressure value in the intake manifold or the exhaust manifold is equal to or less than a predetermined value, and the engine rotation is decelerated. If the value is less than a predetermined value, it is judged that the exhaust brake system circuit has failed, the exhaust brake control is stopped, the intake bypass valve and idle speed control valve are closed, and the engine braking force is increased by the intake resistance. Exhaust brake control method is provided.

According to the present invention, an exhaust brake is provided in an exhaust pipe, a bypass passage is provided in an intake pipe to bypass a throttle valve, and an exhaust brake of an engine is provided in the bypass passage. In the control device, a pressure sensor that detects an intake pressure is provided in the intake pipe, and a rotation speed sensor that detects a rotation speed is provided in the engine,
A control device is provided for controlling the exhaust shutter, the intake bypass valve, and the idle speed control valve based on signals from the pressure sensor and the rotation speed sensor.

According to the present invention, an exhaust brake is provided in an exhaust pipe, an intake pipe is provided with a bypass passage bypassing a throttle valve, and the bypass passage is provided with an intake bypass valve. In the control device, a pressure sensor for detecting the exhaust pressure is provided in the exhaust pipe, and a rotation speed sensor for detecting the rotation speed is provided in the engine,
A control device is provided for controlling the exhaust shutter, the intake bypass valve, and the idle speed control valve based on signals from the pressure sensor and the rotation speed sensor.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

Prior to the description, the prior art will be described first.

In FIG. 1, a turbocharger 2 and a muffler 3 are interposed in an exhaust pipe 1 of an engine E.
An exhaust shutter 4 is provided between the supercharger 2 and the muffler 3. An air cleaner 5 is provided on the suction side of the supercharger 2, and a mixer indicated by reference numeral 8 is provided on the discharge side connected to an intake pipe of the engine via an air cooler 7 by a discharge pipe 6. I have. The mixer 8 includes a venturi 9, a throttle valve 10 having a throttle valve opening sensor 10a, an air-fuel ratio control valve 11, a main adjustment screw (MAS) 12, and a fuel cut valve 13. An intake pipe 14 is connected to the outlet side of the mixer 8, and a bypass pipe 15 that bypasses the mixer 8 is provided between the intake pipe 14 and the discharge pipe 6. The bypass pipe 15 has an intake bypass valve 16.
Is provided. The fuel cut valve 13 is a solenoid valve 1
7, and the intake bypass valve 16 is connected to a solenoid valve 18.

On the other hand, the exhaust shutter 4 is connected to an exhaust brake valve 19, and an air-fuel ratio sensor 20 is provided upstream of the exhaust shutter 4. These members 10, 11, 17, 18, 19, and 20 are respectively connected to a control unit 30. The control unit 30 includes a clutch pedal sensor 21, an exhaust brake operation switch 22, a transmission neutral sensor 23, a power A spark plug 26, a boost pressure sensor 27, and a crank angle sensor 28 are connected via a transistor 24 and an ignition coil 25, respectively. Reference numeral 29 in the figure denotes a fuel regulator.

Hereinafter, a portion according to the present invention will be described.

In FIG. 2, a bypass passage 15 provided to bypass a venturi 9 of a mixer and a throttle valve 10 connected to an intake pipe 6 (corresponding to a discharge pipe of a compressor in the case of a turbo type). Is provided with an intake bypass valve 16. Also, the throttle valve 10
A conventionally known idle speed control valve (hereinafter, ISC valve) 31 is provided in a bypass passage 31a formed so as to bypass the ISC valve. A bypass passage 32a provided to bypass the ISC valve is turned on / off. A well-known fast idle control device valve (hereinafter, FICD valve) 32 for increasing an idle speed when the air conditioner is operated to a predetermined speed is attached.

An intake pressure sensor 33 for detecting intake pressure is attached downstream of the throttle valve 10, and a rotational speed sensor 38 is provided in the engine. The ISC valve 31, the FICD valve 32, the intake pressure The sensor 33 and the engine speed sensor 38 are each connected to the control device 30 by an electric circuit, and an alarm lamp 40 is connected to the control device 30. Then, referring to the block diagram shown in FIG.
The operating means includes an intake pressure sensor 33, a rotational speed sensor 38, an operating state detecting means 42, an exhaust shutter closing operation confirming means 43, and an exhaust brake releasing means 4.
4. Intake resistance increasing means 4 including ISC valve and FICD valve
5, and an exhaust brake failure indicating means 4 including a warning light 40
6 are connected.

Here, reference numeral 30a denotes an input interface, 30b denotes an output interface, 30c denotes a CPU,
0Dd is RAM, 30f is ROM, 34 is an intake valve, 35
Denotes an exhaust valve, 36 denotes a water temperature sensor, and 37 denotes an exhaust temperature sensor.

Hereinafter, referring to the flowchart of FIG.
The operation will be described.

First, the exhaust brake operation switch 22 is turned on. Start the exhaust brake check routine,
It is determined whether or not the exhaust brake is operating (step S1).
If NO, return. If YES, read the engine rotation speed (Ne) (step S2) and determine whether the rotation speed is higher than a predetermined rotation speed (for example, 1000 rpm) (step S3). ). In the case of NO, the return is performed, and in the case of YES, the deceleration (△ Ne) of the engine rotation is calculated (step S4). It is determined whether or not the exhaust shutter drive output port, that is, the output circuit is abnormal, based on whether the deceleration value is smaller than a predetermined value (step S5). In the case of NO, it is determined whether or not the intake bypass valve drive output port is abnormal based on a predetermined abnormality determination value (see the map in FIG. 5) (step S6). NO
In the case of, the deceleration value is the upper limit of the deceleration judgment value (DECREV
1) It is determined whether or not the value is larger than the value (step S7).
If the answer is S, it is determined that there is no abnormality in the exhaust brake system and the operation is returned (step S15). YES in step S5
In the case of (2), since there is an abnormality in the exhaust shutter system (step S16), as a countermeasure, the intake bypass valve 16, the ISC valve 31, and the FICD valve 32 which are the intake resistance increasing means are fully closed (steps S17 and S13), The warning light 40 which is the brake failure display means is turned on (step S
14) Return, and if YES is determined in step S6, there is an abnormality in the intake bypass valve system.
1. The FICD valve 32 is fully closed (steps S17,
3) Then, the warning light 40 is turned on (step S14), and the return is performed. In the case of NO in step S7, it is determined whether the deceleration determination value is between the upper limit (DECRV1) and the lower limit (DECRV2). (Step S8). If NO, proceed to S16, S17, S13, S14, and if YES, read the intake pressure (Pb) (step S
9) It is determined whether or not the intake bypass valve abnormality determination value (see FIG. 6) is smaller than a lower limit (EXHPB1) (step S10). In the case of NO, it is determined whether or not it is within the range of OK (step 11), and in the case of YES, there is no abnormality in the exhaust brake system, and the process is returned.
3. The process proceeds to S14 and returns.

That is, if there is no abnormality in the exhaust brake system, the system is returned. If there is an abnormality, the intake system is closed to increase the intake resistance and increase the engine braking force for emergency response.

FIG. 7 is a control flow chart showing another embodiment of the present invention. In the flowchart of FIG. 5, it is determined up to step S7 that there is no abnormality in the exhaust brake system. The determination flow has been simplified so that the abnormality of the intake bypass valve system is determined only in the range,
If there is no abnormality in the exhaust brake system, the engine is controlled to increase the amount of work by sufficiently sucking air into the engine to increase the braking force of the exhaust brake. Also, a pressure sensor is provided upstream of the exhaust shutter of the exhaust manifold in place of the pressure sensor provided in the intake manifold,
The same configuration can be made even when the determination is made based on the signal from the pressure sensor and the deceleration of the engine, and the operation and effect are the same.

[0020]

The present invention is configured as described above,
Failure determination is performed by the failure determination device provided in the exhaust brake system.In the event of a failure, the intake system is closed and braking is performed by increasing the intake resistance. is there.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention.

FIG. 2 is a configuration diagram showing a main part of FIG. 1;

FIG. 3 is a block diagram of the control shown in FIG. 2;

FIG. 4 is a flowchart of the control in FIG. 2;

FIG. 5 is a determination value for detecting an abnormality based on intake pressure.

FIG. 6 is a determination value for detecting an abnormality based on the deceleration of the engine.

FIG. 7 is a flowchart of another control of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Exhaust pipe 3 ... Muffler 4 ... Exhaust shutter 5 ... Air cleaner 7 ... Air cooler 8 ... Mixer 10 ... Throttle valve 14 ... Intake pipe 15 ... Bypass pipe 16 ... Intake bypass valve 30 ... Control device 31 ... ISC valve 32 ... FICD valve 33 ... Pressure sensor 38 ... Rotation sensor 40 ... Alarm light

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02D 41/12 360 F02D 41/12 360 43/00 301 43/00 301Y 301K 301L F-term (Reference) 3G065 AA11 CA34 CA40 DA04 EA03 GA03 GA06 GA08 GA09 GA10 GA28 GA29 GA31 GA41 HA03 KA36 3G084 BA06 BA08 BA24 CA03 DA26 DA33 EA04 EA11 EB22 FA00 FA11 FA34 3G301 HA11 JB02 JB07 JB10 KA07 LA00 LA04 NA08 PA07Z PA11ZPD03Z11 PDZZ03Z11

Claims (3)

[Claims] An exhaust pipe provided with an exhaust shutter, and an intake pipe provided with a bypass passage for bypassing a throttle valve;
In an exhaust brake control method for an engine in which an intake bypass valve is provided in the bypass passage, when the exhaust shutter is closed and the intake bypass valve is opened to operate the exhaust brake, the pressure in the intake manifold or the exhaust manifold is reduced. If the value is equal to or less than the predetermined value and the deceleration of the engine rotation becomes equal to or less than the predetermined value, it is determined that the exhaust brake circuit has failed, the exhaust brake control is stopped, and the intake bypass valve and the idle speed control valve are closed. An exhaust braking control method characterized by increasing engine braking force by means of intake resistance. 2. An exhaust pipe is provided with an exhaust shutter, and an intake pipe is provided with a bypass passage which bypasses a throttle valve.
In an exhaust brake control device for an engine in which an intake bypass valve is provided in the bypass passage, a pressure sensor for detecting an intake pressure is provided in an intake pipe, a rotational speed sensor for detecting a rotational speed is provided in the engine, and a pressure sensor and An exhaust brake control device comprising a control device for controlling an exhaust shutter, an intake bypass valve, and an idle speed control valve by a signal from a rotation speed sensor. 3. An exhaust pipe is provided with an exhaust shutter, and an intake pipe is provided with a bypass passage which bypasses a throttle valve.
In an exhaust brake control device for an engine in which an intake bypass valve is provided in the bypass passage, a pressure sensor for detecting exhaust pressure is provided in an exhaust pipe, a rotational speed sensor for detecting a rotational speed is provided in the engine, and a pressure sensor and An exhaust brake control device comprising a control device for controlling an exhaust shutter, an intake bypass valve, and an idle speed control valve in accordance with a signal from a rotation speed sensor.