JPH0643232U - Engine exhaust brake device - Google Patents

Abstract

(57) [Summary] [Object] The present invention has an object to provide an exhaust gas rake device for an engine, which operates even in a vehicle equipped with a premix engine by detecting that fuel does not remain in the intake system. [Structure] An oxygen concentration sensor 29 is provided in the exhaust pipe 5 by providing stop means for stopping fuel supply based on an exhaust brake operation signal.
A control device 26 is provided which operates the actuator 28 of the exhaust shutter 27 after detecting that the oxygen in the exhaust gas has reached the same concentration as the oxygen in the atmosphere by the signal from the oxygen concentration sensor 29.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an engine exhaust brake device having an exhaust shutter in an exhaust pipe.

[0002]

[Prior art]

 It is known that large vehicles equipped with a diesel engine are equipped with an exhaust brake equipped with an exhaust shutter on the exhaust pipe to improve deceleration performance.

[0003]

[Problems to be solved by the device]

 However, in a premix engine that inhales a mixture of fuel and air, such as a gas engine, the mixture remains in the intake pipe even if the fuel valve is closed when the exhaust shutter is attached, so backfire, etc. Therefore, the above-mentioned exhaust break is not equipped.

On the other hand, when a gas engine or the like, which is a modified diesel engine, is mounted, the reduction in deceleration performance impairs traveling in a vehicle having a large load, which is not preferable in terms of safety.

Therefore, it is an object of the present invention to provide an engine exhaust brake device that operates even in a vehicle equipped with a premixed engine by detecting that fuel does not remain in the intake system.

[0006]

[Means for Solving the Problems]

 According to the present invention, in an engine exhaust brake device having an exhaust pipe in an exhaust pipe, a stop means is provided for stopping fuel supply based on an exhaust brake operation signal, and an oxygen concentration sensor is provided in the exhaust pipe. A control device is provided that activates the actuator of the exhaust shutter after detecting that the concentration of oxygen in the exhaust gas is the same as the concentration of oxygen in the atmosphere from the signal from the concentration sensor.

[0007]

[Action]

 In the engine exhaust brake device configured as described above, when the exhaust brake switch is turned on, the control device causes the oxygen concentration in the exhaust pipe to change to the atmospheric oxygen concentration by the signal from the oxygen concentration sensor installed in the exhaust pipe. Backfire does not occur because the actuator of the exhaust shutter is activated after detecting that they are the same, that is, no fuel remains.

[0008]

[Preferred Embodiment]

 It is preferable to provide an air bypass passage that bypasses the throttle valve of the mixer, and to provide an opening / closing valve in the bypass passage so that the bypass valve is opened during exhaust braking because the compression loss becomes large.

[0009]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, an exhaust manifold 2 is attached to an engine E, and an exhaust pipe 3 is provided in the exhaust manifold 2 with a catalyst 4 and a muffler 5 interposed. An intake pipe 6 is provided in the intake manifold 1 via a throttle valve 7 and a mixer 8, and an air duct 9 is attached to the intake pipe 6.

The cylinder 10 is provided with a filling port 12 via a check valve 11, and from the side close to the cylinder 10, the emergency shutoff valves 13, 14, the primary pressure reducing valve 15, the secondary pressure reducing valve 16, the safety valves 18, 3 The next pressure reducing valve 17 and the shutoff valve 19 are connected to the mixer 8 by the fuel circuit 22.

The fuel bypass valve 23 is interposed between the fuel circuit 22 downstream of the shutoff valve 19 and the intake pipe 6, and the secondary pressure reducing valve 16 and the tertiary pressure reducing valve 17 are air ducts in the air circuit 20. 9, the primary pressure reducing valve 15 is connected to the water circuits 15a and 15b and is cooled.

The fuel bypass valve 23 is connected to the control unit 21 by an electric circuit.

The intake duct 9 and the intake pipe 6 are bypassed by an air bypass passage 24, and an opening / closing valve 25 is interposed in the air bypass passage 24. The opening / closing valve 25 is connected to a control device 26 by an electric circuit, and the control device 26 connects the shutoff valves 14 and 19 and an engine rotation sensor F, an exhaust brake operation switch H, an accelerator pedal sensor J and a clutch pedal sensor G (not shown). It is connected.

An exhaust shutter 27 is openably and closably attached to the exhaust pipe 5, the exhaust shutter 27 is connected to an air cylinder 28, and an oxygen concentration sensor installed in the air cylinder 28 and the exhaust pipe 5. An electric circuit 29 is connected to the control device 26.

FIG. 2 shows a configuration of a main part of the embodiment of FIG. 1, and the same reference numerals as those in FIG.

The operation will be described below with reference to FIGS. 3 and 2.

At the time of operation, it is determined whether or not the exhaust brake operation switch H is ON (step S1). If YES, it is judged whether the clutch pedal is OFF, the throttle, that is, the throttle valve 7 is in the idle position, or the engine speed F is equal to or more than the specified value (steps S2, 3, 4). 19 is operated (step S5). Then, the oxygen concentration sensor 29 determines whether or not it is equal to or more than the specified value (step S6). If NO, the process returns. If YES, the air bypass valve 25 and the exhaust brake valve 27 are turned on and the process returns (steps S7 and S8).

If NO in step S1 and if any of steps S2, 3, 4, is NO, it is determined whether or not the exhaust brake is operating (step S9). If YES, the process returns. If NO, the air bypass valve 25 is turned off and closed, the exhaust brake valve 27 is turned off (steps S10, 11), and the fuel cutoff valves 14, 19 are turned off after a certain period of time. Fuel is supplied to the engine and the process returns (steps S12 and S13).

[0020]

[Effect of device]

 Since the present invention is configured as described above, it is possible to provide an exhaust brake even in a premix engine such as a gas engine to operate it safely.

Therefore, even in a commercial vehicle having a large load capacity, the deceleration performance is excellent and the vehicle is safe.

[Brief description of drawings]

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

FIG. 2 is a schematic diagram showing a configuration of a main part of FIG.

FIG. 3 is a flowchart of the control of FIG.

[Explanation of symbols]

 1 ... Intake manifold 2 ... Exhaust manifold 6 ... Intake pipe 7 ... Throttle valve 8 ... Mixer 9 ... Intake duct 14, 19 ... Cutoff valve 15 ... Primary pressure reducing valve 16 ... Secondary pressure reducing valve 17 ... Third pressure reducing valve 24 ... Air Bypass passage 25 ... Open / close valve 26 ... Control device 27 ... Exhaust shutter 29 ... Oxygen concentration sensor

Claims (1)

[Scope of utility model registration request] 1. An exhaust brake device of an engine having an exhaust shutter in an exhaust pipe, wherein stop means for stopping fuel supply based on an exhaust brake operation signal is provided, and an oxygen concentration sensor is provided in the exhaust pipe. An exhaust brake device for an engine, characterized in that a control device for activating an actuator of an exhaust shutter is provided after detecting that the oxygen in the exhaust gas has reached the same concentration as the oxygen in the atmosphere by a signal from a sensor.