JPS6224052Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an ignition timing control device for purifying exhaust gas of an internal combustion engine.

Conventionally, ignition timing has been delayed as a means of purifying hydrocarbons HC and nitrogen oxides NOx contained in the exhaust gas of an internal combustion engine (hereinafter referred to as engine). However, when exhaust gas is purified by controlling ignition timing, fuel efficiency and drivability of a vehicle equipped with the engine tend to deteriorate. Of course, the degree of this deterioration varies depending on the operating condition of the engine, so it is difficult to effectively purify exhaust gas without significantly deteriorating fuel efficiency and drivability depending on each operating condition of the engine. However, the process of purifying the exhaust gas has become complicated.

The purpose of this invention is to provide an engine ignition timing control device that, despite its simple structure, effectively purifies exhaust gas under various operating conditions of the engine and prevents deterioration of fuel efficiency and drivability. .

This invention will be explained below with reference to drawings showing embodiments. In the figure, 1 is an engine carburetor and 2 is a throttle valve. A dotted line 2 indicates the position of the throttle valve when the engine is idling, and an advance port 3 is provided in the intake passage 1a of the carburetor 1 immediately upstream of the throttle valve when the engine is idling. Throttle valve 2
Downstream from this is an intake pipe, and an intake pipe port 4 is provided here.

5 is a two-stage negative pressure advance device, and main negative pressure advance device 6
and a sub negative pressure advance device 7, each negative pressure advance device 6, 7 having a negative pressure chamber 6a, 7a. A rod 7b fixed to the diaphragm 7c of the sub negative pressure advance device 7 is connected to a breaker plate 8a of the distributor 8.
The diaphragm 7c of the sub negative pressure advance device 7 is connected to the rod 6b of the main negative pressure advance device 6.
The rod 6b has a locking piece 6e at its end, and when strong negative pressure is introduced into the negative pressure chamber 6a of the main negative pressure advance device 6, the locking piece 6e engages with the diaphragm 6c and moves. (to the right in the diagram) is the diaphragm 6c
The rod 6b does not move even if the diaphragm 6c moves to the left. Therefore, when negative pressure acts on the negative pressure chamber 6a of the main negative pressure advance device 6, the rod 7b is moved via the rod 6b and diaphragm 7c, but no negative pressure is applied to the negative pressure chamber 7a of the sub negative pressure advance device 7. Even if the rod 7b moves to the right as a result, the diaphragm 6c of the main negative pressure advance device 6 is not moved by the rod 6b. The negative pressure chamber 6a of the main negative pressure advance device 6 has a negative pressure port 6d, and the negative pressure chamber 7a of the sub negative pressure advance device 7 has a negative pressure port 7.
d is provided.

9 is a control device that includes three negative pressure switching valves 10, 11,
It is electrically connected to 12. The first negative pressure switching valve 10 switches between negative pressure and atmospheric pressure, and its inlet port 10a communicates with the advance port 3 through a negative pressure passage 13, and the outlet port 10a communicates with the advance port 3 through a negative pressure passage 13.
b communicates with the negative pressure port 6d of the negative pressure chamber 6a of the main negative pressure advance device 6 through the negative pressure passage 14. 1
0c is an air filter. Third negative pressure switching valve 11
The inlet port 10a is connected to the outlet port 12b of the second negative pressure switching valve 12, and the outlet port 11b of the third negative pressure switching valve 11 is connected to the sub-pressure by the negative pressure passage 21. It communicates with the negative pressure port 7d of the negative pressure chamber 7a of the negative pressure advance device 7. 11c is an air filter. The second negative pressure switching valve 12 has two inlet ports 12.
The inlet port 12a communicates with the negative pressure passage 13 through a negative pressure passage 15, and the inlet port 12c communicates with the intake pipe port 4 through a negative pressure passage 16.

The control device 9 includes an engine speed sensor 17, an intake pipe negative pressure sensor 18, and an EGR valve sensor 19.
(When the engine intake system negative pressure acting on the EGR valve is above the set value, the valve opens (turns on), and when the intake system negative pressure is less than the set value, the valve closes (off).) and the engine water temperature sensor 20. electrically connected. The engine speed sensor 17 outputs a signal 1 when the engine speed is lower than a set value, and outputs a signal 0 when the engine speed is higher than the set value. Intake pipe negative pressure sensor 18
outputs a signal 1 when the intake pipe negative pressure is lower than the set value, and outputs a signal 0 when it is above the set value. The EGR valve sensor 19 outputs a signal 1 when it is on, and outputs a signal 0 when it is off. The water temperature sensor 20 outputs a signal 1 when the engine water temperature is lower than the set value.
If the value exceeds the set value, a signal of 0 is output.

In the above configuration, the sum of the above four signals is 0
In other words, when the engine is operating in such a state that the engine speed, engine water temperature, and intake pipe negative pressure are all higher than the set value and the four conditions for turning off the EGR valve are met, the negative pressure switching valves 10, 11, and 12 are all turned off. The atmosphere is set to be in the negative pressure chamber 6a of the main negative pressure advance device 6 and the negative pressure chamber 7a of the sub negative pressure advance device 7 in the first and third negative pressure switching valves 10 and 11, respectively.
It will be introduced after. Therefore, the data distributor 8
does not advance.

When the sum of the above four signals is 1, that is, the above four signals
When the engine is in an operating state where one of the conditions is lacking, the first and second negative pressure switching valves 10 and 12 are set to be off, and the third negative pressure switching valve 11 is on. The pressure is in the negative pressure passage 13,
15, the negative pressure chamber 7a of the sub negative pressure advance device 7 via the second and third negative pressure switching valves 12, 11 and the negative pressure passage 21.
The sub negative pressure advance device 7 advances the angle. Note that atmospheric pressure is introduced into the negative pressure chamber 6a of the negative pressure advance device 6.

When the sum of the above four signals is 2 or more, that is, when the engine is in an operating state where two or more of the above four conditions are missing, the third and second negative pressure switching valves 11 and 12 are turned off, and the third and second negative pressure switching valves 11 and 12 are turned off. 1 Negative pressure switching valve 10 is set to be on, and advance port 3
The negative pressure of It will be done. Note that atmospheric air is introduced into the negative pressure chamber 7a of the sub negative pressure advance device 7 by the third negative pressure switching valve 11. In other words, the sub-negative pressure advance device 7 does not advance the angle, but if the third negative pressure switching valve 11 is set to be on, the advance port is set in the negative pressure chamber 7a of the sub-negative pressure advance device 7. 3 negative pressure is introduced through the second negative pressure switching valve 12, and the sub negative pressure advance device 7 can also advance the angle.

When the engine is idling, the first negative pressure switching valve 10 is off, and the third and second negative pressure switching valves 11,1
2 is set to be turned on, and the negative pressure in the intake pipe port 4 passes through the negative pressure passage 16, the second and third negative pressure switching valves 12, 11, and the negative pressure passage 21, and then reaches the sub negative pressure advance device. 7, and the device 7 advances the ignition timing to obtain the optimum ignition timing.

As mentioned above, this device combines a two-stage negative pressure advance device, a control device, and three negative pressure switching valves, and inputs engine operating conditions that require advance into the control device to switch the negative pressure. Since the valve and the two-stage negative pressure advance device perform advance and non-advance, the deterioration of engine drivability and fuel efficiency can be minimized and exhaust gas can be purified. have an effect. Furthermore, since the device is small and simple, it is easy to install it in the engine.

[Brief explanation of drawings]

The drawing is an explanatory diagram of an embodiment of this invention. 3... Advance port, 4... Intake pipe port, 5... Two-stage negative pressure advance device, 9... Control device,
10...First negative pressure switching valve, 11...Third negative pressure switching valve, 12...Second negative pressure switching valve, 17...Engine speed sensor, 18...Intake pipe negative pressure sensor, 19
...EGR valve sensor, 20...Water temperature sensor.

Claims (1)

[Scope of utility model registration request] A two-stage negative pressure advance device 5 consisting of a main negative pressure advance device 6 and a sub negative pressure advance device 7, a first negative pressure switching valve 10, a second negative pressure switching valve 12, and a third negative pressure switching valve. 11
and a control device 9 electrically connected to these three negative pressure switching valves, and the first negative pressure switching valve 10 is located at the advance port 3 immediately upstream of the throttle valve in the idling state of the internal combustion engine. The second negative pressure switching valve 12 switches between the negative pressure of the advance port 3 and the atmospheric pressure and transmits it to the negative pressure chamber of the main negative pressure advance device 6. The third negative pressure switching valve 11 switches between atmospheric pressure and the negative pressure from the second negative pressure switching valve 12 and transmits it to the negative pressure chamber of the sub negative pressure advance device 7 for control. The device 9 is electrically connected to the engine speed sensor, intake pipe negative pressure sensor, EGR valve on/off sensor, and engine water temperature sensor, and detects when the intake pipe negative pressure, engine speed, and engine water temperature exceed set values.
When the engine is operating under the four conditions that the EGR valve is off, atmospheric air is introduced into the main and sub negative pressure advance devices 6 and 7 through the first and third negative pressure switching valves 10 and 11, and the advance is not performed. In the operating state of the engine where one of the four conditions is missing, the negative pressure in the advance port 3 is introduced to the sub negative pressure advance device 7 via the second and third negative pressure switching valves 12 and 11 to advance the angle. was carried out, 4
In the operating state of the engine where two or more of the conditions are lacking, the negative pressure in the advance port 3 is switched to the first negative pressure switching valve 10.
The negative pressure is introduced into the main negative pressure advance device 6 through at least the first negative pressure changeover valve 10 of the third negative pressure changeover valve 11 for advancement, and when the engine is idling, the negative pressure in the intake pipe port 4 is An ignition timing control device for an internal combustion engine, characterized in that the ignition timing control device is introduced into a sub negative pressure advance device 7 via second and third negative pressure switching valves 12 and 11 to advance the angle.