阅读说明：本技术 一种防止电子油泵失效的诊断及控制方法 (Diagnosis and control method for preventing electronic oil pump from failing ) 是由 戴振坤 吕永安 李卫强 吴潇潇 于 2020-05-21 设计创作，主要内容包括：本发明涉及一种防止电子油泵失效的诊断及控制方法,在电子油泵的非工作状态,周期性给电子油泵特定的命令转速,防止电子油泵从长时间的非工作状态变为工作状态时,因长时间不工作出现卡滞或吸真空,避免电子油泵失效；同时,综合判断电子油泵实际转速、电压、电流,确定电子油泵故障类型,再根据故障对电子油泵进行相应的控制,使得电子油泵恢复止常,该诊断在电子油泵的工作过程中同样适用。(The invention relates to a diagnosis and control method for preventing failure of an electronic oil pump, which periodically gives a specific command rotating speed to the electronic oil pump in a non-working state of the electronic oil pump, and prevents the electronic oil pump from being blocked or vacuumized due to long-time non-working when the electronic oil pump is changed from the non-working state to the working state; meanwhile, the actual rotating speed, voltage and current of the electronic oil pump are comprehensively judged, the fault type of the electronic oil pump is determined, the electronic oil pump is correspondingly controlled according to the fault, the electronic oil pump is recovered to be normal, and the diagnosis is also applicable to the working process of the electronic oil pump.)

1. A method for operating an electronic oil pump, comprising the steps of:

when the electronic oil pump is in a non-working state, judging whether the power supply voltage of the electronic oil pump is normal or not;

if not, forbidding the electronic oil pump to enter a working state;

if the feedback rotation speed is normal, periodically applying a command rotation speed signal to the electronic oil pump, and judging whether the feedback rotation speed is normal according to the feedback rotation speed of the electronic oil pump; and if the feedback rotating speed is abnormal, prohibiting the electronic oil pump from entering a working state.

2. The method for operating an electronic oil pump according to claim 1, characterized in that:

and if the difference value between the feedback rotating speed and the command rotating speed is within a preset range, judging that the feedback rotating speed is normal, otherwise, judging that the feedback rotating speed is abnormal.

3. The method for operating an electronic oil pump according to claim 2, characterized in that:

the predetermined range is 20 rpm.

4. The method for operating an electronic oil pump according to claim 2 or 3, characterized in that:

and if the feedback rotating speed is normal, further judging whether the feedback current is normal, and if the feedback current is normal, allowing the electronic oil pump to enter a working state.

5. The method for operating an electronic oil pump according to claim 4, characterized in that:

if the feedback current is abnormal, gradually increasing the command rotating speed, and if the feedback current is recovered to be normal before the limit of the command rotating speed is reached, allowing the electric pump to enter a working state; and otherwise, prohibiting the electronic oil pump from entering the working state.

6. The method for operating an electronic oil pump according to claim 5, characterized in that:

and sending a fault indication when the electronic oil pump is forbidden to enter a working state, wherein the fault indication adopts a fault lamp or voice prompt mode.

7. The method for operating an electronic oil pump according to any one of claims 1 to 6, characterized in that: the electronic oil pump is used for providing lubrication and oil pressure for the transmission.

8. The method for operating an electronic oil pump according to claim 7, characterized in that: the transmission is applied to a pure electric vehicle, a hybrid electric vehicle or a fuel vehicle.

9. The method for operating an electronic oil pump according to any one of claims 1 to 8, characterized in that: and when the electronic oil pump is forbidden to enter the working state, the engine starting and stopping functions of the vehicle where the electronic oil pump is located are forbidden at the same time.

Technical Field

The invention belongs to the field of transmissions, and particularly relates to a diagnosis and control method for preventing an electronic oil pump from failing.

Background

In a transmission, a mechanical oil pump and an electronic oil pump are generally provided at the same time, wherein the mechanical oil pump serves as a main oil pump, and the electronic oil pump generally serves as an auxiliary oil pump. The electronic oil pump has the following functions: firstly, main oil pressure is provided when a mechanical oil pump cannot provide the main oil pressure, and the condition is that a vehicle with a start-stop function is in a state that an engine stops working or a multi-gear pure electric vehicle starts for example; secondly, lubricating oil pressure or flow of the lubricating system is provided, for example, under special working conditions (low rotating speed, large torque and the like) of vehicle operation, when the mechanical oil pump cannot provide enough lubricating flow, the electronic oil pump intervenes in work to provide extra lubricating flow. Of course, in the design of the hydraulic system, the lubrication flow may also be provided entirely by the electronic oil pump.

As is apparent from the above description, since the electronic oil pump is generally operated as an auxiliary oil pump, the electronic oil pump is in a non-operating state for most of the time during which the vehicle is running. This makes it possible for the electronic oil pump to fail, such as failure to reach the target rotational speed, normal rotational speed but failure to build up oil pressure, etc., by vacuuming, pump sticking, failure to build up oil pressure, etc., when switching from the non-operating to the operating state.

Although there is a detection device for detecting the operating parameters of the electronic oil pump, such as the rotation speed and the voltage of the electronic oil pump, the operating parameters of the electronic oil pump can only be obtained in real time when the electronic oil pump is operating, and it is impossible to diagnose in advance whether the electronic oil pump is out of order or not and to prevent the failure of the electronic oil pump.

Disclosure of Invention

The invention provides a control method when an electronic oil pump is in a non-working state, which periodically monitors the state of the electronic oil pump, ensures that the electronic oil pump can be switched to the working state at any time and can correctly respond.

To this end, the invention proposes a method for operating an electronic oil pump, comprising the steps of:

when the electronic oil pump is in a non-working state, judging whether the power supply voltage of the electronic oil pump is normal or not;

if not, forbidding the electronic oil pump to enter a working state;

if the feedback rotation speed is normal, periodically applying a command rotation speed signal to the electronic oil pump, and judging whether the feedback rotation speed is normal according to the feedback rotation speed of the electronic oil pump; and if the feedback rotating speed is abnormal, prohibiting the electronic oil pump from entering a working state.

Further, if the difference value between the feedback rotating speed and the command rotating speed is within a preset range, the feedback rotating speed is judged to be normal, otherwise, the feedback rotating speed is judged to be abnormal.

Further, the predetermined range is 20 rpm.

Further, if the feedback rotating speed is normal, whether the feedback current is normal is further judged, and if the feedback current is normal, the electronic oil pump is allowed to enter a working state.

Further, if the feedback current is not normal, gradually increasing the command rotation speed, and if the feedback current returns to normal before reaching the limit of the command rotation speed, allowing the electric pump to enter a working state; and otherwise, prohibiting the electronic oil pump from entering the working state.

Further, when the electronic oil pump is forbidden to enter the working state, a fault indication is sent out, and the fault indication adopts a fault lamp or voice prompt mode.

Further, the electronic oil pump is used for providing lubrication and oil pressure for the transmission.

Further, the transmission is applied to a pure electric vehicle, a hybrid electric vehicle or a fuel vehicle.

Further, when the electronic oil pump is prohibited from entering the working state, the engine start-stop function of the vehicle where the electronic oil pump is located is prohibited at the same time.

According to the technical scheme, the electronic oil pump periodically gives a specific command rotating speed to the electronic oil pump in the non-working state of the electronic oil pump, so that the electronic oil pump is prevented from being blocked or vacuumized due to long-time non-working when the electronic oil pump is changed from the non-working state to the working state, and the electronic oil pump is prevented from being out of work; meanwhile, the actual rotating speed, voltage and current of the electronic oil pump are comprehensively judged, the fault type of the electronic oil pump is determined, the electronic oil pump is correspondingly controlled according to the fault, the electronic oil pump is recovered to be normal, and the diagnosis is also applicable to the working process of the electronic oil pump.

The invention has the following advantages: 1. whether the electronic oil pump fails or not can be judged in advance; 2. if the electronic oil pump fails, the fault type of the electronic oil pump can be accurately positioned; 3. the failure of the electronic oil pump can be solved to a certain extent. Therefore, the present invention improves the reliability of the electronic oil pump as a whole.

Other advantages of the present invention will be more readily understood after reading the detailed description of the technical solutions of the present invention taken in conjunction with the accompanying drawings.

Drawings

Fig. 1 shows a schematic flow diagram of an embodiment of the invention.

Detailed Description

The core concept of the invention is based on the consideration that: since the electronic oil pump itself is an auxiliary oil pump, the time of being in the non-operating state is relatively long, which makes it difficult to detect whether it is out of order, and therefore, it is detected whether the electronic oil pump can operate normally by periodically rotating the electronic oil pump at a prescribed rotation speed while it is in the non-operating state.

Referring to fig. 1, a schematic flow chart diagram of one embodiment of the present invention is shown. Firstly, whether the electronic oil pump is in a non-working state or not is judged, and when the electronic oil pump is determined to be in the non-working state, whether the power supply voltage of the electronic oil pump is normal or not is further judged. If the power supply voltage is normal, the next control is carried out, otherwise, the electric pump is forbidden to enter a working state. Accordingly, since it has been judged that the electronic oil pump cannot normally operate at this time, the engine start-stop function is prohibited in the vehicle having the start-stop function.

Further, when the power supply voltage of the electronic oil pump is judged to be normal, a specific command rotating speed signal is applied to the electronic oil pump, and parameters such as the period, the size, the acting time and the like of the command rotating speed can be calibrated. The commanded speed signal may be issued by a Transmission Controller (TCU) or other control module.

The application of the electronic oil pump can be considered when the cycle, the acting time, and the like of the signal are calibrated. For example, the period of the command revolution of the electronic oil pump for the start-stop function can be relatively long, with a short action time; the period of the command rotating speed of the electronic oil pump for the lubricating function can be comprehensively judged according to the vehicle speed, the torque signal and the like, and the action time can be longer; the initial command rotating speed of the electronic oil pump is preferably selected to be a small rotating speed on the premise of meeting the performance requirement.

Subsequently, it is determined whether the feedback rotation speed of the electronic oil pump at this time is within a predetermined range. And if the absolute value of the difference value between the feedback rotating speed and the command rotating speed is in a preset range, judging that the feedback rotating speed is normal. The predetermined range may be calibrated according to the use or the like, for example, the absolute value is less than 20 rpm.

And if the absolute value of the difference value between the feedback rotating speed and the command rotating speed exceeds a preset range, judging that the feedback rotating speed is abnormal, and forbidding the electric pump to enter a working state at the moment. Accordingly, the start stop function of the vehicle may be disabled.

The application of a specific command speed signal to the electronic oil pump is the control core of the present invention. The inventor of the invention finds that under the condition that the electronic oil pump does not work for a long time, on one hand, oil filling in an oil inlet pipeline may not be carried out, and on the other hand, if the electronic oil pump is used in combination with the one-way valve, the one-way valve is blocked when not working for a long time, and the instant opening pressure is increased, so that the electronic oil pump can cause oil absorption difficulty or accidental oil absorption failure, and the pump fails. Based on the above findings, the present invention periodically operates the electronic oil pump once in a short time, and determines whether the electronic oil pump is in a normal state.

As a preferred embodiment of the present invention, after the above step, if it is determined that the feedback rotation speed is normal, it is further determined whether the feedback current of the electronic oil pump is normal. On the premise that the feedback rotating speed is normal, if the feedback current is always smaller than a specified value (the value can be calibrated), the feedback current is considered to be abnormal, and at the moment, the electric pump recovery step is carried out; if the feedback current is normal, allowing the electronic oil pump to enter a working state; and continues to apply the commanded speed to the electric pump for a given period.

In the electric pump recovery step, the commanded speed of the electric pump is increased in steps, the increment being calibratable. If the feedback speed and current of the electric pump can be recovered to normal before the command speed is increased to the preset limited speed, the electronic oil pump is allowed to enter the working state, and the command speed is continuously applied to the electric pump according to the given period. Otherwise, if the rotating speed and the current fed back by the electronic oil pump are still abnormal when the command rotating speed reaches the limit, the electronic oil pump is forbidden to enter the working state, and the corresponding fault lamp can be simultaneously lightened to prompt the electronic oil pump to have a fault.

From the above, the present invention proposes a method for diagnosing whether an electronic oil pump, which is an auxiliary oil pump, fails in a non-operating state, and proposes a corresponding recovery measure. Further, although the above embodiment has been described with the electronic oil pump as the auxiliary oil pump of the mechanical oil pump, it is apparent that the present invention may be applied to a case where the electronic oil pump is used alone.

Various embodiments of the present invention have been described in detail above. Those skilled in the art can make numerous possible variations and modifications to the described embodiments, or modify equivalent embodiments, without departing from the scope of the invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technology of the present invention are within the protection scope of the present invention, unless the content of the technical solution of the present invention is departed from.