JPS5943506Y2 - Ignition timing control device for supercharged engines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for controlling the ignition timing of an internal combustion engine equipped with a supercharger in accordance with air supply.

This type of device has already been published in Japanese Patent Application Laid-open No. 54-109534 (
It was published in Japanese Patent Application No. 16443/1983 (hereinafter referred to as the prior application).

In this prior application, in an engine that has a turbocharger upstream of a throttle valve, the port is connected to the port by mocha, which is located upstream when the throttle valve is fully closed and downstream when the throttle valve is fully closed. When the port is under negative pressure, the ignition timing is advanced, and when the port is under positive pressure, the ignition timing is retarded.

By the way, as a supercharged engine, in addition to one in which a supercharger is provided on the upstream side of a throttle valve as in the prior application, there are also those in which a supercharger is provided on the downstream side of a throttle valve.

However, when the ignition timing control device of the earlier application is adopted for a supercharged engine such as the latter, the following problems occur.

First, if there is a throttle valve upstream of the supercharger, the mocha appearing at the port is always only negative pressure, so supercharging occurs and the ignition timing must be controlled to the retarded side. Even in this case, the ignition timing is advanced to 11, which can easily cause knocking.

In view of these problems, an object of the present invention is to provide an ignition timing control device suitable for use in an engine in which a throttle valve is provided upstream of a supercharger.

To achieve this purpose, the present invention senses the negative pressure in a port that is located upstream when the throttle valve is fully closed and downstream when the throttle valve is opened to a predetermined degree. In the above cases, a supply air valve is provided on the downstream side of the turbocharger, and in other cases, a sensing valve is provided that outputs atmospheric pressure, and the advance angle is controlled according to the supplied negative pressure.
A controller is provided for retarding the ignition timing in accordance with the supplied positive pressure, and the output of the sensing valve is supplied to the controller to advance or retard the ignition timing.

According to the present invention, the ignition timing of an engine in which a supercharger is provided downstream of a throttle valve can be optimally controlled according to the load state and supercharging state of the engine.

Hereinafter, an example of the illustrated embodiment of the present invention will be described in detail.

FIG. 1 is a schematic diagram of an embodiment of the present invention, in which a supercharger 2 is provided in an air supply/exhaust passage 7.8 of an engine 3.

The throttle valve 1 is located in the carburetor 9 on the upstream side of the air supply path 7 from the supercharger 2.

As is well known, the supercharger 2 includes a turbine 21 disposed in an exhaust passage 8 and a compressor 22 disposed in an air supply passage 7.
The exhaust gas energy drives the turbine 21, and the compressor 22 driven together with the turbine 21 supercharges the air-fuel mixture to the engine 3.

A port 4 bored in the side wall of the carburetor 9 is located on the upstream side when the throttle valve 1 is fully closed, and on the downstream side when the throttle valve 1 is fully opened, and communicates with the pressure chamber 51 of the pressure sensitive valve 5. has been done.

The pressure-sensitive valve 5 includes a diaphragm 53 that defines a pressure chamber 51 together with a housing 52, and the diaphragm 53 integrally fixes a valve body 54.

Further, the nozzling 52 defines the valve chamber 55, and the valve chamber 5
5 has three po) 56, 57, 58 formed.

Then, the port 56/I'i is connected to the controller 6, which will be described later.
Port 57 is connected to the atmosphere via filter 59, port 58
are in communication with ports 10 bored in the side wall of the air supply path 1 on the downstream side of the supercharger 2, respectively.

In the pressure sensitive valve 5, the spring 60 presses the valve body 54 against the port 58 and blocks communication between the valve chamber 55 and the port 10 while negative pressure is not supplied to the pressure chamber 51.

Therefore, at this time, the ports 56 and 57 communicate with each other via the valve chamber 55, and the controller 6 is supplied with atmospheric air via the filter 59.

When a negative pressure of a predetermined value or more is supplied to the broken pressure chamber 51,
The diaphragm 53 moves against the pressure of the spring 60 to close the pressure chamber 51.
The valve body 54 also moves upward in the drawing to block the port 57 and close the port 58 to the valve chamber 5.
Connect to 5.

Therefore, at this time, the ports 56 and 58 are connected to the valve chamber 55.
The supply air of the port 10 is supplied to the communication controller 6 via the communication controller 6.

The controller 6 then has a pressure chamber 61 which is supplied with the output of the pressure-sensitive valve 5 and is defined by a housing 62 and a diaphragm 63.

The diaphragm 63 has a rod 6 extending therethrough.
As is well known, a rod 64 rotates a cam plate (not shown) in the distributor 11 to control the ignition timing.

A spring holder 65 is fixed to the housing and the rod 64 so that its position can be adjusted, and the spring 6 is placed between the spring holder 65 and a spring holder 66 placed on a stopper 69 integrated with the nozzle 62.
7 is arranged in a mo-contracted manner.

Further, a spring 6 is also provided between the spring receiver 66 and the housing 62.
8 are arranged in a compact arrangement.

Next, the action will be explained.

When the engine 3 is in an idling state, the port 4 supplies substantially atmospheric pressure to the pressure-sensitive valve 5 , so the pressure-sensitive valve 5 supplies atmospheric pressure to the controller 6 .

Therefore, no force acts on the diaphragm rotor 3 of the controller 6, and the rod 64 is in the illustrated state 11.

First, the ignition timing is maintained at its initial setting without being advanced or retarded.

Next, when the throttle valve 1 opens more than a predetermined degree and a negative pressure of more than a predetermined amount is generated in the port 4, the pressure-sensitive valve 5 starts supplying air from the port 10 to the controller 6. rod 6 of controller 6 according to the mocha that appears in
4 will move.

During the time when the supercharging by the supercharger 2 is not yet sufficiently performed, negative pressure is obtained from the port 10, so the pressure chamber 61 of the controller 6 also becomes negative pressure, and the diaphragm 63 The pressure chamber 61 is deformed against the spring 68 so as to contract.

Therefore, the rod 64 moves to the left in the drawing to advance the ignition timing.

In Figure 2, the advance/retard angle characteristics of the controller 6 are shown with negative pressure N1 on the left on the horizontal axis, positive pressure PXi on the right, and retard angle R on the vertical axis with advance angle A1 below. However, in this case, the advance angle is controlled in accordance with the negative pressure of the port 10 to the left of the vertical axis.

Furthermore, when the energy of the exhaust gas from the engine 3 increases, the turbine 21 rotates at high speed, and the compressor 22 performs sufficient supercharging, positive pressure is obtained at the port 10, so the controller 6 pressure chamber 61
A positive pressure is applied inside the chamber, and the diaphragm 63 deforms against the spring 67 so as to expand the dark force chamber 61.

Therefore, the rod 64 moves to the right in the drawing to retard the ignition timing.

In this case, the retard angle dust is controlled as shown on the right side of the vertical axis in FIG. 2 according to the strength of the positive pressure supplied to the controller 6 through the port 10.

Although the illustrated embodiment has been described above, the present invention is not limited to this embodiment, and various practical aspects may be included in the present invention within the scope of the claims for utility model registration. For example, as a pressure-sensitive valve, in addition to the valve of the embodiment, a negative pressure of a predetermined value or more at port 4 is sensed by an electrical negative pressure switch, and a separate valve is activated by a signal from the negative pressure switch. Even in a configuration that operates a solenoid valve installed in
The pressure sensitive valve of the present invention can be constructed.

Further, regarding the configuration of the controller, the controller may have a configuration similar to that of the earlier application described above.

As described above, the present invention uses a sensing valve to supply the supply air on the downstream side of the turbocharger to the ignition timing control controller according to the negative current of the port drilled near the throttle valve. Since this arrangement is provided, it is possible to optimally control the ignition timing of an engine in which a supercharger is provided on the downstream side of the throttle valve depending on the engine load and supercharging state.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing the lead/lag ratio by the controller. 1... Throttle valve, 2... Supercharger, 3... Internal combustion engine body, 4... Port, 5... Sensing valve, 6... Controller.

Claims (1)

[Scope of utility model registration request] In engines where a supercharger is installed downstream of the throttle valve,
The upstream side of the throttle valve is fully closed, and the downstream side of the turbocharger is sensed when the negative pressure is above a predetermined value. Air supply mode, other times,
A sensing valve that outputs atmospheric pressure is provided, and a controller is provided that advances the ignition timing in accordance with the supplied negative pressure and retards the ignition timing in accordance with the supplied positive pressure. An ignition timing control device for a supercharged engine, characterized in that the output of the MO valve is supplied to the controller to advance or retard the ignition timing.