JPS5918153Y2 - Internal combustion engine control device - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a control device for an internal combustion engine.

Normally, in an internal combustion engine, the ignition timing is delayed in order to prevent large amounts of HC and NOx from being emitted during warm-up operation when the engine temperature is low.

In this way, as an ignition timing control device that can retard the ignition timing during warm-up operation, the negative pressure chamber of the diaphragm device for negative pressure advancement of the diesel repeater is connected to the carburetor through a temperature-sensitive switching valve that can communicate with the atmosphere. Connects to the advanced port of
When the engine temperature is low, the negative pressure chamber of the diaphragm device for negative pressure advance is connected to the atmosphere by the switching operation of the temperature-sensitive switching valve, and the negative pressure advance action is stopped.On the other hand, when the engine temperature is high, the temperature-sensitive switching valve is switched. An ignition timing control device that connects the negative pressure chamber of the diaphragm device for negative pressure advance to advance spokes 1 to 1 through a switching operation to perform a negative pressure advance action was developed in Engine Repair Manual 18 R-GEU (1971). It is publicly known as described on page 135 (Published by Toyota Motor Sales Co., Ltd., Service Department, September 4).

However, after such a temperature-sensitive switching valve is used for a long period of time, it becomes impossible to completely shut off the atmosphere communication hole due to wear or dust accumulation on the switching valve. Even if the negative pressure chamber of the diaphragm device is switched to connect with the advance port, atmospheric air leaks and the negative pressure in the negative pressure chamber decreases, thus preventing the predetermined optimum ignition timing from reaching the optimum ignition timing. There is a risk that it will be difficult to set up.

Therefore, in this type of ignition timing control device, the negative pressure conduit connecting the negative pressure chamber of the negative pressure advance diaphragm device and the advance port is equipped with a switching valve that can communicate with the atmosphere where there is a risk of atmospheric leakage. The current situation is that we do not want to insert .

On the other hand, in an internal combustion engine, recirculation of exhaust gas is stopped during warm-up operation when the engine temperature is low.

In this way, in order to stop the recirculation of exhaust gas during warm-up operation, the negative pressure chamber of the diaphragm device for controlling the flow rate of recirculated exhaust gas is connected to the intake manifold via a temperature-sensitive switching valve that can communicate with the atmosphere. When the engine temperature is low, the negative pressure chamber of the diaphragm device for controlling the flow rate of recirculated exhaust gas is connected to the atmosphere by switching the temperature-sensitive switching valve to stop the exhaust gas recirculation, while when the engine temperature is high, the temperature-sensitive switching valve It is conceivable that the negative pressure chamber of the recirculation exhaust gas flow control valve is connected to the intake manifold by a switching action of the switching valve to recirculate the exhaust gas.

However, even if a temperature-sensitive switching valve is used in this way, after long-term use, the temperature-sensitive switching valve's atmosphere communication hole cannot be completely shut off, resulting in exhaust gas being recirculated during warm-up operation. A problem arises in that combustion deteriorates due to the increased pressure.

The present invention makes it possible to reliably set the optimal ignition timing even if it becomes impossible to completely shut off the air communication hole of the temperature-sensitive switching valve after long-term use, and also to perform exhaust gas recirculation control. An object of the present invention is to provide a control device for an internal combustion engine that is capable of controlling an internal combustion engine.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Referring to the drawings, 1 is an engine body, 2 is an intake manifold, 3 is a carburetor, 4 is a carburetor throttle valve, 5 is an exhaust manifold, 6 is a recirculation exhaust gas (hereinafter referred to as EGR) flow control valve, and 7 is a 8 is a diaphragm device for advancing the negative pressure of the pistol repeater 7, and 9 is a temperature-sensitive switching valve.

The negative pressure advance diaphragm device 8 has an advance chamber 11 and a retard chamber 12 that are separated by a diaphragm 10 .
3 are concatenated.

On the other hand, a compression spring 1 for pressing the diaphragm is provided in the advance chamber 11.
4 is inserted, and a collar 15 that can come into contact with the diaphragm 10 is arranged in the retard chamber 12.

On the other hand, the EGR flow control valve 6 has a negative pressure chamber 17 and a pressure control chamber 18 separated by a diaphragm 16, and a compression spring 19 for pressing the diaphragm is inserted into the negative pressure chamber 17.

A valve body 22 that controls opening and closing of the valve port 21 is disposed within the valve chamber 20 of the EGR flow control valve 6, and this valve body 22 is connected to the diaphragm 16.

This valve chamber 20 is connected on the one hand via an EGR line 23 into the intake manifold 2 and on the other hand via an EGR line 24 into the exhaust manifold 5.

On the other hand, the temperature-sensitive switching valve 9 has a temperature-sensitive portion 26 immersed in the cooling water 27 in the engine water jacket at the tip of the housing 25, and further includes a valve chamber 28 and an air filter 29 inside the housing 25. Atmospheric chamber 3 connected to the atmosphere via
0 is formed.

A valve body 31 and a compression spring 32 for pressing the valve body are inserted into the valve chamber 28 , and a valve port 33 communicating with the atmospheric chamber 30 and an intake air pipe 34 are inserted into the valve chamber 28 . A valve port 35 connected to a negative pressure port 43 opening into the manifold 2 is arranged facing the valve body 31 .

On the other hand, a bimetal element 36 is inserted into the atmospheric chamber 30, and the tip of a rod 37 fixed to the bimetal element 36 comes into contact with the valve body 31.

Further, the valve chamber 28 is connected to the retard chamber 12 and the pressure control chamber 18 via a conduit 38.

The drawing shows a state where the engine cooling water temperature is above a predetermined temperature, and at this time the valve body 31 closes the valve port 35.

Therefore, at this time, the inside of the valve chamber 28 is at atmospheric pressure, and thus the inside of the retard chamber 12 and the pressure control chamber 18 are also at atmospheric pressure.

On the other hand, when the engine cooling water temperature is low, the bimetal element 36 is reversed and curved in the opposite direction to the drawing.
1 moves to the left in the drawing by the spring force of the compression spring 32 to close the valve port 33 and open the valve port 35.

The retardation chamber 12 and the pressure control chamber 18 are then connected to the intake manifold 2 via the conduit 38, the valve chamber 28 and the vacuum conduit 34.

On the other hand, as shown in the drawings, the carburetor 3 is formed with an advance spoke 40 that opens into the intake passage 39 near the throttle valve 4.

This advance port 40 has a thrower I as shown in the drawing.
- When the throttle valve 4 is in the idling position, it opens into the intake passage 39 upstream of the throttle valve 4, and when the throttle valve 4 opens, it opens into the intake passage 39 downstream of the throttle valve 4.

The advance gear 40 is connected to the advance chamber 11 via a negative pressure conduit 41 on the one hand, and to the negative pressure chamber 17 via a negative pressure conduit 42 on the other hand.

When the temperature of the engine cooling water 27 is lower than a predetermined temperature, the valve body 31 of the temperature-sensitive switching valve 9 closes the valve port 33 and opens the valve port 35, as described above, and thus the negative pressure advance diaphragm device 8 retard chamber 12 and EGR flow control valve 6
The pressure control chamber 18 is connected within the intake manifold 2.

At this time, when the throttle valve 4 is in the idling position as shown in the drawing, almost atmospheric pressure is applied to the advance port (40), while when the throttle valve is open, negative pressure is applied to the advance port 40. is equal to the negative pressure inside the intake manifold 2.

Therefore, when the engine cooling water temperature is lower than the predetermined temperature, the negative pressure in the retard chamber 12 is greater than or equal to the negative pressure in the advance chamber 11.

At this time, the diaphragm 10 is moved toward the retard side by the spring force of the compression spring 14 and comes into contact with the stopper 15, thereby retarding the ignition timing.

On the other hand, at this time, the negative pressure in the pressure control chamber 18 of the EGR flow control valve 6 is also greater than or equal to the negative pressure in the negative pressure chamber 17.

In this way, the diaphragm 16 is lowered by the spring force of the compression spring 19, so that the valve body 22 closes the valve port 21, thereby stopping the supply of EGR gas.

On the other hand, when the temperature of the engine cooling water 27 reaches a predetermined temperature or higher, the valve body 31 closes the valve port 35 and opens the valve port 33 as shown in the drawing, so that the retardation chamber 12 and the pressure control chamber 18 are exposed to the atmosphere. Concatenated.

Therefore, at this time, normal ignition advance action and EGR gas supply control are performed.

As is clear from the drawing, the negative pressure advance diaphragm device 8
The negative pressure conduit 41 that connects the advance chamber 11 and the advance port 40 is not provided with any conventional switching valve, so even if used for a long time, the predetermined The optimal ignition timing can be set accurately at all times.

Furthermore, the negative pressure conduit 42 that connects the negative pressure chamber 17 of the EGR flow control valve 6 and the advance port 40 is not provided with any switching valve as has been conventionally used. Even if EGR gas is used, recirculation control of EGR gas can be performed reliably.

In addition, a temperature-sensitive switching valve 9 that can communicate with the atmosphere is provided in the negative pressure conduit that connects the retard chamber 12 of the negative pressure advance diaphragm device 8 and the inside of the intake manifold 2. Even if the valve body 31 cannot completely close the valve port 33 that communicates with the atmosphere, and as a result, the atmosphere leaks and the negative pressure in the retard chamber 12 decreases to some extent, the advance chamber 11 and the retard chamber 1
The compression spring 14 has a stronger force pushing the diaphragm 10 toward the retard angle side than the force pushing the diaphragm 10 toward the advance angle side due to the pressure difference between the compression spring 14 and the diaphragm 10.
continues to be in contact with the stopper 15.

Furthermore, even if the negative pressure inside the pressure control chamber 18 decreases to some extent due to air leakage as described above, the spring force of the compression spring 19 will cause the valve body to
2 will keep valve port 21 closed.

Furthermore, the temperature-sensitive switching valve 9 can be a thermowax type switching valve or an electromagnetic switching valve instead of the diaphragm type shown in the figure, and instead of detecting the cooling water temperature, it can be used to detect the intake temperature, exhaust temperature, or intake manifold temperature. The temperature of the riser portion may also be detected.

Further, in the illustrated embodiment, the stopper 15 is fixed on the wall surface of the retardation chamber of the diaphragm device, but instead of such a stopper 15, the stopper may be fixed to the negative pressure advance shaft 13 or the diaphragm 10. However, the stopper can also be formed from an annular plate movably inserted into the negative pressure advance shaft 13.

As described above, according to the present invention, it is possible to always ensure the optimum advance effect of the ignition timing, and also to perform the optimum flow rate control of the EGR gas.

Another advantage is that a common temperature-sensitive switching valve can be used for the negative pressure advance diaphragm device and the EGR flow rate control valve.

[Brief explanation of the drawing]

The figure is an overall view of the ignition timing control device according to the present invention.

Claims (1)

[Scope of utility model registration request] The negative pressure advance diaphragm device of the distributor includes a diaphragm connected to the negative pressure advance shaft of the distributor, and an advance chamber and a retard chamber formed on both sides of the diaphragm, and the diaphragm device is configured to provide recirculation exhaust gas. The gas flow rate control valve includes a diaphragm connected to a valve body provided in the recirculation exhaust gas conduit, and a negative pressure chamber and a pressure control chamber formed on both sides of the diaphragm. The chamber and the negative pressure chamber are connected to an advance port that opens into the intake passage near the carburetor throttle valve, and the retardation chamber and the pressure control chamber are connected to a negative pressure port that opens into the intake passage downstream of the carburetor throttle valve. They are connected via a common conduit, and a temperature-sensitive switching valve that responds to the engine temperature and can communicate with the atmosphere is provided in the conduit, and when the engine temperature is lower than a predetermined temperature, the retardation chamber and the pressure control chamber are The retardation chamber and pressure control chamber are connected to the pressure port to retard the ignition timing and stop the supply of recirculated exhaust gas into the intake passage, and when the engine temperature is higher than a predetermined temperature, the retardation chamber and the pressure control chamber are opened to the atmosphere. A control device for an internal combustion engine, wherein the ignition timing and the amount of recirculated exhaust gas are controlled by the negative pressure applied to the advance angle chamber and the negative pressure chamber.