JPS62276270A - Ignition timing controller for engine - Google Patents

Abstract

PURPOSE:To secure combustion stabilization at the time of engine low temperature, by installing a timing delay prohibiting device which prohibits any operation of timing delay control at a time when engine temperature is low as receiving output of an engine temperature detecting device. CONSTITUTION:In this controller, there are provided with an engine temperature detecting device 108 detecting the extent of engine temperature and a timing delay prohibiting device 109 which receives the output and prohibits any operation of a timing delay controlling device 107 at the time of engine low temperature. Therefore, when a fact that engine temperature is low is detected by the engine temperature detecting device 108, timing delay control by the timing delay controlling device 107 is prohibited by the timing delay prohibiting device 109 so that combustion is stabilizable. At the time of engine low temperature when prohibiting this timing delay control, since a combustion speed is originally slow and quiet, the wosening of cab noises due to the timing delay control prohibition is little. Accordingly, combustion stabilization is securable at the time of engine low temperature while reducing combustion noises.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (Field of Industrial Application) The present invention sets the ignition timing based on the operating state of the engine, and also applies the set ignition timing to the This invention relates to an ignition timing control device for an engine that performs retard control when the engine is in a low gear position.

(Prior art) In general, in engine ignition timing advance control, the ignition timing is advanced so that maximum output can be obtained with emphasis on fuel efficiency. Although this improves fuel efficiency, the engine shakes! ! lJ
@The sound level becomes higher.

By the way, engine noise becomes a problem when the transmission is in low gears (1st, 2nd, and 3rd) and when it is in high gears (4th and 5th). This is unlikely to be a problem (see Figure 4). Therefore, a means to detect the state of the low speed gear is provided.

A system has been proposed that uses this detection output to delay the ignition timing from the optimum ignition timing that yields maximum output, thereby reducing combustion noise, thereby minimizing deterioration of fuel efficiency, and improving engine noise inside the car. (See, for example, Japanese Patent Laid-Open No. 165771/1983).

(Problems to be Solved by the Invention) However, in the above-mentioned engine, there is a problem in that car knock is likely to occur when the engine temperature is low. That is, when the engine temperature is low, the temperature of the intake manifold is low, fuel is difficult to atomize, and a large amount of fuel propagates on the wall surface of the intake manifold as droplets, resulting in poor distribution between cylinders. Further, since the intake air temperature is low and the combustion chamber temperature is also low, it is difficult to ignite the engine, but by delaying the ignition timing, combustion becomes unstable and, in some cases, there is a risk of misfire. For this reason, the 0th and 5th order components due to combustion become large, and this causes resonance in the V dynamic system, resulting in car knock.

The present invention has been made in view of this point, and can be achieved without impairing combustion stability at low engine temperatures.

The purpose is to reduce combustion noise.

(Means for Solving the Problems) The configuration of the present invention for achieving the above object will be explained based on FIGS. 1 and 2, which correspond to embodiments.

The present invention provides an operating state detecting means 101 for detecting the operating state of the engine, for example, a first cylinder compression TOP position detecting means 10.
2 (crank angle sensor 8), engine rotation speed detection means 1
03, a throttle opening detection means 104 (throttle sensor 5), an ignition timing setting means 105 that receives the output of the operating state detection means 101 and sets the ignition timing, and a transmission 7.
and shift position detection means 106 for detecting the shift position.

The ignition timing control device for an engine is assumed to have a retard control means 107 which receives the output of the shift position detection means 106 and retards the ignition timing when the gear is in a low speed gear position.

The present invention further includes an engine temperature detection means 108 (cooling water temperature sensor 9) for detecting the engine temperature, and a retard angle control means 107 that receives the output of the engine temperature detection means 108 and prohibits the operation of the retard control means 107 when the engine temperature is low. Prohibited means 10
9.

(Operation) When the engine temperature detecting means 108 detects that the engine is at a low temperature, the retardation inhibiting means 109 prohibits the retardation control by the retardation control means 107, thereby stabilizing combustion. At low engine temperatures, when this retard control is prohibited, the combustion speed is slow and quiet, so
The deterioration of interior noise due to prohibition of retard control is small.

(Example) Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, 1 is a four-cylinder engine, 2 is an intake manifold, 3 is an exhaust manifold, 4 is a throttle valve disposed at the gathering part of the intake manifold 2, and 5 is a throttle that detects the opening degree of the throttle valve 4. A sensor 6 is a shift j~position upper position that detects the gear position of the transmission 7, 8 is a crank angle sensor, 9 is a coolant temperature sensor that detects the temperature of engine coolant, and 10 is an igniter 11 and a power distributor 12. In the ignition device, each spark plug 13a, 13
b.

Controls the ignition timing of 13e and 13d.

14 is a control unit, which includes a throttle sensor 5,
The ignition timing for each cylinder is set based on the output of the crank angle sensor 8 and the engine speed sensor (not shown) that detects the engine speed, and the ignition timing control signal is sent to the ignition device 1.
ignition timing setting means 105 that outputs an output to zero, and retard control means 107 that receives the output of the shift position sensor 6 and retards the ignition timing when the ignition timing is in a low speed gear position (first speed, second speed, or third speed position). has. Further, the retard control operation of the retard control means 107 is prohibited when the engine coolant temperature is lower than the set temperature in response to the output of the coolant temperature sensor 9, and the retard control is performed even when the engine is in a low gear position. It also has a retard prohibition means 109 for preventing this from occurring.

Next, the flow of processing of the control unit 14 will be explained with reference to FIG. 3.

First, when starting, the operating status of the engine is read. That is, the first cylinder TOP position is read in response to the output of the crank angle sensor 8 serving as the first cylinder TOP position detection means (step St), the engine rotation speed is read in response to the output of the rotation speed sensor (step S2), The throttle opening is read in response to the output of the throttle sensor 5 serving as a throttle opening detection means (step S3).

Based on the first cylinder TOP position, engine speed and throttle opening read in this way, MBT (
minimum 5park Advance
for Be5t.

Torque) based on the ignition timing (■ in Figure 3)
(displayed as g, T) on the map (Ig, Timing ma
p) to determine (step S4).

Then, upon receiving the output of the shift position sensor 6 as a shift position detection means, the gear position 1sh is read (step S5), and based on this, it is determined whether the gear position sh is lower than the third speed (step S5). S6).

When in the low gear position, the engine coolant temperature Tw is read in response to the output of the coolant temperature sensor 9 as an engine temperature detection means (step S?), and this is the set water temperature T.
It is determined whether or not the engine is at a high temperature higher than WO (for example, 40 to 60 degrees Celsius) (step S6), and when the engine is at high temperature, the ignition timing is retarded by 15 degrees to reduce combustion noise (step S59). When the temperature is low, the combustion variation between cylinders is large and car knock is likely to occur. Therefore, the ignition timing determined in step S4 is maintained without retarding, and the ignition timing signal (Ig.

T signal) is output to the ignition device 10 (step 5ro)
- On the other hand, when the gear position is on the high speed side, first step Sr+ is performed to determine whether or not the gear position sh is the fifth speed.
), when in 5th gear, adjust the ignition timing by 5° to improve output.
If not, a predetermined ignition timing signal is output without advancing the ignition timing (step S+o).

It has been confirmed that the noise inside the car changes as shown in the table below.

From the table above, it can be seen that the noise inside the vehicle is reduced when the vehicle is in low gear (first, second, and third).

In the above embodiment, when the gear is in a low speed gear position, the angle is retarded regardless of the load.

When the boost pressure is at a low load equal to or higher than the set pressure, there are few charging intervals and combustion is not rapid, so the timing may be retarded only at high loads equal to or higher than the set load.

(Effects of the Invention) As described above, the present invention inhibits the retard control for reducing combustion noise when the engine temperature is low, thereby reducing combustion noise and improving combustion stability at low engine temperatures. Can be secured.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention. Fig. 1 is an overall configuration diagram of an engine ignition timing control device, Fig. 2 is a block diagram of an ignition timing control system including a control unit, and Fig. 3 is a block diagram of an ignition timing control system including a control unit. FIG. 4 is a flowchart showing the process flow, and is a diagram showing the relationship between vehicle speed and vehicle interior noise using gear position as a parameter. ■・・・Engine, 5...Throttle sensor, 6...Shift position sensor, 8...
・Crank angle sensor, 9...Cooling water temperature sensor,
10...Ignition device, 14...Control unit, lOl...i Dry m detection means,
105... Ignition timing setting means, 106...
...Shift position detection means, 107...Retard angle control means, 108...Engine temperature detection means, 10
9...Means for inhibiting retardation. Ko 1 figure also 3 solid

Claims (1)

[Claims] (1) an operating state detecting means for detecting the operating state of the engine; an ignition timing setting means for receiving the output of the operating state detecting means and setting the ignition timing based on the operating state of the engine;
Detecting engine temperature in a device having a shift position detecting means for detecting a gear position of a transmission, and a retard control means for receiving an output of the shift position detecting means and retarding ignition timing when the gear is in a low speed gear position. engine temperature detection means;
An ignition timing control device for an engine, comprising: a retard inhibiting means for receiving an output from the engine temperature detecting means and inhibiting operation of the retard controlling means when the engine temperature is low.