Summary of the invention
For solving the problems of the technologies described above, object of the present invention is for providing a kind of monitoring method and monitoring system of engine exhaust and brake state.This monitoring method and monitoring system can monitor the exhaust brake condition of motor effectively in time, improve the safety coefficient of driving.
The monitoring method of engine exhaust and brake state provided by the invention, comprises the steps:
Preset motor when exhaust brake condition, the position signal of exhaust valve;
When exhaust brake condition, detect in real time the actual position signal of exhaust valve;
Whether the actual position signal that judges exhaust valve conforms to predeterminated position signal, does not conform to, and exhaust brake is abnormal.
Preferably,
In engine exhaust pipeline, be provided with butterfly valve, by closing butterfly valve unlatching exhaust valve, carry out exhaust brake;
The predeterminated position signal of exhaust valve is: motor is when compression stroke and expansion stroke, and exhaust valve is enforced opening under exhaust pressure; Motor is when exhaust stroke, and exhaust valve is normally opened.
Preferably, default exhaust back pressure limit value; When exhaust brake condition, also detect in real time exhaust back pressure, when exhaust back pressure exceeds exhaust back pressure limit value, exhaust brake is abnormal.
Preferably, when exhaust brake condition, also detect the state signal of the solenoid valve of controlling described butterfly valve keying, and/or the state signal of described butterfly valve; When the actual position signal of exhaust valve does not conform to predeterminated position signal, analyze the state signal of described solenoid valve and/or described butterfly valve.
Preferably,
Motor is opened exhaust valve by mechanical-hydraulic drive system and is carried out exhaust brake;
The predeterminated position signal of exhaust valve is: motor is when compression stroke, and exhaust valve is opened under the effect of mechanical-hydraulic drive system.
Preferably, high pressure and the low-voltage signal of hydraulic circuit in default mechanical-hydraulic drive system; When exhaust brake condition, detect the actual fuel injection pressure signal of hydraulic circuit, and the piston position signal of piston in mechanical-hydraulic drive system;
When the actual position signal of judgement exhaust valve conforms to predeterminated position signal, following two conditions are set up simultaneously:
In compression stroke, before piston approaches compression stroke tip position, actual fuel injection pressure signal conforms to default high-voltage signal; After compression stroke, actual fuel injection pressure signal conforms to default low-voltage signal.
Preferably, when exhaust brake condition, also obtain the oil spout state signal of oil sprayer, oil sprayer oil spout, exhaust brake is abnormal.
Preferably, the default abnormal restriction operating mode of exhaust brake, when the actual conditions of abnormal gas exhaust reaches default restriction operating mode, the output torque of limiting engine, rotating speed.
The present invention also provides a kind of monitoring system of engine exhaust and brake state, and engine system is provided with exhaust brake switch, comprises the position detecting device and the controller being connected with brake switch signal of exhaust valve;
Described controller is preset motor when exhaust brake condition, the position signal of exhaust valve;
When described position detecting device detects exhaust brake condition in real time, the actual position signal of exhaust valve;
Described controller receives after the exhaust brake start signal of exhaust brake switch, judges whether the actual position signal of exhaust valve conforms to predeterminated position signal, does not conform to, and exports the abnormal signal of exhaust brake.
Preferably,
In engine exhaust pipeline, be provided with butterfly valve, by closing butterfly valve unlatching exhaust valve, carry out exhaust brake;
In controller, the predeterminated position signal of default exhaust valve is: motor is when compression stroke and expansion stroke, and exhaust valve is enforced opening under exhaust pressure; Motor is when exhaust stroke, and exhaust valve is normally opened.
Preferably, also comprise back pressure detection device; Described controller is preset exhaust back pressure limit value; Exhaust back pressure when described back pressure detection device detects exhaust brake condition in real time also exports described controller to, when described controller judgement exhaust back pressure exceeds exhaust back pressure limit value, exports the abnormal signal of exhaust brake.
Preferably, also comprise detector for state of electromagnetic valve and/or butterfly valve condition checkout gear, when exhaust brake condition, for detection of the state signal of controlling the solenoid valve of described butterfly valve keying, and/or the state signal of described butterfly valve, and export described controller to; When the actual position signal of described controller judgement exhaust valve does not conform to predeterminated position signal, analyze the state signal of described solenoid valve and/or described butterfly valve.
Preferably,
Motor is opened exhaust valve by mechanical-hydraulic drive system and is carried out exhaust brake;
The predeterminated position signal of the exhaust valve that controller prestores is: motor is when compression stroke, and exhaust valve is opened under the effect of mechanical-hydraulic drive system.
Preferably, in described controller, preset high pressure and the low-voltage signal of hydraulic circuit in mechanical-hydraulic drive system; Also comprise oil pressure detection device, piston position detecting device, the actual fuel injection pressure signal of hydraulic circuit while being respectively used to detect exhaust brake condition, and the piston position signal of piston in mechanical-hydraulic drive system;
When the actual position signal of described controller judgement exhaust valve conforms to predeterminated position signal, following two conditions are set up simultaneously:
In compression stroke, before piston approaches compression stroke tip position, actual fuel injection pressure signal conforms to default high-voltage signal; After compression stroke, actual fuel injection pressure signal conforms to default low-voltage signal.
Preferably, also comprise the oil spout detection device that detects oil sprayer oil spout state signal; Described controller receives the exhaust brake start signal of exhaust brake switch, and while receiving the fuel injection signal of described oil spout detection device, the abnormal signal of output exhaust brake.
Preferably, described controller is preset the abnormal restriction operating mode of exhaust brake, when the actual conditions of described controller judgement abnormal gas exhaust reaches default restriction operating mode, and the output torque of export-restriction motor, the signal of rotating speed.
Preferably, the position detecting device of exhaust valve comprises sensor probe and sensor control unit; The spring seat of honour of exhaust valve is provided with the mounting bracket circumferentially extending along it, and described mounting bracket is provided with mounting hole, and described sensor probe inserts described mounting hole, and described sensor control unit is fixed on the cylinder cap of motor.
This monitoring method and supervisory system, after receiving the exhaust brake start signal of exhaust brake switch, exhaust valve actual position signal and the comparison of predeterminated position signal that position detecting device can be detected, if do not conform to, show that exhaust valve is according to expection unlatching, exhaust brake is not yet in effect to carry out, and exhaust brake is abnormal, and controller is by the abnormal signal of output exhaust brake.The state that driver can complete monitoring engine exhaust and brake, thus auxiliary braking reasonably controlled, to improve the safety coefficient of driving.
Embodiment
In order to make those skilled in the art understand better technological scheme of the present invention, below in conjunction with the drawings and specific embodiments, the present invention is described in further detail.
Please refer to Fig. 1-2, Fig. 1 is the structural representation at the exhaust valve spring seat of honour in exhaust brake condition monitoring system provided by the present invention; Fig. 2 is the structural representation that in Fig. 1, the position detecting device of exhaust valve is installed at the exhaust valve spring seat of honour.
The monitoring system of engine exhaust and brake state in this embodiment, comprises position detecting device and the controller of exhaust valve 50.Engine control system is provided with exhaust brake switch, exhaust brake switch can be located in operator cabin, while needing exhaust and brake system to carry out auxiliary braking, driver starting exhaust brake switch, exhaust brake switch can be mechanical switch, can be also by display screen, to carry out the intelligent switch of signal instruction input.The controller of monitoring system is connected with exhaust brake switch, and driver input is opened after the instruction of exhaust and brake system, and controller can obtain the signal that exhaust brake is opened.
In addition, default when exhaust brake condition in controller, the position signal of exhaust valve 50, while carrying out normal exhaust brake, exhaust valve 50 should residing position.Below put up with and close butterfly valve and carry out exhaust brake and carry out two kinds of modes of exhaust brake by machinery hydraulic system, introduce respectively the predeterminated position of exhaust valve 50 when braking.
When the position detecting device of exhaust valve 50 detects exhaust brake condition in real time, the actual position signal of exhaust valve 50.Exhaust valve 50 is installed on the spring seat of honour 10 conventionally, and when exhaust valve 50 moves along keying direction, move with it at the spring seat of honour 10, therefore the displacement at the detection springs seat of honour 10 can be learned the position information of exhaust valve 50.
As shown in Figure 1, the spring seat of honour 10 is provided with the mounting bracket 101 circumferentially extending along it, and on mounting bracket 101, processes mounting hole 101a; The position detecting device of exhaust valve 50 specifically comprises sensor probe 30 and sensor control unit (main body of detection device).Sensor probe 30 can insert above-mentioned mounting hole 101a, and as shown in Figure 2, sensor control unit is fixed on the cylinder cap (not shown) of motor.So, sensor probe 30 can be connected with the sensor control unit that is positioned at motor top and is fixed on cylinder cap by valve mechanism cover, thereby realizes the output of signal.
The position detecting device of above-mentioned exhaust valve 50 can be hall sensor; because its sensor control unit is fixed on cylinder cap; approach with oil sprayer position; therefore the wire harness of position detecting device can the integrated setting with the oil sprayer wire harness of motor; so that saving space, and sensor is played to certain protective action.
As shown in Figure 2, the top at the spring seat of honour 10 need to arrange air valve bridge 20, therefore the spring seat of honour 10 is made improvements, processes mounting bracket 101, sensor probe 30 not with air valve bridge 20 interferences.Certainly, mounting bracket 101 is not set, it is also feasible directly the mounting hole 101a of sensor installation probe 30 being located to the spring seat of honour 10, just, the spring seat of honour 10 need to arrange the mounting groove of linking springs 40 and exhaust valve 50, processing space is limited, special mounting bracket 101 is set and is easy to actual processing.
Please refer to Fig. 3, Fig. 3 is the flow chart of a kind of embodiment of exhaust brake condition monitoring method provided by the present invention.
The monitoring method of this supervisory system, carries out according to following step:
S1, default motor when exhaust brake condition, the position signal of exhaust valve 50;
S2, when exhaust brake condition, detect in real time the actual position signal of exhaust valve 50; By above-mentioned position detecting device, detect.
S3, judge whether the actual position signal of exhaust valve 50 conforms to predeterminated position signal, does not conform to, and enters step S4;
S4, exhaust brake are abnormal.
Controller receives after the exhaust brake start signal of exhaust brake switch, exhaust valve 50 actual position signals and the comparison of predeterminated position signal that position detecting device is detected, if do not conform to, show that exhaust valve 50 is according to expection unlatching, exhaust brake is not yet in effect to carry out, exhaust brake is abnormal, and controller is by the abnormal signal of output exhaust brake.Controller can directly be exported the abnormal voice signal of exhaust brake or be shown in the display screen in operator cabin, for driver, understand in time, and can directly give alarm, or, controller is directly shown exhaust valve 50 actual position signals, predeterminated position signal, whether abnormal driver, by observation, analyze braking state.The signal or the judged result that detect all can export CAN instrument to by the CAN bus of vehicle, so that driver observation.
Controller can be integrated in the OBD (On-Board Diagnostics (OBD)) of current vehicle, to utilize OBD to carry out anomaly analysis, result storage, or trigger alarm function.
Introduce under two kinds of exhaust brake modes concrete monitoring system and monitoring method below:
The first: be provided with butterfly valve in engine exhaust pipeline, when motor realizes exhaust brake by cutting out butterfly valve unlatching exhaust valve 50 (principle can be understood with reference to background technique), supervisory system can be worked in accordance with the following steps:
S11, default motor when exhaust brake condition, the position signal of exhaust valve 50;
The predeterminated position signal of exhaust valve 50 is: motor is when compression stroke and expansion stroke, and exhaust valve 50 is enforced opening under exhaust pressure; Motor is when exhaust stroke, and exhaust valve 50 is normally opened (cam mechanism drives it to open);
S12, when exhaust brake condition, detect in real time the actual position signal of exhaust valve 50;
S13, judge whether the actual position signal of exhaust valve 50 conforms to predeterminated position signal, does not conform to, and exhaust brake is abnormal.
The carrying out of each stroke of motor has strict program setting in its control unit, and controller can be known carrying out time or the characterization parameter of each stroke, when suction stroke end of a period, compression stroke start, can carry out exhaust valve 50 location comparison analyses.Normal exhaust brake, in four stroke engine, under the exhaust pressure effect raising after butterfly valve cuts out, in compression stroke, expansion stroke and three strokes of exhaust stroke, exhaust valve 50 is all opened.Suppose, after driver starting exhaust brake switch, the testing result of position detecting device shows that exhaust valve 50 continues open or do not open, or in above-mentioned three strokes, at least one stroke exhaust valve 50 is not opened, and exhaust brake must occur extremely.
Certainly, even if exhaust valve 50 is normally opened in above-mentioned three stroke procedure, in order to ensure exhaust brake safety, still can further determine that whether exhaust valve 50 braking states are normal by detecting other parameters.
Be in step S11, can also in controller, preset exhaust back pressure limit value;
Exhaust back pressure: engine exhaust pipe is because exhaust pressure and resistance cause gas exhaust manifold rear portion to possess certain pressure.
In step S12, when exhaust brake condition, go back real-time detection practical exhaust back pressure;
Exhaust back pressure can detect by back pressure detection device.Exhaust back pressure detection device can be back pressure transducer, and back pressure transducer can be installed on the upstream of butterfly valve.Such as, back pressure transducer can be arranged on pressurized machine or the pressurized machine back-end location of gas exhaust piping, now, back pressure transducer can with the integrated setting of pressurized machine wire harness, to save installing space, and protect back pressure transducer.
In step S13, when controller judgement actual exhaust air back pressure exceeds exhaust back pressure limit value, also can export the abnormal signal of exhaust brake.
During exhaust brake, butterfly valve cuts out, to stop the gas in gas exhaust piping, discharge, exhaust pressure raises, the corresponding rising of exhaust back pressure, but actual exhaust air back pressure is while exceeding back pressure limit value, damage possibly butterfly valve, and affect normal exhaust brake, therefore the setting of exhaust back pressure limit value, with the comparison of actual exhaust air back pressure, can further guarantee exhaust brake safety.
For butterfly valve, close the embodiment of braking, can also make further improvement.The keying of butterfly valve is generally by electromagnetic valve.Therefore corresponding detector for state of electromagnetic valve and/or butterfly valve condition checkout gear can be set, when exhaust brake condition, can detect respectively the state signal of solenoid valve and/or the state signal of butterfly valve (such as, detect the angular signal of butterfly valve).When the actual position signal of controller analysis exhaust valve 50 does not conform to predeterminated position signal, further the solenoid valve of analyzing and testing is, the state signal of butterfly valve.
As mentioned above, when exhaust brake condition, exhaust valve 50, except normally opening in exhaust stroke, at compression and expansion stroke, mainly relies on butterfly valve to cut out the exhaust pressure enforced opening of rear rising.If exhaust valve 50 is not opened according to expection, showing that butterfly valve is not yet in effect closes, exhaust pressure cannot reach the force value of enforced opening exhaust valve 50, putting before this, by the state signal of solenoid valve and butterfly valve, driver not only can learn that exhaust valve 50 is not forced to open and the exhaust brake that causes is abnormal, also can know that exhaust valve 50 is not forced to the concrete reason of opening, to make indication for next step maintenance.
The second: motor is opened exhaust valve 50 by mechanical-hydraulic drive system and carried out exhaust brake (principle can be understood with reference to background technique), and now, supervisory system can be worked in accordance with the following steps:
S21, default motor when exhaust brake condition, the position signal of exhaust valve 50;
The predeterminated position signal of exhaust valve 50 is: motor is when compression stroke, and exhaust valve 50 is opened under the effect of mechanical-hydraulic drive system.
Close from above-mentioned butterfly valve that to carry out exhaust brake different, this mode of braking is equivalent to force the driving mechanism of its unlatching for exhaust valve 50 is specially provided with one group when the exhaust brake, therefore can control accurately exhaust valve 50, when opens.In four strokes, the energy of compression stroke is maximum, now, opens exhaust valve 50, and obviously the largest ground consumption of engine energy, reaches good auxiliary braking effect.
S22, when exhaust brake condition, detect in real time the actual position signal of exhaust valve 50;
S23, judge whether the actual position signal of exhaust valve 50 conforms to predeterminated position signal, does not conform to, and exhaust brake is abnormal.
For this kind of mode of braking, also can make further improvement.
In step S21, can be in controller preset high-pressure and low-voltage signal;
As stated in the Background Art, mechanical-hydraulic drive system comprises hydraulic circuit, hydraulic circuit is when high pressure, the piston movement of mechanical-hydraulic drive system, and finally drive exhaust valve 50 to open, otherwise hydraulic circuit pressure release is low pressure, exhaust valve 50 cuts out or in exhaust stroke, opens under normal driving mechanism.Default high pressure and low-voltage signal, when those skilled in the art can normally carry out according to exhaust brake, the force value of the hydraulic circuit of concrete type is definite, and high pressure and low-voltage signal can be value ranges.
In step S22, when exhaust brake condition, also detect the actual fuel injection pressure signal of hydraulic circuit in mechanical-hydraulic drive system, and piston position signal;
Actual fuel injection pressure signal and piston position signal, oil pressure detection device and the piston position detecting device that can by supervisory system, arrange respectively obtain, and export controller to.
In step S23, when the actual position signal of judgement exhaust valve 50 conforms to predeterminated position signal, following two conditions are inevitable to be set up simultaneously:
In compression stroke, before the piston in cylinder approaches compression stroke tip position, actual fuel injection pressure signal need be in high pressure (can discharge the gas of compression after exhaust valve 50 is opened guaranteeing) in time; After compression stroke, fuel injection pressure signal is in low pressure (exhaust valve 50 is without enforced opening).
If controller judgement exhaust valve 50 actual position signals do not conform to predeterminated position signal, exhaust brake is abnormal, after learning the comparison result of above-mentioned actual fuel injection pressure signal and default fuel injection pressure signal, can further analyze the reason that exhaust valve 50 is not opened according to expection, may be to press pressure release extremely to cause by building of hydraulic circuit.Such as, hydraulic circuit obstruction, leakage etc., or the solenoid valve of controlling decompression pressure release breaks down, and now, can also further detect the state signal of solenoid valve in mechanical-hydraulic drive system.If fuel injection pressure signal comparison is normal, may be that the mechanical structure in mechanical-hydraulic drive system breaks down, such as, ad hoc piston or cam break down, and can detect such parameter, so that driver is determined failure cause simultaneously.
No matter be butterfly valve braking or the braking of mechanical-hydraulic drive system, oil sprayer injection time and engine exhaust and brake time should keep coordinating, and during exhaust brake, oil sprayer should stop oil spout; After end of braking, oil sprayer in expansion stroke oil spout to carry out normal expansion stroke.Therefore, when exhaust brake condition, all can obtain the oil spout state signal of oil sprayer, if oil sprayer oil spout also belongs to exhaust brake abnormal.During exhaust brake, oil sprayer should whole process stop oil spout, in order to avoid cause unnecessary waste, and when exhaust brake lost efficacy, can correspondingly reduce engine power.Oil spout condition checkout gear can be set, to detect oil sprayer state signal, or directly from the control unit of oil sprayer, obtain.The control unit of the control unit of oil sprayer and butterfly valve, mechanical-hydraulic drive system should be coordinated, so that the injection time of oil sprayer and period of braking keep the regular hour poor, each control unit can be integrated in the same electronic control unit of motor.
If be appreciated that, oil sprayer continues oil spout after braking starts or after end of braking injection delay excessive, i.e. oil spout too early or excessively late, can cause OBD fault, can judge that accordingly exhaust brake is abnormal, this kind of abnormal conditions also can be shown in the CAN instrument of vehicle.
For above-mentioned arbitrary embodiment, all can in controller, preset the abnormal restriction operating mode of exhaust brake.As mentioned above, the abnormal reason of exhaust brake has multiple, for example, solenoid valve or butterfly valve fault, exhaust back pressure transfinites, or hydraulic circuit build press that pressure release is abnormal, the mechanical structure in mechanical-hydraulic drive system breaks down, oil sprayer oil spout is abnormal etc.According to the corresponding signal detecting, can judge whether exhaust brake fault can threaten traffic safety, or major injury component, this type of fault can be set as limiting operating mode, such as, exhaust back pressure exceeds back pressure limit value certain value, solenoid valve or butterfly valve and without any response, oil sprayer fuel injection quantity, reaches setting value etc. for operation signal.When the actual conditions of controller judgement abnormal gas exhaust reaches default restriction operating mode, the rotating speed of exportable limiting engine, the instruction of output torque, with the lifting of control engine power, to protect the safety of motor, driver.
Above the monitoring method of a kind of engine exhaust and brake state provided by the present invention and monitoring system are all described in detail.Applied specific case herein principle of the present invention and mode of execution are set forth, above embodiment's explanation is just for helping to understand method of the present invention and core concept thereof.It should be pointed out that for those skilled in the art, under the premise without departing from the principles of the invention, can also carry out some improvement and modification to the present invention, these improvement and modification also fall in the protection domain of the claims in the present invention.