JP3316631B2 - Output shaft torque control device for vehicle drive train - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque control device for an output shaft of a vehicle drive system such as an output shaft of an automatic transmission.

[0002]

2. Description of the Related Art For example, conventionally, in order to reduce a shift shock during a shift of an automatic transmission for a vehicle, the ignition timing of the engine is retarded to reduce the torque generated by the engine, thereby reducing the output shaft of the transmission. It is known to suppress sudden changes in torque.

[0003]

However, torque reduction by retard control of the ignition timing is limited due to exhaust performance and the like, and a sufficient shift shock reduction effect may not be obtained. Therefore, the present applicant performs the shift-time torque down control by using both the ignition timing retard control and the control for stopping the fuel supply to some cylinders of the engine (fuel cut cylinder number control). (Japanese Patent Application Hei 3-
27357).

Specifically, during a gear shift period, the actual torque of the transmission output shaft is detected, and the ignition timing is feedback-controlled so as to approach the target torque. In such a case, the number of fuel cut cylinders is increased. That is, while the actual torque is largely changed by the fuel cut, fine adjustment of the actual torque is performed by feedback control of the ignition timing.

However, in this system, the number of fuel cut cylinders is increased when the deviation between the actual torque and the target torque is equal to or greater than a predetermined value. If the ignition timing (retard amount) reaches the limit value during the feedback control, effective control is not performed until the torque deviation becomes equal to or more than a predetermined value after the limit value is reached, and the actual torque is reduced. far from the target torque, and followability to the target torque deteriorates, whereby a problem that leads to occurrence of shift shock there Ru.
Therefore, when the ignition timing reaches the limit value, the fuel is cut immediately.
Generates and executes a control request to control the ignition timing control amount
Return to the amount of retard that matches the output shaft torque after
Control is conceivable. However, changing the ignition timing control amount
If executed immediately when a charge cut control request occurs,
Before the torque-down effect of the
Changes in the ignition timing control amount will affect other cylinders that are not fuel cut.
Affect the output shaft torque.
There is room for improvement in followability. It should be noted that when fuel cut
Japanese Patent Laid-Open No. 2-196 describes an ignition timing control device for controlling the ignition timing.
No. 33 discloses this fuel cut.
When the condition is satisfied, the execution of the fuel cut is delayed,
Correct ignition timing based on engine speed during delay period
Is what you do. In other words, the above-mentioned publication discloses the actual fuel cut.
The ignition timing is changed before
Torque cut effect after fuel cut
Other control variables are changed when the fruits actually appear
And different.

[0006] The present invention has been made in view of the above, the number of fuel cut cylinders controlling the ignition timing feedback control or the like in combination with other control in controlling the output shaft torque of the vehicle drive system, other Reaches the limit value
When executing a fuel cut, the effect of the fuel cut
It is another object of the present invention to further improve the ability to follow the target torque by changing the other control amounts at the time of the start.

[0007]

SUMMARY OF THE INVENTION Accordingly, the present invention provides
Vehicle drive using both charge cut cylinder number control and other controls
Output shaft torque of the vehicle drive system that controls the output shaft torque of the vehicle
In the control device, as shown in FIG. 1, output shaft target torque setting means for setting a target torque of an output shaft of a vehicle drive system when a torque control request is generated, and detecting an actual torque of the output shaft during the generation of the torque control request. Actual torque detection means, torque control amount feedback control means for feedback-controlling the control amount of the other control so that the actual torque approaches the target torque while the torque control request is generated, and control feedback-controlled by the feedback control means The fuel cut cylinder number increase / decrease setting means for increasing / decreasing the number of fuel cut cylinders based on a request for increasing / decreasing the number of fuel cut cylinders generated when the amount reaches a predetermined limit value, and the fuel cut cylinder number increase / decrease setting means. Fuel cut control means for stopping supply of fuel to some cylinders of the engine corresponding to the number of fuel cut cylinders, Fuel after the serial fuel cut increase or decrease request generation
A control amount switching means for switching the control amount to be feedback-controlled based on a change in the number of fuel cut cylinders after a predetermined time corresponding to the engine rotation speed from the injection timing of the partial cylinder to be cut.

[0008] Further, the control amount switching means may be configured to perform a fuel cut after the fuel cut increase / decrease request is issued.
The control amount may be switched after a predetermined time set in advance from the fire timing .

[0009]

In the above arrangement, when a torque control request is issued, the output shaft target torque setting means sets the target torque of the output shaft of the vehicle drive system. Then, the actual torque detecting means detects the actual torque, and the feedback control means feeds back a control amount such as an ignition timing for controlling the output shaft torque other than the fuel cut so that the actual torque approaches the target torque. Control.

When the control amount reaches a predetermined limit value during the feedback control, the fuel cut cylinder number increase / decrease setting means increases / decreases the number of fuel cut cylinders based on a request to increase / decrease the fuel cut cylinder generated at this time. You. At this point, the control amount of the feedback control is not yet switched. Thereafter, the engine rotation speed is detected at the injection timing of a part of the cylinders to be fuel cut , and after a predetermined time corresponding to the engine rotation speed , the control amount switching means performs feedback control according to increase and decrease of the fuel cut cylinders. The control amount is switched. The switching of the control amount may be performed after a lapse of a predetermined time from the ignition timing of the fuel-cut partial cylinder.

[0011] This makes it possible to linearly control the transmission output shaft torque by ignition timing control while simultaneously using fuel cut for some cylinders. If the torque deviation cannot be completely eliminated by the ignition timing control alone, the fuel By increasing or decreasing the number of cut cylinders, the ability to follow the target torque can be improved. In addition, since the feedback control amount is switched not at the time when the request for increasing or decreasing the fuel cut cylinder is generated but at the time when the effect of the torque change due to the increase or decrease of the fuel cut cylinder actually appears, the accuracy of following the target torque can be improved. Can be further enhanced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to output shaft torque control during shifting of an automatic transmission will be described below with reference to the drawings. In FIG. 2 showing the configuration of this embodiment, an automatic transmission 2 is connected to the output side of the engine 1. The automatic transmission 2
A torque converter 3 interposed on the output side of the engine 1 and a gear type transmission 4 connected via the torque converter 3
And a hydraulic actuator 5 for connecting and releasing various transmission elements in the gear type transmission 4. The operating oil pressure for the hydraulic actuator 5 is ON / OFF controlled through various electromagnetic valves (not shown).

The control unit 6 receives signals from various sensors. Examples of the various sensors include an opening degree T of a throttle valve 7 of an intake system of the engine 1.
A throttle sensor 8 for detecting VO is provided.
Further, a crank angle sensor 9 is provided on the crank shaft of the engine 1 or a shaft that rotates in synchronization with the crank shaft. The signal from the crank angle sensor 9 is, for example, a pulse signal for each reference crank angle position, and the engine rotation speed N is calculated from the cycle thereof.

A vehicle speed sensor 11 for detecting a vehicle speed VSP by obtaining a rotation signal from an output shaft 10 of the automatic transmission 2 is provided. Further, a magnetostrictive torque sensor 12 is provided as actual torque detecting means which is attached to the output shaft 10 of the automatic transmission 2 as an output shaft of the vehicle drive system and detects the output shaft torque T.

The control unit 6 includes, for example,
An integrated type that incorporates an engine control CPU and an automatic transmission control CPU, and uses a dual-port RAM accessible from both CPUs. With this configuration, data calculated by both CPUs Can be shared.
The engine control CPU controls the fuel injection timing, the fuel injection amount, and the like by controlling the fuel injection pulse signal to the fuel injection valve 13 provided for each cylinder in the intake system of the engine 1 based on the engine operating state. Further, the ignition timing is controlled by controlling an ignition signal to an ignition coil (not shown) connected to the ignition plug 14 of each cylinder based on the engine operating state.

When the select lever is in the D range based on the operation position signal of the select lever operated by the driver, the automatic transmission control CPU operates the first to fourth shift positions according to the throttle valve opening TVO and the vehicle speed VSP. Is automatically set, and gear shift control for controlling the gear type transmission 4 to its shift position via the hydraulic actuator 5 is performed. In addition, the automatic transmission control CPU performs the shift torque-down control in order to reduce the shift shock in accordance with the flowchart shown in FIG. 3 and sends the result to the engine control CPU to control the ignition timing retard control and the fuel cut cylinder. Perform numerical control.

Next, regarding the torque reduction control during shifting,
This will be described with reference to the flowchart shown in FIG. In this embodiment, functions as an output shaft target torque setting unit, a control amount (ignition timing in this embodiment) feedback control unit, a fuel cut cylinder number increase / decrease setting unit, a fuel cut control unit, and a control amount switching unit are as follows. The software is provided as shown in the flowchart of FIG.

In step 1 (denoted by S1 in the figure, the same applies hereinafter), it is determined whether or not a torque down request has been issued due to the start of a shift. For example, the output shaft torque T suddenly decreases by disengaging the clutch at the start of the shift, and then rapidly increases by the start of the clutch connection. If it is determined that the torque reduction request onset production, the process proceeds to step 2.

In step 2, a target torque T ₀ of the transmission output shaft 10 is set. Here, the output shaft torque T, the engine speed N, the throttle valve opening TVO immediately before the start of the shift,
The shift is performed based on the gear ratio GR (= Ga / Gb) obtained from the gear ratio Gb before the shift and the gear ratio Ga after the shift according to the shift type (first speed → second speed, second speed → third speed, etc.). It sets a target torque waveform of time, reading the target torque T ₀ at the moment from the target torque waveform.

In step 3, the actual torque T of the transmission output shaft 10 is detected based on the signal from the torque sensor 12.
In step 4, a deviation ΔT = T−T ₀ between the actual torque T and the target torque T ₀ is calculated. In step 5, the torque deviation ΔT is set so that the actual torque T approaches the target torque T _0.
, The ignition timing retard amount is set, and the ignition timing retard control is executed.

In step 6, the set retard amount is compared with a predetermined set value (limit value), and if retard amount ≦ set value, this routine is terminated. If the retard amount is greater than the set value, it is determined that the retard amount has reached the limit value, and the routine proceeds to step 7. Here, the set value is determined in consideration of backfire, catalyst damage, and the like. In step 7, a request to increase the number of fuel cut cylinders is issued.

In step 8, based on the signal from the crank angle sensor 9, it is determined whether or not the fuel injection has been canceled at the fuel injection timing of the cylinder in which the current fuel cut is to be performed as shown in FIG. When it is confirmed that the injection has been canceled and the fuel has been cut, step 9 is executed,
The engine speed N is detected. In step 10, based on the engine rotational speed N detected in the step 9, a predetermined time t ₁ is the waiting time until the start of switching the ignition timing to be described later from the injection Tanmingu point shown in FIG. The predetermined time t ₁ is set at a time when the effect of the torque reduction actually appears due to the fuel cut, that is, at a time when the flame propagation time when normal fuel injection is performed after ignition of the fuel cut cylinder is performed. Is done. Therefore, the predetermined time t ₁ becomes shorter when the engine speed N is high, and becomes longer when the engine speed N is low.

In step 11, it is determined whether or not the elapsed time t from the injection timing has reached the predetermined time t ₁ set in step 10, and if t ≧ t ₁ ,
Proceed to 12. In step 12, the control amount of the ignition timing is switched, and the retard amount of the ignition timing at the limit value is returned to the retard amount corresponding to the output shaft torque after the fuel cut. That is, the ignition timing is returned to the advanced side.

As described above, as shown in FIG. 4, when the retard amount of the ignition timing reaches the limit value and a request to increase the number of fuel cut cylinders is issued, the control amount of the ignition timing is immediately switched at the time of this occurrence. If the ignition timing control amount is switched at the point where the effect of the fuel cut actually appears after the ignition operation of the fuel cut cylinder, the torque reduction effect by the fuel cut and the torque increase by switching the ignition timing control amount of the other cylinders By offsetting the effect, the actual torque can be accurately maintained near the target torque.

Next, another embodiment of the torque reduction control during shifting will be described with reference to the flowchart of FIG. In this embodiment, steps 21 to 28 are the same as those in the above-described embodiment, and a description thereof will be omitted. In step 29, it is determined whether or not it is the ignition timing of the fuel cut cylinder. When the ignition timing has come, the routine proceeds to step 30.

In step 30, an elapsed time t from the time when the ignition timing is reached is set to a predetermined time t _2.
Is determined. Step when t ≧ t ₂
Proceeding to 31, the ignition timing control amount is switched, and the ignition timing retard amount at the limit value is returned to the retard amount corresponding to the output shaft torque after the fuel cut. That is, in this embodiment, the switching of the control amount of the ignition timing is executed after a predetermined time has elapsed from the ignition timing of the fuel cut cylinder. In this way, compared to the case where the control amount switching timing of the ignition timing is set according to the engine speed N at the injection timing, the fluctuation of the engine rotation speed from the injection timing to the control amount switching time is compared. The accuracy of the output shaft torque control is further improved as compared with the above-described embodiment.

In this embodiment, the ignition timing is used as the control amount for controlling the output shaft torque other than the fuel cut. However, the present invention is not limited to this, and the intake air amount may be controlled. However, when controlling the intake air amount, it is necessary to perform switching at a timing earlier than the switching timing in the case of the ignition timing in consideration of the response delay. Also,
The present embodiment is applied to the control of the transmission output shaft torque for reducing the shift shock of the transmission, but can also be applied to the traction control.

[0028]

As described above, according to the present invention, the transmission output shaft torque is linearly changed by other control such as the ignition timing while simultaneously performing the fuel cut for a part of the cylinders. In addition to performing the control, the torque deviation cannot be completely eliminated only by the control other than the fuel cut, and when the control amount reaches a limit value, a request to increase or decrease the number of fuel cut cylinders is generated, and the fuel is cut this time. Cylinder injection timing
By switching the control amount at a point in time when the effect of the fuel cut actually occurs after a predetermined time from the starting or ignition timing, the ability to follow the target torque can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a configuration of the present invention.

FIG. 2 is a system diagram of an embodiment of the present invention.

FIG. 3 is a flowchart of a shift torque-down control according to an embodiment of the present invention;

FIG. 4 is an explanatory diagram of ignition timing switching timing.

FIG. 5 is a flowchart of another embodiment of the torque reduction control during shifting.

[Explanation of symbols]

 Reference Signs List 1 engine 2 automatic transmission 3 torque converter 4 gear type transmission 6 control unit 8 throttle sensor 9 crank angle sensor 10 transmission output shaft 11 vehicle speed sensor 12 torque sensor 13 fuel injection valve 14 spark plug

Continuation of the front page (56) References JP-A-2-19633 (JP, A) JP-A-2-45627 (JP, A) JP-A-3-275950 (JP, A) JP-A-3-51148 (JP) , U) Japanese Utility Model 1-111157 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02D 41/00-45/00 F02D 29/00 F16H 59/00-61/12 F16H 61/16-61/24 F16H 63/40-63/48

Claims (2)

(57) [Claims] (1) The fuel cut cylinder number control and other control are performed together.
Drive system that controls the output shaft torque of the vehicle drive system by using
In the output shaft torque controller, and an output shaft target torque setting means for setting a target torque of the output shaft of the vehicle drive system when the torque control request occurs, the actual torque detection for detecting an actual torque of the torque control request generated the output shaft Means, a torque control amount feedback control means for feedback-controlling the control amount of the other control so that the actual torque approaches the target torque during generation of the torque control request, and a control amount feedback-controlled by the feedback control means is predetermined. The fuel cut cylinder number increase / decrease setting means for increasing / decreasing the number of fuel cut cylinders based on a request for increasing / decreasing the fuel cut cylinder generated when the fuel cut cylinder number increases / decreases, and the fuel cut cylinder set by the fuel cut cylinder number increase / decrease setting means Fuel cut control means for stopping supply of fuel to some cylinders of the engine corresponding to the number of fuels; The injection part cylinders Timing of fuel cut after cut cylinders decrease request generation
After a predetermined time in accordance with the engine rotational speed from the ring time, the output shaft of the vehicle drive system characterized in that a control quantity switching means for switching based on the fuel cutoff number cylinders change in the controlled variable to be the feedback control Torque control device. 2. The ignition of the partial cylinder, wherein the control amount switching means cuts off fuel after the fuel cut cylinder increase / decrease request is issued.
2. An output shaft torque control device for a vehicle drive system according to claim 1, wherein the control amount is switched after a predetermined time set in advance from the timing .