JP2004138105A - Control method for protecting drive system component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent damages caused by slips at an engaging part by estimating or detecting an abrupt acceleration state and an abrupt deceleration state and by properly enhancing transmission torque between transmission members on the basis of the states. <P>SOLUTION: The power transmission device 10 of a vehicle is provided with a transmission means to transmit the drive force from an engine 30 to the wheel side by frictional engagement between rotation members. The power transmission device 10 of the vehicle has following characteristics. It is provided with a vehicle state detecting means 20, which estimates or detects the abrupt deceleration state of the vehicle and an idling state of the wheel, and an engaging force increasing means 20 to increase the engaging force of the frictional engagement between the rotation members when the abrupt deceleration state or the idling state is estimated or detected by the detecting means 20. The engaging force increasing means 20 drastically executes the increase of the engaging force during the idling state compared with the increase of the engaging force during the abrupt deceleration state. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a drive system component protection control method. Specifically, in a vehicle equipped with a power transmission device such as an automatic transmission (A / T), a continuously variable transmission (CVT), and a torque converter direct-coupled clutch, the input from the tire side is detected or predicted to secure the strength of the drive system. Control method.
[0002]
[Prior art]
Conventionally, in a vehicle equipped with a power transmission device such as an automatic transmission, a continuously variable transmission, and a torque converter direct-coupled clutch, transmission by a clutch and a transmission belt is performed so that a transmission torque capacity required for an input torque from an engine is minimized. Generally, torque is adjusted to reduce power loss due to excessive transmission force.
Specifically, these devices detect the throttle opening of the engine, the amount of fuel injection, and the like, and adjust the transmission torque in the clutch and the transmission belt in accordance with the detection to secure a sufficient transmission torque capacity.
[0003]
However, in these devices, no safety measures are taken to secure torque capacity against excessive input from the tire side.
This is because there is little recognition of the magnitude of excessive input from the tire side which occurs transiently, but recent research has shown that the value of the input from the tire side is 80% of the maximum input input from the engine side to the drive train. It has been found that some sort of measure is needed.
[0004]
Therefore, when driving on rough roads, for example, when the rotation speed of the wheels is suddenly reduced due to the wheels climbing on a rock and an excessive torque or a torque change is suddenly generated in the power transmission system, a power transmission path is formed. 2. Description of the Related Art A technique for releasing an automatic clutch has been known for the purpose of preventing damage to a power transmission path of each of the constituent parts (for example, see Patent Document 1).
[0005]
Further, in the belt type CVT, a technique is known in which, when at least one of the wheel rotation speeds suddenly rises or falls to such a degree as to cause slippage of the transmission belt, the clamping force of the variable pulley on the transmission belt is increased (for example, Patent Document 1).
[0006]
[Patent Document 1]
JP 2000-291695 A
[Problems to be solved by the invention]
However, the technique according to Patent Document 1 does not predict the rapid acceleration / deceleration state, and controls the transmission torque when the vehicle enters the rapid acceleration / deceleration state based on the rotation speed and the rotational acceleration of the wheels. In some cases, accurate control of torque could not be performed.
[0008]
That is, while the input torque from the tire side at the time of sudden deceleration is continuous, the input torque from the tire side at the time of sudden acceleration such as gripping after a wheel spins increases rapidly or Although sudden, the increase in transmission torque during rapid acceleration (frictional engagement force between rotating members) is not greater than the increase in transmission torque during sudden deceleration, so the transmission torque rises in time. In some cases, slippage occurs between the members, resulting in wear and deterioration of durability.
[0009]
The present invention has been made in view of the above conventional technology, and has as its object to predict or detect a wheel idling state or a sudden deceleration state and appropriately control a transmission torque between transmission members based on these states. .
[0010]
[Means for Solving the Problems]
A drive system component protection control method according to a first aspect of the present invention for solving the above-mentioned problems is a power transmission system for a vehicle including transmission means for transmitting a driving force from an engine to wheels by frictional engagement between rotating members. In the device, when the vehicle is rapidly decelerated, and the vehicle state detecting means for predicting or detecting the idling state of the wheels, and the detecting means predicts or detects the rapid deceleration state or the idling state, the engagement force of the frictional engagement is determined. An engaging force increasing means for increasing the engaging force in the idling state with respect to an increase in the engaging force in the rapid deceleration state. .
[0011]
A drive system component protection control method according to a second aspect of the present invention for solving the above-mentioned problems includes a braking operation detecting means for detecting a braking operation according to the first aspect, and the idling state of the wheel is predicted or detected by the detecting means. In this case, when the braking operation is detected by the braking operation detecting means, the engaging force increasing means further increases the engaging force.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention solves the above-mentioned disadvantages of the prior art, predicts or detects a case where excessive torque is input from the tire side, and appropriately secures a torque capacity safety factor in a transmission means such as a clutch or a belt of these devices. It is assumed that.
Here, the excessive input of torque from the tire side includes (1) re-grip after idling of the tire, and (2) reaction force of inertia inertia accompanying sudden deceleration such as sudden stop during sudden braking. .
[0013]
As a method for detecting the input torque from the tire side, a vehicle speed sensor attached to these devices can be used. For (1), the vehicle speed is detected by the vehicle speed sensor, and the theoretical speed and throttle opening obtained at that time can be obtained. When the acceleration equal to or higher than the acceleration continues for a predetermined time or more, the engagement hydraulic pressure is increased to perform control to prevent the engagement portion from slipping. For (2), a predetermined deceleration is detected when a brake lamp lighting signal is detected. When the above is detected, control for increasing the oil pressure is performed.
[0014]
【Example】
Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.
FIG. 1 shows a drive system component protection control device according to an embodiment of the present invention.
As shown in FIG. 1, the electronic control unit (ECU) 20 receives a gear position signal and a vehicle speed signal from the drive system component 10, a throttle opening signal from the engine 20, and a brake signal from the brake switch 40. You.
[0015]
The drive system component 10 specifically refers to an automatic transmission, a continuously variable transmission, a torque converter direct-coupled clutch, a starting clutch, and the like. The drive force from the engine 30 is transmitted between rotating members (in the case of an automatic transmission, a wet clutch, Transmission means for transmitting to the wheel side by frictional engagement with a frictional engagement element such as a brake or a transmission belt and a pulley in the case of a continuously variable transmission.
The throttle opening signal is a signal indicating the opening of a throttle valve provided in the intake system of the engine 30, and increases when the accelerator pedal is depressed.
[0016]
The brake signal is for detecting a braking operation of a braking device (brake), and for example, a lighting signal of a brake lamp can be used.
The electronic control unit 20 takes in the vehicle speed, the gear position, the throttle opening sensor and the brake signal, calculates the acceleration based on the input signal as described later, and changes the engagement hydraulic pressure of the drive system component 10. And performs the following drive system component protection control.
[0017]
{Circle around (1)} Drive system component protection control when the wheels are idling When the time change (acceleration) of the vehicle speed is sufficiently large in view of the current gear position and throttle opening, it is predicted that the wheels will be idling, and when the wheel is gripped after idling. The engaging force of the drive system component 10 with respect to the transmission means is increased in advance in preparation for the input excessive torque.
(2) Drive system component protection control during rapid deceleration The brake ON signal and the throttle opening fully closed are detected to detect that the vehicle speed deceleration exceeds a predetermined value, and the engaging force of the transmission system component 10 in the transmission means is detected. Enhance.
[0018]
As described above, in this embodiment, while the vehicle including the transmission means such as the automatic transmission and the continuously variable transmission is operating in the forward gear or the R range, the vehicle speed is detected by the output shaft rotation sensor or the wheel speed sensor of the transmission, and the vehicle speed is detected. When the increase (positive acceleration) exceeds the value obtained at the current throttle opening and the shift speed for a predetermined period of time, it is assumed that an excessive torque is predicted to be input from the tire side thereafter. The engagement force, specifically, the engagement oil pressure is increased, so that the engagement portion can be prevented from slipping.
Similarly, when the decrease in vehicle speed (negative acceleration) continues for a predetermined value or more for a predetermined period of time, an input of excessive torque is predicted from the tire side, and the engaging force of the power transmission means of the drive system component 10 is increased. In addition, the engagement portion can be prevented from sliding.
[0019]
FIG. 2 shows a specific flowchart of the drive system component protection control method during wheel idling according to the present embodiment.
First, when the ignition is ON and the gear is in the forward gear or the R range, the theoretical acceleration A is obtained based on the gear and the throttle opening (step S1). Then, the output shaft rotation sensor or the wheel speed sensor of the transmission is obtained. The actual measured acceleration B is obtained by detecting and differentiating the actual vehicle speed (step S2).
Subsequently, the theoretical acceleration A and the actually measured acceleration B are compared by the following equation (1) (step S3).
B> A · α (1)
Here, α is a predetermined value and can be determined experimentally or theoretically.
[0020]
Then, the equation (1) determines whether or not to continue a predetermined time T ₀ (step S4), and when continued for a certain time T _0, the input of the excessive torque from the tire side when the re grip rear wheel idles prediction As a result, the engagement force (engagement hydraulic pressure) of the power transmission means of the drive system component 10 is increased in advance (step S5).
Here, T ₀ is a predetermined value and can be determined experimentally or theoretically.
Temporal rate of change of the engagement hydraulic pressure [Delta] P ₁ set by the step S5 shown in Figure 4 (a).
The rate of change ΔP ₁ refers to the amount of change per unit time from the current engagement oil pressure to the target engagement oil pressure.
On the other hand, if the above equation (1) is not satisfied in step S3, or in step S4, when the above equation (1) is not continued for a fixed time T ₀ is the engaging force in the power transmission means of the drive system components 10 (engaging pressure ) Is maintained as it is (step S6).
[0021]
FIG. 3 shows a specific flowchart of the drive system component protection control method during rapid deceleration according to the present embodiment.
First, a predetermined value D is set as the deceleration (step T1). Next, under the condition that the ignition is ON and the brake signal is ON, the vehicle speed is detected and differentiated to determine the deceleration C. Calculation is performed (step T2).
Subsequently, the deceleration C is compared with the predetermined value D by the following equation (2) (step T3).
C> D (2)
Then, the equation (2) determines whether or not a predetermined time T ₀ is continued (step T4), a predetermined time T ₀ when the continued input of excessive torque from the tire side is predicted by the sudden deceleration, such as sudden braking The engagement force (engagement hydraulic pressure) of the power transmission means of the drive system component 10 is increased in advance (step T5).
[0022]
Here, T ₀ is a predetermined value and can be determined experimentally or theoretically.
Temporal change rate [Delta] P ₂ of the engagement oil pressure to be set in step T5 shown in Figure 4 (b).
The change rate [Delta] P _2, refers to the amount of change per unit time from the current engagement oil pressure to the engagement oil pressure as a target.
On the other hand, if the above equation (1) is not satisfied in step T3, or, in step T4, when the expression (2) does not continue a predetermined time T ₀ will maintain engagement pressure of the drive system components 10 intact (step T6).
[0023]
Here, as shown in FIGS. 4A and 4B, comparing the temporal change rates ΔP ₁ and ΔP ₂ of the engagement hydraulic pressure set in step S5 or T5, the following equation (3) is obtained. ΔP ₁ is greater than ΔP ₂ .
ΔP ₁ > ΔP ₂ (3)
That is, while the input torque from the tire side at the time of sudden deceleration is continuous, the input torque from the tire side at the time of re-grip after wheel idling is abrupt or sudden. Therefore, by making the change rate ΔP ₁ of the engagement force (engagement oil pressure) during wheel idling larger than the change rate ΔP ₂ of the engagement pressure during rapid deceleration, that is, by rapidly increasing the engagement force, Slip at the engagement portion can be reliably prevented.
[0024]
Further, in this embodiment, the brake unit switch 40 is provided as the braking operation detecting means, and when the braking operation is detected by the brake unit switch 40 when the idling of the wheel is predicted or detected, the engagement force is reduced. It is desirable to further increase.
For example, when the vehicle is slipping on the ice while the wheels are slipping, when trying to brake with the brake, the input of excessive torque from the tire side for braking may be particularly increased. This is because it is considered that it is necessary to further increase the engagement force (engagement oil pressure) in the power transmission means of the drive system component 10 in response to the above.
[0025]
In the above-described embodiment, the input of the excessive torque from the tire side is predicted based on the gear position signal or the vehicle speed signal from the drive system component 10. However, the present invention is not limited to this. The input of excessive torque from the side may be detected, and the engagement force (engagement pressure) of the power transmission means of the drive system component 10 may be increased to prevent the engagement portion from slipping.
[0026]
【The invention's effect】
As described above, according to the present invention, according to the present invention, an automatic transmission, a continuously variable transmission, a torque converter direct-coupled clutch, a starting clutch is detected by detecting or predicting an excessive torque input from the tire side. Thus, the strength of the drive system can be ensured. That is, for the excessive torque input to the drive system from the tire side, this is predicted or detected, and in order to increase the torque transmission capacity of the engagement portion, damage due to slippage is prevented. Power transmission is possible with torque capacity, ensuring durability and low fuel consumption.
In particular, when the braking operation is detected when the slipping of the wheels is predicted or detected, the engagement force is further increased. Therefore, even when the excessive torque input from the tire side is particularly increased by the braking, the power transmission device Slip can be reliably prevented.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a drive system component protection control device according to one embodiment of the present invention.
FIG. 2 is a flowchart illustrating a drive system component protection control method during wheel idling.
FIG. 3 is a flowchart illustrating a drive system component protection control method during rapid deceleration.
FIG. 4 is a graph showing a change in engagement pressure.
[Explanation of symbols]
10 drive system component 20 electronic control unit (ECU)
30 Engine 40 Brake switch

Claims (2)

In a vehicle power transmission device provided with a transmission means for transmitting a driving force from an engine to a wheel side by frictional engagement between rotating members, a vehicle state in which a sudden deceleration state of the vehicle and a wheel idling state are predicted or detected. A detecting means, and an engagement pressure increasing means for increasing an engagement force of frictional engagement between the rotating members when the sudden deceleration state or the idling state is predicted or detected by the detection means, and the engagement pressure increasing means is provided. A drive system component protection control method, wherein the increase in the engagement force in the idling state is rapidly performed with respect to the increase in the engagement force in the sudden deceleration state. A braking operation detecting means for detecting a braking operation, wherein when the idling state of the wheel is predicted or detected by the detecting means, the braking pressure detecting means detects the braking operation; The drive system component protection control method according to claim 1, wherein the engagement force is further increased.

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