JPH0610449B2 - Vehicle drive force control device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vehicle drive force control device.

[Conventional technology]

As a conventional vehicle driving force control device, for example, Japanese Patent Laid-Open No.
There is one such as that described in Japanese Patent Application Laid-Open No. 0-104730.

It is a drive wheel speed detecting means for detecting the drive wheel speed,
Driven wheel speed detecting means for detecting the driven wheel speed, engine speed detecting means for detecting the engine speed, and control means for controlling fuel supply based on the drive wheel speed, the driven wheel speed and the engine speed. And torque control means for controlling the engine torque of the vehicle based on a signal from the control means. By controlling the fuel supply in accordance with the engine speed, the running stability of the vehicle is improved. And to improve acceleration and drivability.

[Problems to be solved by the invention]

However, in such a conventional vehicle driving force control device, when the vehicle is in a slip state, the number of cylinders to which fuel is supplied is changed according to the engine speed, In the fuel supply control performed according to the engine speed, when the vehicle starts, not only when the engine speed is increased, but also when the engine speed is not increased so much, fuel to all cylinders is increased. Since the supply is cut off, there is a risk that engine stall or the like cannot be started due to the cutoff of fuel supply to all cylinders. In particular, in the primary transmission, there is a problem that a slight difference in clutch meet timing at the time of gear change causes discomfort due to the difference between when the fuel is cut and when the fuel is not cut.

[Means for solving problems]

The present invention has been made in view of such a conventional problem, and as shown in the basic configuration diagram of FIG. 1, a drive wheel that detects the rotation speed of the drive wheel and outputs a detection signal thereof. Rotational speed detecting means, non-driving wheel rotational speed detecting means for detecting the rotational speed of the non-driving wheel and outputting the detection signal, and detection from these driving wheel rotational speed detecting means and non-driving wheel rotational speed detecting means Slip ratio calculating means for calculating the slip ratio between the tire and the road surface based on the signal, and a slip ratio determining means for judging whether or not the slip ratio is larger than a set value based on the calculation result of the slip ratio calculating means. When the slip ratio is greater than the set value based on the determination result of the slip ratio determining means and the detection signal from the non-driving wheel rotation speed detecting means, the fuel of the plurality of cylinders is selected according to the non-driving wheel rotation speed. Is supplied A fuel supply control means capable of changing the number of binders, the fuel supply control means comprising a non-driving wheel rotation speed judging means for judging whether or not the non-driving wheel rotation speed is equal to or lower than a predetermined rotation speed; And a cylinder number regulating means for regulating that the number of cylinders is not more than a predetermined number when the non-driving wheel rotational speed is less than or equal to the predetermined rotational speed based on the determination result of the non-driving wheel rotational speed determining means. The present invention is characterized by solving the above-mentioned problems by providing a vehicle driving force control device.

[Action]

In the present invention, the rotation speed of the drive wheel is detected by the drive wheel rotation speed detection means, and the rotation of the non-hollow wheel is detected by the non-drive wheel rotation speed detection means. The slip ratio calculation means calculates the slip ratio between the tire and the road surface based on the rotation speed, and the slip ratio control means determines whether or not the calculated slip ratio is larger than a set value. Is larger than the set value, the number of cylinders of the engine supplied by the fuel supply control means is changed.

When the non-driving wheel rotation speed determining means of the fuel supply control means determines that the non-driving wheel rotation speed is less than or equal to the predetermined rotation speed, that is, the vehicle speed is less than or equal to the predetermined vehicle speed, the number of cylinders of the fuel supply control means The regulation means regulates that the number of cylinders to be changed is less than or equal to a predetermined number, so that the number of cylinders to which fuel is supplied is predetermined even if the slip ratio becomes larger than a set value when the vehicle starts or runs at low speed. The number is not less than the number, and therefore, it is possible to avoid the situation where the driving force becomes extremely small and the vehicle cannot start.

〔Example〕

 Hereinafter, the present invention will be described based on illustrated embodiments.

2 and 3 show an embodiment of the present invention and are views applied to a rear-wheel drive vehicle.

First, the configuration will be described. 1 shown in FIG. 2 is a control device, and the control device 1 includes a microcomputer 2 and
An A / D converter 3, an F / V converter 4, an output circuit 5,
And an A / D converter 3 connected to the F / V converter 4 and an output circuit 5 are connected to the microcomputer 2.

The microcomputer 2 has an interface circuit 2
a, an arithmetic processing unit (CPU) 2b, and a storage device 2c such as a RAM and a ROM, and the voltage output from the F / V converter 4 is arithmetically processed through the A / D converter 3 and the interface circuit 2a. The arithmetic processing unit 2b is supplied to the device 2b, and the arithmetic processing unit 2b is operated according to a program previously stored in the storage unit 2c. The storage device 2c is provided with a reference slip ratio storage area 2d in which a preset reference slip rate So is stored and a reference rotational speed storage area 2e in which a preset reference meeting point number Vfo is also stored. There is.

Further, the F / V converter 4 includes a rear wheel from a rear wheel rotation speed detector 8 which is a driving wheel rotation speed detecting means for detecting the rotation speed of the rear right wheel 6 and the left wheel 7 which are drive wheels. Rotation speed signal DV
r and the right front wheel from the right front wheel rotation detector 12 and the same left wheel rotation detector 13 which are non-driving wheel rotation detecting means for individually detecting the rotation speeds of the front right wheel 10 and the left wheel 11 which are non-driving wheels. The left front wheel rotation speed signals DVfr and DVfl are respectively supplied. The rear wheel rotation speed detector 8 detects the rotation speed of the drive wheel by detecting the rotation speed of the differential gear 14 that transmits the driving force to the rear left and right wheels 6 and 7, and detects the rotation speed of the drive wheel. Rear wheel speed signal DVr consisting of pulse signal
Is output. Further, the right front wheel rotation speed detector 12 and the left front wheel rotation speed detector 13 directly detect the rotation speeds of the front left and right wheels 10 and 11, and the right front wheel and the left front wheel are pulse signals having a frequency corresponding to the rotation speeds. The rotation speed signals DVfr and DVfl are output respectively.

The F / V converter 4 to which the respective rotation speed signals DVr, DVfr and DVfl of the front wheels and the rear wheels are supplied, converts the input signals into voltages according to the respective frequencies, and the rotation speed signals DV are A / It is sent to the D converter 3. The A / D converter 3 to which these rotation speed signals DV are supplied converts them into digital signals and outputs them to the microcomputer 2.

As a result, the microcomputer 2 executes a control process described later based on the input rotation speed signals DV from the three rotation speed detectors 8, 12, 13 and the slip ratio S and the non-driving wheel rotation speed Vf. A control signal CS corresponding to (corresponding to the vehicle speed) is output to the output circuit 5. As a result, the output circuit 5
Is a control signal C supplied from the microcomputer 2.
A drive signal CA as an exciting current or a degaussing current to each coil of the first relay 15 and the second relay 16 based on S
₁ and CA ₂ are individually output. Two relays 15, 16
Each have a normally-closed contact, and when each coil is excited, the circuit in which the relays 15 and 16 are inserted is opened.

The relays 15 and 16 have six cylinders 18a to 18a.
The fuel supply control device 17 for controlling the fuel supplied to the engine having f is individually provided in the two electric circuits 20, 21 of the fuel supply control device 17, and is output from the fuel supply control device 17 to the first electric circuit 20. No. 1 cylinder 18a to No. 3 cylinder ₁ according to fuel injection signal FS _{1 which} is a pulse signal
Fuel supply to 3 cylinders up to 8c is controlled,
Further, the fuel injection signal FS ₂ which is also a pulse signal output from the fuel supply control device 17 to the second electric circuit 21.
The fuel supply amount to the three cylinders from the fourth cylinder 18d to the sixth cylinder 18f is controlled by.

The arithmetic processing unit 2b of the microcomputer 2 is R
Pre-stored in the OM, for example, as shown in FIG.
The arithmetic processing is executed in accordance with the timer interrupt processing program executed every 00 msec.

That is, in the step, the rear wheel rotation speed signal DVr of the rear wheel rotation speed detector 8 is read, the rotation speeds of the rear wheels 6 and 7 which are the drive wheels are calculated based on the read signal DVr, and this is calculated as the drive wheel rotation speed V.
It is temporarily stored in a predetermined storage area of the storage device 2c as r.

Next, shifting to step, the front right wheel rotation speed detector 12
The right front wheel rotation speed signal DVfr is read, the rotation speed of the right front wheel 10 which is a non-driving wheel is calculated based on the read signal, and this is temporarily stored in a predetermined storage area of the storage device 2c as the right non-driving rotation speed Vfr.

Then, the process proceeds to step, and the left front wheel rotation speed detector 13
The front left wheel rotation speed signal DVfl is read, the rotation speed of the left front wheel 11 which is a non-driving wheel is calculated based on the read signal, and this is temporarily stored in a predetermined storage area of the storage device 2c as the left non-driving wheel rotation speed Vfl.

Next, the process proceeds to step, and the right non-driving wheel rotational speed Vfr of the step and the left non-driving wheel rotational speed Vfl of the step are read out, and based on these left and right non-driving wheel rotational speeds Vfr, Vfl Is calculated and is temporarily stored in a predetermined storage area of the storage device 2c as the non-driving wheel rotation speed Vf. As the non-driving wheel rotational speed Vf, the average value of the rotational speeds of the right and left front wheels 10 and 11 is used in this embodiment.

Next, the process proceeds to step, and the driving wheel rotational speed Vr of the step and the non-driving wheel rotational speed Vf of the step are read out, and the driving wheels 6 and 7 are driven based on the respective rotational speeds Vf and Vr of the front and rear wheels. The slip lip ratio S between the tire and the road surface of the entire vehicle generated between the tire and the road surface is calculated.

Next, the process proceeds to step, and the reference slip ratio S _o (for example, 0.2) stored in advance in the reference slip ratio storage area 2d of the storage device 2c and the slip ratio S calculated in step are read out, and the slip ratio is Reference slip rate S _o
Determine if it is greater. As a result of the determination, when the slip ratio S is smaller than the reference slip ratio S _o , the process shifts to step and the drive signals CA ₁ and CA ₂ (for degaussing both the coil of the first relay 15 and the coil of the second relay 16). For example, a control signal CS for outputting a “Low” signal) is output.

This completes the timer interrupt process and returns to the main program.

On the other hand, when the determination result of the step is S> S _o ,
After shifting to the step, the reference rotation speed Vfo (for example, the rotation speed corresponding to a vehicle speed of 10 km / h) prestored in the reference rotation speed storage area 2e of the storage device 2c and the non-driving wheel rotation speed Vf calculated in the step. Is read to determine whether the non-driving wheel rotation speed Vf is higher than the reference rotation speed Vfo.
As a result of the determination, the non-driving wheel rotation speed Vf is the reference rotation speed Vfo.
When it is smaller, the process proceeds to step, and the drive signal CA ₁ (for example, “H”) for exciting the coil of the first relay 15 is excited.
i "signal) and a control signal CS for outputting a drive signal CA ₂ (" Low "signal) for deactivating the coil of the second relay 16. Then, the timer interrupt process is completed. Return to the main program.

On the other hand, when the determination result of the step is Vf> Vfo, the drive signals CA ₁ and CA ₂ (““ that cause the coil of the first relay 15 and the coil of the second relay 16 to exemplify the transition to the Sopp. The control signal CS for outputting the "Hi" signal) is output. Then, it returns to the main program.

Boss step-step processing constitutes slip ratio calculation means, step processing constitutes slip ratio determination means, and further step-step processing and two relays 15 and 16 constitute fuel supply control means. Then, the processing of step constitutes the non-driving wheel rotation speed judging means, and the processing of step constitutes the cylinder number regulating means.

Next, the operation will be described.

Assuming that the vehicle is now in the start state, when the timer interrupt processing of FIG. 3 is executed at predetermined time intervals in this state, first, in a step, the rear wheel rotation speed signal DVr is read, and the drive wheel is based on this. The rotation speed Vr is calculated, the right front wheel rotation speed signal DVfr is read in a step, the right non-driving wheel rotation speed Vfr is calculated based on this, and the left front wheel rotation speed signal DVfl is read in a step. The driving wheel rotation speed Vfl is calculated.

Next, the process proceeds to step, the right non-driving wheel rotation speed Vfr in step and the left non-driving wheel rotation speed Vfl in step are read out, the non-driving wheel rotation speed Vf is calculated based on these, and in the next step, step Drive wheel speed Vr
And the slip ratio S between the tire and the road surface of the driving wheel is calculated based on the non-driving wheel rotation speed Vf of the step. Then, the process proceeds to step S and the reference slip ratio S of the reference slip ratio storage area 2d provided in the storage device 2c.
_o is read, and the slip ratio S calculated in the step is compared with this reference value S _o to determine the magnitude thereof.

In this case, as in the case of slow start is a high dry pavement road friction coefficient, the vehicle (in particular the driving wheels) slip rate calculated in the step of representing the slip state S the reference slip ratio S _{o (e.g.} S _{If o} = 0.2) or less, S ≦ S _o is determined in the step,
Moving to the step, the control signal CS for demagnetizing the two relays 15 and 16 together is output to the output circuit 5. This allows the output circuit 5 to connect the two relays 15, 1
Degaussing currents (“Low” signals), which are drive signals CA ₁ and CA ₂ , are supplied to the coils of 6 and are demagnetized together so that the normally closed contacts both maintain the closed state.

As a result, the fuel supply control device 17 outputs the fuel injection signals FS ₁ and FS ₂ that continue supplying fuel to the two sets of cylinder groups 18a to 18c and 18d to 18f. Therefore, in this case, the six cylinders 18i (i = a ...
Fuel is supplied to all of f), and normal engine driving is performed.

On the other hand, as in the case of starting at a low speed on a wet paved road where the friction coefficient of the road surface is low, the slip ratio S of the vehicle rises above the reference slip ratio S _o , while the non-driving wheel rotation Vf exceeds the reference rotation speed Vfo. If it does not increase, the process proceeds to step, and it is determined that Vf ≦ Vfo at the step. Therefore, the control shifts to step and energizes the other relay 15 with one relay 16 demagnetized. The signal CS is output to the output circuit 5. As a result, the drive signal C is output from the output circuit 5 to the coil of the relay 16 on one side.
A demagnetizing current (“Low” signal) that is A ₂ is supplied, and an exciting current (“Hi” signal) that is the drive signal CA ₁ is supplied to the coil of the other relay 15, and the normally closed contact of the relay 16 is supplied. Keeps the closed state, while the normally closed contact of the relay 15 is opened.

Therefore, the fuel supply control device 17 outputs the fuel injection signal FS ₁ for cutting off the fuel supply to one set of cylinder groups 18a to 18c, while the other set of cylinder groups 18d to 18d.
The fuel injection signal FS ₂ for continuing the fuel supply to 18f is output. Therefore, in this case, the six cylinders 18i
Half of three cylinders 18a to 1 of (i = a to f)
Fuel is supplied only to 8c, and the remaining three cylinders 18d
Since the fuel supply to ~ 18f is cut off, the driving force of the engine is slightly reduced.

As a result, due to the slight decrease in the driving force, the slip generated in the vehicle can be suppressed at an early stage, and therefore, the running stability of the vehicle at low speed start on the low friction coefficient road surface can be ensured, and Fuel efficiency can be improved.

In addition, as in the case of starting at high speed on a wet paved road where the friction coefficient of the road surface is low, the slip ratio S of the vehicle is equal to the reference slip ratio S.
and the non-drive wheel rotational speed Vf of the reference rotation speed V rises above _o
When it becomes larger than fo, it is judged that Vf> Vfo in the step through the processing of the step, and therefore the control signal CS for exciting the two relays 15 and 16 together is output to the output circuit 5 in the step. Is output. As a result, the exciting currents (“Hi” signals) that are the drive signals CA ₁ and CA ₂ are supplied from the output circuit 5 to the coils of the two relays 15 and 16, and they are excited together so that the normally closed contacts are formed. Open together.

Therefore, the fuel supply control device 17 outputs the fuel injection signals FS ₁ and FS ₂ that cut off the fuel supply to the two sets of cylinder groups 18a to 18c and 18d to 18f. Therefore, in this case, the six cylinders 18i (i = a ...
Since the fuel is not supplied to all of f), the driving force of the engine is significantly reduced.

As a result, due to the drastic reduction of the driving force, the slip generated in the vehicle can be suppressed at an early stage, and therefore, the traveling stability of the vehicle at the time of high-speed start on the low friction coefficient road surface can be ensured, The fuel efficiency can be greatly improved.

As described above, in this embodiment, even when the slip ratio S of the vehicle (driving wheel) calculated from the driving rotation speed Vr and the non-driving wheel rotation speed Vf is equal to or higher than the reference slip ratio S _o , for example, at the time of starting or When the non-driving wheel rotation speed Vf is smaller than the reference rotation speed Vf ₀ , such as during low-speed traveling, the fuel cut may be performed on a partial cylinder to reduce the number of cylinders to which fuel is supplied to zero. Since it does not exist, the driving force will not be extremely reduced and the vehicle will not fall into a situation such as unable to start.

In other words, if the configuration of the present embodiment is zero, it is possible to effectively suppress the vehicle slip at the time of starting, etc. while securing the minimum driving force, and improve the starting performance and the low-speed traveling performance.
Therefore, it is possible to secure the traveling stability when the vehicle slips in medium- and high-speed traveling.

Note that the control device 1 is not limited to the above configuration, and can be configured by an electronic circuit such as a subtraction circuit, a comparison circuit, and a logic circuit. Further, although the relays 15 and 16 are used as the fuel supply control means in the above-described embodiment, the fuel supply control means is not limited to this, and may be constituted by, for example, a switch. Further, in the above embodiment, the example of the rear-wheel drive vehicle has been described, but it goes without saying that the present invention can be applied to the front-wheel drive vehicle.

〔The invention's effect〕

As described above, according to the present invention, the slip ratio between the tire and the road surface is calculated based on the drive wheel rotation speed detection means, the non-drive wheel rotation speed detection means, and the rotation speeds of the drive wheel and the non-drive wheel. And a slip ratio determining means for determining whether or not the slip ratio is greater than a set value, and when the slip ratio is greater than the set value for the previous period, the fuel is output according to the non-driving wheel rotational speed. And a fuel supply control means capable of changing the number of cylinders supplied to the vehicle drive force control device, and the fuel supply control means has a non-driving wheel rotation speed not more than a predetermined rotation speed. The non-driving wheel rotational speed determining means for determining whether or not, and when the non-driving wheel rotational speed is less than or equal to a predetermined rotational speed based on the determination result of the non-driving wheel rotational speed determining means, the number of cylinders is less than or equal to a predetermined number. Shirin to regulate things When the vehicle is in a slip state of a predetermined slip ratio or more, the number of cylinders to which fuel is supplied is changed according to the vehicle speed represented as the non-driving wheel rotation speed. Specifically, the number of cylinders to which fuel is supplied does not fall below a predetermined number even when the vehicle slip ratio is high during low speed traveling. Therefore, even if the vehicle slips at the time of starting, it is possible to prevent an excessive reduction in the driving force by performing the fuel cut on the partial cylinders.
The starting performance of the vehicle can be improved. Moreover, when the vehicle slips at medium and high speeds, the fuel is cut off for all cylinders, so the driving force can be reduced early, the running stability of the vehicle can be ensured, and Similarly, the effect that the fuel consumption can be improved can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a basic configuration of the present invention, FIG. 2 is a schematic explanatory diagram showing an embodiment of the present invention, and FIG. 3 is a processing procedure of a control device according to the present invention. It is a flow chart showing an example. 1 ... Control device, 2 ... Microcomputer, 2a ...
... interface circuit, 2b ... arithmetic processing unit, 2c
...... Memory device, 3 ... A / D converter, 4 ... F / V converter, 5 ... Motor drive circuit, 6,7 ... Rear wheel (driving wheel), 8 ... Rear wheel rotation speed detection Unit (driving wheel rotation speed detecting means) 10, 11 ... Front wheel (non-driving wheel), 12, 13 ...
... Front wheel rotation speed detector (non-driving wheel rotation speed detection means), 1
5, 16 ... Relay, 17 ... Fuel supply control device, 18
a to 18f ... Cylinder

Claims (1)

[Claims] 1. A drive wheel rotation speed detecting means for detecting a rotation speed of a drive wheel and outputting a detection signal thereof, and a non-drive wheel rotation speed detection for detecting a rotation speed of a non-driving wheel and outputting the detection signal. Means, a slip ratio calculating means for calculating the slip ratio between the tire and the road surface based on the detection signals from the driving wheel rotation speed detecting means and the non-driving wheel rotation speed detecting means, and the slip ratio calculating means and the calculation result. Based on the slip ratio determination means for determining whether the slip ratio is larger than a set value based on the determination result of this slip ratio determination means and the detection signal from the non-driving wheel rotation speed detection means, the slip ratio is set as described above. A fuel supply control means capable of changing the number of cylinders to which fuel is supplied among a plurality of cylinders according to the non-driving wheel rotation speed when the fuel supply control means is larger than the value.
Non-driving wheel rotation speed determining means for determining whether or not the non-driving wheel rotation speed is less than or equal to a predetermined rotation speed, and the non-driving wheel rotation speed is the predetermined rotation speed based on the determination result of the non-driving wheel rotation speed determining means. A driving force control device for a vehicle, comprising: a cylinder number regulating means for regulating that the number of cylinders is equal to or less than a predetermined number when it is below.