JP2527323Y2 - Vehicle driving force control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a driving force control device for a vehicle.

<Related Art> Generally, a vehicle travels according to a driver's intention by opening and closing a throttle valve via an accelerator device.

In recent years, in order to improve the drivability and comfort of vehicles,
In addition to the usual accelerator device, many of them are provided with an actuator which operates by an electric signal to open and close a throttle valve.

For example, recently, with the improvement of the trunk line automobile network, there are more opportunities to drive the vehicle at a constant vehicle speed without repeating acceleration and deceleration, so that the desired vehicle speed can be maintained without operating the accelerator pedal. A constant speed traveling device (hereinafter, AS
CD: Auto Speed Control Device)
Already installed in some vehicles.

<Problem to be solved by the invention> However, in a vehicle having such a conventional normal accelerator device or a vehicle equipped with an ASCD, the accelerator device or the ASCD has a failure and the accelerator pedal is not depressed. Nevertheless, when the engine output does not decrease, especially in a vehicle with an automatic transmission, when the select position is outside the [P] or [N] range, the driving force from the engine is always transmitted to the drive wheels. Therefore, there is a problem that even if the brake pedal is depressed, the driving force and the braking force compete with each other, and it becomes difficult to stop the vehicle.

Incidentally, as shown in JP-A-61-272445,
When the engine speed reaches a predetermined value, the fuel supply is cut off. However, since the engine speed is set to be higher than the normal maximum speed, there is little effect.

Therefore, the present invention reduces the drive torque transmitted to the drive system when the vehicle is kept at a high vehicle speed without a decrease in the engine output due to a malfunction of the accelerator device or ASCD, etc., even though the brake pedal is depressed. It is an object of the present invention to make the vehicle easier to stop and to improve the traveling safety of the vehicle by lowering the vehicle.

<Means for Solving the Problems> In order to achieve the above object, a vehicle driving force control device according to the present invention includes, as shown in FIG. 1, first detecting means for detecting the speed of a vehicle, and an actual engine. Second detecting means for detecting the output state of the brake, and third detecting means for detecting the operating state of the brake.
Based on signals from the first to third detecting means, when the vehicle speed is equal to or higher than a predetermined low vehicle speed, the engine output is equal to or higher than a predetermined output, and the brake is in an operating state. Signal output means for outputting a driving force reduction signal, and driving force reduction for controlling an automatic transmission including a torque converter to reduce driving force transmitted to a driving system in accordance with the driving force reduction signal from the signal output means. Means are provided.

<Operation> In the present invention, when the vehicle speed is equal to or higher than a predetermined low vehicle speed, the engine is in a high output state, and the brake is in operation, the drive system automatic transmission is controlled and transmitted to the drive. The force is operated in the downward direction.

Therefore, even when a failure occurs in the accelerator device, the ASCD, or the like, the vehicle can be easily stopped. Here, one of the driving force reduction conditions is that the vehicle speed is equal to or higher than a predetermined low vehicle speed, and prohibiting the reduction of the driving force below the predetermined low vehicle speed is performed on a low μ road (such as a snowy road). This is to ensure a smooth start / run by using the brakes in the step ()). In addition, since the accelerator opening is generally small at low vehicle speeds, the amount of change in the drive torque with respect to the amount of change in the accelerator opening is large, and therefore the driver may want to suppress the drive torque in combination with the brake. is there.

<Example> An example of the present invention will be described below.

2 and 3 are views showing an embodiment of the driving force control device for a vehicle according to the present invention.

First, the configuration will be described. In FIG. 2, reference numeral 1 denotes a vehicle speed sensor as first detecting means, which outputs a signal corresponding to the vehicle speed.

Reference numeral 2 denotes an engine output (load) sensor as a second detecting means, for example, a fuel supply amount supplied to the engine (a fuel injection pulse width when an electronic control fuel injection device is provided), an engine suction negative pressure (suction). The engine output is detected from various physical quantities related to the output of the engine, such as a negative pressure sensor output) or an intake air flow rate (air flow meter output), and a signal corresponding thereto is output.

Reference numeral 3 denotes a brake sensor as third detection means,
For example, a brake switch attached to a brake pedal (not shown) is used. The brake switch detects that the brake pedal is depressed, and outputs an ON signal. In addition, a brake fluid pressure sensor that detects the brake fluid pressure and outputs a signal corresponding to the brake fluid pressure, or a pressure switch that outputs an ON signal when the brake fluid pressure is equal to or higher than a predetermined value may be used.

A control unit 4 has a function as a signal output unit. That is, CPU, ROM, RA (not shown)
M, input / output ports, etc., the CPU sequentially executes the programs stored in the ROM, accesses the input ports, takes in the vehicle speed signal, engine output signal, brake signal, etc., and based on these signals, Processing (described later) is performed. As a result, when each of the signals satisfies a predetermined condition, an output port is accessed and a driving force reduction signal is output through the port.

Reference numeral 5 denotes an actuator as driving force reduction means, which controls the automatic transmission according to the driving force reduction signal from the control unit 4 to reduce the driving force transmitted to the driving system. The specific configuration of the driving force lowering means will be described later with reference to various examples.

 Next, the operation will be described.

FIG. 3 is a flowchart showing a control program executed in the control unit 4. This program is stored in the ROM of the control unit 4 and is executed at predetermined time intervals.

Hereinafter, description will be made according to this flowchart. First,
In step 1 (shown as S1 in the figure, the same applies hereinafter), the abnormality flag FLG is determined. If FLG = 0, step 2 is performed.
Reads various signals such as a vehicle speed signal, an engine output signal, and a brake signal. Next, at step 3, it is determined whether or not the vehicle speed is equal to or higher than a predetermined value. If the vehicle speed is equal to or higher than the predetermined value, the process proceeds to step 4, where the read engine output is compared with the predetermined value to determine whether the engine is in a predetermined high output state. If the engine is in the predetermined high output state, the routine proceeds to step 5, where it is determined based on the brake signal whether or not the brake is operating (for example, the brake pedal is being depressed or the brake fluid pressure is a predetermined value or more). In the case of the brake operation state, regardless of the brake operation state, the engine generates an output equal to or more than a predetermined value and the vehicle is running at high speed. After FLG is set to 1, the process proceeds to step 7, in which a driving force reduction signal is output to operate the actuator 5.

Also, once the abnormality flag FLG is set to 1,
In the determination in step 1, the process proceeds to step 7, in which the driving force reduction signal is output and the actuator 5 is continuously operated.

Thereby, the actuator 5 receives the driving force reduction signal and reduces the driving force transmitted to the driving system.

As a result, the driving force transmitted to the driving system is reduced, and as a result, the braking force due to the depression of the brake pedal is effectively exerted, and the vehicle can quickly stop at a reduced speed. Therefore, it is possible to easily stop the vehicle and improve the traveling safety of the vehicle.

On the other hand, when it is determined in step 3 that the vehicle speed is lower than the predetermined value and the vehicle is traveling at low speed, when it is determined in step 4 that the engine output is in a low output state equal to or less than the predetermined value, or in step 5 the brake is released. If it is determined that it is in the non-operation state, it is determined that it is normal in step 8, and the abnormality flag is held at 0.

Next, a specific configuration example of the driving force reducing means (actuator 5) will be described.

Fig. 4 shows an automatic transmission (A / T)
Using the control device 80)
The gear position is configured to be neutral.

In FIG. 4, an A / T control unit 81 is constituted by a microcomputer or the like, and based on various signals (not shown), that is, a vehicle speed signal, an accelerator opening signal, a shift operation signal, and the like, determines an optimal gear position corresponding to a traveling state. Decide,
The shift signal S _SEL indicating the determined shift configuration is changed to A / T82.
And when the driving force reduction signal is input,
The shift signal S _SEL is forcibly set to the [N] position and output. A /
T82 turns on / off a plurality of shift valves (not shown) according to the shift signal S _SEL , selectively switches the hydraulic circuit to supply hydraulic pressure to a plurality of friction elements, and sets the shift speed indicated by the shift signal S _SEL. To achieve. Alternatively, when the shift signal S _SEL indicates the [N] or [P] position, the power transmission system is opened without achieving any shift speed. The driving force from the engine 83 passes through the torque converter 84 in the A / T 82 and the achieved shift speed, and is torque-converted according to the speed ratio of the shift speed,
The power is transmitted from the output shaft 85 to the drive system. Alternatively, when the power transmission system is open, transmission of the driving force from the engine is not performed.

In such a configuration, the A / T control unit 8
When the operation signal _SCT is input to the A / T control unit 81, the A / T control unit 81 forcibly selects the [N] position and outputs a shift signal S _SEL indicating the [N] position to the A / T. Therefore, A / T82
Does not transmit the driving force to the driving system.

FIG. 5 shows a configuration in which an A / T governor pressure control device 90 is used as an actuator, and the shift stage is shifted to the highest stage in response to a driving force reduction signal.

In FIG. 5, reference numeral 91 denotes a governor valve provided in an A / T (not shown). The governor valve 91 controls the line pressure adjusted to a predetermined pressure according to the vehicle speed,
As shown in FIG. 6, a governor pressure having such a characteristic that the pressure becomes minimum at a vehicle speed of "0" and becomes a line pressure at a predetermined high vehicle speed is output. These line pressure and governor pressure are respectively applied to the ports s and t of the electromagnetic switching valve 92, and the electromagnetic switching valve 92 is of a single-electromagnetic spring offset type having two ports and two positions. The electromagnetic switching valve 92 normally closes the ports s and t with the illustrated position as a normal position, and when a driving force reduction signal is input, the electromagnet operates to open the ports s and t.

Therefore, when the driving force reduction signal is input, the governor pressure is increased to the line pressure regardless of the vehicle speed, and the shift valve and the timing valve (not shown) which operate under the governor pressure act as if the vehicle speed reaches a predetermined high vehicle speed. As described above, the A / T achieves the highest gear. For example, the third-speed A / T achieves the third speed, and the fourth-speed A / T achieves the fourth speed, that is, the overdrive OD.

As a result, the driving force transmitted to the driving system becomes smaller in accordance with the gear ratio of the uppermost stage, and the vehicle can be easily stopped. It is to be noted that the same effect as that of the above embodiment can be naturally obtained by directly driving the existing shift solenoid for selecting the uppermost gear position based on the driving force reduction signal.

FIG. 7 shows an example in which a predetermined A / T fastening element is fastened by the A / T fastening control device 100 based on a driving force reduction signal. Generally, the A / T selects a gear position based on the vehicle speed and the degree of depression of an accelerator pedal while the vehicle is running, and at this time, achieves a predetermined gear position by fixing or releasing each part of the planetary gear. . Such fixation and release are performed by selectively supplying hydraulic pressure to a plurality of fastening elements, and the fastening element to which hydraulic pressure is supplied is determined in advance depending on whether the gear is forward or backward, or which of the forward gears, etc. Stipulated. For example, a low & reverse brake to which the hydraulic pressure is applied when the vehicle is reversing is not engaged when the vehicle is moving forward, and rotates relatively to the rotation direction of the power transmission shaft. Therefore, when the low & reverse brake is fastened to a member that rotates integrally with the transmission shaft at the time of forward movement, the braking force acts and the driving force transmitted to the driving system can be reduced.
Hereinafter, a specific method will be described with reference to FIG.
In the A / T not shown, an electromagnetic switching valve 101 is provided, and the electromagnetic switching valve 101 normally supplies a line pressure B sent from a manual valve (not shown) at the time of retreat from a manual valve (not shown) to a port y, Via z, for example, a low & reverse brake is sent, and the reverse, low & reverse brake is engaged. On the other hand, the closed port of the electromagnetic switching valve 101 is restricted to the traveling range. Now, when the driving range is in the forward range, when the driving force decrease signal is applied, the electromagnetic switching valve 101 switches the ports and communicates with the ports x ′,
The line pressure A is supplied to the low & reverse brake via z '. As a result, the driving force transmitted to the driving system by the action of the brake can be reduced.

8 and 9 show other specific examples of the actuator.

In FIG. 8, in this embodiment, an A / T 111 is provided with an electromagnetic switching valve 112 which is activated by input of a driving force reduction signal. FIG. 9 is a diagram showing a main part in the A / T 111. Ninth
In the figure, 11 is the control valve assembly in the A / T111
(Not shown).
The manual valve 113 is provided in the driver's seat and reciprocates in a direction indicated by an arrow F in the figure in response to a shift operation of a shift lever (not shown). The illustrated position of the manual valve 113 indicates a case where the shift lever select position is at the [N] position. The manual switching valve 113 has an electromagnetic switching valve 1
A line pressure is supplied from an oil pump (not shown) via a line 12, and the line pressure is selectively distributed and supplied to the circuits A to D with the reciprocating movement of the manual valve 113. These circuits A to D alone or in plural form a hydraulic circuit necessary for each of the select positions P, R, D, II, I, and supply a line pressure to a number of friction elements (not shown) to a predetermined pressure. Achieve the gear. Also, the two-port (a, b) 2
A single electromagnet spring offset type is used. The electromagnetic switching valve 112 normally supplies the line pressure to the manual valve 113 with the illustrated position as a normal position. However, when a driving force reduction signal is input, the electromagnets operate to close the ports a and b. Therefore, when the driving force reduction signal is input, the line pressure to the manual valve 113 is cut off, and at least the circuit A related to the traveling range
To D is prohibited, and the engagement of a friction element (not shown) is released. As a result, all of the friction elements are released to be in the neutral state, and the transmission of the driving force to the driving system is not performed.

In addition to the methods as in the above embodiments, for example, (a) in the case of an A / T with lock-up, by operating a lock-up solenoid or the like according to a driving force decrease signal, by operating a lock-up clutch By operating the lock-up clutch, the torque-up effect of the torque converter can be eliminated, and the driving force to the drive system can be reduced.

(B) A / T equipped with a line pressure solenoid that can change the line pressure by operating with a predetermined duty signal
In the case of, the duty ratio of the duty signal is changed according to the driving force reduction signal, and the line pressure is reduced to the minimum pressure, so that the transmission torque capacity of the A / T can be reduced, and the driving force to the driving system is reduced. be able to.

Alternatively, it is preferable to optimally combine the above various methods, since the driving force can be further reduced.

<Effects of the Invention> As described above, according to the present invention, even when the brake pedal is depressed, the engine output does not decrease due to the failure of the accelerator device, the ASCD, etc., and the vehicle remains in the high vehicle speed state. Therefore, the driving torque transmitted to the driving system can be reduced, and the vehicle can be stopped quickly and easily by operating the brake pedal. On the other hand, when the vehicle speed is lower than the predetermined low vehicle speed, a decrease in the driving force is prohibited, so that a smooth start / run or the like can be ensured by using a brake on a low μ road (such as a snowy road). Therefore, the traveling safety of the vehicle can be improved. In addition, when the driving force is reduced on the engine side, there is often a problem that the exhaust emission is deteriorated.However, according to the present invention, the A / T is controlled to reduce the driving force. Thus, the effect that such a problem can be prevented can be obtained. Also, in a vehicle equipped with an automatic transmission, when starting on a slippery road surface such as a snowy road, to control the driving force,
The driver may operate the accelerator and the brake at the same time, but in this case the vehicle speed is lower than the predetermined low vehicle speed and the driving force is not reduced by the driving force reduction means, so the vehicle starts reliably be able to. Furthermore, when performing a stall test on an automatic transmission at a maintenance shop, etc., it is necessary to operate both the accelerator and the brake to detect a failure in the torque converter or the engine of the automatic transmission based on the engine speed at that time. However, in the present invention, the driving force does not decrease below a predetermined low vehicle speed, so that the stall test can be reliably performed.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a configuration of the present invention, FIG. 2 is an overall configuration diagram showing an embodiment of a vehicle driving force control apparatus according to the present invention, FIG. 3 is a flowchart of a control program thereof, FIG. FIGS. 5, 5 and 7 to 9 each show a specific configuration example of the driving force reducing means, and FIG. 6 shows governor pressure characteristics of the automatic transmission. REFERENCE SIGNS LIST 1 vehicle speed sensor 2 engine output sensor 3 brake sensor 4 control unit 5 actuator 80 A / T control device 82 A / T 90 A / T governor pressure control device 100 ... A / T engagement control device, 111 ... A / T, 112 ... Solenoid switching valve

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location F16H 59:74 (56) References JP-A-58-1612771 (JP, A) JP-A-58- 38347 (JP, A) JP-A-62-292536 (JP, A)

Claims (1)

(57) [Scope of request for utility model registration] A first detecting means for detecting a speed of the vehicle; a second detecting means for detecting an actual output state of the engine; a third detecting means for detecting an operating state of a brake; A driving force reduction signal is output based on a signal from the first to third detection means when the vehicle speed is equal to or higher than a predetermined low vehicle speed, the engine output is equal to or higher than a predetermined output, and the brake is operating. And a driving force reduction unit that controls an automatic transmission including a torque converter to reduce a driving force transmitted to a driving system in accordance with a driving force reduction signal from the signal output unit. A driving force control device for a vehicle, comprising: