JPS6133231Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a control device that aims to reduce the generation of harmful gases such as HC generated during deceleration without impairing the deceleration feeling in an internal combustion engine for an automobile. be.

When decelerating an internal combustion engine by rapidly closing the throttle valve, the negative pressure in the intake passage suddenly increases to the vacuum side, and gas exchange within the combustion chamber rapidly deteriorates, resulting in insufficient air or mixture failure. Temporarily thickening of air can cause misfire or incomplete combustion in the combustion chamber, resulting in a rapid increase in harmful gases such as HC, as well as afterburn in the exhaust passage from the engine and damage to purification equipment, etc. damage to the exhaust system. In this case, it is known that when the intake negative pressure during deceleration increases beyond a value on the vacuum side (approximately -600 mmHg), the generation of HC etc. increases significantly.

Therefore, in recent engines, a throttle control device such as a dart pot or a throttle positioner is installed in conjunction with the rotating operation of the throttle valve, which controls various operating states, and the throttle valve is adjusted to a certain opening degree when closing the throttle valve. A gradual closing stroke is provided that gradually closes the angle between the opening and the fully closed position (idle opening) to prevent a sudden increase in intake negative pressure when the engine is decelerated.

However, in conventional throttle control devices such as dart pots and throttle positioners, the speed at which the throttle valve is gently closed during the gentle closing stroke is always constant regardless of the engine speed and vehicle speed. Although setting the slow closing speed in the stroke can reduce HC during deceleration from all engine speed ranges and all vehicle speed ranges, when decelerating from medium or low engine speeds and medium or low vehicle speed ranges, Engine braking is poor and dangerous, and deceleration feeling deteriorates. In addition, if the slow closing speed in the slow closing stroke is increased to improve the effectiveness of engine braking, the HC
could only be reduced slightly.

The present invention provides the throttle control device including:
By adjusting and controlling the slow closing speed of the throttle valve during the slow closing stroke according to three conditions: intake negative pressure, engine speed, and vehicle speed, the slow closing speed of the throttle valve is increased during deceleration when HC is less likely to occur. While improving the efficiency of engine braking,
During deceleration, when HC occurs frequently, the slow closing speed of the throttle valve is slowed down to prevent a sudden rise in intake negative pressure.

Therefore, the present invention connects a pressure chamber in a pressure-operated throttle control device provided for a throttle valve of a carburetor to the atmosphere or an intake passage through a passage in which an orifice and a check valve are arranged in parallel. ,
A bypass passage is provided in the passage to bypass the orifice and the check valve, and the bypass passage is provided with an orifice and a normally open valve device in series, and the valve device is connected to the intake air downstream of the throttle valve. When the rotation speed and vehicle speed are below a certain set value and the intake negative pressure is larger than a certain set value on the vacuum side, the valve device closes and the intake negative pressure is reduced. The valve device is configured such that the valve device closes when is smaller than a certain setting value on the atmospheric side and when both the rotational speed and the vehicle speed are above a certain setting value.

Embodiments of the present invention will be described below with reference to the drawings. In the drawings, 1 is an engine, 2 is an intake passage, 3 is a carburetor attached to the intake passage 2, and 4 is an air cleaner, which is not shown in the carburetor 3. A lever 9 is fixed to the shaft 6 of the throttle valve 5, which is biased in the normally closed direction by a spring or the like, and is connected via a wire 8 or the like to an accent pedal 7 that is installed inside the vehicle.

Reference numeral 10 denotes a pressure-operated throttle control device such as a dash pot attached to an appropriate location on the main body of the carburetor 3. In the throttle control device 10, a diaphragm 12 defining a pressure chamber 11 is provided with the lever 9. It is provided with a rod 14 that comes into contact with the adjusting screw 13 at the tip, and a spring 15 that biases the rod 14 in the protruding direction is provided in the pressure chamber 11, and the pressure chamber 11 is connected to the air communication area such as the air cleaner 4 or the intake passage 2. (however, FIG. 1 shows the case where it is connected to the atmosphere communication point, and FIG. 2 shows the case where it is connected to the intake passage 2 through the passage 16'), an orifice 18 and an air cleaner are connected to the passage 16. 4 or a check valve 19 that opens only in the direction from the intake passage to the pressure chamber 11.
While the delay device 17 is provided, the passage 16 is provided with a bypass passage 20 for the first delay device 17, and the bypass passage 20 includes an orifice 22 and an air cleaner 4 or an air cleaner 4 or an intake passage 2 that opens only in the direction of the pressure chamber 11. A second delay device 21 is provided in parallel with a check valve 23, and a solenoid valve 24 which is normally closed and opens when energized is provided.

In the electric circuit 26 connecting the electromagnetic valve 24 and the battery 25, there is a connection between the solenoid valve 24 and the battery 25, in which the intake negative pressure is higher than a certain value (for example, −600 mmHg) on the vacuum side. If it becomes OFF
A negative pressure switch 27 is provided in the electrical circuit 26, and a rotary switch 28 is provided in the electric circuit 26, which turns off when the engine speed exceeds a certain value (for example, 2000 rpm). and the vehicle speed is related to the vehicle speed (e.g. 40
A vehicle speed switch 29 is provided in parallel with the vehicle speed switch 29, which turns off when the vehicle speed becomes faster than (Km/hr).

In this configuration, at the throttle opening when the throttle valve 5 is in an idling state, the intake negative pressure is not high enough to the vacuum side to turn the negative pressure switch 27 OFF, and the negative pressure switch 27 is ON. Since the engine speed and vehicle speed are low and the switches 28 and 29 are ON, the solenoid valve 24 in the bypass passage 20 is open. From this state, when the throttle valve 5 is opened wide by depressing the accelerator pedal 7, the engine speed and vehicle speed increase. Since the force that biases the valve in the closing direction is removed, the rod 14 causes both delay devices 17,
Orifices 18, 22 and check valve 1 in 21
As pressurized fluid on the atmospheric side is further rapidly sucked in from 9 and 23, it protrudes almost simultaneously with the throttle valve 5.

Next, during deceleration when the throttle valve 5 is suddenly closed by releasing the accelerator pedal 7, the lever 9 on the shaft 6 of the throttle valve 5 is moved before the throttle valve 5 reaches the closed position (idle opening). Since the rod 14 comes into contact with the protruding rod 14 and a force that biases the throttle valve 5 in the closing direction acts on the rod 14, the throttle valve 5 during the closing movement acts on the rod 14.
is the pressure chamber 11 in the throttle control device 10
As the fluid in the first delay device 17 exits from the orifice 18 of the first delay device 17 or the orifices 18, 22 of both the first and second delay devices 17, 21, the spring 15 is compressed and gradually reaches the closed position (idle opening degree). Thus, the period from the position where it abuts the protruding rod 14 to the closed position is maintained in the gentle closing stroke range.

When decelerating by rapidly closing the throttle valve 5,
If the intake negative pressure is the set value of the negative pressure switch 27 (for example -
600mmHg) and increases toward the vacuum side,
HC in the exhaust gas increases significantly. When the intake negative pressure exceeds the set value during this deceleration, the negative pressure switch 27 is turned OFF, the solenoid valve 24 is closed, and the fluid in the pressure chamber 11 of the throttle control device 10 is released only through the orifice 18 in the first delay device 17. In particular, since the speed of gradual closing of the throttle valve 5 is slowed, there is no sudden rise in the intake negative pressure thereafter, and the occurrence of HC is prevented.

Also, during deceleration, the intake negative pressure is switched to the negative pressure switch 2.
Even if the engine speed and vehicle speed do not exceed the set values of rotation switch 28 and vehicle speed switch 29 (for example, 2000 rpm, 40 Km/hr)
When decelerating from an operating condition exceeding
is much less than when exceeding the set value of , but
It takes time for the rotational speed and vehicle speed to decelerate from the high speed range, and during this time the HC increases in total.During such deceleration, even if the negative pressure switch 27 is ON, the rotation switch 28 and the vehicle speed switch are 29 are both OFF, so the solenoid valve 24 is closed, and fluid flow is performed only through the orifice 18, and the throttle control device 1
Since the slow closing speed of the throttle valve 5 due to 0 is slowed down, the intake negative pressure does not rise rapidly toward the vacuum side, and the concentration of HC in the exhaust gas is reduced, making it possible to reduce the total amount of HC.

Then, the rotation speed of the engine is determined by the rotation switch 28.
Even if it is above the set value (e.g. 2000r.pm),
When the vehicle speed is set to the vehicle speed switch 29 (for example, 40
Km/hr), when decelerating from a state where the vehicle speed is higher than the setting value of the vehicle speed switch 29 but the rotation speed is lower than the setting value of the rotation switch 28, or when the rotation speed and speed are lower than the setting value of the rotation switch 28. When decelerating from a state where the vehicle speed is lower than each set value, HC
The occurrence of this is extremely rare, and deceleration can be achieved in a short period of time. During such deceleration, while the negative pressure switch 27 is ON, one or both of the rotation switch 28 and the vehicle speed switch 29 are ON.
When ON, the solenoid valve 24 of the bypass passage 20 is opened, so the fluid in the pressure chamber 11 in the throttle control device 10 escapes from the orifices 18, 22 in the delay devices 17, 21, and the throttle valve 5 is turned on. The speed of gradual closing is faster than in the case described above, and therefore the efficiency of engine braking is improved.

In the above embodiment, both the delay devices 17 and 21 were provided with the check valves 19 and 23, respectively, but the second delay device 21, that is, the bypass passage 20
Needless to say, the check valve 23 is not necessarily provided in the engine, and the set values for the intake negative pressure, rotational speed, and vehicle speed may be arbitrarily set according to the characteristics of the engine.

As described above, the present invention uses a normally open valve device installed in a bypass passage for a pressure chamber in a pressure-operated throttle control device to control the intake negative pressure downstream of the throttle valve, the engine speed, and the vehicle speed.
When the rotation speed and vehicle speed are below a certain set value and the intake negative pressure is larger on the vacuum side than a certain set value, and when the intake negative pressure is smaller than a certain set value on the atmospheric side, and the rotation speed and vehicle speed are are related to each other so that they are closed when both of them are above a certain set value, and when the throttle valve is slowly closed by the throttle control device from a certain opening degree to the closed position during deceleration to rapidly close the throttle valve. , during deceleration when HC in the exhaust gas is large, the slow closing speed can be slowed down, and during deceleration when HC in the exhaust gas is low, the slow closing speed can be increased to improve the efficiency of engine braking. In automobile engines, HC can be used without impairing the deceleration feeling during deceleration from any operating range.
It has the effect of reliably and accurately reducing harmful gases such as, and preventing afterburn.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the first embodiment of the present invention, and FIG.
The figure shows a second embodiment. 1...engine, 2...intake passage, 3...carburizer,
5... Throttle valve, 10... Throttle control device, 14... Rod, 12... Diaphragm, 1
DESCRIPTION OF SYMBOLS 1... Pressure chamber, 16... Passage, 17... First delay device, 18... Orifice, 19... Check valve, 2
0... Bypass passage, 21... Second delay device, 2
2... Orifice, 23... Check valve, 24... Solenoid valve, 27... Negative pressure switch, 28... Rotation switch, 29... Vehicle speed switch.

Claims (1)

[Scope of utility model registration request] A pressure chamber in a pressure-operated throttle control device provided for a throttle valve of a carburetor is connected to the atmosphere or an intake passage through a passage in which an orifice and a check valve are arranged in parallel; and a bypass passage that bypasses the check valve, and the bypass passage is provided with an orifice and a normally open valve device in series, and the valve device is connected to the intake negative pressure downstream of the throttle valve and the engine rotation speed. The valve device closes when the rotation speed and vehicle speed are below a certain set value and the intake negative pressure is greater than the certain set value on the vacuum side, and the intake negative pressure is lower than the certain set value. 1. A deceleration control device for an internal combustion engine for an automobile, characterized in that a valve device is connected to close when the rotational speed is small to the atmosphere side and when both the rotational speed and the vehicle speed are above a certain set value.