CN102102589A - Method for adjusting low-speed marine diesel engine electronic variable oil injection timing device - Google Patents

Abstract

The invention discloses a method for adjusting a low-speed marine diesel engine electronic variable oil injection timing device. The method comprises the following steps of: statically adjusting an input (I/P) pressure converter to make an input signal and an output signal of the converter meet certain linear relation; calculating Ki when the load of a diesel engine is 90 percent; and calculating Kc when the load of the diesel engine is 100 percent. By the method, the debugging efficiency and the reliability of an electronic video image terminal (VIT) are improved, a learner in the first stage can easily master the method, and the time for debugging the performance of the diesel engine is also shortened.

Description

A kind of low powered adjusting method of diesel engine electronic variable injection timing device

Technical field

The present invention relates to the low speed marine diesel engine, particularly relate to the adjusting method of a kind of low powered with diesel engine electronic variable injection timing device.

Background technique

Marine diesel engine generally adopts variable injection timing device (Variable InjectionTiming is hereinafter to be referred as VIT), according to the size of load, adjusts injection timing automatically, to improve the Economy of main frame operation, satisfies the fierce competitive market demand.Electronics VIT has been widely used in two stroke diesel engine peculiar to vessel because of the convenience and the reliability of its adjustment.The adjustment process of electronics VIT device has also just become diesel engine to debug requisite link.

Critical component I/P pressure converter in the electronics VIT device, its function mainly are that the current signal that controller is exported is converted to required air pressure signal of VIT implementation period, drive implementation period adjusting fuel pump, and end reaction is to the pressure of explosion Pmax that needs adjustment.Therefore, the adjustment of VIT system mainly is the linear relationship of adjusting between electric current and the pressure of explosion Pmax.Speed regulator is an auxiliary control appliance of marine diesel engine, and 4～20mA electric current of I/P pressure converter is by its setting.

For a long time; the adjustment content of electronics VIT device focuses on the solution procedure of Ki and Poffset; and ignored the adjustment of the critical component I/P pressure converter in the electronics VIT device, thereby the time regular meeting find the influence of compensate for ambient variation automatically of VIT device.

Summary of the invention

In order to overcome above-mentioned the deficiencies in the prior art, the invention provides the adjusting method of a kind of low powered, to improve the adjustment efficient and the reliability of electronics VIT device with diesel engine electronic VIT device.

The technological scheme that the present invention solves the problems of the technologies described above is as follows:

A kind of low powered comprises the steps: with the adjusting method of diesel engine electronic variable injection timing device

1. (the Z/R potentiometer is parts of I/P pressure converter inside to the Z/R potentiometer on the static adjustment I/P pressure converter, be used to regulate the pressure size), the input current signal of this I/P pressure converter and the linear relationship of output voltage signal are met the following conditions:

A) when set fuel oil quality by speed regulator detonation pressure is done the parameter value of adjusting, i.e. Poffset value, when making input current be minimum current 4mA signal, the delivery pressure of correspondence is 0.5bar, VIT tooth bar lattice number is 0;

B) when setting the Poffset value by speed regulator, when making input current be maximum current 20mA signal, corresponding delivery pressure is 5.0bar, and VIT tooth bar lattice number is a full scale;

2. when diesel engine moves to the turning point load:

A) set the Poffset value by speed regulator, making output current is I=4mA, measures the pressure of explosion Pmax of this moment ₀With compression pressure Pcom ₀, calculate Δ P ₀=Pmax ₀-Pcom ₀

B) set the Poffset value by speed regulator, make pressure of explosion reach specified maximum outbreak pressure value, or VIT tooth bar maximum scale, record output current I ₁, measure the pressure of explosion Pmax of this moment ₁With compression pressure Pcom ₁, calculate Δ P ₁=Pmax ₁-Pcom ₁

C) calculate $\mathrm{Ki}=\frac{I_1-4}{\mathrm{\&Delta;}{P}_1-\mathrm{\&Delta;}{\mathrm{<figure-callout\; id="0"\; label="P"\; filenames="HDA0000049075060000011.png,HDA0000049075060000012.png"\; state="\{\{state\}\}">P</figure-callout>}}_0};$

D) with the parameter pressure differential deltap P of speed regulator _kBe set at Δ P ₁-Δ P ₀

E) by speed regulator the Poffset value is made as 0 again, Ki is made as calculated value in the step c);

3. when diesel engine moves to load for MCR rated power 100%: measure compression pressure Pcom, the scavenging pressure Pscav of this moment, and calculate

4. the parameter K c of speed regulator is set at the calculated value of step in 3.;

5. measure the pressure of explosion Pmax of this moment ₂Satisfy specified pressure of explosion, VIT adjusts end.

The parameter K i of electronics VIT device is the corresponding relation of device output current and Pmax.Under the perfect condition, the Ki of diesel engine of the same type is consistent.Yet, all affect the linear relationship of electric current and Pmax directly or indirectly owing to the even part gap of existence, the plunger guide bush in the fuel pump of manufacturing tolerances and the factors such as cracking pressure of oil sprayer.Therefore in the debug process, we need readjust definite to the Ki of every diesel engine.

Compared with prior art, the invention has the beneficial effects as follows:

Because the inventive method adopts

Computational methods, the debugging efficiency of electronics VIT and reliability are improved.Average every machine diesel engine electronic VIT performance adjustment saving of time 1.5 hours, approximately can be saved 30,000 yuans by about 20,000 pieces/hour according to the test run cost of present 6S60MCC machine.Make the beginner be easy to grasp, shorten the time of diesel engine performance debugging simultaneously.

Description of drawings

Fig. 1 is the low powered of the present invention input current of I/P pressure converter in the diesel engine electronic VIT device and the linear relationship schematic representation of delivery pressure.

Fig. 2 is the linear relationship schematic representation of low powered of the present invention with diesel engine electronic VIT device output current and pressure of explosion.

Embodiment

The invention will be further described below in conjunction with embodiment and accompanying drawing, but should not limit protection scope of the present invention with this.

Embodiment 1: with the 7S60MCC type is example, and the configuration and the performance parameter of a two-stroke low speed marine diesel engine are as follows: when 7S60MCC-85# type 90% and 100% load, surveying specified maximum outbreak pressure value is 163bar.

The adjusting method of this two-stroke low speed marine diesel oil organic electronic VIT device comprises the steps:

1. the static Z/R potentiometer of adjusting on the I/P pressure converter meets the following conditions the linear relationship (as shown in Figure 1) of the input current signal and the output voltage signal of this I/P pressure converter:

A) when set fuel oil quality by speed regulator detonation pressure is done the parameter value of adjusting, i.e. Poffset value, when making input current be minimum current 4mA signal, the delivery pressure of correspondence is 0.5bar, VIT tooth bar lattice number is 0;

B) when setting the Poffset value by speed regulator, when making input current be maximum current 20mA signal, corresponding delivery pressure is 5.0bar, and VIT tooth bar lattice number is a full scale 9;

2. move to turning point load promptly during 90% load, (output current of electronics VIT device and the linear relationship of pressure of explosion are as shown in Figure 2) when diesel engine:

A) set the Poffset value by speed regulator, making output current is I=4mA, measures the pressure of explosion Pmax of this moment ₀=145bar and compression pressure Pcom ₀=140bar calculates pressure differential deltap P ₀=Pmax ₀-Pcom ₀=5bar;

B) set Poffset value by speed regulator, when making pressure of explosion reach specified maximum outbreak pressure value 163bar, write down output current I ₁=14.6mA, the pressure of explosion Pmax of this moment ₁=163bar measures compression pressure Pcom ₁=131bar calculates pressure differential deltap P ₁=Pmax ₁-Pcom ₁=32bar;

C) calculate the ratio that electric current changes and detonation pressure changes:

$\mathrm{Ki}=\frac{I_1-4}{\mathrm{\&Delta;}{P}_1-\mathrm{\&Delta;}{\mathrm{<figure-callout\; id="0"\; label="P"\; filenames="HDA0000049075060000011.png,HDA0000049075060000012.png"\; state="\{\{state\}\}">P</figure-callout>}}_0}=0.39\mathrm{mA}/\mathrm{bar};$

D) with the parameter Δ P of speed regulator _kBe set at Δ P ₁-Δ P ₀=32-5=27bar;

E) by speed regulator the Poffset value is made as 0 again, Ki is set at 0.39mA/bar;

3. move to load greater than turning point load promptly during 100% load when diesel engine: measure compression pressure Pcom=145bar, the scavenging pressure Pscav=27bar of this moment, and calculate the ratio of compression pressure and scavenging pressure:

Bar abS/barabs;

4. the parameter K c with speed regulator is set at 37.4;

5. measure the Pmax of this moment ₂=163bar satisfies specified maximum outbreak pressure, and VIT adjusts end.

The results showed that low powered of the present invention is improved its debugging efficiency and reliability with the adjusting method of diesel engine electronic variable injection timing device, shorten the time of diesel engine performance debugging simultaneously, the beginner is easy to grasp.

Claims (1)

1. the adjusting method of a low powered usefulness diesel engine electronic variable injection timing device is characterized in that this method comprises the steps:

1. the static Z/R potentiometer of adjusting on the I/P pressure converter meets the following conditions the input current signal of this I/P pressure converter and the linear relationship of output voltage signal:

A) when setting the Poffset value by speed regulator, when making input current be minimum current 4mA signal, corresponding delivery pressure is 0.5bar, and VIT tooth bar lattice number is 0;

B) when setting the Poffset value by speed regulator, when making input current be maximum current 20mA signal, corresponding delivery pressure is 5.0bar, and VIT tooth bar lattice number is a full scale;

2. when diesel engine moves to the turning point load:

A) set the Poffset value by speed regulator, making output current is I=4mA, measures the pressure of explosion Pmax of this moment ₀With compression pressure Pcom ₀, calculate pressure differential deltap P ₀=Pmax ₀-Pcom ₀

B) set Poffset value by speed regulator, make pressure of explosion reach the maximum value of permission, or VIT tooth bar maximum scale, output current I write down ₁, measure the pressure of explosion Pmax of this moment ₁With compression pressure Pcom ₁, calculate pressure differential deltap P ₁=Pmax ₁-Pcom ₁

C) calculate $\mathrm{Ki}=\frac{I_1-4}{\mathrm{\&Delta;}{P}_1-\mathrm{\&Delta;}{P}_0};$

D) with the parameter pressure differential deltap P of speed regulator _kBe set at Δ P ₁-Δ P ₀

E) by speed regulator the Poffset value is made as 0 again, Ki is made as calculated value in the step c);

3. when diesel engine moves to load and loads greater than turning point: measure compression pressure Pcom, the scavenging pressure Pscav of this moment, and calculate

4. the parameter K c of speed regulator is set at the calculated value of step in 3.;

5. measure the pressure of explosion Pmax of this moment ₂Satisfy specified pressure of explosion, VIT adjusts end.

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