JPH1151129A - Controller of vehicle provided with continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To securely prevent the slide of a belt of a transmission when an output of an internal combustion engine is changed over by controlling belt nip pressure to a condition corresponding to a high output side when it is judged that at least one of signals related to shift control of the internal combustion engine and the transmission is on the high output side. SOLUTION: An engine 10 is controlled in such a manner that it provides the optimum air-fuel ratio by an electronic control means (ECU) 30. A CVT (continuously variable transmission) is controlled by a transmission control means 54 consisting of a transmission electronic controller 56 and a hydraulic control circuit 58. The electronic controller 56 and ECU 30 are connected mutually by two signal lines 66, 68. The signal line 66 transmits a first lean stoichiometric (ENGLS) signal, and the signal line 68 transmits a second lean stoichiometric (CVTLS) signal. The electronic controller 56 controls the hydraulic control circuit 58 in such a way that nip pressure of a transmission belt 48 of the CVT is in a condition corresponding to a high output side when at least one of the CVTLS signal and the ENCLS signal is on the high output side (stoichiometric side).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuously variable transmission in which the speed ratio of a continuously variable transmission can be changed steplessly and the output of an internal combustion engine can be switched to at least two stages. The present invention relates to a vehicle control device provided with the vehicle.

[0002]

2. Description of the Related Art In a vehicle equipped with a lean burn internal combustion engine (hereinafter referred to as "lean burn engine") and a continuously variable transmission, a plurality of types of lean burn engines (for example, a lean burn engine) are used to purify exhaust gas from automobiles. , Lean / stoichiometric) combustion state is selected according to the operating environment such as load. In the case of a continuously variable transmission, the speed ratio of the continuously variable transmission is continuously adjusted so that the engine operates in accordance with an optimum fuel consumption curve, thereby improving the fuel efficiency of the vehicle (Japanese Patent Laid-Open No. 4-1992). 255541).

[0003] An engine control device for controlling the engine of such a vehicle determines lean / stoichiometric switching based on information on the running state of the vehicle such as the accelerator opening and determines the combustion state of the engine based on the determination. Controlling.

In the continuously variable transmission, the speed ratio is changed on the input pulley side, and belt clamping pressure is applied on the output pulley side so that the transmission belt does not slip.

A transmission control device for controlling the continuously variable transmission is connected to the engine control device via a signal line.
Based on the information sent from the engine control device via the signal line, it is determined whether the engine is in a lean state or a stoichiometric state, and the speed ratio and belt clamping pressure of the continuously variable transmission are optimized according to the determination result. Is controlled.

The optimal control of the belt clamping pressure and the like based on the information on the engine output as described above is because if the belt clamping pressure exceeds the pressure required for the engine output, the fuel consumption and the power performance are reduced. On the other hand, if the belt clamping pressure is less than the required pressure, the belt slips and power cannot be transmitted satisfactorily.

[0007]

As described above, the engine control device and the transmission control device are connected by a signal line,
In the case where information from the engine control device is supplied to the transmission control device, if the information is fixed in the lean state due to a failure such as disconnection or short circuit, the engine control device may be used. However, even if the stoichiometric combustion control is performed, the transmission control device determines that the engine is in the lean combustion state and performs the shift control of the transmission. Therefore, there is a problem that the belt slips and the power transmission becomes poor.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has a stepless transmission capable of reliably preventing the belt of the stepless transmission from slipping when switching the output of the internal combustion engine. An object of the present invention is to provide a control device for a vehicle including:

[0009]

According to the present invention, as shown in FIG. 1, the speed ratio of a continuously variable transmission can be changed steplessly, and the output of an internal combustion engine can be reduced to at least two stages. A control device for a vehicle having a continuously variable transmission configured to be switchable, wherein: an internal combustion engine control means capable of controlling switching of the output of the internal combustion engine in at least two stages; Transmission control means capable of performing switching control in response to engine output switching control, and transmission means for transmitting and receiving signals relating to respective switching control between the internal combustion engine control means and the transmission control means, Wherein at least one of the signals relating to the switching control is determined to be on the high output side, the belt clamping pressure of the continuously variable transmission is controlled to a state corresponding to the high output side. By including the one in which to achieve the above objects.

According to the present invention, both the internal combustion engine control means and the transmission control means exchange engine output switching information with each other. If it is determined that at least one of the transmitted and received outputs is on the high output side, the belt clamping pressure of the non-transmission is controlled to a state corresponding to the high output side. As a result, even if disconnection or short circuit of the circuit means occurs, the belt can be prevented from slipping.

Here, the transmission control means determines an output to be generated in the internal combustion engine based on accelerator opening information and the like, and sends a signal relating to switching control of the determined output to the internal combustion engine control means. A better result can be obtained if the internal combustion engine control means transmits the signal relating to the currently executed switching control to the transmission control means based on the signal relating to the switching control.

That is, in a conventional vehicle control device of this type,
Since the engine control device determines the power performance of the engine based on the accelerator opening information and the like, it is inevitable that the engine control device transmits a lean
Switching information such as stoichiometry was sent.

According to this method, since the transmission control device estimates the engine torque based on the switching information from the engine control device, a delay in torque estimation is inevitable. In this case, if the torque estimation is delayed when the engine output changes from “low” to “high”, such as when switching from lean to stoichiometric, the continuously variable transmission is delayed by the estimated delay time. Due to the control, there is a problem that the belt may slip for an instant without being in agreement with the actual engine output. Therefore, by utilizing the fact that there is a signal line for communication from the transmission control means to the engine control means side, the transmission control means side determines the power performance of the engine such as lean stoichiometry, and the engine control means When the actual control information is sent to the transmission control means while controlling the engine in response to this, when any of the information is on the high output side, such a problem occurs that the system is controlled to the state corresponding to the high output side. Can be reliably prevented.

Further, there is an advantage that it is not necessary to add a further signal line as described later.

[0015]

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

FIG. 2 is a block diagram schematically showing a control device for a vehicle having a continuously variable transmission to which the present invention is applied.

In FIG. 2, an engine 10 includes a torque converter 12, a forward / reverse switching device 14, and a continuously variable transmission (CV).
T) The drive wheels 24 provided on the axle 22 are driven via the reduction gear device 18 and the differential gear device 20.

The engine 10 is controlled by an engine electronic control means (ECU) 30 so as to obtain an optimum air-fuel ratio. Specifically, the adjustment is performed using the linkless throttle 26 and the injector 28. Note that the ECU 30
Although not shown, it is configured by a microcomputer including a CPU, a RAM, a ROM, an input / output interface, and the like.

The throttle opening sensor 32 detects the opening of the linkless throttle 26. The engine speed sensor 34 detects the speed of the engine 10 from the speed of the crankshaft 36 of the engine 10. The accelerator opening sensor 38 detects the accelerator opening that the driver steps on.
The vehicle speed sensor 40 detects the vehicle speed from the rotation of the output shaft 42 of the reduction gear device 18. These detection signals are transmitted to the ECU 3
Sent to 0.

CVT 16 is known per se,
An input pulley 44 provided on the input shaft, an output pulley 46 provided on the output shaft, a transmission belt 48 wound around the input pulleys 44, 46, and an input shaft side hydraulic pressure for changing the effective diameter of the input pulley 44 A cylinder (not shown) and an output shaft side hydraulic cylinder (not shown) for adjusting the belt clamping pressure of the output pulley 46 so that the transmission belt 48 does not slip.
And an input shaft rotation sensor 50 for detecting a rotation speed of the input shaft.
And an output shaft rotation sensor 52 for detecting a rotation speed of the output shaft.
And

The CVT 16 is controlled by the transmission control means 54. The transmission control means 54 includes a transmission electronic control unit 56 and a hydraulic control circuit 58. Transmission electronic control unit 56 receives detection signals from accelerator opening sensor 38, vehicle speed sensor 40, input shaft rotation sensor 50, and output shaft rotation sensor 52. The transmission electronic control unit 56 determines and determines the target power performance in accordance with the running state of the vehicle based on the detection signals, and controls the hydraulic control circuit 58 based on the determination result. The hydraulic control circuit 58 controls the transmission ratio by supplying hydraulic oil to the input shaft side hydraulic cylinder and changing the effective diameter on the input pulley 44 side under the control of the transmission electronic control unit 56 as described above. In addition, the hydraulic oil is supplied to the output shaft side hydraulic cylinder to control the belt clamping pressure on the output pulley 46 side to prevent the transmission belt 48 from slipping.

The transmission electronic control unit 56 of the transmission control means 54 and the ECU 30 are connected by two signal lines 66 and 68 as transmission means. The signal line 66 is EC
Lean from U30 to transmission electronic control unit 56
A stoichiometric (ENGLS) signal (a first signal relating to switching control) is transmitted, and a signal line 68 is connected to the transmission electronic control unit 56.
Stoichiometric (CVTL) to supply from ECU to ECU30
S) A signal (second signal related to switching control) can be transmitted.

The ENGLS signal and the CVTLS signal are designed to determine a stoichiometric combustion state when the signal is at a low level. This is because the transmission electronic control unit 56 or the ECU 30 determines that the (safe side) stoichiometric combustion state occurs when the signal line 66 or the signal line 68 is disconnected in view of the fact that a failure due to “disconnection” is most likely to occur. This is to make it possible.

The transmission electronic control unit 56 makes a basic lean / stoichiometric determination of the engine and sends a CVTLS signal to the ECU 30 so as to output an engine output commensurate with the lean / stoichiometric determination. On the other hand, the ECU 30 gives the actual electronic control state of the engine to the transmission electronic control unit 56 as an ENGLS signal.

The electronic control unit 56 of the transmission transmits the judgment result (CVTLS signal) sent to the signal line 68 to the ECU 30
(ENGLS) received through the signal line 66 from the
When at least one of the signals is on the high output side (stoichiometric side), the hydraulic control circuit 58 is controlled so that the belt clamping pressure of the CVT 16 corresponds to the high output side (stoichiometric side). Accordingly, the hydraulic control circuit 58
Hydraulic oil is supplied to the output shaft side hydraulic cylinder of the CVT 16 and the belt clamping pressure is adjusted so as to be in a state corresponding to the stoichiometric side.

Next, the operation of the present embodiment will be described with reference to FIGS.

[Schematic Operation of ECU 30] FIG.
30 is a flow chart for explaining the operation of No. 30. This processing routine is executed at predetermined time intervals. In this figure, in step 301, the ECU 30 takes in detection signals from the throttle opening sensor 32, the engine rotation speed sensor 34, the accelerator opening sensor 38, and the vehicle speed sensor 40, and controls the transmission electronic control of the transmission control means 54. A process of taking in a CVTLS signal (lean stoichiometric instruction signal) from the device 56 via the signal line 68 is executed.

Next, in step 303, the ECU 30 determines lean stoichiometry based on the CUTLS signal.

When it is determined in step 303 that the engine should be in the lean combustion state, the ECU 30 proceeds to step 304.
Injector 28 is set to be in a lean combustion state at
Is executed, and in step 305, ENGL indicating that lean combustion is (currently) being executed.
The S signal is sent to the transmission control means 54 via the signal line 66, and the process exits from this processing routine.

On the other hand, when it is determined in step 303 that the stoichiometric combustion state is to be set, the ECU 30 executes control for injecting fuel from the injector 28 in step 306 such that the stoichiometric combustion state is established. Is transmitted to the transmission control means 54 via the signal line 66 to the effect that (currently) is being executed, and the processing routine is exited.

[Schematic Operation of Transmission Control Means 54] FIG.
5 is a flowchart for explaining a schematic operation of the transmission control means. This processing routine is also executed at predetermined time intervals.

In FIG. 4, the transmission electronic control unit 56 of the transmission control means 54 determines in step 401 the accelerator opening sensor 38 and other signals (for example, a detection signal from the vehicle speed sensor 40, an input shaft rotation sensor 50). From the output shaft rotation sensor 52). Next, the transmission electronic control unit 56 executes step 4
In 02, what kind of output (driving force) the engine 10 should output is calculated. As described above, in this embodiment, the output to be generated by the engine 10 is basically determined by the transmission electronic control unit 56 (not by the ECU 30).

Next, in step 403, the transmission electronic control unit 56 confirms whether to set the stoichiometric combustion state or the lean combustion state based on the calculation result.

If it is determined in step 403 that the stoichiometric combustion state should be set, the transmission electronic control unit 56 transmits a CVTLS signal indicating that the stoichiometric combustion state should be set in step 404 via the signal line 68 to the ECU 30. To send to. If it is determined in step 403 that the vehicle should be in the lean combustion state, the CVTLS signal to be brought into the lean combustion state in step 405 is supplied to the EC via the signal line 68.
Output to U30.

On the other hand, the transmission electronic control unit 56 receives the ENGLS signal from the signal line 68 in step 406. In step 407, the CVTLS signal transmitted to the signal line 68 and the signal
It is determined whether or not at least one of the ENGLS signals received via the P.6 is on the high output side (stoichiometric side). If the determination is YES, the hydraulic pressure control circuit 58 is controlled in step 408 so that the belt clamping pressure of the CVT 16 corresponds to the high output side (stoichiometric side) state. As a result, the hydraulic control circuit 58 sets the hydraulic oil to CVT.
The belt clamping pressure is adjusted so as to be supplied to the 16 output shaft side hydraulic cylinders so as to correspond to the stoichiometric side state.

On the other hand, in step 407, it is determined that both the CVTLS signal transmitted to the signal line 68 and the ENGLS signal received from the ECU 30 via the signal line 66 are on the low output side (lean side). In some cases, in step 409, the hydraulic control circuit 58 is controlled so that the belt clamping pressure of the CVT 16 corresponds to the low output side (lean side) state. Accordingly, the hydraulic control circuit 58
Hydraulic oil is supplied to the output shaft side hydraulic cylinder of the CVT 16 to adjust the belt clamping pressure so as to correspond to the lean state. When these processes are completed, the process proceeds to another process.

[When the ENGLS Signal Line 66 Fails] FIG. 5 (a) is a diagram for explaining the state of each unit when the ENGLS signal transmission line 66 fails. FIG. Have been.

(Example 1 of disconnection failure) First, the signal line 66 transmitting the ENGLS signal is disconnected and the CVT is failed.
A first example in which the LS signal is a command to set a lean combustion state will be described.

The transmission electronic control unit 56 sends a CVTLS signal of the lean combustion state command to the ECU 3 via a signal line 68.
0 (see the CVTLS signal column in Example 1 in FIG. 5A). Thereby, the ECU 30 sets the injector 2
8 to control the engine 10 in the lean combustion state (see the ENG control column of Example 1 in FIG. 5A).

On the other hand, if the signal line 66 fails to open,
The ENGLS signal is transmitted via signal line 66 to transmission control means 5.
4 is not transmitted to the transmission electronic control unit 56, but the signal level itself of the signal line 66 is at a low level.

As a result, the transmission electronic control unit 56 determines that the signal level of the ENGLS signal received from the signal line 66 is low (Step 406 in FIG. 4).
5) The ECU 30 determines that the engine is in the stoichiometric combustion state (see the ENGLS signal column in Example 1 in FIG. 5A). Further, the hydraulic pressure control circuit 58 is controlled so that the belt squeezing pressure control corresponds to the high output side (stoichiometric side) state (at step 407) (see the column of belt pressure control in Example 1 in FIG. 5A). As a result, the CVT is
High output side (stoichiometric side) for 16 output shaft side hydraulic cylinders
Hydraulic oil is supplied so as to correspond to the state.

Although the supply corresponding to the high output need not necessarily correspond to the high output side, one of the effects of the present invention is that the supply is controlled to the safe side. . In any case, no slip occurs on the transmission belt 48 of the CVT 16 (see the belt slip column in Example 1 of FIG. 5A).

(Example 2 of disconnection failure) Next, the signal line 66 for transmitting the ENGLS signal is disconnected and the CVT is failed.
A second example in which the LS signal is a command to set the stoichiometric combustion state will be described.

The transmission electronic control unit 56 determines from the information on the running state of the vehicle that the vehicle should be in a stoichiometric combustion state by CVTLS.
A signal is given to the ECU 30 via the signal line 68 (see the column of CVTLS signal in Example 2 in FIG. 5A). Thus, the ECU 30 controls the engine 10 to the stoichiometric combustion state (see the ENG control column in Example 2 in FIG. 5A).

On the other hand, as described above, the transmission electronic control unit 5
In the case of No. 6, since the ENGLS signal is at the low level due to the disconnection of the signal line 66, it is determined that the stoichiometric condition is detected (FIG.
(See the column of ENGLS signal in Example 2 of (a)).

Further, the transmission electronic control unit 56 determines that the ECU 30 is in the stoichiometric combustion state in step 406 of FIG. 4 and that the CVTLS signal is also in the stoichiometric combustion state. The hydraulic control circuit 58 is controlled so that the pressure control corresponds to the high output side (stoichiometric side) state (see the column of belt pressure control in Example 2 in FIG. 5A).

Accordingly, the CVT 16
Is supplied to the output shaft side hydraulic cylinder of the CVT 16 in such a manner as to correspond to the high output side (stoichiometric side) state. Does not occur (see the belt slip column in Example 2 in FIG. 5A).

[When the ENGLS Signal Line 66 Has Short-Circuit Failure] FIG. 5B is an explanatory diagram of the state of each unit when the ENGLS signal transmission signal line 66 short-circuits failure, showing two examples. Have been.

(Example 1 of short-circuit failure) First, the signal line 66 for transmitting the ENGLS signal is short-circuited and the CVT
A first example in which the LS signal is a command to set a lean combustion state will be described.

The transmission electronic control unit 56 determines from the information on the running state of the vehicle that the vehicle should be in the lean combustion state, and sends a CVTLS signal to that effect via the signal line 68 to the ECU 30.
(See the CVTLS signal column in Example 1 in FIG. 5B). Thereby, the ECU 30 sets the injector 28
To control the engine 10 in the lean combustion state (see the ENG control column in Example 1 in FIG. 5B), and outputs a signal in the lean combustion state to the signal line 66.

On the other hand, when the signal line 66 is short-circuited, the transmission electronic control unit 56 sends the ECU 30
Is determined to be in a lean combustion state (FIG. 5B)
Of the ENGLS signal of Example 1). That is, since the signal to be received coincides with the signal actually received as a result of the failure (accidentally), the same judgment is made as if the judgment was correct. Accordingly, the transmission electronic control unit 56 determines that the ECU 30 is controlled to the lean combustion state in step 406 of FIG. 4 and that the CVTLS signal is also a command for the lean combustion state,
In step 7, the hydraulic control circuit 58 is controlled so that the belt squeezing pressure control is in a state corresponding to the low output side (lean side) (FIG. 5B)
Of Example 1). Thus, the hydraulic oil is supplied from the hydraulic control circuit 58 to the output shaft side hydraulic cylinder of the CVT 16 so as to correspond to the low output side (lean side) state. Although the signal line 66 has failed due to a short circuit,
The actual output of the engine 10 and the state of the actual hydraulic oil of the CVT 16 match, and no slip occurs on the power transmission belt 48 of the CVT 16 (see the belt slip column of Example 1 in FIG. 5B).

(Example 2 of short-circuit failure) Next, the signal line 66 for transmitting the ENGLS signal is short-circuited and the CVT
A second example in which the LS signal is a command to set the stoichiometric combustion state will be described.

The transmission electronic control unit 56 determines from the information on the running state of the vehicle that the vehicle should be in the stoichiometric combustion state by CVTLS.
A signal is given to the ECU 30 via the signal line 68 (see the column of CVTLS signal in Example 2 in FIG. 5B). Thereby, the ECU 30 controls the engine 10 to the stoichiometric combustion state (see the ENG control column in Example 2 in FIG. 5B).

On the other hand, the electronic control unit 56 of the transmission determines (erroneously) that the engine 10 is in the lean combustion state from the ENGLS signal because the signal line 66 is short-circuited and failed (FIG. 5B). (See the ENGLS signal column in Example 2). However, the transmission electronic control unit 56 is operating in the lean combustion state even if the ENGLS signal indicates that the CVTLS signal transmitted by the transmission electronic control unit 56 is a signal to be set to the stoichiometric combustion state. Even if it can be determined, the hydraulic pressure control circuit 58 is controlled so that the belt squeezing pressure control is in a state corresponding to the high output side (stoichiometric side) in step 407 (the belt pressure control in the example 2 in FIG. 5B). Column).

Therefore, the hydraulic control circuit 58 sends the CVT 16
Is supplied to the output shaft side hydraulic cylinder of the CVT 16 so as to correspond to the high output side (stoichiometric side) state.
No slippage occurs in No. 8 (see the column of belt slip in Example 2 in FIG. 5B).

As described above, no matter what state the ENGLS signal should be in and how it fails, the transmission belt 48 of the CVT 16 does not slip.

[Case where CVTLS Signal Line 68 Fails to Disconnect] FIG. 6A is an explanatory diagram of the state of each part when the disconnection of the signal line 68 for transmitting the CVTLS signal fails.

In this case, the transmission electronic control unit 56 controls the signal line 68 to be disconnected when the lean combustion state command or the stoichiometric combustion state command is sent as the CVTLS signal from the information on the running state of the vehicle. Therefore, the information of the signal line 68 received as the ECU 30 is (Lo)
w) level. Therefore, the ECU 30
Based on the information on the signal line 68, it is determined that the stoichiometric combustion state is to be controlled (see the CVTLS signal column in FIG. 6A).
The engine 10 is controlled to the stoichiometric combustion state by controlling the fuel injection amount of the injector 28 (see the ENG control column in FIG. 6A). Also, the ECU 30 determines that the control state of the engine 10 is currently in the stoichiometric combustion state.
The LS signal is transmitted to the signal line 66 (ENG in FIG. 6A).
LS signal column).

On the other hand, the transmission electronic control unit 56 determines that the ENGLS signal received from the signal line 66 is in a stoichiometric combustion state, so that even if the transmitted CVTLS signal is in a stoichiometric combustion state, In step 406 of FIG. 4, the "CVTLS signal or ENGL
It is determined that at least one of the S signals is in the stoichiometric combustion state ", and in step 407, the hydraulic control circuit 58 is controlled so that the belt squeezing pressure control corresponds to the high output side (stoichiometric side) state (FIG. )) Section). Accordingly, even if the signal line 68 fails, the hydraulic oil is supplied from the hydraulic control circuit 58 to the output shaft side hydraulic cylinder of the CVT 16 in a state corresponding to the high output side (stoichiometric side) state. No slip occurs at 48 (see the column of belt slip in FIG. 6A).

[Case where CVTLS Signal Line 68 Fails Short-Circuit] FIG. 6B is an explanatory diagram of the state of each unit when the signal line 68 transmitting the CVTLS signal fails short-circuit.

When the signal line 68 for transmitting the CVTLS signal is short-circuited and failed, the signal indicating that the ECU 30 should be set to the lean combustion state regardless of whether the actual CVTLS signal is the command for the lean combustion state or the stoichiometric combustion state. (See the CVTLS signal column in FIG. 6B). Thereby, the ECU 30 sets the injector 28
To control the engine 10 in the lean combustion state (see the ENG control column in FIG. 6B), and outputs a signal in the lean combustion state to the signal line 66.

Therefore, when the signal line 68 is short-circuited, the transmission electronic control unit 56 determines that the ECU 30 is in the lean combustion state based on the ENGLS signal (the ENGLS signal in FIG. 6B). Column). Therefore, the transmission electronic control unit 56 executes step 406 in FIG.
In step 407, if the CVTLS signal transmitted by itself is also in a lean combustion state, the belt squeezing pressure control is made to correspond to the low output side (lean side) state in step 407. However, the CVTLS signal transmitted by itself is a signal of the stoichiometric combustion state. , The hydraulic control circuit 58 is controlled to correspond to the high output side (stoichiometric side) state (FIG. 6).
(Refer to the section of belt pressure control in (b)). In any case, C
Slip does not occur on the transmission belt 48 of the VT 16 (FIG. 6).
(Refer to the belt slip column in (b)).

As described above, according to the present embodiment, ENGL
Even if the signal line 66 for transmitting the S signal or the signal line 68 for transmitting the CVTLS signal is broken or short-circuited, if one of the ENGLS signal or the CVTLS signal is on the high output side, the high output side (stoichiometric) is used. Side) Since the CVT 16 is controlled so as to correspond to the state, both fail in such a manner that the signal line 68 is disconnected and the signal line 66 is short-circuited, and an extremely special case in which the original judgment is “lean”. Except for a simple case, it is possible to reliably prevent the transmission belt 48 from slipping.

FIGS. 7A and 7B are timing charts for explaining the second embodiment. FIG. 7A shows the state from the lean combustion state to the stoichiometric combustion state, and FIG. 7B shows the state from the stoichiometric combustion state to the lean combustion state. An example of a switching state is shown. In FIG. 7, the horizontal axis represents time, the vertical axis represents a CVTLS signal,
The ENGLS signal, the actual engine torque state, and the belt clamping pressure control are shown, respectively.

As shown in (a), when the CVTLS signal output from the transmission electronic control unit 56 switches from the lean combustion state to the stoichiometric combustion state,
The switch 30 immediately switches from the lean combustion state to the stoichiometric combustion state and outputs an ENGLS signal. In practice, however, the switching is performed by control for gradually switching the engine 10 from the lean combustion state to the stoichiometric combustion state. At this time, the transmission electronic control unit 56 also outputs the CVTLS signal to the EN
Since the GLS signal is also switched to the stoichiometric state (immediately), the CVT 16 is switched so that the belt squeezing pressure is changed from the state corresponding to the low output side (lean side) to the state corresponding to the high output side (stoichiometric side) at the time of the switching. Controlling.
Therefore, when the actual engine torque state is an intermediate state between lean and stoichiometric (indicated by a circle in the figure), the CVT 16 is in a state corresponding to stoichiometric combustion, so that the transmission belt 48 does not slip.

On the other hand, when the CVTLS signal output from the transmission electronic control unit 56 switches from the stoichiometric combustion state to the lean combustion state, the ECU 30 changes the ENGLS signal to the stoichiometric combustion state as shown in FIG. Does not immediately switch to the lean combustion state,
Switches the ENGLS signal to lean in a state in which the state is completely switched from the stoichiometric combustion state to the lean combustion state through the lean-stoichiometric intermediate region (indicated by a circle in the figure). Therefore, during the period when the engine 10 actually switches from the stoichiometric combustion state to the lean combustion state, the ENGLS signal is in the stoichiometric combustion state.
Is in the state corresponding to the high output side (stoichiometric side).
, The CVT 16 can be kept in the stoichiometric combustion state, and in a state where the engine 10 is actually completely switched from the stoichiometric combustion state to the lean combustion state, the transmission electronic control unit is controlled by a change in the ENGLS signal. 5
Numeral 6 can control the hydraulic control circuit 58 from a state corresponding to a high output side (stoichiometric side) to a state corresponding to a low output side (lean side). This is an example in which the effect of "supplying hydraulic oil corresponding to the stoichiometric combustion state when one of the signals is in the stoichiometric combustion state" according to the present invention is successfully used to solve the problem of the time lag at the time of switching. It is one of.

In the above-described embodiment, an example is described in which the combustion state of the engine 10 is switched between the two output states by setting the combustion state to the lean combustion state or the stoichiometric combustion state. There is no particular limitation on whether the switching can be performed (in multiple stages) depending on the configuration.

For example, a configuration may be adopted in which the number of cylinders for injecting fuel of the engine 10 is switched from six cylinders to four cylinders or two cylinders from four cylinders to six cylinders so as to be adjusted in multiple stages. Even when the above-described control method is applied to a vehicle in which the number of cylinders for injecting fuel is switched to switch the output of the engine 10 to at least two states, completely the same operation and effect can be obtained.

Further, even for a vehicle in which the output is made variable by (arbitrarily) switching the amount of air-fuel mixture supplied to the engine, such as a so-called switching type supercharger (mechanical supercharger). Similarly, the present invention can be applied.

In any case, even if there is a failure such as a disconnection or short circuit in the signal line for transmitting the switching information of the output of the engine 10, the transmission electronic control unit 56 operates the CVT 16
Can be controlled to a state corresponding to the high output side (stoichiometric side), so that the transmission belt can be prevented from slipping.

In addition, in the present embodiment, since the transmission control means 54 determines whether the engine should be in a lean state or a stoichiometric combustion state, the transmission control means 54 has original switching information. Therefore, it is possible to obtain a simple and reliable fail judgment and response.

For example, if the ECU 50 determines whether to perform the lean combustion state or the stoichiometric combustion state (by a method generally performed conventionally), the switching information is transmitted to the ECU 50 side. It is inevitable for the ECU 50 to determine the mismatch between the transmitted information and the received information.
It will be done on the side. Therefore, in this case, an additional signal line for transmitting the determination result to the transmission control means again is required. Of course, if such a signal line is further added, it can be used for purposes other than the present purpose. However, handling of the added signal line for failure also poses a new problem. .

In the present embodiment, since the transmission control means 54 determines which one to switch to, such a problem does not occur at all.

[0074]

As described above, according to the first aspect of the present invention, when the internal combustion engine control means and the transmission control means transmit switching information to each other, at least one of them is on the high output side. Since the belt clamping pressure of the non-transmission is controlled in accordance with the state of the high output side, the transmission belt does not slip even if the output of the internal combustion engine is switched to either.

According to the second aspect of the present invention, the target power performance is determined based on the accelerator opening and the result of the determination is sent to the internal combustion engine control means. In this case, it is possible to effectively prevent the transmission belt from slipping due to the response delay, and to obtain an advantage that it is not necessary to add a new communication line.

[Brief description of the drawings]

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

FIG. 2 is a configuration diagram schematically showing a control device for a vehicle including a continuously variable transmission to which the present invention is applied.

FIG. 3 is a flowchart for explaining a schematic operation of the ECU of the embodiment.

FIG. 4 is a flowchart for schematically explaining the operation of the transmission electronic control device of the embodiment.

FIG. 5 is an explanatory diagram of a control state at the time of disconnection failure and short-circuit failure of the signal line for the ENGLS signal in the embodiment.

FIG. 6 is an explanatory diagram of a control state at the time of a disconnection failure and a short-circuit failure of a signal line for a CVTLS signal according to the first embodiment.

FIG. 7 is a timing chart for explaining an operation state of another example of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Engine 12 ... Torque converter 14 ... Forward / reverse switching device 16 ... Continuously variable transmission (CVT) 18 ... Reduction gear device 20 ... Differential gear device 24 ... Drive wheel 30 ... Engine electronic control unit (ECU) 32 ... Throttle opening Degree sensor 38 ... Accelerator opening sensor 44 ... Input pulley 46 ... Output pulley 48 ... Transmission belt 54 ... Transmission control means 56 ... Transmission electronic control unit 58 ... Hydraulic control circuit 66, 68 ... Signal line

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F16H 59/14 F16H 59/14 61/02 61/02 // F16H 59:18 59:74 63:06

Claims (2)

[Claims] 1. A control device for a vehicle equipped with a continuously variable transmission configured such that the speed ratio of a continuously variable transmission can be changed steplessly and the output of an internal combustion engine can be switched to at least two stages. An internal combustion engine control means capable of switching control of the output of the internal combustion engine in at least two stages; and a transmission control means capable of switching control of the belt clamping pressure of the continuously variable transmission in accordance with the switching control of the output of the internal combustion engine. The internal combustion engine control means and the transmission control means include transmission means for mutually transmitting and receiving signals relating to respective switching control, and when at least one of the signals relating to the switching control is determined to be on the high output side, A control device for a vehicle equipped with a continuously variable transmission, wherein a belt clamping pressure of the continuously variable transmission is controlled to a state corresponding to a high output side. 2. The internal combustion engine according to claim 1, wherein the transmission control means determines an output to be generated in the internal combustion engine based on accelerator opening information and the like, and outputs a signal relating to switching control of the determined output. And continuously transmitting to the transmission control means a signal related to the switching control currently being executed based on the signal related to the switching control. Control device for a vehicle equipped with a machine.