JPS61167135A - Knocking controller - Google Patents

Abstract

PURPOSE:To nicely evade knocking while trying to improve air consumption by setting limit opening of a throttle valve depending on the state of atmo sphere, so as to enable knocking to be prevented. CONSTITUTION:The maximum opening of a throttle valve 2 for preventing knocking is operated by a controller 3, with engine speed as parameter, depending on the state of atmosphere detected by a temperature detecting sensor St, a humidity detecting sensor Sh and an atmospheric pressure detecting sensor Sp. A step motor 4 is operated by output of the controller 3, and the throttle valve 2 is set to the maximum opening less wide than the full opening position.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine knock control device.

In general, engine matching (air-fuel ratio A/F).

It is desirable to optimize the ignition timing (ignition timing) according to atmospheric conditions such as temperature, humidity, and atmospheric pressure.In recent years, with the rapid development of electronic control technology, it has become possible to realize such technical issues. be. However, if we focus on when the engine is under high load, knocking tends to occur at high loads, so it is recommended to make the air-fuel ratio A/F a little richer and the ignition timing a little retarded. This setting places emphasis on preventing knocking. Making the air-fuel ratio a bit rich and making the ignition timing a bit retarded will also lead to deterioration of fuel efficiency and the like.

The present invention has been made in view of the above points, and an object of the present invention is to provide a knocking control device that can effectively avoid knocking regardless of atmospheric conditions and can improve fuel efficiency. shall be.

The present invention will be explained below based on one embodiment.

In FIG. 1, reference numeral 1 indicates an engine body, 2 a throttle valve, 3 a control device, and 4 a step motor as an example of a throttle valve driving device. Further, 8 indicates a temperature detection sensor, SH indicates a humidity detection sensor, and Sp indicates a pressure detection sensor, and the atmospheric condition is detected by each of these detection sensors.

The knocking control device of this embodiment uses the engine rotational speed as a parameter to determine the maximum opening degree of the throttle valve 2 on the fully open side to prevent knocking, in accordance with the atmospheric conditions detected by each of the detection sensors described in section 2. , is processed by the control device 3, and the step motor 4 is actuated by the output of the control device to set the throttle valve 2 to the limit opening degree, which is closer to the fully open position than this position.

FIG. 2 shows a characteristic curve of the throttle valve fully open limit opening degree using the engine speed as a parameter. The solid line indicates ideal atmospheric conditions (high humidity,
This is a characteristic curve when the temperature is low (temperature is low). For example, in the speed increasing region after around Nl RPM, the throttle valve 2 is fully open (100
%). As an example, if we look at humidity and consider water vapor as an inert gas, when the humidity is high, knocking tends to be inhibited. Therefore, when the humidity is low, knocking tends to occur easily, and among atmospheric conditions, humidity in particular is the factor that has the most influence on knocking. The dashed line is the characteristic curve in winter (low humidity and low temperature). These characteristic curves are created by varying the atmospheric conditions using the engine speed as a parameter and plotting the critical throttle valve opening value at which knocking occurs or not. From the characteristic curve obtained in this way, it can be seen that knocking is more likely to occur in winter than in summer, and that knocking is more likely to occur at low rotation speeds.

FIGS. 3, 4, and 5 are coefficient maps relating to temperature, humidity, atmospheric pressure, etc., which are obtained based on various characteristic curves as described above. FIG. 6 is a schematic control flow relating to this knocking control device.

In FIG. 6, first, the atmospheric condition at the relevant time point is detected by the temperature detection sensor s-r, humidity detection sensor S) (and atmospheric pressure detection sensor Sp) shown in FIG. 1. Next, the coefficients are called from each coefficient map. .

Here, assuming that it is now winter, the temperature at this point in time is low, T□°C1, and the humidity is also low, H1%. T□ is selected from the temperature coefficient map in FIG. 3, and the temperature coefficient KT at the N1 rotation is called as 0.95. , Hl is selected from the humidity coefficient map in FIG. 4, and the humidity coefficient KH at the time of N□ rotation is called as 0.90. moreover,
From the atmospheric pressure coefficient map in Figure 5, the atmospheric pressure P2 at the relevant time point is
is selected, and the pressure coefficient Kp during N rotation is 0.9.
Called as 9.

Here, when each coefficient at the time of N□ rotation is tabulated, it is as follows.

Temperature coefficient KT...0.95 Humidity coefficient KH...0.90 Pressure coefficient Kp...0.99 Using the above values, determine the upper limit e max of the throttle valve 2 opening. calculate. The calculation formula is as follows.

In this equation, θbase is the opening degree of the throttle valve under ideal atmospheric conditions in which knocking in FIG. 2 is less likely to occur.

emax=niding X K)l X Kp X0
baseθbase is at the time of N0 rotation in Fig. 2,
], so if we include this value and each coefficient value above, we get
It will look like this:

θmax=o, 95X0.90X0.99X 1 now 0.
85 e max is 0.85, which means that the throttle valve is closed by 15% compared to fully open (100%). That is, in the winter characteristic curve shown in FIG. 2, the throttle valve is set at the limit opening of 85% of the fully open position at Nl RPM, which is closer to the fully open position. This setting is performed regardless of whether the accelerator pedal is depressed. Characteristic surface # shown in Figure 2
J% (one-dot chain line or two-dot chain line) is calculated by plotting the characteristic value of whether or not knocking occurs while cross-correlating variable factors such as temperature, humidity, and atmospheric pressure with the engine speed as a parameter. , can be created in large numbers.

In addition, in the knocking control device of the present invention, since the throttle valve is controlled in the direction of closing, the engine output will be reduced to some extent. ), it is also possible to control the throttle valve to open more than the limit opening.

As described above, according to the present invention, the limit opening of the throttle valve is set according to the atmospheric condition using the engine speed as a parameter so as to prevent knocking, so that knocking can be prevented regardless of the season. In addition to providing comfortable drivability, the air-fuel ratio is slightly richer,
Alternatively, there is no need to delay the ignition timing, and as a result, thermal efficiency is improved and fuel efficiency can be significantly improved.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the device according to the embodiment of the present invention, Fig. 2 is a diagram showing the throttle valve fully open limit opening characteristic curve, Figs. 3 to 5 are coefficient maps relating to temperature, humidity, and atmospheric pressure.
The figure is a schematic control flow diagram of the apparatus of the above embodiment. 2... Throttle valve, 3... Control device, 4...
・Step motor for throttle valve drive, 8 teeth...
Temperature detection sensor, SH...Humidity detection sensor, Sp...
・Atmospheric pressure detection sensor.

Claims (1)

[Claims] The system inputs the engine throttle valve, a detection sensor that detects atmospheric conditions such as temperature, humidity, and atmospheric pressure, and the detection signal from the sensor, and prevents knocking by using the engine speed as a parameter according to the atmospheric condition at the time. a control device for calculating the fully open side limit opening of the throttle valve; and a throttle for setting the throttle valve to a limit opening that is closer to the fully open position than the fully open position, based on the output of the control device. A knocking control device equipped with a valve drive device.