JPH02173318A - Slip controller for vehicle - Google Patents

Abstract

PURPOSE:To improve the responsive quality of a slip control, by providing a bypass passage at a space between the upper stream side of a supercharger at an air intake passage and the upper stream side of a throttle valve, and providing at its halfway point an air feed bypass valve at which a negative pressure source is changed over according to the decision result of a slip presence. CONSTITUTION:The compressor portion 8 of a turbo charger 7 is provided at the halfway portion of an air intake passage 4, and an intercooler 9 and a throttle valve 10 are provided on its lower stream side. Also, a bypass passage 11 is provided at a space between the upper stream side of the compressor 8 at the air intake passage 4 and the upper stream side of the throttle valve 10, and a valve seat 12 at which the valve body 13 of an air feed bypass valve 14 can be seated, is formed at an opening portion opening to its lower stream side end portion. A negative pressure chamber 16 divided by means of the diaphragm 18 of the air feed bypass valve 14 is made to be connectable to an air intake manifold 2 or a boost tank 21 through a changeover valve 20, and the changeover valve 20 conduct 5 control so that the negative pressure chamber 16 may be changed over to a side connecting to the boost tank 21 by means of a control circuit 23, in the case of a slip presence decision having been made.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a slip control device for a vehicle that controls the drive torque of drive wheels to prevent slip of the vehicle.

(Prior Art) In a vehicle in which a throttle valve driven by a stepper motor or the like is installed in the intake passage of the engine, when the driving wheels spin or slip during acceleration of the vehicle, a signal from a slip determining means is used to control the throttle valve. A slip control device is known that prevents slippage by automatically closing the valve and reducing the drive torque of the drive wheels.

On the other hand, the performance of vehicle engines continues to improve, and supercharging systems such as turbochargers use engine exhaust energy to drive a turbine and use this power to drive a compressor to precompress intake air or air-fuel mixture. Vehicles equipped with this machine are becoming popular.

(Problem to be Solved by the Invention) By the way, in a vehicle equipped with a supercharger, the above-mentioned slip determination means and a signal from the slip determination means drive a stepper motor to close a throttle valve and reduce the driving torque. When slip control is performed, the relationship between the opening degree of the throttle valve and the output torque of the engine changes due to a change in the supercharging pressure of the supercharger. Since the opening degrees of the throttle valves are different and the control accuracy is significantly reduced, it becomes difficult to perform accurate slip suppression control using the throttle valves.

In addition, if the throttle valve is suddenly controlled in the valve closing direction during supercharging, it will cause surging in the supercharger, which will affect the accuracy of the air flow sensor's air flow sensor's till accuracy. may cause rapid reflux of water.

In addition, in engines equipped with a supercharger, a bypass passage is provided between the upstream side of the supercharger and the Miura side of the throttle valve, and a bypass control is provided in this bypass passage that opens and closes depending on the pressure of the intake manifold downstream of the throttle valve. A bypass control valve is provided, and a bypass control valve is closed by the increase in pressure in the intake manifold during acceleration.
Some engines are designed to open the intake manifold due to a pressure drop during deceleration, thereby bypassing a portion of the supercharged air to the Miura side of the supercharger via a bypass passage.

However, when the drive wheels slip during acceleration, the pressure in the intake passage downstream of the thrower I/le valve becomes ■pressure due to the supercharging of the supercharger until the throttle valve closes, and this pressure causes the bypass control valve to The pressure decreases to such a level that the throttle valve opens only after a certain amount of air in the intake passage downstream of the throttle valve has been drawn into the engine. Therefore, even after the throttle valve is closed, the bypass control valve remains closed for a while, so if the throttle valve is closed, surging will occur, and if the throttle valve is left open for a certain amount of time, the turbocharger will supercharge the valve. Since the air continues to be drawn into the engine through the throttle valve, the reduction in driving torque is delayed and slip cannot be reduced immediately, making it impossible to achieve both surging prevention and traction control.

This invention was made in view of the above circumstances, and its purpose is to prevent surging of the supercharger.
Another object of the present invention is to provide a slip control device for a vehicle that can instantly reduce drive torque when a drive wheel slips and can perform appropriate traction control.

[Structure of the invention] (Means and effects for solving the problem) This invention has the following features:
In order to achieve the above object, a supercharger is provided in the middle of the intake passage, a throttle valve is provided downstream of the supercharger, and the upstream side of the supercharger and the upstream side of the throttle valve are bypassed. A bypass passage is provided, a diaphragm-type air supply bypass valve that opens when the negative pressure chamber becomes lower than a predetermined pressure in the bypass passage, a boost tank whose interior is maintained in a negative pressure state, and one end of which is connected to the negative pressure. a switching valve for communicating the negative pressure chamber with either the intake manifold or the boost tank by switching a valve control passage communicating with the chamber; a slip determination section for determining whether or not a drive wheel is in a slip state; When the determining section determines that there is no slip, the switching valve is set so that the negative and positive chamber communicates with the intake manifold, and when the determination section determines that there is slip, the negative pressure chamber communicates with the boost tank. A control circuit is provided for controlling.

When no slip occurs in the drive wheels, the switching valve communicates the negative pressure chamber with the intake manifold under control of the control circuit according to the slip determination section's determination of no slip. The pressure in the intake manifold decreases as the throttle valve closes, so when accelerating, the pressure in the negative pressure chamber increases and closes the intake air bypass valve, supplying air supercharged by the supercharger to the engine. During deceleration, the pressure in the negative pressure chamber decreases to open the air supply bypass valve, thereby preventing surging. Further, when a slip occurs in the driving wheels, the switching valve communicates the negative and positive chambers with the boost tank under the control of the control circuit in accordance with the determination of the presence of slip by the slip determination section. Since the pressure in the boost tank is negative even when the throttle valve is open, the air supply bypass valve opens and the supercharged air is released to the upstream side of the supercharger through the air supply bypass valve. This reduces the boost pressure.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is an engine, 2 is an intake manifold, and 3 is an exhaust manifold. One end of an intake passage 4 is connected to the intake manifold 2, and an intake air intake 6 having an air flow sensor 5 is provided at the other end. Further, a compressor section 8 of a turbocharger 7, for example, as a supercharger is located in the middle of the intake passage 4.
An intercooler 9 is provided downstream of the intercooler 9, and a throttle valve 10 is provided further downstream.

This throttle valve 10 is operated by a stepper motor (
(not shown) to control the opening degree.

Further, a bypass passage 11 is provided between the upstream side of the compressor section 8 and the upstream side of the throttle valve 10 in the intake passage 4 . A valve seat 12 is provided at one end of the bypass passage 11 at an opening between the intercooler 9 of the intake passage 4 and the throttle valve 10, and a valve body that moves toward and away from the valve seat 12. A supply air bypass valve 14 with 13 is provided. The air supply bypass valve 14 is of a diaphragm type, and a diaphragm 18 is provided inside the valve case 15 to partition the valve into an upper chamber 16 and a lower chamber 17 as negative pressure chambers.

The base end of the valve body 13 is connected to this diaphragm 18, and as the diaphragm 18 moves up and down, the valve body 13 approaches and separates from the valve seat 12, that is, the bypass passage 11
It is designed to open and close.

Further, the upper chamber 16 of the air supply bypass valve 14 is connected to the valve control passage 1
The valve control passage 19 communicates with the intake manifold 2 through a passageway 9, and a switching valve 20 consisting of a three-way solenoid is provided in the middle of the valve control passage 19.

The valve control passage 19 communicates with a boost tank 21 via this switching valve 20.
is connected to the intake manifold 2 via the one-way valve 22.
By communicating with the intake manifold 2, internal air is sucked out to the intake manifold 2, and the interior maintains a negative pressure state. Further, the switching valve 20 is switched on and off by a signal from a control circuit 23 such as an ECU, and when it is on, the upper chamber 16 of the air supply bypass valve 14 is connected to the boost tank 23.
1, and when off, the same chamber 16 connects to the intake manifold 2.
It will be communicated to. The control circuit 23 receives signals from a slip determining means 24 and the like that determines the slip state of the driving wheels.

Next, the operation of the vehicle slip control device configured as described above will be explained.

In normal running conditions, the switching valve 20 is in the OFF state, and the upper chamber 16 of the air supply bypass valve 14 communicates with the intake manifold 2 via the valve control passage 19. Therefore, the pressure of the intake manifold 2 is applied to the upper chamber 16 of the air supply bypass valve 14, but the pressure of the intake manifold 2 increases when the throttle valve 10 is opened during acceleration, and when the throttle valve 10 is closed during deceleration. During acceleration, the valve body 13 is pushed down and closed via the diaphragm 18, and during deceleration, it is pulled up and opened. When the throttle valve 10 closes and the air supply bypass valve 14 opens, a portion of the supercharged air in the intake passage 4 is returned to the upstream side of the compressor section 8 downstream of the air flow sensor 5 via the bypass passage 11, thereby eliminating surging. It can be prevented.

Furthermore, when the driving wheels slip while driving, the slip determination means 24 determines whether or not there is a slip, and when it is determined that a predetermined acceleration slip has occurred, an ON signal is sent to the switching valve 20 via the control circuit 23. is input. therefore,
The switching valve 20 communicates with the upper chamber 6 of the air supply bypass valve 14 and the boost tank 21 via a valve control passage 19. The air in the boost trunk 21 is sucked out into the intake manifold 2 via the one-way valve 22 when the pressure inside the intake manifold 2 becomes negative, and the air in the boost tank 21 is sucked out into the intake manifold 2 through the one-way valve 22.
Since a negative pressure state is maintained inside, the air supply bypass valve 14
Negative pressure of the boost tank 21 is applied to the upper chamber 16 of the boost tank 21 . When the pressure in the upper chamber 16 of the air supply bypass valve 14 becomes negative, the valve body 13 is pulled up via the diaphragm 18, and the air supply bypass valve ]-4 is opened even during acceleration. Therefore, a part of the supercharged air in the intake passage 4 escapes to the upstream side of the compressor section 8 downstream of the air flow sensor 5 via the bypass passage 11, and the supercharging pressure decreases. As a result, even during acceleration, when the drive wheels slip, the supercharging pressure is instantly reduced, eliminating the delay in reducing the driving force caused by the continued supply of supercharged air to the engine. In addition to improving the responsiveness of the suppression, the occurrence of surging can be prevented by letting the supercharged air escape upstream of the compressor section 8.

In addition, since the supercharged air is returned downstream of the air flow sensor 5 through the bypass passage 11, the air returned through the bypass passage 11 is measured again by the air flow sensor 5, and the amount of air actually taken in is smaller than the amount of air actually taken in. It will no longer be falsely detected that a large amount of air has been inhaled.

In the above embodiment, the bypass passage 1 was provided between the ``-stream side'' of the compressor section 8 of the intake passage 4 and the ''-stream side of the throttle valve 10. A bypass passage 11 may be provided between the Miura side and the upstream side of the intercooler 9.

〔Effect of the invention〕

As explained above, according to the present invention, a bypass passage is provided between the upstream side of the supercharger and the upstream side of the throttle valve in the intake passage, and the bypass passage is closed during acceleration.
Since an air supply bypass valve is provided that opens during deceleration, surging can be prevented from occurring. In addition, even during acceleration, when the drive wheels slip, the supercharging pressure can be instantly lowered to eliminate the delay in reducing the driving force due to the continued supply of supercharged air to the engine. It is possible to improve the responsiveness of slip suppression, and to prevent the occurrence of surging due to closing of the throttle valve to reduce slip.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a sleeve/tub control device showing an embodiment of the present invention. 1...Engine, 2...Intake manifold, 4...
Intake passage, 6...Intake air intake, 7...Turbocharger (supercharger) 10...Throttle knob, 11...Bypass passage, 14...Intake air valve ,] 4...Upper chamber (negative pressure chamber) 1...Valve control passage, 20...Switching valve, 2]...Boost tank, 23
...Control circuit. Applicant's agent Patent attorney Takehiko Suzue Figure 1

Claims (1)

[Claims] An intake passage that has an intake air intake at one end and is connected to the engine's intake manifold at the other end, a supercharger installed in the middle of this intake passage, and a throttle valve located downstream of the supercharger. a bypass passage that bypasses the upstream side of the supercharger and the upstream side of the throttle valve; and a diaphragm-type air supply bypass valve that is provided in the bypass passage and opens when the negative pressure chamber becomes lower than a predetermined pressure. , a boost tank whose interior is maintained in a negative pressure state, and a switching valve that switches a valve control passage whose one end communicates with the negative pressure chamber to communicate the negative pressure chamber with either the intake manifold or the boost tank. and a slip determination section that determines whether or not the driving wheels are in a slip state; and when the slip determination section determines that there is no slip, the negative pressure chamber communicates with the intake manifold, and it is determined that there is slip. and a control circuit for controlling a switching valve so that the negative pressure chamber communicates with the boost tank.