JPS5965543A - Engine control device - Google Patents

Abstract

PURPOSE:To aim at a distinct improvement in fuel consumption in time of deceleration as well as to control a shock in time of quick acceleration, by keepping the ignition timing at the lag timing control side in time of deceleration when engine speed goes beyond the specified value, while composing the ignition timing so as to cut fuel in a slow system. CONSTITUTION:In time of running when engine speed goes beyond the specific value (about 1,600r.p.m.) as well as in time of deceleration when a throttle valve 4 is almost fully closed, a speed detector switch 11 is turned off while a vacuum switch 13 is on whereby a relay 10 is energized with a continuous rating current and its suction pressure contact 102 is closed. Accordingly, a fuel control valve 7 is closed and a slow fuel passage 5 is cut off, and simultaneously a distributor (unillustrated herein) is adjusted to the lag timing control side by dint of high suction pressure to be added to a first diaphragm of a vacuum control device 3 and via a rod 24. Afterward when the throttle valve 4 is quickly opened, a second diaphragm 18 shifts to the timing control side at a specified time lag by the action of a throttle 23 provided inside an air passage 22 so that any possible shock in time of quick acceleration is eventually controlled to be checked.

Description

[Detailed description of the invention] This invention is a fuel system that works in conjunction with the engine's intake system.

The present invention relates to a device for controlling an ignition system.

The output of an engine, such as a gasoline engine, must be adjusted depending on the driving condition of the vehicle, and means for adjusting the amount of air-fuel mixture by controlling the cab 1/inverter is usually used frequently. In this case, the air-fuel mixture flowing into the combustion chamber through the cab 1/2 is ignited at an appropriate ignition timing, so that it can be combusted with appropriate combustion efficiency and generate appropriate output. Incidentally, when the vehicle is running, the engine installed in the vehicle advances the ignition timing by a predetermined amount to increase combustion efficiency as much as possible, thereby efficiently extracting output. In contrast, when decelerating,
Even though the engine speed is relatively high, it acts as an engine brake with a small valve opening (slot) and generates a load.

At this time, the manifold negative pressure increases downstream of the throttle valve of the capretor in the intake system, and fuel is excessively jetted from the slow nozzle of the fuel system that opens in that area.

This results in an increase in harmful components such as hydrocarbons (1-10) in the exhaust gas, and also causes the disadvantage of increased fuel consumption. In such cases, it is desirable to reduce the amount of hydrocarbons in the exhaust gas as much as possible. On the other hand, when the engine decelerates, the combustion pressure P in the combustion chamber is small, as shown in area a in Figure 1, and when the engine accelerates rapidly, the throttle valve opens rapidly and the combustion pressure, I), increases rapidly. do. When the combustion pressure 1 changes discontinuously in this way, an undesirable shock is applied to the vehicle. To prevent this fL.

During deceleration, the engine's ignition timing is kept as retarded as possible, and during sudden acceleration, the ignition timing is delayed from moving to the advanced side.
It is presumed that it is effective to suppress the combustion efficiency and control the combustion pressure P to gradually increase as shown in FIG. 1(I).

SUMMARY OF THE INVENTION An object of the present invention is to provide an engine control device that maintains the ignition timing on the retarded side during engine deceleration and at the same time cuts the fuel in the slow system.

The engine control device according to the present invention includes a vacuum advance device that advances or retards the ignition timing in response to negative pressure in the engine intake system, and an opening near the downstream side of the throttle valve of the carburetor that forms the intake system; The vacuum advance device has an advance-side negative pressure chamber that receives negative pressure, and a retard valve that can communicate with the downstream side of the throttle valve. two movable partition walls that move toward and away from each other and move forward and backward;
means for delaying the movement of gas in the retard side negative pressure chamber, the engine rotation speed is greater than a set value, and
During deceleration, when the negative pressure downstream of the throttle valve is greater than a set value, both of the two movable bulkheads operate to the retard side, and the slow system is equipped with a valve that cuts off fuel during deceleration.

According to such an engine control device, it is possible to improve fuel efficiency during deceleration and prevent shock during sudden acceleration by keeping one ignition timing retarded.

The present invention will be described below with reference to the accompanying drawings.

Fig. 2 shows an engine control device 1 as one of the fruits of this invention. This engine control device is formed over a slow system in a fuel system, such as a cab 1/2, which forms part of an intake system of an engine (not shown), and a vacuum advance device 3 for an ignition system. A throttle valve 4 is attached to the capretor 1, and a slow fuel passage 5 forming a slow system and an idle port 6 as an opening thereof are formed near the downstream side of the throttle valve 4. A fuel control valve 7 is installed in the middle of the slow fuel path 5, and when it receives an activation signal and turns on, the slow fuel path 5 is kept open rather than closed. Incidentally, reference numeral 8 indicates an idle adjustment screw 2, which adjusts the amount of fuel sucked out from the idle boat. The fuel control valve 7 is a solenoid valve, and one end of its wiring is connected to the power supply 9 (11), and the other end is connected in parallel so that the engine rotation speed is set to I)-10 (here, 1600 rpm). It is connected to an engine rotation speed detection switch (hereinafter simply referred to as the first switch) 11 which is turned on in the following. When the relay 10 is turned off and does not receive an activation signal, the ground contact 101i closes, thereby keeping the fuel control (1 valve 7) in the on state. Conversely, when the relay 10 is turned on, the pair of ground contacts 101i are closed. It opens, and closes some negative pressure contacts 102 at the extending ends of the respective wirings of the switching valve 12 and the first switch J1, which will be described later.

In this way, I/-10 converts the negative pressure at the F position near the downstream side of the throttle valve 4 (hereinafter simply referred to as F negative pressure) into the third air passage 3.
4 and this is the setting value (here 309mm)
1g) It is operated by the vacuum switch (hereinafter simply referred to as the second switch) 13 which is turned on.

Note that reference numeral 14 indicates a control valve that allows air to bypass the throttle valve 4, which is close to fully closed, to flow in through the bypass passage 15 side for a certain period of time immediately after engine deceleration.

The vacuum advance device 3 has an outer shape formed by a substantially cylindrical case 16, and includes a first negative pressure chamber 18 on the advance side formed by the left side of the case 16 and a first diaphragm 17 as a movable partition;
A second negative pressure chamber 20 on the retard side formed by the right side of the case 16 and the second diaphragm 19 as an oJ dynamic partition wall is provided on the left and right sides. The first negative pressure chamber 18 is a first negative pressure chamber equipped with a switching valve 12.
It passes through the air passage 21 and receives Tispoust negative pressure (hereinafter simply referred to as D negative pressure) located at Dfi near the upstream side of the throttle valve.

The second negative pressure chamber 20 receives F negative pressure through the second air passage 22 .

The switching valve 12 is a three-way valve that is switched by a solenoid 121, and is turned off when it does not receive a human input signal.

J) Disboost boat 122 receiving negative pressure and the first
Communicate with the advance side port 123 on the negative pressure chamber 18 side. When it receives an activation signal and turns on, it operates to switch, and communicates the F boat 124 that receives the F negative pressure with the advance side boat 123. This switching valve 12 is connected in series to the power supply 9 at its main end, and also connected in series to a pair of negative pressure contacts 102 at the other end and the first switch 11. Therefore, the second switch 130 is turned on. Only when the closing operation of the negative pressure contact 102 and the ON operation of the first switch 11 occur together.

When the switching valve 12 receives the activation signal, it is turned on and the first negative pressure chamber 1 is turned on.
8, introduce F negative pressure instead of D negative pressure.

A throttle 23 is installed near the second negative pressure chamber 20 in the second air passage 22 to delay the flow of gas so that the high negative pressure gas in the second negative pressure chamber does not decrease suddenly. Note that, depending on the case, a throttle 24 that delays the flow of gas may be installed near the first negative pressure chamber 18 in the first air passage 21 .

As shown in FIG. 3, the first diaphragm 17 of the vacuum advance angle device 3 is connected to a breaker plate 26 of a distributor 25 via a rod 24.

At the same time, the rotor 251 is rotating in the pilot direction (see FIG. 3(a)). $2 Diagram 19 has rod 2 in the center
A cylindrical body 2 integral with the case 16 is formed with a hole into which the cylindrical body 4 is loosely fitted.
The hollow chamber 28 side end of 7 is tightly fixed to the peripheral edge of the hole of the second diaphragm 19. The rod 24 has an advanced side in the direction of the pilot A, and a retard side in the direction of the pilot R.

The first diaphragm 17 is attached to the first hook piece 2 from the side of the hollow chamber.
9, second die 77, ym 19)! Nakashiba room 111! l
tfir, r') m2:y The pick pieces 30 are respectively extended. The tip of the first hook piece 29 is bent to form a first pressing surface 291 in the retard direction and a first tension surface 292 in the advance direction. On the other hand, the second hook piece 3
The tip of 0 is bent into a U-shape, and the first suppression surface 2 is placed there.
91 and a second tension surface 302 that can come into contact with the first tension surface 301 and the first tension surface 302 are formed, respectively, so that both diaphragms 17 and 19 are formed.
can be relatively moved by the distance of the gap between the U-shaped parts, and if it exceeds this, both move in the same direction. Second diaphragm 1
A stopper piece 31 is attached to the retard angle 1111.1 of 9, and the tip of this piece projects into the annular groove 271 of the cylindrical body 27. Further, in the first negative pressure chamber, there is a first spring 32 that presses the first diaphragm 17 toward the retard angle +i+o Jr., and in the second negative pressure chamber 2(), there is a first spring 32 that presses the second diaphragm 19 toward the advance side A. Two springs 33 are respectively attached. 2. Reference numeral 34 in FIG. 2 indicates a main switch that is linked to the ignition switch.

The operation of such an engine control device will be investigated for each engine operating state.

]) When the engine is stopped 1] Both the negative pressure and the F negative pressure are at atmospheric pressure, fuel control valve No. 7 is in the OFF state, and the switching valve 12 is also in the OFF state.

For this reason, the rod 24 of the vacuum advance angle device 3 is held at the neutral position Po shown in FIG. 3, with both diaphragms 17 and 19 receiving only the elastic force of both springs 32 and 33.

At this time, the first pressing surface 291 of the first hook piece and the second pressing surface 301 of the second hook piece are in pressing contact.

2) When the vehicle is running, the main switch 34 is turned on and the throttle valve 4 is maintained at a relatively large open IW. At this time, the F negative pressure is small (see FIG. 4), the second switch 13 is off, and the relay 10 is also kept off. Therefore, the ground contact 101 of the S1NO remains closed, and the fuel control valve 7 is turned on to open the slow fuel passage 5. The switching valve J2 maintains an off state because the negative pressure contact 102 is open, and I) leads negative pressure to the first negative pressure chamber 18. Therefore, the second diaphragm 19 does not operate much, and the first
Only the diaphragm 17 moves the rod 24 to the advance angle side A, resulting in the advance angle X shown by line a in FIG. in this case,
The maximum advance angle X is maintained at the position where the first tension member 292 and the second tension member 111I]3o2 come into contact. When driving with the ignition timing on the advance side A, engine fuel efficiency and output are improved.

3) During deceleration, the throttle valve 4 is almost closed, D negative pressure becomes atmospheric pressure, and 1゛ negative pressure indicates a high negative pressure value. At this time, the second switch 13 is turned on, the relay 10 is turned on, the ground contact 101 opens, and the negative pressure contact 102 closes. Moreover, the first switch 11 has an engine speed of 1.
Since it is above 60 Or, p, m・, it is in the off state,
The fuel control valve 7 is turned off and one slow fuel passage 5 is opened. Therefore, fuel is not sucked out from the idle boat 6 even though the negative pressure D is high. On the other hand, even if the negative pressure contact 102 of the switching valve 12 is closed, the first switch 11 is turned off.

Keep it off. Therefore, the first diaphragm 17
Only the pressing force of the first spring 32 is applied to the diaphragm 19, high negative pressure is applied to the second diaphragm 19, the rod 24 moves to the retard side, and the gripping angle Yi changes along the r line in FIG. and maintain the maximum retardation angle Y, yr.

4) During sudden acceleration after deceleration, the throttle valve 4 suddenly operates intermittently, so the D negative pressure does not change much, but the F negative pressure decreases sharply.

At this time, the high negative pressure inside the second negative royal chamber 20 is 114! The second spring 33 works to lower the negative pressure, but the flow rate of the gas passing through the second air passage 22 is greatly regulated by the throttle 23, and the speed at which the second diaphragm 19 moves to the advance side A is delayed, and the rod 24 causes a time lag compared to when moving to the retard side R.

By such an operation, the ignition timing of the engine changes from the retard angle IM YI to the advance angle X1, as shown by the dashed line in FIG.

That is, compared to when the ignition timing fluctuates gradually, the time period during which the ignition timing remains on the retarded side becomes longer.

5) During idling, the throttle valve 4 is almost closed, the negative pressure D is close to atmospheric pressure, and the negative pressure F shows a relatively high negative pressure. On this occasion.

The second switch 13 is turned on, and the IJ l/-10 also closes the negative pressure contact 102 and opens the ground contact 101. Moreover, the engine speed becomes 16 oor-p.In" or less, and the first switch 11 is turned on. Therefore, the fuel control valve 7 is turned on and fuel is injected from the idle boat 6.

Further, the switching valve 12 is also turned on, and the F negative pressure is guided to the first negative pressure chamber 18. At this time.

Since the second negative pressure chamber 20 is also receiving negative pressure, the second diaphragm 17, 19 is connected to the tension surface 292 of the knock piece of the second negative pressure chamber 20.
．． 302 come into contact with each other and attract each other. In the balanced state, the rod 24 is connected to the advance side A of the first diaphragm 17.
The idle advance angle Zs k is advanced by an amount obtained by subtracting the amount of movement of the second diaphragm 19 toward the retard side R from the amount of movement to Hold.

When each region of the operating conditions described above is plotted on the engine performance curve, Figure 6 is obtained. Here the engine speed is 1
Advance angle A of 60 Or-p・1η・ or more is ■, engine speed is 1600 r, advance angle 111 of I)-In- or less.
! l A to 0. Retard angle Rw@ during deceleration, advance angle FTF during idle! It was shown as lZ'xO.

In this way, the engine control device 1 keeps the ignition timing retarded during deceleration, so if there is subsequent rapid acceleration, the throttle 23
works, and the ignition timing can be maintained at the retarded angle Y for a long time. Therefore, the engine combustion pressure does not rise suddenly and the first
In a state close to the characteristics shown in Figure (b), the combustion pressure P rises smoothly and shock to the vehicle body can be prevented. Furthermore, the fuel control valve 7 is turned off during deceleration, and fuel from the idle boat 6 is not spouted out, making it possible to reduce harmful components such as hydrocarbons in the exhaust gas. Furthermore, because the ignition timing is maintained at the advance angle Z during idling, fuel efficiency during idling can be improved.

FIG. 7 shows an engine control device 40 as an embodiment of the flf+ of the present invention. This engine side tilting device 1 has the same members as the device 1 shown in FIG. 2, and henceforth, the same members will be given the same reference numerals and their repeated explanation will be omitted.

The engine 11 river illumination device t40 has a manifold negative pressure at the M (ff position (hereinafter simply referred to as M negative pressure, V'')'f
The first air passage 21 to be guided is directly connected to the first negative pressure chamber 18, and the second air passage 22 is connected to the second negative pressure chamber 20 via the throttle 23.
There is.

The 117!2 switch 42, which receives F negative pressure through the third air passage 34, is turned on when the negative pressure value is below 300 mmHg, and turned off when it exceeds this. One end of the wiring of the fuel control valve 7 is connected to the power source 9 side, and the other end is connected to the first switch 11 and the second switch 42 in parallel. Furthermore, the switching valve 43 has an engine rotation speed of 160Or-I)-
It turns off when the pressure is above 160 (lr-p-rn) and opens the first negative pressure chamber 18 to the atmosphere, and turns on when the pressure is below 160 (lr-p-rn) and the first
Negative pressure chamber 1.8I! Maintain a=M negative pressure.

When such an engine control device 40 is running, the second switch 42 is turned on, the fuel control valve 7 is turned on, and the switching valve 43 is also turned on, as shown in FIG. 8. /1- As shown in FIG. During deceleration, the second switch 42 is turned off, the fuel control valve 7 is turned off, and fuel injection from the idle boat 6 is prevented. At this time, the switching valve 43 is also turned off, the first negative pressure chamber 18 is maintained at atmospheric pressure, and the ignition timing is maintained at the retarded position Y. When the vehicle accelerates more rapidly than this, the second switch 42 turns off.

The fuel side ω1j valve 7 is turned on, and the switching valve 43 is also turned on.

At this time, the high negative pressure in the second negative pressure chamber 20 is gradually reduced to a low negative pressure by the throttle 23. During idling, the F negative pressure and M negative pressure are both high, the first switch 11 is turned on, and the second switch 11 is turned on.
The switch 42 is turned off, the fuel control valve 7 is turned on, and the switching valve 43 is turned on. As a result, the ignition timing maintains the idle advance angle Z (see FIGS. 6 and 8).

- This engine control device 40 also exhibits the same effects as the device 1 in FIG. Moreover, the number of parts per unit is smaller, making it easier to reduce costs.

[Brief explanation of drawings]

Approximate side sectional view % Figure 3 is an explanatory diagram of the operation of the vacuum advance device in the engine control device in Figure 2, Figure 4 is a characteristic diagram of 1) negative pressure, and Figure 5 is the engine control diagram in Figure 2. The ignition timing characteristic diagram of the control device 111, FIG. 6, shows the operating range of the engine control device of FIG. 2 -T#j! 8 and 8 respectively show ignition timing characteristic diagrams obtained by the engine control device shown in FIG. 7. 1.40... Engine open side 1 device, 3...
Vacuum advance angle' device, 4...Throttle valve. 5... Slow fuel path, 6... Idle port, 7... Fuel side 1 valve, 17.19.
... diaphragm, 18... first negative pressure chamber,
20... 2nd negative pressure chamber Ryo 9 Z 2 ports, 7 Torr open scale

Claims (1)

[Claims] A vacuum advance device that advances or retards the ignition timing in response to negative pressure in the engine intake system, and a jet port that opens near the downstream side of the throttle valve of the captor that forms the intake system and that spouts fuel for the slow system. The vacuum advance device has an advance side negative pressure chamber that receives negative pressure, a retard side negative pressure chamber that can communicate with the downstream side of the throttle valve, and the advance 0fIl negative pressure chamber and the retard side negative pressure chamber. Two movable partition walls that move the side negative pressure chambers toward and away from each other and advance and retard; and means for delaying the flow of gas in the retarded side negative pressure chamber, and the engine speed is greater than a set value, During deceleration, when the negative pressure on the downstream side of the throttle valve is greater than the set value, both of the two 0■ dynamic bulkheads operate to the retard side, and the slow system is equipped with a valve that cuts off fuel during deceleration. .