CN204024837U - A kind of cylinder of diesel engine internal pressure feed back control system - Google Patents

Abstract

The utility model relates to a kind of cylinder of diesel engine internal pressure feed back control system, and each cylinder cylinder of this device presses sensing device to be connected with the input of burning feedback unit with corner marking instrument; The output of burning feedback unit is connected to the input of oil spout wear control unit; The output of oil spout wear control unit is connected to Engine ECU and tutorial light.Burning feedback unit presses signal and corner signal to calculate the combustion phase CA50 of each cylinder according to cylinder, and oil spout wear control unit compares each cylinder Actual combustion phase place CA50 and combustion phase CA50 theoretical value the revised injection advance angle of output and then revises CA50; By revised injection advance angle and theoretical injection advance angle comparison, judge whether oil sprayer occurs excessive abrasion simultaneously.The utility model can be realized the wearing and tearing judgement to single oil sprayer, revises the deviation of oil sprayer CA50 deviation and fuel injection quantity, and in the time that wearing and tearing are excessive, prompting is changed, thereby can save user's use and maintenance cost.

Description

A kind of cylinder of diesel engine internal pressure feed back control system

Technical field

The utility model belongs to control technique field, relate to a kind of can be for the in-cylinder pressure feed back control system of large diesel engine and LD-diesel.

Background technique

At present, cylinder of diesel engine presses feedback control technology at home in conceptual phase, is mainly the low-temperature burning technology of pressing feedback control based on cylinder.Be mainly abroad to press feedback control technology at low-temperature burning field application cylinders such as HCCI, can effectively control in-cylinder combustion state, make low-temperature burning stability and high efficiency.Cylinder presses feedback control technology also to can be applicable to the each cylinder nonuniformity of improvement simultaneously, improves system scattered error, improves the fuel tolerance of motor, and monitoring combustion regime, and the Fast Calibration aspect of oil sprayer, can strengthen system robustness greatly.

Domestic common rail system type is more and more, is characterized in that the relative mechanical pump injection pressure of injection pressure is high, and system high pressure part is prone to problem, also occurs a lot of oil sprayer wearing and tearing cases.Some international suppliers are as the company such as BOSCH, denso, its Diagnostic Strategy of controlling computer can judge oil sprayer wearing and tearing according to oil pump feed state, prompting user maintenance, but cannot point out single oil sprayer wearing and tearing, also cannot identify the wearing and tearing of single oil sprayer completely in maintenance station, conventionally take to change the method for whole oil sprayers, make user bear very large economic pressures.Oil sprayer wearing and tearing can cause burn deterioration simultaneously, and oil consumption raises, and the companies such as current BOSCH, denso do not carry out oil spout correction, and this is the main cause that causes oil consumption to increase.

Summary of the invention

The technical problems to be solved in the utility model is to provide a kind of cylinder of diesel engine internal pressure feed back control system that can realize single oil sprayer wearing and tearing differentiation and the oil sprayer that occurs wearing and tearing is carried out to parameter correction.

In order to solve the problems of the technologies described above, cylinder of diesel engine internal pressure feed back control system of the present utility model comprises the each cylinder cylinder pressure of motor sensing device, burning feedback unit, oil spout wear control unit, corner marking instrument, tutorial light; Described each cylinder cylinder presses sensing device to be connected with the input of burning feedback unit with corner marking instrument; The output of burning feedback unit is connected to the input of oil spout wear control unit; The output of oil spout wear control unit is connected to Engine ECU and tutorial light.

Described cylinder presses sensing device to comprise cylinder pressure sensor, charge amplifier; Cylinder pressure sensor is the sensor of output charge signal, and its output is connected with the input of charge amplifier; The output of charge amplifier is connected with the input of burning feedback unit.

It is the cylinder pressure sensor of voltage signal that described cylinder presses sensing device can also adopt output signal.

Described burning feedback unit can adopt microprocessor.

Described burning feedback unit can also adopt the hardware circuit being made up of signal processing module, burning calculation process module, power module, communication module; Each cylinder cylinder presses sensing device to be connected with the input of signal processing module with corner marking instrument, and the output of communication module is connected to oil spout wear control unit.

Described oil spout wear control unit can be made up of CA50 correcting module and fuel injection quantity correcting module; CA50 correcting module in oil spout wear control unit is made up of the first subtraction circuit, the first comparison operation circuit, PID control circuit; Fuel injection quantity correcting module is made up of the second subtraction circuit, the second comparison operation circuit, proportional integral circuit; The output of burning feedback unit and Engine ECU is connected to the input of the first subtraction circuit, and the output of the first subtraction circuit is connected to the input of the first comparison operation circuit, and the output of the first comparison operation circuit is connected to the input of PID control circuit; The output of PID control circuit and Engine ECU is connected to the input of the second subtraction circuit, and the output of the second subtraction circuit is connected to the input of the second comparison operation circuit, and the output of the second comparison operation circuit is connected to tutorial light; The output of the second comparison operation circuit is connected to the input of proportional integral circuit simultaneously; The output of proportional integral circuit is connected to the input of Engine ECU.

Each cylinder cylinder presses the cylinder that sensing device detects to press the corner signal of signal and corner marking instrument detection to output to burning feedback unit simultaneously, and burning feedback unit presses signal and corner signal to calculate the combustion phase CA50 of each cylinder according to cylinder.Each cylinder Actual combustion phase place CA50 and combustion phase CA50 theoretical value are done poor comparison by oil spout wear control unit, and by PID control circuit export revised injection advance angle so that revise CA50 (injection advance angle and CA50 are substantially linear, can change CA50 by adjusting injection advance angle), make the theoretical CA50 value of actual CA50 infinite approach, complete the correction to CA50; PID control circuit export theoretical injection advance angle that revised injection advance angle and ECU send do relatively poor, when departure exceedes threshold value, judge that excessive abrasion appears in oil sprayer, the corresponding tutorial light of output signal control is opened, when departure do not exceed threshold value passing ratio integration circuit export revised fuel injection quantity, complete the correction to fuel injection quantity.This device can detect the state of wear of every cylinder injector and can revise separately each cylinder injector, prompting replacing when wear extent exceeds extent of amendment.

Brief description of the drawings

Below in conjunction with the drawings and specific embodiments, the utility model is described in further detail.

Fig. 1 is cylinder of diesel engine internal pressure feed back control system structural representation of the present utility model.

Fig. 2 is in-cylinder pressure feedback control flow process figure in embodiment 1.

Fig. 3 is the structural representation of the utility model embodiment 2 burning feedback unit.

Fig. 4 is the structural representation of the utility model embodiment 2 oil spout wear control unit.

Embodiment

As shown in Figure 1, cylinder of diesel engine internal pressure feed back control system of the present utility model comprises the each cylinder cylinder pressure of motor sensing device, burning feedback unit 3, oil spout wear control unit 4, corner marking instrument 5, tutorial light 6.

Embodiment 1

Cylinder of diesel engine internal pressure feed back control system of the present utility model comprises the each cylinder cylinder pressure of motor sensing device, burning feedback unit 3, oil spout wear control unit 4, corner marking instrument 5, tutorial light 6.Described cylinder presses sensing device to comprise cylinder pressure sensor 1, charge amplifier 2, described cylinder pressure sensor 1 is that output signal is the sensor of charge signal, its output is connected with the input of charge amplifier 2, in-cylinder pressure is converted into charge signal by the piezoelectric crystal of sensor internal, and charge signal is converted into 0～10v voltage signal by charge amplifier 2.The output of charge amplifier 2 and corner marking instrument 5 is connected with burning feedback unit, the output of burning feedback unit 3 is connected to the input of oil spout wear control unit 4, the output of oil spout wear control unit 4 is connected to tutorial light 6 and Engine ECU 7, and wherein burn feedback unit 3 and oil spout wear control unit 4 adopt microprocessor.

As shown in Figure 2, in-cylinder pressure feedback control realizes by microprocessor and related peripheral circuit, and flow process is specific as follows:

The voltage signal that the representative cylinder that a, reception charge amplifier 2 are exported is pressed, and it is carried out to AD conversion;

The corner signal that b, reception corner marking instrument 5 are exported is also synchronously processed it;

C, press signal and corner signal to calculate the combustion phase CA50 of each cylinder according to cylinder;

CA50 formula:

$Q_{\mathrm{net}}={\∫}_0^{720}(\frac{k}{k-1}p\frac{\mathrm{dV}}{\mathrm{d\θ}}+\frac{1}{k-1}V\frac{\mathrm{dp}}{\mathrm{d\θ}})\mathrm{d\θ}$

${\∫}_0^{\mathrm{CA}50}(\frac{k}{k-1}p\frac{\mathrm{dV}}{\mathrm{d\θ}}+\frac{1}{k-1}V\frac{\mathrm{dp}}{\mathrm{d\θ}})\mathrm{d\θ}=\frac{1}{2}{Q}_{\mathrm{net}}$

CA50 draws by the upper limit of integral of asking above formula.

If $\frac{k}{k-1}p\frac{\mathrm{dV}}{\mathrm{d\θ}}+\frac{1}{k-1}V\frac{\mathrm{dp}}{\mathrm{d\θ}}$ Original is F (θ),

$F\left(\mathrm{CA}50\right)=F\left(0\right)+\frac{1}{2}{Q}_{\mathrm{net}}---\left(3\right)$

$\mathrm{CA}50=F^{-1}[F\left(0\right)+\frac{1}{2}{Q}_{\mathrm{net}}]---\left(4\right)$

In formula, Q _netfor the clean thermal discharge of fuel combustion, by calculating;

K is isentropic exponent, and heat enginnering general k is got constant 1.37;

P is cylinder pressure, is recorded by cylinder pressure sensor;

V is volume of cylinder, motor physical parameter;

θ is crank angle, is measured by corner marking instrument.

D, current actual CA50 and CA50 theoretical value are done relatively poor, and controlled the revised injection advance angle of output and then revise CA50 by PID, make actual CA50 infinite approach theory CA50 value, complete the correction to CA50.

Described microprocessor control flow process also comprises the steps:

E, that the theoretical injection advance angle that revised injection advance angle and ECU are sent does is relatively poor, when departure exceedes threshold value, judge that excessive abrasion appears in oil sprayer, the corresponding tutorial light of output signal control is opened, when departure do not exceed threshold value passing ratio integration circuit export revised fuel injection quantity, correction result send to Engine ECU carry out corrective action.

Embodiment 2

Cylinder of diesel engine internal pressure feed back control system of the present utility model comprises the each cylinder cylinder pressure of motor sensing device, burning feedback unit 3, oil spout wear control unit 4, corner marking instrument 5, tutorial light 6.Described cylinder presses sensing device to adopt the cylinder pressure sensor that output signal is voltage signal.As shown in Figure 3, burning feedback unit 3 adopts the hardware circuit (referring to Huang Ying application Tsing-Hua University Master of engineering academic dissertation " a new generation towards diesel combustion closed loop control controls study of platform and application ") being made up of signal processing module 31, burning calculation process module 32, power module 33, communication module 34.Each cylinder cylinder presses the charge amplifier of sensing device to be connected with the input of signal processing module 31 with corner marking instrument 5, and the output of communication module 34 is connected to oil spout wear control unit 4.Burning feedback unit 3 also can be realized by microprocessor.

As shown in Figure 4, oil spout wear control unit 4 is made up of CA50 correcting module and fuel injection quantity correcting module; CA50 correcting module in oil spout wear control unit 4 is made up of the first subtraction circuit 41, the first comparison operation circuit 42, PID control circuit 43; Fuel injection quantity correcting module is made up of the second subtraction circuit 44, the second comparison operation circuit 45, proportional integral circuit 46.

The output of burning feedback unit 3 and Engine ECU 7 is connected to the input of the first subtraction circuit 41, the output of the first subtraction circuit 41 is connected to the input of the first comparison operation circuit 42, actual CA50 and theoretical CA50 are done to poor comparison, and the output of comparative result is connected to the input of PID control circuit 43; The output of PID control circuit 43 and Engine ECU 7 is connected to the input of the second subtraction circuit 44, the output of the second subtraction circuit 44 is connected to the input of the second comparison operation circuit 45, actual fuel injection advance angle and theoretical injection advance angle are done to poor comparison, comparative result is exported by the second comparison operation circuit 45, this output is connected to tutorial light 6, comparative result exceed threshold value tutorial light be lit; The output of the second comparison operation circuit 45 is connected to the input of proportional integral circuit 46 simultaneously, comparative result is less than threshold value and carries out the fuel injection quantity after computing output adjustment by proportional integral circuit, the output of proportional integral circuit 46 is connected to the input of Engine ECU 7, by fuel injection quantity correction value input ECU.

Claims (5)

1. a cylinder of diesel engine internal pressure feed back control system, it is characterized in that comprising the each cylinder cylinder pressure of motor sensing device, burning feedback unit (3), oil spout wear control unit (4), corner marking instrument (5), tutorial light (6); Described each cylinder cylinder presses sensing device to be connected with the input of burning feedback unit (3) with corner marking instrument (5); The output of burning feedback unit (3) is connected to the input of oil spout wear control unit (4); The output of oil spout wear control unit (4) is connected to Engine ECU and tutorial light (6).

2. cylinder of diesel engine internal pressure feed back control system according to claim 1, is characterized in that described cylinder pressure sensing device comprises cylinder pressure sensor (1), charge amplifier (2); Cylinder pressure sensor (1) is the sensor of output charge signal, and its output is connected with the input of charge amplifier (2); The output of charge amplifier (2) is connected with the input of burning feedback unit (3).

3. cylinder of diesel engine internal pressure feed back control system according to claim 1, is characterized in that described cylinder pressure sensing device adopts the cylinder pressure sensor that output signal is voltage signal.

4. cylinder of diesel engine internal pressure feed back control system according to claim 1, is characterized in that described burning feedback unit (3) adopts microprocessor.

5. cylinder of diesel engine internal pressure feed back control system according to claim 1, is characterized in that described oil spout wear control unit (4) is made up of CA50 correcting module and fuel injection quantity correcting module; CA50 correcting module is made up of the first subtraction circuit (41), the first comparison operation circuit (42), PID control circuit (43); Fuel injection quantity correcting module is made up of the second subtraction circuit (44), the second comparison operation circuit (45), proportional integral circuit (46); The output of burning feedback unit and Engine ECU is connected to the input of the first subtraction circuit, and the output of the first subtraction circuit is connected to the input of the first comparison operation circuit, and the output of the first comparison operation circuit is connected to the input of PID control circuit; The output of PID control circuit and Engine ECU is connected to the input of the second subtraction circuit, and the output of the second subtraction circuit is connected to the input of the second comparison operation circuit, and the output of the second comparison operation circuit is connected to tutorial light; The output of the second comparison operation circuit is connected to the input of proportional integral circuit simultaneously; The output of proportional integral circuit is connected to the input of Engine ECU.