Vehicle warning system

Abstract

The present invention provides a vehicle warning device that detects in advance when the torque converter is in a lost drive state and notifies the driver accordingly. [Solution] This vehicle warning device detects that the vehicle is in a lost drive state and issues a notification that it cannot start moving at this time if the oil temperature of the ATF (automatic transmission fluid) at the end of the previous drive is above a predetermined value, the time from the end of the previous drive until the indicator light for the current drive is illuminated is above a predetermined time, and furthermore, the shift operation to the driving range is performed within a predetermined time from the time the indicator light for the current drive is illuminated.

Description

Technical Field

[0001] The present invention relates to a warning device for a vehicle that pre-detects that a torque converter is in a lost drive state and notifies the same.

Background Art

[0002] Conventionally, due to the accumulation of bubbles in the automatic transmission fluid (hereinafter referred to as ATF) of a torque converter, a state where the rotation speed of a turbine does not increase and power is not transmitted, a so-called lost drive state, may occur. Further, this lost drive state is promoted by the fact that when the engine is stopped and the vehicle is left unattended for a long time, the oil in the torque converter drops, and it is difficult for the oil pressure to rise early when the engine is restarted.

[0003] Therefore, in Patent Document 1, after the engine is started, by supplying oil under high pressure, the lost drive state is eliminated, and a vehicle control device that predicts the input / output torque of the torque converter and determines whether the lost drive state has been eliminated is disclosed.

[0004] Also, in Patent Document 2, a vehicle control device is disclosed that determines that a torque converter is in a lost drive state when the rotation speed of a turbine is lower than a predetermined determination threshold value according to the rotation speed of the engine after the engine is started.

[0005] Furthermore, in Patent Document 3, a vehicle control device is disclosed that determines the occurrence of a lost drive state based on the fact that the increase rate obtained from the increase amount between the rotation speed of the engine at the start of the engine and the rotation speed of the engine after a predetermined time is equal to or higher than a preset determination threshold value.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] According to Patent Documents 1 to 3, if a lost drive condition is detected during or after engine startup, countermeasures are taken by the respective means. However, as a driver of a vehicle, you cannot know what is happening during that time and you have to spend the time as is, which can cause anxiety and discomfort when the vehicle cannot start.

[0008] This invention has been made in view of the above-mentioned technical problems, and the object of this invention is to provide a vehicle warning device that can detect in advance whether or not the torque converter is in a lost drive state and notify the user accordingly. [Means for solving the problem]

[0009] The vehicle warning device of the present invention, in order to achieve the above objective, is a vehicle warning device that detects in advance whether or not a power transmission device equipped with a torque converter is in a lost drive state and notifies the user accordingly, and detects that the vehicle is in a lost drive state and notifies the user that it cannot start if the oil temperature of the ATF (automatic transmission fluid) at the end of the previous drive is above a predetermined value, the time from the end of the previous drive until the current ready-to-drive indicator lights up is above a predetermined time, and furthermore, the shift operation to the driving range is performed within a predetermined time from the time the current ready-to-drive indicator lights up. [Effects of the Invention]

[0010] The vehicle warning device of the present invention detects whether the torque converter is in a lost drive state at an early stage before the vehicle starts moving and notifies the driver accordingly. The requirements for detecting whether or not the vehicle is in a lost drive state are as follows: First, the temperature of the ATF oil is detected. This is because the higher the ATF temperature, the faster oxidation and foaming are accelerated, leading to increased bubble accumulation. If the ATF temperature at the end of the previous drive is above a predetermined value, there is a high possibility of a lost drive, and this is considered to be the cause. Second, the time (standing time) from the end of the previous drive until the current drive-ready indicator (so-called Ready-ON indicator) lights up is detected. This is because if the engine remains stopped for a predetermined time or longer (long-term standing), oil leakage continues for a long time, increasing the likelihood of a lost drive, and this is considered to be the cause. Third, the time from the lighting of the current drive-ready indicator to the shift operation to the driving range (so-called D range) is detected. This detects the time until driving standby, and if this time is shorter than a predetermined time, there is a high possibility that the system is in the process of addressing the lost drive state, and this is considered to be the cause. The system determines the three factors mentioned above, and if all of them are present, it detects that the vehicle is in a lost drive state, or is highly likely to be in such a state, and issues a notification that it cannot start at this time. As a result, the driver can be informed in advance that the torque converter is in a lost drive state and that it cannot start at this time, thus alleviating anxiety and discomfort. [Brief explanation of the drawing]

[0011] [Figure 1] This is a block diagram showing the schematic configuration of a vehicle relating to one embodiment of the present invention. [Figure 2] This is a flowchart showing the operation of a vehicle alarm system according to one embodiment of the present invention. [Figure 3] This is a time chart showing the behavior of ATF in a vehicle alarm system according to one embodiment of the present invention. [Modes for carrying out the invention]

[0012] Hereinafter, one embodiment of the present invention will be described with reference to the attached drawings. Note that the embodiments described below are merely examples of how the present invention may be implemented and do not limit the present invention.

[0013] Figure 1 shows a block diagram illustrating the general configuration of the vehicle. Vehicle 1 is equipped with the following main components: an engine 2 as a power source, a power transmission system 4 with a torque converter 3, an automatic transmission 5 with a CVT (Continuously Variable Transmission), a hydraulic control device 6, a differential mechanism 7, a drive shaft 8, drive wheels 9, and an ECU (Electronic Control Unit) 10. Therefore, the power output from the engine 2 is transmitted from the torque converter 3 of the power transmission system 4 to the differential mechanism 7 via the CVT of the automatic transmission 5, and drives the drive wheels 9 via the drive shaft 8. The configuration of the power transmission system 4 will be described below, and the descriptions of the other components will be omitted.

[0014] The power transmission unit 4 is located between the engine 2 and the automatic transmission unit 5, and its role is to transmit power from the engine 2 to the automatic transmission unit 5. The torque converter 3, although not shown in the diagram, is equipped with a pump impeller, a turbine runner, and a stator. ATF oil is filled between the pump impeller and the turbine runner, and power is transmitted via the oil. In other words, when the engine's power rotates the pump impeller via the crankshaft, oil flows from the pump impeller to the turbine runner, and the oil rotates the turbine runner, which in turn rotates the turbine shaft connected to the automatic transmission unit.

[0015] In vehicle 1, for example, if the vehicle has been parked for a long period of time, such as a week, and the start button 11 is pressed to start the engine, and the shift lever 12 is immediately shifted to the driving position (e.g., D range), a state in which vehicle 1 cannot start, known as a lost drive state, may temporarily occur. The mechanism by which the lost drive state occurs is that, when the oil level is insufficient after engine start-up, even if the shift lever is immediately shifted to the D range, the rise in turbine rotation speed in the torque converter is slow, and power cannot be sufficiently transmitted from the engine to the automatic transmission. This lost drive state is more likely to occur when air bubbles accumulate inside the torque converter due to long-term parking, etc., and oil leakage has progressed. Based on the above, the factors that make the lost drive state more likely to occur are, firstly, the environment in which air bubbles accumulate and oil leakage is likely to occur, secondly, the length of time the vehicle has been left unattended, and thirdly, the length of time until the driving position (D range operation). Therefore, in the present invention, the above three items are used as determination criteria for detecting in advance whether or not a lost drive state has occurred.

[0016] Figure 2 is a flowchart illustrating the operation of a vehicle alarm system according to one embodiment of the present invention. First, the driver assumes a driving position when the Ready-ON indicator lights up (S-105). The ATF oil temperature stored at the end of the previous trip (previous drive) is retrieved, and it is determined whether this temperature is above a predetermined value (S-110). The higher the ATF oil temperature, the more the air bubbles in the torque converter are accelerated, making a lost drive condition more likely. If the previous drive was long and hard, the oil temperature will be higher, and it can be said that there is a potential for a lost drive. Therefore, as the first determination criterion, it is determined whether the ATF oil temperature at the time the engine was stopped last time was above a predetermined temperature. If it is determined that the oil temperature is above a predetermined value (YES), the process proceeds to the determination of the second criterion. The predetermined value of the oil temperature can be a value determined experimentally in advance.

[0017] Next, the elapsed time since the previous trip (previous driving), that is, the elapsed time, is calculated from the time memorized at the end of the previous trip and the time when Ready-ON is performed this time, and it is determined whether or not this elapsed time is equal to or greater than a predetermined value (S-120). It can be said that the longer the vehicle is left unattended, the more the oil drains in the torque converter is accelerated, making it easier for the lost drive state to occur, and having the potential to result in a lost drive. Therefore, as the second determination requirement, it is determined whether or not the elapsed time from when the previous engine was stopped until the current restart is equal to or greater than a predetermined value set in advance. Here, if it is determined that the elapsed time is equal to or greater than the predetermined value set in advance (YES), the process proceeds to the determination of the next third requirement. Note that the predetermined value of the elapsed time may be a value experimentally determined in advance.

[0018] And when the shift position is operated to the drive range (D range) (S-130), here, it is determined whether or not the time from Ready-ON to the shift operation to the drive range is within a predetermined time (S-140). Operating the shift to the drive range indicates the intention to drive immediately, but if the time until the shift operation is short, there is a possibility that the countermeasures against the lost drive have not been taken yet, or the vehicle is in the process of countermeasures (for example, the process of filling oil). Therefore, in order to determine the situation of the countermeasures against the lost drive, it is determined whether or not the time until the shift operation is within a predetermined time set in advance. Here, if it is determined that the shift operation to the drive range is within the predetermined time (YES), the process proceeds to the next notification operation (S-150).

[0019] Still, the predetermined time here may also be a value determined experimentally in advance, but it can be determined considering the following circumstances. For example, it is preferable to set it in consideration of the time required to supply the amount of oil necessary for starting. This will be described later. Also, the shorter the standing time used in S-120, the shorter the predetermined time can be set. As described above, the longer the standing time, the higher the possibility of being in the lost drive state. Conversely, when the standing time is short, it can be estimated that the risk of lost drive is low, so the determination time can be set short. On the other hand, it is preferable to set the predetermined time longer as the oil temperature at the end of the previous run used in S-110 is higher. As described above, the higher the oil temperature, the easier it is for the lost drive state to occur. Therefore, even when the time until the shift operation is long, it is estimated that it takes time to eliminate the lost drive, and a longer time is set to surely take countermeasures.

[0020] Finally, when all of the above three determinations are YES, the vehicle is determined to be in the lost drive state, and a notification to the effect that 'it is currently in a situation where it cannot start' is made (S-150). Then, the determination flow ends (S-160). Still, in the determinations of S-110, S-120, and S-140, if even one NO determination is made, it is regarded that it is not in the lost drive state and the determination flow ends.

[0021] Next, FIG. 3 is a time chart showing the behavior of the ATF in the vehicle's warning device. The vertical axis represents the amount of oil in the torque converter, and the horizontal axis represents time. And (1) to (6) noted on the horizontal axis indicate the times related to the steps of the flowchart in FIG. 2, and i to he noted on the vertical axis indicate the behavior of the oil amount at the times of (1) to (6) above. Still, in the figure, the numbers noted on the horizontal axis are shown as circled numbers.

[0022] First, at the end of the previous trip (previous drive) in (1), the oil level (I) is higher than the amount of oil needed to start the vehicle. However, after (1), a period of inactivity begins, and the oil level will gradually decrease over time. The oil temperature and time are recorded at this point in (1).

[0023] Next, during the period of inactivity up to (2), the oil level ☐ is still short, and it holds the amount necessary for starting. Therefore, if Ready-ON is executed during the inactivity period a (arrow range a) from (1) to (2), S-120 is likely to be determined as NO (not in a lost drive state), and the oil level ☐ also meets the required amount, so starting is possible. However, the oil temperature determination S-110 needs to be performed separately, so the outcome depends on that result.

[0024] During the period between (2) and (3), the idle time is extended, and the oil level decreases over time. Therefore, if Ready-ON is executed during the idle time b (arrow range b) between (2) and (3), S-120 is determined to be YES (lost drive state).

[0025] Next, (3) is the point at which the Ready-ON state is activated, and as the engine starts, oil is supplied by the hydraulic control device and the oil level begins to rise.

[0026] Subsequently, if the shift is performed to the driving range at point (4), the oil level ni is still in the process of rising and is within the oil supply completion time c (arrow range c). Therefore, it is considered that the oil level required for starting has not been reached and the lost drive condition has not been resolved. As a result, S-140 determines YES (lost drive condition) until point (5) when the oil level ho required for starting is reached. This determination continues until the oil supply completion time c is finished, so it is preferable to set the predetermined time set in S-140 taking the oil supply completion time c into consideration.

[0027] Next, if the shift is made to the driving range at point (6), the oil level will have exceeded the predetermined time c (arrow range c) and will be sufficient to meet the oil level required for starting. Therefore, S-140 will determine NO (not in a lost drive state), and starting will be possible at this point.

[0028] Through the above flow and operation, the torque converter can detect in advance that it is in a lost drive state and inform the driver that "it cannot start now." Therefore, the driver can know the situation they are in at an early stage before starting, thus alleviating any anxiety or discomfort.

[0029] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above and can be implemented with appropriate modifications as needed. For example, the vehicle can be any automatic transmission vehicle equipped with a torque converter, and can also be electric vehicles or hybrid vehicles. Furthermore, the predetermined values ​​set in determining the ATF oil temperature and the vehicle's storage time may be predetermined experimental values, but it is desirable to set them considering, for example, oil characteristics such as oil viscosity and the ambient temperature of the place where the vehicle is stored. [Explanation of Symbols]

[0030] 1: Vehicle 2: Engine 3: Torque converter 4: Power transmission device 5: Automatic transmission 6: Hydraulic control device 7: Differential mechanism 8: Drive shaft 9: Drive wheels 10: ECU

Claims

[Claim 1] A vehicle warning device that detects in advance whether a power transmission system equipped with a torque converter is in a lost drive state and notifies the user accordingly. The ATF oil temperature at the end of the previous run was above a specified value, and the time elapsed from the end of the previous run until the "ready to drive" indicator light illuminated was above a specified time. Furthermore, this vehicle warning device is characterized by detecting a lost drive state and issuing a notification that the vehicle cannot start if the vehicle shifts into the driving range within a predetermined time after the indicator light for driving is illuminated.

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