JPH0326304Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an ignition timing control device for a spark-ignition internal combustion engine.

[Prior art]

It is necessary to increase the idling speed when auxiliary equipment such as a vehicle air conditioner compressor, automatic transmission device, or generator is activated. For this reason, it has become common practice to increase the idling opening of the throttle valve using a fast idling device to perform a fast idling operation.

It is also well known to incorporate an ignition timing advance device into the distributor to advance the ignition timing in accordance with the engine load.

On the other hand, in the prior art, it is known to simultaneously perform fast idling and advance the ignition timing in order to stabilize idling when the engine is cold (Japanese Utility Model Publication No. 71034/1983). For this reason,
When the engine is cold, the negative pressure input to the negative pressure actuator of the first idle device is guided to the negative pressure actuator for advancing the ignition timing.

By the way, in order to further improve the fuel efficiency of automobiles, it is effective to advance the ignition timing as much as possible. However, if the ignition timing is advanced by more than the conventional advance amount, knocking tends to occur in the engine when a load is applied to the engine due to the operation of auxiliary equipment during idling. Such knocking would not be a problem if the ignition timing advance amount was limited within a certain level as in the past.

[Purpose of invention]

An object of the present invention is to provide an ignition timing control device that can further improve fuel efficiency and does not cause knocking during fast idling due to the load of auxiliary equipment.

[Structure and action of the device]

In the ignition timing control device of the present invention, the ignition timing is set in advance to the advance side, and the ignition timing control device includes means for limiting the amount of advance of the ignition timing when the fast idle device is activated.

This advance angle limiting means communicates with the advance port, which is located on the intake upstream side of the throttle valve when the throttle valve is fully closed, and is located on the intake downstream side when the throttle valve is opened, and is communicated with this advance port and is controlled by the action of the intake negative pressure. The engine is comprised of an ignition timing control device that advances the ignition timing, and means for reducing the intake negative pressure that acts on the ignition timing control device during first idle. Further, this advance amount limiting means is an air bleed device that can introduce bleed air into the negative pressure transmission pipe of the negative pressure actuator for ignition timing advancement in accordance with the input negative pressure of the negative pressure actuator of the first idle device. Can be configured with a valve. As the bleed air intake port of this air bleed valve, an existing sensing port (EGR sensing port) for controlling the exhaust gas recirculation control valve (EGR valve) can be used.

Because of this configuration, when the fast idling device is activated to perform fast idling due to the operation of the auxiliary equipment, the negative pressure acting on the negative pressure actuator of the ignition timing advance device is reduced by bleed air. , the amount of ignition timing advance is limited.
Therefore, knocking during fast idling is prevented from occurring. At times other than fast idling, the ignition timing is advanced by more than the conventional amount, improving fuel efficiency.

〔Example〕

Next, embodiments of the present invention will be described with reference to the accompanying drawings. Referring to FIG. 1, 10 is an intake pipe of the engine. When the fuel supply device includes a carburetor, the carburetor is connected to the upstream side of the intake pipe 10, and the downstream side is connected to the intake port of the engine. In the case of a fuel injection engine, an injector is installed at an appropriate location in the intake system.

The intake pipe 10 is provided with a throttle valve 12 linked to an accelerator pedal (not shown), and the throttle valve 12 is provided with a fast idle device 14. First idle device 14
This is a diaphragm type negative pressure for fast idle equipped with a fast idle lever 20 connected to the throttle shaft 16 at one end and equipped with an adjusting screw 18 at the other end, and an output rod 22 that regulates the position of the adjusting screw 18. and an actuator 24. The negative pressure chamber 26 of the negative pressure actuator 24 is connected to the negative pressure outlet port 34 of the intake pipe 10 via a negative pressure transmission line 28, a first idle solenoid valve 30, and a negative pressure transmission line 32. The solenoid 36 of the solenoid valve 30 is connected to a power source 42 via a switch 38 and an ignition switch 40.
When the switches 38 and 40 are closed, the valve element 44 is sucked to transfer the negative pressure of the negative pressure outlet port 34 to the negative pressure chamber 26 of the negative pressure actuator 24, thereby moving the output rod 22. The idle opening degree of the throttle valve 12 is increased. The switch 38 is linked to auxiliary equipment such as the air conditioner switch and the shift position sensor of the automatic transmission, and is turned on when the air conditioner switch is turned on or when the automatic transmission shifts from the neutral range to the drive range. This is the result.

The ignition timing control device 46 is the distributor 4
8, a negative pressure chamber 52 of the actuator 50 is connected to an advance port 56 of the intake pipe 10 via a negative pressure transmission line 54. This advance port 56 is a port for extracting negative pressure to be input to the negative pressure actuator 50 for ignition timing control, and when the throttle valve 12 is in the fully closed position, no negative pressure acts and the throttle valve 12 opens slightly. It is located in such a position that negative pressure is applied when it is turned off.

Upstream of the advance port 56, the intake pipe 1
0 has an EGR sensing port 58,
This port 58 is connected via a negative pressure transmission line 60.
Connected to the EGR valve (not shown). The EGR sensing port 58 controls the amount of exhaust gas recirculation by operating the EGR valve in response to the negative pressure acting there.

The configuration of the fast idle device described above is substantially the same as the conventional one. The ignition timing control device 46 differs from the conventional one only in that the ignition timing is adjusted in advance to be more advanced than the conventional one.

This ignition timing control device is provided with means for limiting the amount of ignition timing advance during fast idling. In the illustrated embodiment, this advance angle limiting means is constituted by an air bleed device. This air bleed device is equipped with a negative pressure responsive air bleed valve 62, and its bleed air intake pipe 64 is
It is connected to the negative pressure transmission line 60 for the EGR valve,
The bleed air output pipe 66 is connected to the negative pressure transmission pipe 54 of the negative pressure actuator 50 for ignition timing control. The output conduit 66 is provided with a throttle 68 . Bleed air flowing from the intake pipe 64 to the output pipe is controlled by a valve body 72 provided on a diaphragm 70, and the negative pressure chamber 74 of the air bleed valve 62 is controlled by the negative pressure transmission pipe 76. It is connected to the conduit 28 of the idle negative pressure actuator 24.

Next, to explain the operation, as mentioned above,
The ignition timing of the ignition timing control device 46 is set in advance to be more advanced than usual. When the engine load increases due to the operation of auxiliary equipment while idling, switch 3
8 is closed, current flows through the solenoid 36 of the solenoid valve 30, attracting the valve element 44 and opening the valve. Therefore, the negative pressure generated downstream of the throttle valve 12 is transferred to the negative pressure outlet port 34, the pipe line 32,
38 to the negative pressure chamber 26 of the first idle negative pressure actuator 24, and the output rod 2
2 through the first idle lever 20.
The throttle valve 12 is rotated by a predetermined angle counterclockwise in the figure to increase the idling opening degree of the throttle valve 12 and increase the idling rotation speed.

On the other hand, the negative pressure in the pipe 28 acts on the negative pressure chamber 74 of the air bleed valve 62 through the pipe 76, so when the negative pressure exceeds the set value, the valve body 72 rises and the bleed air intake pipe 64 and output It communicates with the pipe 66. The EGR sensing port 58 is located upstream from the advance port 56, and the EGR sensing port 58 is
Since the negative pressure acting on the advance port 56 is smaller than the negative pressure acting on the advance port 56, air bleed is performed from the conduit 60 to the conduit 54 via the air bleed valve 62. Therefore, the negative pressure acting on the negative pressure chamber 52 of the negative pressure actuator 50 of the ignition timing control device decreases, and the amount of advance of the ignition timing decreases. Therefore, knocking caused by ignition timing advance is prevented during fast idling. Note that the restriction 68 is provided in the bleed air output pipe 66 because in this embodiment, the EGR sensing port 58 is used as the bleed air intake port, so when the pipe 60 is connected to the pipe 54, the EGR valve In order to prevent the possibility of exhaust gas recirculation occurring during idling due to the increased negative pressure that is applied, and by restricting the introduction of bleed air into the pipe 54, it is possible to reduce the load from medium to high loads. This is to prevent the ignition timing from being advanced as much as possible.

When the auxiliary equipment becomes inactive, the switch 38 is opened and the solenoid valve 30 is closed, so that no negative pressure is output to the negative pressure actuator 24 and the air bleed valve 62. Therefore, the throttle valve 12
The idle opening degree returns to the initial state. At the same time, the air bleed valve 62 closes, and the ignition timing control negative pressure actuator 50 operates in response to the negative pressure from the advance port 56. Since the ignition timing of the ignition timing control device 46 is advanced more than usual, fuel efficiency is improved by advancing the ignition timing at times other than fast idling.

FIG. 2 is a graph showing the negative pressure acting on the negative pressure actuator for ignition timing control in the ignition timing control device of the present invention and the conventional device in relation to the vehicle speed of a vehicle with an automatic transmission. As is clear from this graph, with the device of this invention, the vehicle speed
At speeds above 30 km/h, the working negative pressure is greater than the negative pressure that provides the maximum amount of advance, while at low speeds the working negative pressure is sufficiently smaller than the negative pressure of the conventional device, making it difficult to advance the ignition timing. Indicates a value that can be restricted.

[Effect of idea]

As described above, the ignition timing control device of the present invention is configured so that the ignition timing advance amount is limited during fast idling, and the ignition timing is advanced more than before during normal operation. It is possible to improve fuel efficiency while reliably preventing the occurrence of knocking.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of an intake pipe equipped with an ignition timing control device and related devices according to an embodiment of the present invention, and FIG. 2 is an operation of a negative pressure actuator for ignition timing control in the device of the present invention and a conventional device. It is a graph showing the relationship between negative pressure and vehicle speed. 10... Intake pipe, 12... Throttle valve, 14
...Fast idle device, 24...Negative pressure actuator for first idle, 30...Solenoid valve, 34...Negative pressure outlet port, 38...
Switch, 46...Ignition timing control device, 48...
Distributor, 52...Negative pressure actuator for ignition timing control, 56...Advance port,
58...EGR sensing port, 62...Air bleed valve, 76...Negative pressure transmission line for the air bleed valve.

Claims (1)

[Scope of utility model registration request] In the spark ignition internal combustion engine, the spark ignition internal combustion engine is equipped with an ignition timing control device that advances the ignition timing according to the engine load, and a fast idle device that increases the idle opening of the throttle valve of the intake system according to the engine load. The ignition timing of the ignition timing control device is set in advance to the advance side, and means is provided for limiting the amount of advance of the ignition timing control device when the first idle device is activated, and this advance amount limiting device is configured to control the throttle valve. Ignition timing control that communicates with the advance port, which is located on the intake upstream side of this throttle valve when fully closed and located on the intake downstream side when the throttle valve is opened, and advances the ignition timing by the action of intake negative pressure. 1. An ignition timing control device for a spark-ignition internal combustion engine, comprising: a device; and an air bleed means for reducing intake negative pressure acting on the ignition timing control device during first idle.