JP2995635B2 - Power control device for vehicles with automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a power control device for a vehicle with an automatic transmission, which prevents an input torque exceeding an allowable torque from being applied to a drive train system by reducing engine torque by engine torque reduction means.

[Prior art]

It is known that when the engine is under a high load stall such as when the brake and the accelerator are simultaneously depressed, the load applied to the drive train system is considerably larger than the load applied during normal start acceleration. Conventionally, when a load greater than the load applied at the time of normal start acceleration is applied, a drive train system such as an automatic transmission by automatically reducing the engine torque, for example, a propeller shaft, a differential gear, Alternatively, a technique has been proposed in which the load applied to an input shaft such as a drive shaft is reduced to protect these devices and to reduce the weight accordingly (for example, SAE paper 870081).

[Problems to be solved by the invention]

However, in a vehicle configured to reduce the engine torque when a load exceeding the allowable input torque is applied to any part of the drive train system, if any means for reducing the engine torque is used, If it does not work properly for some reason, the load that is not reduced will be applied to the drive train system,
There is a possibility that the durability of the drive train system is reduced. The present invention has been made in view of such a conventional problem, and even if a situation in which the engine torque reducing means does not operate normally for some reason occurs, an excessively large drive train system is required. It is an object of the present invention to provide a power control device capable of preventing a heavy load from being applied and maintaining the durability of the drive train system satisfactorily.

[Means for Solving the Problems]

As shown in FIG. 1, the present invention provides an automatic transmission with an engine torque reduction means for preventing an input torque exceeding an allowable torque from being applied to a drive train system by reducing the engine torque. In the vehicle power control device, means for detecting whether the vehicle is running in reverse, means for detecting whether the engine torque reducing means has failed, and means for performing reverse driving and the engine torque reducing means. Means for setting the shift stage of the automatic transmission to the high-speed reverse stage when it is determined that the automatic transmission has failed has achieved the above object. Further, the present invention provides a power control device for an automatic transmission-equipped vehicle in which an input torque exceeding an allowable torque is applied to a drive train system by reducing an engine torque by an engine torque reducing means. Means for detecting whether or not the engine is in a high-load stall state, means for detecting whether or not the engine torque reducing means has failed, and that the engine is in a high-load stall state and the engine torque reducing means has failed. Means for setting the gear position of the automatic transmission to a higher gear position when the determination is made, the above object is also achieved.

[Action]

The present invention includes means for detecting whether the vehicle is in reverse running or whether the engine is in a high load stall state, and means for detecting whether or not the engine torque reduction means has failed. When it is determined that the vehicle is in reverse running or that the engine is in a high-load stall state and that the engine torque reducing means has failed, the gear position of the automatic transmission is changed to the higher gear side (in reverse running, (High-speed reverse stage side). The cause of the failure of the engine torque reducing means is, for example, a failure of the motor for rotating the sub-throttle valve, a failure of the throttle sensor for detecting the opening of the throttle valve, or a connection between these devices and the computer. Possibility is considered. As a means for determining whether or not the engine torque reducing means has failed, for example, a computer that controls the engine issues a flag to the computer that controls the automatic transmission to indicate whether the torque reducing means is normal, A computer that controls the transmission determines the failure state by looking at the value of this flag. When the computer controlling the engine determines that the engine torque should be reduced in its own computer in order to cope with the above-described cause of the failure, the current to the motor of the sub-throttle valve corresponds to that. The failure state can be determined by checking whether or not the failure has occurred. When it is determined that the engine torque reducing means has failed in this way, the gear position of the automatic transmission is set to the higher gear position. For example, in the forward range, the first speed is omitted, and the shift is executed using only the second speed or higher.
When the reverse range is set, the reverse traveling is performed using only the high-speed reverse range among the reverse ranges. By doing so, the input torque is reduced by the amount corresponding to the reduction in the gear ratio in the drive train system, and as a result, it is possible to prevent the input torque exceeding the allowable torque from being applied.

【Example】

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this embodiment, a conventionally well-known traction control system is used as a hardware configuration for changing the engine torque when a load exceeding the allowable input is applied to the drive train system. A traction control system adjusts the output of the engine when the vehicle starts or accelerates, and the engine output is too large for the coefficient of friction between the road surface and tires, causing a slip. Start or acceleration can be performed. An outline of this system will be described with reference to FIG. The air taken into the engine 20 is taken in via the main throttle valve 24 and the sub throttle valve 26. Engine 20
The intake air amount of the engine, that is, the engine output is
The opening is adjusted by the opening of the sub throttle valve 26 and the opening of the sub throttle valve 26. The main throttle valve 24 is connected to an accelerator pedal 28, and the opening of the main throttle valve 24 is adjusted according to the amount of depression of the accelerator pedal 28. The sub-throttle valve 26 is connected to a motor 30, and by electrically operating the motor 30,
The intake air amount can be changed independently of the accelerator pedal 28. The EFI computer 32 is mainly used for controlling the combustion of the engine, the TRC computer 34 is mainly used for controlling the aforementioned motor 30, that is, for traction control and excessive input prevention control, and the ECT computer 36 is mainly used for the automatic transmission 22. Used for hydraulic control for gear shifting. The EFI computer 32 calculates whether the engine torque should be reduced in its own computer, and detects whether a corresponding current is supplied to the motor 30 based on the calculation result. Based on the detection result, a failure of the engine torque reduction control system is determined, and if it is determined that a failure has occurred, the ECT computer 36 is notified via the communication line 39 to that effect. When receiving this signal, the ECT computer 36 changes the gear position of the automatic transmission 22 as described later. As shown in FIG. 3, the automatic transmission 22 includes a torque converter 120 as a transmission portion thereof,
A transmission section 140 and a first transmission section 160 having three forward speeds and one reverse speed
And The torque converter 120 includes a pump 121, a turbine 12
2, a stator 123 and a lock-up clutch 124 are provided. The pump 121 is connected to the crankshaft 20 a of the enclosure 20, and the turbine 122 is connected to the carrier 141 of the planetary gear set in the second transmission section 140. In the second transmission section 140, a planetary pinion 142 rotatably supported by the carrier 141 is provided.
Are in mesh with the sun gear 143 and the ring gear 144. or,
A clutch C0 and a one-way clutch F0 are provided between the sun gear 143 and the carrier 141, and a brake B0 is provided between the sun gear 143 and the housing Hu. The first transmission section 160 is provided with two rows of front and rear sides as planetary gear units. This planetary gear unit has a common sun gear 161 and ring gear 16
2, 163, planetary pinions 164, 165, and carrier 16
It consists of 6,167. The ring gear 144 of the second transmission section 140 is connected to the ring gear 162 via a clutch C1. A clutch C2 is provided between the ring gear 144 and the sun gear 161. Further, the carrier 166 is connected to the ring gear 163, and the carrier 166 and the ring gear 163 are connected to the output shaft 170. On the other hand, a brake B3 and a one-way clutch F2 are provided between the carrier 167 and the housing Hu.
A brake B2 is provided between 1 and the housing Hu via a one-way clutch F1, and a brake B1 is provided between the sun gear 161 and the housing Hu. This automatic transmission is provided with a transmission unit as described above, and is set in advance by an ECT computer 36 to which signals such as a throttle sensor 100 for detecting an opening of the main throttle valve 24 and a vehicle speed sensor 102 for detecting a vehicle speed are inputted. The electromagnetic solenoid valve in the hydraulic control circuit (not shown) is driven and controlled in accordance with the set shift pattern, and a combination of engagement of a clutch, a brake and the like as shown in FIG. 4 is performed to perform shift control. In FIG. 4, a circle indicates an engaged state, and a cross indicates an engaged state only when an engine brake is applied. Next, FIG. 5 shows a control flow executed in the apparatus of the above embodiment. Here, as an example, it is assumed that the engine output is reduced during stall and reverse, and the flow is started when this state is detected. First, in step 201, the state of the communication flag from the EFI computer 32 is checked. In step 202, it is determined based on the value of this flag whether or not the means for decreasing the engine torque is normal. If the engine is normal, the control flow is left as it is, and a predetermined engine torque reduction is executed by a separate routine. If it is determined that the engine torque reducing means is not normal, the process proceeds to step 203 and the first
It is determined whether or not the vehicle is in the gear position. If it is the first speed, the process proceeds to step 204 to execute a 1 → 2 upshift, and thereafter, in step 207, the shift lines of 1 → 2, 2 → 1 are deleted, and in step 208, the current engine torque is reduced. Generates a warning that the means is not working properly and resets. Therefore, traveling in the first gear is prohibited in the future,
Only traveling from the second speed stage to the overdrive stage is permitted. As a result, the torque greatly amplified by the large gear ratio is prevented from being applied to the drive train system. On the other hand, in step 203, the current traveling state is the first
When it is determined that the vehicle is not in the gear position, the routine proceeds to step 205, where it is determined whether or not the current traveling state is in the reverse gear position. If it is not the reverse stage, the process proceeds directly to step 207. On the other hand, when it is determined that the vehicle is in the reverse gear, the routine proceeds to step 206, where the brake B0 is engaged and the clutch C0 is released, and thereafter, the routine proceeds to step 207. As a result, when it is determined that the torque reduction means is not operating normally and the reverse stage is selected, the second
Since the transmission section 140 is in the high speed state, the reverse gear having a smaller gear ratio is achieved. Therefore,
Also in this case, the torque greatly amplified by the large gear ratio can be prevented from being applied to the drive train system. Note that the warning in step 207 is issued in steps 202 and
It may be generated between 203.

【The invention's effect】

As described above, according to the present invention, even if the engine torque reducing means does not operate normally for some reason, it is possible to prevent the input torque exceeding the allowable input from being applied to the drive train system. An excellent effect is obtained that the drive train system can be protected or the durability can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the gist of the present invention, FIG. 2 is a control system diagram of a vehicle automatic transmission and an engine showing an embodiment of the present invention, and FIG. 3 is a schematic diagram of the automatic transmission. FIG. 4 is a diagram showing an engagement state of each frictional engagement device of the automatic transmission in each shift speed, and FIG. 5 is a flowchart showing a control loft executed by the ECT computer. . 20 ... Engine, 22 ... Automatic transmission, 24 ... Main throttle valve, 26 ... Sub throttle valve, 32 ... EFI computer, 34 ... TRC computer, 36 ... ECT computer.

Claims (2)

(57) [Claims] 1. A power control system for a vehicle with an automatic transmission, wherein an input torque exceeding an allowable torque is prevented from being applied to a drive train system by reducing an engine torque by an engine torque reducing means. A means for detecting whether the engine torque reducing means has failed; and a means for detecting whether the engine torque reducing means has failed. Means for setting the gear position of the automatic transmission to the high-speed reverse gear side, and a power control device for a vehicle with an automatic transmission. 2. A power control apparatus for a vehicle with an automatic transmission, wherein an input torque greater than an allowable torque is prevented from being applied to a drive train system by reducing an engine torque by an engine torque reducing means. Means for detecting whether or not the engine is in a load stall condition, means for detecting whether or not the engine torque reducing means has failed, and determining that the engine has a high load stall and the engine torque reducing means has failed. Means for setting the gear position of the automatic transmission to a higher gear side when the instruction is made.