JPH0148384B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a throttle valve control device for an engine.

[Prior art]

Generally, a throttle valve control device for an engine controls the opening and closing of a throttle valve in response to an accelerator operation by a driver. In this device, when the driver takes his foot off the accelerator pedal, the throttle valve will naturally close to the fully closed position and the engine will be decelerated. If the degree is simply the idle opening degree, the intake air filling efficiency decreases and the combustibility worsens, so there is a problem that unburned components in the exhaust gas increase depending on the operating state immediately before deceleration.

One of the devices designed to solve this problem is the so-called throttle positioner, as shown in Japanese Utility Model Application Publication No. 54-145723. During the above deceleration, the fully closed opening of the throttle valve is made slightly larger than the idling opening.

However, with this conventional device, if the set value of the engine speed is set to a small value, the throttle valve will remain open for a long time, or in other words, open more than the idle opening until just before the vehicle stops, impairing the feeling of deceleration. In reality, the set value of the engine rotational speed was set to a relatively large value, and as a result, there was a risk that the unburned components in the exhaust gas could not be sufficiently reduced.

[Purpose of the invention]

SUMMARY OF THE INVENTION In view of these problems, it is an object of the present invention to provide an engine throttle valve control device that can significantly reduce unburned components during deceleration without impairing the feeling of deceleration.

[Structure of the invention]

By the way, when decelerating a vehicle, it is common to not only decelerate the engine by taking your foot off the accelerator pedal as described above, but also to brake the wheels by depressing the brake pedal. During this brake operation, the vehicle is decelerated regardless of the opening degree of the throttle valve, and a sufficient feeling of deceleration can be obtained.

Therefore, the present invention provides an engine throttle valve control device that opens the throttle valve to a greater extent than the idling opening when the engine speed decelerates to a set value or higher. The system is designed to change and correct the value on the rotation side, thereby ensuring a sense of deceleration through brake operation, and reducing unburned components by keeping the throttle valve open for a long time. .

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

The drawing shows an engine throttle valve control device according to an embodiment of the present invention. In the figure, 1 is an intake passage of an engine, and a carburetor 2 is provided in the middle of the intake passage 1.
A throttle valve 3 is disposed on the downstream side, and the throttle valve 3 is opened and closed in conjunction with an access pedal (not shown).

The throttle valve 3 is provided with an actuator 4 that increases its fully closed opening degree. In this actuator 4, a locking lever 5 is integrally formed on the shaft 3a of the throttle valve 3, and the locking lever 5 abuts and locks with a bent portion 6a at the tip of the rod 6. It's summery. The other end of this rod 6 is fixed to the atmospheric pressure chamber 7b side of the diaphragm 7a of the diaphragm device 7,
On the other hand, a spring member 7d is disposed in the negative pressure chamber 7c of the diaphragm device 7 to bias the diaphragm 7a toward the atmospheric pressure chamber 7b. Further, one end of a negative pressure introduction passage 8 is connected to this negative pressure chamber 7c, and the other end of the negative pressure introduction passage 8 is connected to a throttle valve 3 of the intake passage 1.
Connected to the downstream side. A three-way solenoid 9 is interposed in the middle of this negative pressure introduction passage 8, and the three-way solenoid 9 normally introduces atmospheric pressure from its atmosphere opening 9a into the negative pressure chamber 7c, and receives a drive signal b. When this happens, the negative pressure downstream of the throttle valve 3 is introduced into the negative pressure chamber 7c.

Further, in the figure, 10 is a brake pedal, 11 is a brake, 12 is a hydraulic passage that supplies hydraulic pressure to the brake 11 in accordance with the depression operation of the brake pedal 10, and 1
3 is the brake 11 due to the change in oil pressure in the hydraulic passage 12.
14 is an engine rotation speed sensor (engine rotation speed detection means) that detects the engine rotation speed, and 15 is a setting corresponding to the set value of the engine rotation speed. a set voltage generation circuit that generates the voltage a, 16 a voltage correction circuit (set value changing means) that receives the detection signal from the pressure switch 13 and corrects the set voltage a by changing it to a value on the low engine rotation side;
7 is a comparison circuit that compares the output of the engine rotation speed sensor 14 and the output of the voltage correction circuit 16; 18 is an amplifier circuit that amplifies the output of the comparison circuit 17 and applies it as a drive signal b to the three-way solenoid 9; The circuit 15-18 constitutes a determining means for determining that the engine speed is equal to or higher than a set value.

Next, the operation will be explained.

When the engine rotation speed is detected by the engine rotation speed sensor 14, the output of the sensor 14 is transferred to the comparison circuit 1.
7, it is compared with the set voltage a. When the engine speed is higher than the set speed, the comparison circuit 17 outputs a signal "1", and the signal "1" is amplified by the amplifier circuit 18 and applied to the three-way solenoid 9 as a drive signal b. . Then, in the diaphragm device 7, the throttle valve 3 is inserted into the negative pressure chamber 7c.
Downstream negative pressure is introduced, the diaphragm 7a deforms and moves in the direction of arrow A in the figure against the spring force of the spring member 7d, and the rod 6 is in a state of being slid in the direction of arrow A. When the driver takes his foot off the accelerator pedal in this state, the throttle valve 3 rotates in the direction of arrow B in the figure, and the locking lever 5 locks into the bent portion of the rod 6.
When it comes into contact with a, the throttle valve 3 is prevented from rotating, and the throttle valve 3 is held at a fully closed opening larger than the idling opening, thereby decelerating the engine and providing an appropriate amount of intake air. When inhaled, combustibility is ensured and the generation of unburned components is suppressed.

When the engine is decelerated in this manner and the engine speed becomes equal to or less than the set value, the output of the comparator circuit 17 becomes "0" and the output of the drive signal b is stopped. Then, in the diaphragm device 7, atmospheric pressure is introduced into the negative pressure chamber 7c through the atmosphere opening port 9a, and the diaphragm 7a is moved to A by the spring force of the spring member 7d.
The rod 6 deforms and returns in the opposite direction to the direction A, and the locking lever 5 further moves in the direction of arrow B.
The throttle valve 3 closes to the idle opening degree, thereby significantly decelerating the engine.

When the brake pedal 10 is depressed during such engine deceleration, the brake 1
1 is activated, and at that time, the pressure switch 13 detects that the brake 11 is being operated from a change in the oil pressure in the hydraulic passage 12 and outputs a signal "1". In addition, in the circuit 16, the output a of the set voltage generating circuit 15 is corrected to a value on the low rotation side. Then, the comparator circuit 17 generates a signal "1" even in the lower rotation speed range, and the throttle valve 3 is maintained at the fully closed opening, which is slightly larger than the idle opening, even in the lower rotation range compared to when the brake is not operated. It will be done.

In the device of this embodiment as described above, the throttle valve is maintained at a fully closed opening larger than the idling opening even when the engine is in the low rotation range when the engine is decelerating and the brakes are applied. Unburned components in the gas can be significantly reduced, and the feeling of deceleration can be ensured by braking.

In the above embodiment, a diaphragm device is used as the actuator for increasing the fully closed opening degree of the throttle valve, but the actuator may be other than the diaphragm device, such as an electromagnetic solenoid. Further, the brake operation may be detected not from a change in oil pressure in the brake system but from the amount of depression of the brake pedal.

〔Effect of the invention〕

As described above, according to the present invention, in the engine throttle valve control device that opens the throttle valve to a greater extent than the idle opening when the engine speed is decelerated to a set value or more, when the brake is depressed, the Since the numerical setting value is changed and corrected to a value on the low rotation side, there is an effect that the unburned components during deceleration can be significantly reduced without impairing the feeling of deceleration.

[Brief explanation of drawings]

The drawing is a schematic configuration diagram of an engine throttle valve control device according to an embodiment of the present invention. 1... Intake passage, 3... Throttle valve, 4
... Actuator, 13 ... Pressure switch (brake operation detection means), 14 ... Engine speed sensor (engine speed detection means), 16 ... Voltage correction circuit (set value changing means), 19 ... Discrimination means.

Claims (1)

[Claims] 1. A throttle valve installed in the intake passage of the engine, an engine rotation speed detection means for detecting the engine rotation speed, and a determination means for determining whether the engine rotation speed is equal to or higher than a set value based on the output of the detection means. an actuator that receives an output from the discrimination means and increases the fully closed opening degree of the throttle valve when the engine speed is equal to or higher than a set value; and a brake operation detection means that detects that the brake is being operated. A throttle valve control device for an engine, comprising set value changing means for correcting the rotation speed setting value to a value on the low rotation side when the brake is operated in response to the output of the detection means.