JPH01155074A - Ignition timing controller for engine - Google Patents

Abstract

PURPOSE:To make it controllable to optimum ignition timing in response to a variation in the request ignition timing of an engine by controlling it to the ignition timing at the timing delay side according to an exhaust system temperature state at the time of more than the setting engine speed. CONSTITUTION:At a high speed range of more than the setting engine speed, it is controlled to ignition timing at the more timing delay side than the specified ignition timing according to an exhaust gas temperature state of an engine, subject to detection of an exhaust gas temperature sensor 14 by a control circuit. With this control, in a running state at a high speed range, when the ignition timing demanded by an engine 2 is varied by cooling (12) of an exhaust pipe 8, it is controllable to the optimum ignition timing conformed to this variation, so that abnormal combustion due to pre-ignition is preventable. With this constitution, any variations in output attributable to a change in the ignition timing due to the cooling of the exhaust pipe 8 is also preventable, and thus stable output is securable.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an engine ignition timing control device, and particularly to an engine ignition timing control device that controls engine ignition timing by cooling the exhaust system of the engine when the engine is running at a high rotation speed above a set rotation speed. The present invention relates to an engine ignition timing control device that can control the optimum ignition timing in response to changes in the required ignition timing, thereby preventing fluctuations in output due to cooling of the engine exhaust system.

[Conventional technology]

An engine has the best ignition timing that matches various conditions such as its operating state and the air-fuel ratio of the air-fuel mixture. In order to satisfy the optimum ignition timing required by such an engine, an ignition timing control device is provided. These ignition timing control devices include those that mechanically control the ignition timing based on engine speed, intake pipe pressure, etc., and those that electrically control the ignition timing using various sensors.

[Problem to be solved by the invention] By the way, it is known that in high-output engines, if the ignition timing is controlled to the retarded side in the high rotation range above the set rotation speed, the output increases. The amount of retardation at this time is controlled by the engine speed. When controlling the ignition timing to the retarded side in such a high rotation range, the ignition timing required by the engine on the retarded side is influenced by the temperature of the exhaust gas flowing through the exhaust pipe of the engine.

Therefore, as disclosed in Japanese Patent Application Laid-Open No. 62-70660, an optimum exhaust gas temperature that produces the maximum torque corresponding to the engine speed is created and stored in advance, and the actual exhaust gas temperature is adjusted to this optimum exhaust gas temperature. It has been proposed to control the ignition timing to the retarded side in a high rotational speed range above the maximum torque rotational speed so that the gas temperature approaches.

However, the technology disclosed in this publication increases the temperature of exhaust gas by controlling the ignition timing to the retarded side in the high rotation range in order to bring the actual exhaust gas temperature closer to the optimum exhaust gas temperature. It is. Therefore, what is disclosed in this publication actively controls the ignition timing to the retarded side according to the exhaust system temperature state, for example, the exhaust gas temperature, in order to obtain the best ignition timing required by the engine in the high rotation range. It's not a thing.

For this reason, in the high rotation range above the set rotation speed - When the vehicle is running, the cooling condition of the exhaust pipe through which exhaust gas flows changes due to changes in the running condition of the vehicle, which causes the exhaust gas temperature to change. When the ignition timing changes due to this, there is a problem that the ignition timing cannot be controlled to the best ignition timing required by the engine, and as a result, the output characteristics fluctuate and the output decreases.

[Purpose of the invention]

Therefore, an object of the present invention is to control the ignition timing of an engine to a predetermined ignition timing depending on the engine rotation speed, and to control the ignition timing to be retarded than the predetermined ignition timing according to the engine exhaust system temperature condition at the engine rotation speed or higher. By controlling the ignition timing, it is possible to control the ignition timing to the best possible value in response to changes in the ignition timing required by the engine due to cooling of the engine exhaust system during running conditions in a high rotation range above the set rotation speed, Thereby, an object of the present invention is to realize an engine ignition timing control device that can prevent fluctuations in output due to cooling of the engine exhaust system.

[Means for solving problems]

In order to achieve this object, the present invention provides a rotation speed sensor that detects the rotation speed of the engine, an exhaust system temperature state sensor that detects the exhaust system temperature state of the engine,
The ignition timing of the engine is controlled to a predetermined ignition timing based on the engine rotation speed detected by the engine rotation speed sensor, and when the engine rotation speed is higher than the set rotation speed, the ignition timing is controlled to the predetermined ignition timing according to the engine exhaust system temperature state detected by the exhaust system temperature state sensor. The present invention is characterized in that a control means is provided for controlling the ignition timing to be retarded than the ignition timing.

[Effect]

According to the configuration of the present invention, the control means controls the ignition timing of the engine to a predetermined ignition timing based on the engine rotational speed detected by the rotational speed sensor, thereby controlling the ignition timing to the ignition timing required by the engine.

The control means controls the ignition timing of the engine to be retarded than the predetermined ignition timing in accordance with the engine exhaust system temperature state detected by the exhaust system temperature state sensor when the engine speed exceeds the set rotation speed. As a result, the ignition timing is controlled to the best possible value in response to changes in the ignition timing required by the engine due to cooling of the engine exhaust system when running in a high rotation range above the set rotation speed. Prevents output fluctuations due to cooling.

〔Example〕

Next, embodiments of the present invention will be described in detail based on the drawings.

1 to 3 show embodiments of this invention. In FIG. 3, 2 is an engine, 4 is a carburetor, 6 is a spark plug, 8 is an exhaust pipe, and 10 is a motorcycle, which is a vehicle.

An engine 2 mounted on a motorcycle 10, which is a vehicle, is supplied with a mixture generated by, for example, a carburetor 4, ignited by a spark plug 6 to combust the mixture, and exhaust gas generated by the combustion through an exhaust pipe 8. While discharging to the outside,
The generated thermal energy is converted into mechanical energy and extracted, and the motorcycle 10 is driven.

The engine 2 is provided with a rotation speed sensor 12 that detects the engine rotation speed N. The rotational speed sensor 12 detects the engine rotational speed N from the rotational state of a crankshaft (not shown) of the engine 2, for example. Further, the engine 2 is provided with an exhaust gas temperature sensor 14 that detects the temperature state of exhaust gas flowing through the exhaust pipe 8 as an exhaust system temperature state sensor that detects the exhaust system temperature state.

A control circuit 16 is provided as a control means for inputting detection signals from the rotational speed sensor 12 and exhaust gas temperature sensor 14 and controlling the ignition timing as described later.

As shown in FIG. 1, an ignition circuit 18 is connected to the output side of the control circuit 16, and the ignition plug 6 is connected to the ignition circuit 18.

As a result, as shown in FIG. 2, the control circuit 16 controls the ignition timing of the engine 2 to a predetermined ignition timing AM based on the engine rotation speed N detected by the rotation speed sensor 12, and also In the rotation range, the ignition timings A1 to AE are controlled to be retarded than the predetermined ignition times 11' and 11AM, depending on the exhaust gas temperature state of the engine 2 detected by the exhaust gas temperature sensor 14.

Next, the operation will be explained according to FIG.

When the engine 2 is driven, signals are input to the control circuit 16 from the rotation speed sensor 12 and the exhaust gas temperature sensor 14 . The control circuit 16 sets the ignition timing to a predetermined ignition timing A based on the signal of the engine rotation speed N input from the rotation speed sensor 12.
1. control to l. Thereby, the control circuit 16 outputs a signal to the ignition circuit 18 to cause the spark plug 6 to spark at the predetermined ignition timing AM, thereby satisfying the ignition timing required by the engine 2.

When the rotational speed N of the engine 2 is increased and the motorcycle 10 is run in a high rotational speed range equal to or higher than the set rotational speed Ns, the exhaust pipe 8 through which exhaust gas flows changes as the running condition of the motorcycle 10 changes. The ignition timing changes as the cooling condition changes and the exhaust gas temperature changes. For this reason, there is an inconvenience in that it is not possible to control the ignition timing to the optimum ignition timing required by the engine 2, and as a result, there is an inconvenience in that the output characteristics fluctuate, resulting in a decrease in output due to the fluctuation in output.

Therefore, in the high rotation range of the set rotation speed Ns or more, the control circuit 16 controls the ignition timing A1 to be retarded than the predetermined ignition timing AM according to the exhaust gas temperature state of the engine 2 detected by the exhaust gas temperature sensor 14. - Control to A3. That is, when the rotation speed is higher than the set rotation speed Ns, the ignition timing A is retarded from the predetermined ignition timing Ao in accordance with the rise in exhaust gas temperature.
The ignition circuit 18 is sequentially retarded and controlled from 1 to A'3.
A signal is output to cause the spark plug 6 to spark at the retarded ignition timings A1 to A3.

As a result, when the ignition timing required by the engine 2 changes due to cooling of the exhaust pipe 8 in a driving state in a high rotation range of the set rotation speed Ns or more, the control circuit 16 adjusts the ignition timing to the optimum ignition timing in response to this change. Since the timing can be controlled, abnormal combustion due to early ignition can be prevented. Further, this makes it possible to prevent fluctuations in output due to changes in ignition timing due to cooling of exhaust pipe 8, and to obtain stable output.

In this embodiment, the temperature of the exhaust gas is detected as the exhaust system temperature state to control the ignition timing, but the ignition timing can also be controlled by detecting the surface temperature of the exhaust pipe 8.

〔Effect of the invention〕

As described above, according to the present invention, by controlling the ignition timing of the engine to a predetermined ignition timing using the engine rotation speed detected by the rotation speed sensor, the ignition timing required by the engine can be satisfied. can.

The control means controls the ignition timing of the engine to be retarded than the predetermined ignition timing in accordance with the engine exhaust system temperature state detected by the exhaust system temperature state sensor when the engine speed exceeds the set rotation speed. As a result, it is possible to control the ignition timing to the best possible value in response to changes in the ignition timing required by the engine due to cooling of the engine exhaust system when driving in a high rotation range above the set rotation speed, and to prevent abnormal combustion due to premature ignition. In addition, it is possible to prevent fluctuations in output due to changes in ignition timing due to cooling of the engine exhaust system, thereby making it possible to obtain stable output.

[Brief explanation of the drawing]

1 to 3 show embodiments of this invention, and the first
FIG. 2 is a block diagram of the ignition timing control device, FIG. 2 is a diagram showing the relationship between engine speed and ignition timing, and FIG. 3 is a schematic configuration diagram of an engine mounted on a motorcycle. In the figure, 2 is an engine, 4 is a carburetor, 6 is a spark plug, 8 is an exhaust pipe, 10 is a motorcycle, 12 is a rotation speed sensor, 14 is an exhaust gas temperature sensor, 16 is a control circuit, 18
is the ignition circuit. Patent applicant Suzuki Automobile Industry Co., Ltd.

Claims (1)

[Claims] A rotation speed sensor is provided to detect the rotation speed of the engine, an exhaust system temperature state sensor is provided to detect the exhaust system temperature state of the engine, and the ignition timing of the engine is determined by the engine rotation speed detected by the engine rotation speed sensor. Control means is provided for controlling the ignition timing and for controlling the ignition timing to be retarded than the predetermined ignition timing in accordance with the exhaust system temperature state of the engine detected by the exhaust system temperature state sensor when the engine speed exceeds a set rotation speed. An engine ignition timing control device characterized by: