JPS5849390Y2 - Engine output control device - Google Patents

Description

[Detailed description of the invention] This invention is designed to reduce the low output force that occurs at the beginning of acceleration in an engine equipped with an exhaust gas recirculation device that recirculates a part of the exhaust gas emitted from the engine to the intake system. This invention relates to an engine output control device.

BACKGROUND ART Conventionally, as an exhaust gas purification device, the technical concept of suppressing the maximum combustion temperature in an engine by using recirculated exhaust gas to prevent the generation of NOx is well known.

Furthermore, focusing on the fact that the generation of NOx components in exhaust gas is high when the engine is accelerating and low during steady running, a recirculation passage that recirculates part of the exhaust gas to the engine intake system is installed downstream of the carburetor throttle valve. A control valve is provided in the recirculation passage to control the amount or timing of recirculation of the exhaust gas, and the control valve recirculates the exhaust gas during acceleration or increases the amount of recirculation of the exhaust gas during acceleration. Exhaust gas recirculation devices have been proposed.

However, in an engine equipped with an exhaust gas recirculation device as described above, during acceleration, engine combustibility deteriorates due to exhaust gas recirculation or an increase in the amount of exhaust gas recirculation, resulting in a decrease in engine output.

In particular, a sudden drop in output occurs at the beginning of acceleration, causing a shock to the driving sensation.Furthermore, the engine does not respond immediately to the acceleration operation of the accelerator pedal, resulting in no acceleration at the beginning of acceleration, resulting in a constant There was an issue where the game would start to accelerate after a time delay.

Therefore, in an engine equipped with the above-mentioned exhaust gas recirculation device, the present invention temporarily supplies auxiliary air to the downstream side of the carburetor throttle valve in the intake passage at the beginning of acceleration to temporarily reduce the amount of exhaust gas recirculation. An object of the present invention is to provide an engine output control device that reduces the output drop at the early stage of acceleration and alleviates the shock to the driving feeling by reducing the engine combustion performance and promoting the combustion performance of the engine.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

In the drawing, 1 is an intake passage that supplies fresh air to the engine (not shown), and the flow rate of fresh air flowing into the intake passage 1 from the direction of the arrow is controlled by the gasification valve that is linked to the accelerator pedal (not shown). It is controlled by the throttle valve 2.

3 is a recirculation passage that recirculates part of the exhaust gas emitted from the engine to the intake system, and one end is connected to the exhaust system (not shown).
The other end opens downstream of the carburetor throttle valve 2 in the intake passage 1, and a reflux valve 5 which is opened and closed by a diaphragm device 4 is interposed in the middle of the reflux passage 3.

This diaphragm device 4 has a negative pressure chamber 4b and an atmospheric chamber 4c partitioned by a diaphragm 4a, a negative pressure introduction passage 6 is connected to the negative pressure chamber 4b, and the diaphragm 4a is connected to the reflux through a rod 4d. It is connected to the valve 5, and is configured to bias the reflux valve 5 in the closing direction by a spring 4e, and open the reflux valve 5 by biasing the diaphragm 4a caused by introducing negative pressure into the negative pressure chamber 4b. ing.

A three-way solenoid valve 8 is interposed in the middle of the negative pressure introduction passage 6 and is operated in conjunction with the square switch 7 in response to a detection signal thereof.

This three-way solenoid valve 8 has a negative pressure chamber side communication port 8a, a negative pressure introduction side communication port 8b, and an atmosphere opening port 8c, and normally the negative pressure introduction side communication port 8b is closed and the negative pressure chamber The side communication port 8a and the atmosphere opening port 8c communicate with each other to open the negative pressure chamber 4b of the diaphragm device 4 to the atmosphere, and during operation, the atmosphere opening port 8c is closed, and the negative pressure chamber side communication port 8a and the negative pressure introduction side It is configured to communicate with the communication port 8b to introduce negative pressure into the negative pressure chamber 4b.

Reference numeral 9 denotes a differential pressure-operated acceleration detection device for detecting the acceleration of the engine, and when the acceleration is detected, the limit switch 7 is activated.
The three-way solenoid valve 8 is operated through the solenoid valve 8.

To explain this differential pressure operated acceleration detection device 9 in detail, a negative pressure outlet 10 is provided in the intake passage 1 on the downstream side of the carburetor throttle valve 2, and a negative pressure passage 11 is connected to this negative pressure outlet 10. ,
This negative pressure passage 11 is branched into a first passage 12 and a second passage 13. The first passage 12 is connected to the first chamber 14a of the diaphragm device 14, and the second passage 13 is connected to the second
They are each communicated with the chamber 14b.

This diaphragm device 14 has the first chamber 14a and the second chamber 14b partitioned by a diaphragm 14c, a rod 14d is connected to the diaphragm 14c, the other end of the rod 14d faces the limit switch 7,
The spring 14e is configured to bias the diaphragm 14c in the opposite direction to the limit switch 7 side, and the spring force of the spring 14e is applied during acceleration when the pressure in the second chamber 14b is lower than the pressure in the first chamber 14a by a set value or more. By biasing the diaphragm 14c, this diaphragm 14
The limit switch 7 is set to be activated by the bias of c.

Furthermore, a delay device 15 is interposed in the middle of the second passage 13, and this delay device 15 is configured to act when the intake negative pressure at the negative pressure outlet 10 is suddenly decreased due to the opening operation of the carburetor throttle valve 2, etc. gradually transmits this decreasing change in intake negative pressure to the second chamber 14b side of the diaphragm device 14, and after a certain period of time, balances the pressure at the negative pressure outlet 10 and the pressure in the second chamber 14b, while conversely When the intake negative pressure at the pressure outlet 10 increases, the intake negative pressure at the throttle 15a and the negative pressure outlet 10 is transferred to the second chamber 14b so that the increased change in the intake negative pressure is immediately transmitted to the second chamber 14b. Opens when it is higher than the negative pressure of 14b (check valve 1
5b are arranged in parallel.

That is, when the intake negative pressure at the negative pressure outlet 10 is higher than the negative pressure in the second chamber 14b of the diaphragm device 14, the check valve isb opens and the pressure difference between the two suddenly disappears, and conversely, the negative pressure at the negative pressure outlet 10 When the negative pressure of the intake air is lower than the negative pressure of the second chambers 1 to 4b, the check valve 15b closes and communication is established only through the throttle 15a, and the pressure difference between the two does not disappear until a certain period of time has elapsed.

As a result of the above, during acceleration, the intake negative pressure rapidly decreases for a set time period, causing the second chamber 14b of the diaphragm device 14 to
A differential pressure-operated acceleration detection device 9 is configured, which detects acceleration by the deflection of the diaphragm 14c that occurs when the royal force becomes lower than the pressure in the first chamber 14a by a set value or more, and operates the limit switch 7.

The limit switch 7 also includes an acceleration fuel correction device 1.
6 are linked together, and when accelerating, acceleration fuel correction is performed based on the detection signal from the limit switch 7.

Reference numeral 17 denotes an air passage for supplying auxiliary air, the = end of which opens into an air cleaner (not shown), and the other end of which opens downstream of the carburetor throttle valve 2 of the intake passage 1.

An output control valve 19 that is opened and closed by a diaphragm device 18 is interposed in the air passage 17 .

The diaphragm device 18 has a first chamber 18b and a second chamber 18c separated by a diaphragm 18a, and the first chamber 18b and the second chamber 18c are connected to the balance hole 18.
d, the first chamber 18b communicates with the downstream side of the carburetor throttle valve 2 of the intake passage 1 via the negative pressure introduction passage 20, and the diaphragm 18a communicates with the output control valve 19 via the rod 18e. The output control valve 19 is pressed in the closing direction by the spring 18f, and when the intake negative pressure downstream of the carburetor throttle valve 2 in the intake passage 1 suddenly decreases during acceleration, this negative pressure is transferred to the first chamber. 18b, and is configured to temporarily open the output control valve 19 by biasing the diaphragm 18a while the pressure in the second chamber 18c and the pressure in the first chamber 18b are balanced by the balance hole 18d. There is.

Next, to explain its operation, during steady running, the intake negative pressure at the negative pressure outlet 10 and the intake negative pressure at the opening 20a of the negative pressure introduction path 20 do not fluctuate, so the first chamber 14a of the diaphragm device 14 The negative pressure in the first chamber 18b and the second chamber 18c of the diaphragm device 18 also does not fluctuate, and the negative pressure in the first chamber 18b and second chamber 18c of the diaphragm device 18 does not fluctuate. 14c and 18a are not biased, so the acceleration detection device 9 does not operate, and the output control valve 19 does not operate.

On the other hand, during acceleration, the carburetor throttle valve 2 opens, so the intake negative pressure at the negative pressure outlet 10 is reduced, and the negative pressure in the first chamber 14a of the diaphragm device 14 also decreases rapidly.

However, at this time, since the intake negative pressure at the negative pressure outlet 10 is lower than the negative pressure in the second chamber 14b of the diaphragm device 14, the check valve 15b of the delay device 15 closes, and the intake negative pressure at the negative pressure outlet 10 is throttled. It is gradually transmitted to the second chamber 14b through 15a.

Therefore, while the pressure in the negative pressure outlet 10 and the pressure in the second chamber 14b are in equilibrium, the negative pressure in the second chamber 14b of the diaphragm device 14 is maintained higher than that in the first chamber 14a, and the pressure is set between the two. A pressure difference greater than the value is generated, and this pressure difference biases the diaphragm 14c against the spring force of the spring 14e, causing the switch 7 to be actuated via the rod 14d.

The three-way solenoid valve 8 is actuated by the detection signal of the limit switch 7, and its atmosphere opening port 8c is closed, and the negative pressure chamber side communication port 8a and the negative pressure introduction side communication port 8b are communicated with each other, so that the diaphragm device 4 Negative pressure is introduced into the negative pressure chamber 4b.

The introduction of this negative pressure biases the diaphragm 4a of the diaphragm device 4, causing the reflux valve 5 to open via the rod 4d.

Therefore, part of the exhaust gas passes through the recirculation passage 3 and is recirculated to the downstream side of the carburetor throttle valve 2 of the intake passage 1, or the amount of exhaust gas recirculation is increased.

The reflux time during this acceleration is determined by the flow path area of the throttle 15a of the delay device 15, which is designed in consideration of the normal acceleration duration.

Further, the acceleration fuel correction device 16 is also activated by the operation of the switch 7 due to the operation of the acceleration detection device 9, and the acceleration fuel is corrected for the set time period.

In this case, simultaneously with the acceleration, the intake negative pressure at the opening 20a of the negative pressure introduction path 20 also decreases, and the negative pressure in the first chamber 18b of the diaphragm device 18 also decreases rapidly through the negative pressure introduction path 20. The intake negative pressure is gradually transmitted through the second chamber 18c and the balance hole 18d.

Therefore, during the moment when the pressure in the first chamber 18b and the pressure in the second chamber 18c of the diaphragm device 18 are balanced, the second chamber 18
Since the negative pressure in c is maintained higher than the negative pressure in the first chamber 18b, the diaphragm 18a is biased against the spring force of the spring 18f due to this pressure difference, and the output control valve 19 is closed via the rod 18e. The opening operation is performed to open the air passage 17.

Therefore, the auxiliary air temporarily enters the intake passage 1 at the beginning of acceleration.
This supply of auxiliary air lowers the intake negative pressure downstream of the throttle valve 2, and this decrease in intake negative pressure reduces the amount of recirculated exhaust gas sucked. This reduces the sudden drop in output at the beginning of acceleration due to the recirculation or increase in the amount of exhaust gas, and after the set time when the auxiliary air is supplied, the output characteristics smoothly return to those in the state of recirculation or increase in the amount of exhaust gas. Transition.

The time for temporarily supplying the auxiliary air at the beginning of this acceleration is naturally shorter than the recirculation time during the acceleration, and is set by the flow path area of the balance hole 18d and the spring force of the spring 18f.

In addition, the supply amount of the auxiliary air at that time is the air passage 170.
It is set by the passage area, for example, the passage area at the valve seat 19a of the output control valve 19.

In the above embodiment, the output control valve 19 is
Although the output control valve 19 is actuated directly through the rod 18e of the diaphragm device 18, the deflection of the diaphragm 18a may be electrically converted to actuate the output control valve 19.

Further, in the above embodiment, the recirculation valve 5 is operated via the acceleration detection device 9, the limit switch 7, the three-way solenoid valve 8, and the diaphragm device 4, but the acceleration detection device 9
The reflux valve 5 may be actuated directly via the rod 14d of the diaphragm device 14.

As described above, according to the present invention, an engine equipped with an exhaust gas recirculation device that recirculates exhaust gas to the downstream side of the carburetor throttle valve in the intake passage or increases the amount of exhaust gas recirculation during acceleration. By temporarily supplying auxiliary air to the downstream side of the carburetor throttle valve in the intake passage at the beginning, it is possible to reduce the sudden drop in output at the beginning of acceleration and alleviate the shock to the driving feel, thereby increasing the output. The characteristics become smoother, and it is possible to obtain acceleration output characteristics that almost respond to the operation of the accelerator pedal.

In addition, normally, when accelerating, the air-fuel ratio of the air-fuel mixture during acceleration is made rich (13 or less) using an acceleration fuel correction device in order to increase the output.In this case, by supplying auxiliary air, the In addition to reducing exhaust gas, the reduction in output can be more effectively suppressed by correcting the air-fuel ratio.

[Brief explanation of drawings]

The drawings are schematic diagrams illustrating embodiments of the invention. 1... Intake passage, 2... Carburetor throttle valve,
3... Reflux passage, 4... Diaphragm device, 5... Reflux valve, 9... Acceleration detection device, 14... Diaphragm device , 15...
...Delay device, 17...Air passage, 18...
...Diaphragm device, 18a...Diaphragm, 18b...First chamber, 18c...
・Second room, 18d...Balance hall, 18e
・・・・・・Rod, 18f・・・Spring,
19... Output control valve, 20... Negative pressure introduction path, 20a... Opening.

Claims (1)

[Scope of utility model registration request] A recirculation passage that recirculates part of the exhaust gas to the engine intake system is opened in the intake passage downstream of the carburetor throttle valve, and a control valve is installed in this recirculation passage to control the amount or timing of recirculation of the exhaust gas. In an engine equipped with an exhaust gas recirculation device that recirculates exhaust gas during acceleration or increases the amount of recirculation of exhaust gas during acceleration using a control valve, air that supplies air to the downstream side of the carburetor throttle valve in the intake passage. An output control device for an engine, characterized in that an air passage is opened and an output control valve that is temporarily opened at an early stage of acceleration is provided in the air passage.