JPH06146933A - Throttle opening control device at deceleration - Google Patents

Abstract

PURPOSE:To prevent deterioration of antistalling property even though engine speed is reduced during operation in the highlands condition, and prevent generation of bad fuel consumption or inferior effect of engine brake during operation in the level land condition. CONSTITUTION:This throttle opening control device is provided with a dash pot 15 to delay sudden return of a throttle, a negative pressure changeover valve 23 to selectively communicate the opening 22 of the dash pot 15 to a negative pressure source or the atmosphere, and an engine control device 12 to control the negative pressure changeover valve 23 according to the atmospheric pressure, and in the highlands condition in which the atmospheric pressure is low, the opening 22 is opened to the atmosphere so as to effectively actuate the dash pot 15 and insure antistalling property during reducing engine speed. Meanwhile, in the level land condition in which the atmospheric pressure is high, the opening 22 is communicated to the negative pressure source so as not to actuate the dash pot 15, and hence bad fuel consumption or inferior effect of engine brake due to slow return of a throttle valve during reducing engine speed is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle opening control device which improves tribalability such as stall resistance by delaying a rapid return of the throttle opening during deceleration of an internal combustion engine. The present invention relates to a throttle opening control device at the time of deceleration capable of ensuring a stall property.

[0002]

2. Description of the Related Art A device using a dashpot with which a throttle valve arm is engaged in order to delay a rapid return of a throttle opening during deceleration of an internal combustion engine is disclosed, for example, in Japanese Utility Model Laid-Open No. 62-171633. It is well known as disclosed.

Recently, an air passage bypassing the throttle valve and a control valve for controlling the amount of air passing through the passage are provided without using a dashpot, and the control valve is opened / closed by detecting the engine speed. Also, there is known one provided with an idle speed control means for always keeping the idle speed constant, including during deceleration.

[0004]

By the way, when operating at high altitudes, the atmospheric pressure is low, and the stall resistance is reduced due to the small amount of oxygen per volume in the air, which reduces the dashpot characteristics (throttle return speed). ) Is adjusted according to the level ground condition, there is a problem that idling instability and engine stall are likely to occur when the vehicle is decelerated during operation under high altitude conditions. Therefore, it is possible to set the dashpot characteristics according to high altitude conditions when there is a possibility of driving in high altitude conditions, but in that case the throttle valve will return too slowly when operating in flat conditions. ,
There was a problem that fuel efficiency deteriorated, the effect of engine braking deteriorated, and the deceleration feeling deteriorated.

Further, in the case where the idling speed control means is provided, the amount of air is controlled so that the idling speed is kept constant even during deceleration under flat conditions, so that the stall resistance does not deteriorate. In addition, a certain number of revolutions is secured even during idle operation in high altitude conditions, but if the speed is reduced during operation in high altitude conditions, the control valve capacity will be insufficient and the stall resistance will drop, causing engine stall. There was a risk of. It is possible to increase the capacity of the control valve so that it can cope with deceleration under highland conditions, but this is not feasible because the cost increases.

In view of the above-mentioned conventional problems, the present invention does not deteriorate stall resistance even when decelerated during operation in high altitude conditions, and deteriorates fuel consumption and causes engine braking when operating in flat conditions. An object of the present invention is to provide a throttle opening control device at the time of deceleration that does not cause ineffectiveness.

[0007]

SUMMARY OF THE INVENTION The present invention is directed to a dashpot that delays the rapid return of the throttle, a negative pressure switching valve that selectively connects the opening of the dashpot to a negative pressure source and the atmosphere, and atmospheric pressure. And means for controlling the negative pressure switching valve in accordance with the above.

Preferably, the negative pressure switching valve control means is constituted by means for controlling according to the opening degree of the control valve in the idle speed control means.

[0009]

According to the present invention, under high altitude conditions where the atmospheric pressure is low, by opening the opening of the dashpot to the atmosphere with the negative pressure switching valve, the dashpot effectively acts and the stall resistance during deceleration is improved. On the other hand, under flat conditions with a high atmospheric pressure, the negative pressure switching valve connects the opening of the dashpot to the negative pressure source, so that the dashpot does not work and the throttle valve returns during deceleration. It is possible to prevent the deterioration of fuel efficiency and the ineffective braking of the engine due to being too late. A dashpot for level ground may be used together as a means for ensuring stall resistance during deceleration under level ground conditions, but if idle speed control means is provided, no special means is required. It is suitable to use together with the idle speed control means. Further, when the idle speed control means is provided, the negative pressure switching valve may be controlled according to the opening degree of the control valve, and the atmospheric pressure detection means need not be provided separately.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A throttle opening control device according to an embodiment of the present invention will be described below with reference to FIGS.

First, the overall construction of the engine intake system will be described with reference to FIG. 1 is a cylinder, 2 is an intake port, 3 is an intake manifold, 4 is an injector, 5 is a surge tank, and 6 is a throttle body. In the intake passage 6a of the throttle body 6, a throttle valve 7 for controlling the amount of intake air is arranged, and first and second bypass passages 8 and 9 for bypassing the throttle valve 7 are provided. Is provided with an idle adjust screw 10, and the second bypass passage 9 is provided with a control valve 11 controlled by an idle speed control unit of an engine control device 12.

As shown in FIG. 2, a throttle valve arm 13 is connected to the throttle valve 7 so as to swing together with the throttle valve 7.
The throttle valve arm 13 is mounted on the throttle body 6 by a bracket 14 and is a dashpot 1
It is configured to be engageable with the rod 16 of No. 5 near the fully closed position of the throttle valve 7.

In the dashpot 15, as shown in FIG. 1, the rod 16 is fixed to a diaphragm 18 arranged so as to face the damper chamber 17, and the rod 19 is fixed by a spring 19.
6 is configured to be urged toward a predetermined protruding position. The damper chamber 17 is in communication with the opening 22 through the throttle hole 20 and the one-way valve 21 which are arranged in parallel, and restricts the outflow of air from the damper chamber 17 so that the inflow of air is performed smoothly. Is configured.

The opening 22 of the dashpot 15 is connected to the outlet port 23a of the negative pressure switching valve 23. Of the two inlet ports 23b and 23c of the negative pressure switching valve 23, one inlet port 23b communicates with an air cleaner or the like and is opened to the atmosphere, and the other inlet port 23c is connected to a negative pressure source such as an intake manifold. There is. Then, the negative pressure switching valve 23 is switching-controlled by the engine control device 12 according to the atmospheric pressure. That is, when the atmospheric pressure is equal to or lower than a predetermined value under the highland condition, the outlet port 23a is communicated with the inlet port 23b which is open to the atmosphere, and when the atmospheric pressure is higher than the predetermined value under the flatland condition, the outlet port 23a is under negative pressure. It is connected to the inlet port 23c which is connected to the source.

As shown in FIG. 3, the idle speed control section of the engine control unit 12 includes a throttle valve 7
The throttle position signal indicating the position of the engine and the engine speed signal are input. When the throttle valve 7 is near the fully closed position, it is determined that the engine is idling, and the control valve 11 is opened according to the engine speed at that time. The engine speed is maintained at a predetermined idle speed by changing the intake air amount by controlling the engine speed. The opening degree of the control valve 11 is controlled by changing the duty ratio of the drive voltage according to the engine speed to change the average current.

Control valve 1 during this idle operation
The opening degree of 1 is large under highland conditions because the amount of oxygen per volume is small, and is small under highland conditions because the amount of oxygen is large. Therefore, when the duty ratio exceeds a predetermined value during idle operation, it is determined that the condition is high altitude, and the negative pressure switching valve 23 is switched to the atmosphere side. If the duty ratio is less than the predetermined value, it is determined that the condition is flat. The negative pressure switching valve 23 is switched to the negative pressure source side.

In the above structure, the outlet port 23a of the negative pressure switching valve 23 is changed to the inlet port 2 by the control signal from the engine control device 12 under the high altitude condition where the atmospheric pressure is low.
The open port 22 of the dashpot 15 is opened to the atmosphere by being communicated with 3b, and the inside of the damper chamber 17 is brought to the atmospheric pressure, so that the dashpot 15 is effectively operated.

That is, when the throttle valve 7 is suddenly closed, the throttle lever 13 contacts the rod 16 of the dashpot 15 before the throttle valve 7 is fully closed. Rod 16
Receives the urging force of the spring 19 and the amount of air outflowing in the damper chamber 17 is limited by the throttle hole 20, so that the valve slowly withdraws and the throttle valve 7 gradually closes. Therefore, the throttle valve 7 is fully closed during deceleration, and the stall resistance is secured.

On the other hand, under the level condition of high atmospheric pressure, if the throttle valve 7 is closed during deceleration, the engine control unit 12
The control valve 11 is controlled by and the stall resistance is secured by performing idle speed control.
Further, at this time, the outlet port 23a of the negative pressure switching valve 23 is communicated with the inlet port 23c, so that the dashpot 15
The opening 22 of is connected to the negative pressure source, and the dashpot 15
Does not work. That is, since the damper chamber 17 becomes a negative pressure, the diaphragm 18 moves against the biasing force of the spring 19, and the rod 16 retracts accordingly, and even if the throttle valve 7 is fully closed, the throttle valve arm is closed. 13 does not come into contact with the rod 16.

Thus, there is no possibility that the dashpot 15 is activated during the deceleration under the level ground condition and the throttle valve 7 returns too slowly, resulting in deterioration of fuel consumption and poor engine braking effectiveness.

In the above embodiment, an example in which the highland condition and the flatland condition are detected by the duty ratio of the drive voltage of the control valve 11 for controlling the idle speed is shown, but other detecting means may be used. For example, as shown in FIG. 3, when a pressure sensor 24 for detecting the intake pressure is provided in the surge tank 5 or the intake manifold 3 for air-fuel ratio control, and the detection signal is input to the engine control device 12. Includes a pressure sensor 24 when the engine is started.
Since the detection signal of 1 corresponds to the atmospheric pressure, the negative pressure control valve 23 may be controlled according to the detection signal.
Further, the atmospheric pressure detecting means may be separately provided.

Further, as a means for ensuring the stalling resistance during deceleration under flatland conditions, a dashpot for flatland can be used together.

[0023]

According to the throttle opening control device for deceleration of the present invention, the dashpot is effective by opening the opening of the dashpot to the atmosphere by the negative pressure switching valve under the high altitude conditions where the atmospheric pressure is low. It is possible to secure the stalling resistance during deceleration, while under the conditions of high level atmospheric pressure, the negative pressure switching valve connects the opening of the dashpot to the negative pressure source so that the dashpot does not work. When the vehicle is decelerating, it is possible to prevent the throttle valve from returning too slowly during deceleration, resulting in deterioration of fuel efficiency and engine braking effectiveness.

Further, when the idle speed control means is provided, if the negative pressure switching valve is controlled according to the opening of the control valve, the atmospheric pressure detection means need not be provided separately.

[Brief description of drawings]

FIG. 1 is a configuration diagram of essential parts of an embodiment of a throttle opening control device during deceleration of the present invention.

FIG. 2 is an arrangement configuration diagram of a throttle valve and a dashpot of the same embodiment.

FIG. 3 is a configuration diagram of an intake system of the same embodiment.

[Explanation of symbols]

 12 Engine control device 15 Dashpot 22 Opening port 23 Negative pressure switching valve

Claims (1)

[Claims] 1. A dashpot for delaying a rapid return of a throttle, a negative pressure switching valve for selectively communicating an opening of the dashpot with a negative pressure source and atmosphere, and a negative pressure switching valve according to atmospheric pressure. A throttle opening control device during deceleration, comprising: a control unit.