Electric pump diagnostic device

Abstract

To provide an electric pump diagnostic device capable of easily and accurately diagnosing a state of an electric pump.SOLUTION: A diagnostic device which diagnoses an electric pump 10 pumping oil comprises: a storage section 13 which stores diagnostic thresholds; and a determination section 14 which compares the diagnostic threshold stored in the storage section 13 with a driving current value I to drive the electric pump 10. The storage section 13 stores, as the diagnostic thresholds, a current upper limit value IH, a first current lower limit value IL1 which is lower than the current upper limit value IH, and a second current lower limit value IL2 which is lower than the first current lower limit value IL1. The determination section 14 notifies a user of: a feature change of the oil or performance reduction of the electric pump 10 when the driving current value I is determined to be equal to or larger than the current upper limit value IH; the feature change of the oil when the driving current value I is determined to be within a range from the first current lower limit value IL1 to the second current lower limit value IL2; and shortage of the oil when the driving current value I is determined to be equal to or less than the second current lower limit value IL2.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a diagnostic device for an electric pump. [Background technology]

[0002] Patent Document 1 discloses a vehicle cooling system that sets a command rotation speed based on the temperature of the refrigerant obtained by a water temperature sensor, and also sets an upper limit rotation speed for determining whether the water pump is normal based on the command rotation speed. In this cooling system, if the rotation speed obtained by the rotation speed sensor is higher than the upper limit rotation speed, it is determined that the water pump is abnormal, and the command rotation speed is set so that the upper limit rotation speed is lower than the maximum rotation speed for a predetermined time after the vehicle is started. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-66279 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the cooling system described in Patent Document 1 determines whether or not there is an abnormality in the water pump only based on the upper limit of the rotation speed, and it is difficult to make a detailed judgment on the situation based on each numerical value.

[0005] The present invention has been made in consideration of the above circumstances, and has an object to provide an electric pump diagnostic device that can easily and accurately diagnose the condition of an electric pump. [Means for solving the problem]

[0006] In order to achieve the above object, the diagnostic device for an electric pump of the present invention comprises: An electric pump diagnostic device for diagnosing an electric pump that pumps a fluid, comprising: A storage unit that stores a diagnostic threshold value; a determination unit that compares the diagnostic threshold value of the storage unit with a drive current value that drives the electric pump; Equipped with the storage unit stores, as the diagnostic thresholds, a current upper limit value, a first current lower limit value lower than the current upper limit value, and a second current lower limit value lower than the first current lower limit value; The determination unit is when it is determined that the drive current value is equal to or greater than a current upper limit value, a change in the nature of the fluid or a deterioration in performance of the electric pump is notified; notifying a change in the nature of the fluid when it is determined that the drive current value is within a range from the first current lower limit value to the second current lower limit value; When it is determined that the drive current value is equal to or less than the second current lower limit value, a shortage of the fluid is notified.

[0007] According to the electric pump diagnostic device having this configuration, the condition of the electric pump can be easily and accurately diagnosed using the drive current value that drives the electric pump, and an abnormality can be determined and notified. Effect of the Invention

[0008] According to the present invention, it is possible to provide an electric pump diagnostic device capable of easily and accurately diagnosing the condition of an electric pump. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of a diagnostic device according to this embodiment. [Diagram 2] FIG. 2 is a graph showing the diagnostic thresholds stored in the storage unit. [Diagram 3] FIG. 3 is a flowchart illustrating the procedure of the diagnosis. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram of a diagnostic device 11 according to this embodiment.

[0011] 1, an electric pump diagnostic device 11 according to this embodiment diagnoses an electric pump 10 and a fluid pumped by the electric pump 10. Here, a case will be described in which the diagnostic device 11 is applied to the diagnosis of an electric oil pump mounted on a vehicle such as an automobile.

[0012] The electric pump 10 is, for example, a pump that pumps oil to a drive unit of a vehicle, and pumps oil under pressure to gears, bearings, motors, and the like that constitute the drive unit to lubricate and cool them.

[0013] The electric pump 10 is provided with an oil temperature sensor 12. This oil temperature sensor 12 detects an oil temperature T, which is the temperature of the oil pumped by the electric pump 10 to the drive unit, and transmits a detection signal of the oil temperature T.

[0014] The diagnostic device 11 has a memory unit 13 and a judgment unit 14. The electric pump 10 and the oil temperature sensor 12 are connected to the diagnostic device 11. Data on the drive current value I that drives the electric pump 10 and a detection signal of the oil temperature T detected by the oil temperature sensor 12 are transmitted to the diagnostic device 11.

[0015] The storage unit 13 stores diagnostic thresholds. The storage unit 13 stores, as the diagnostic thresholds, a current upper limit IH, a first current lower limit IL1, and a second current lower limit IL2.

[0016] FIG. 2 is a graph showing the diagnostic thresholds stored in the storage unit 13. As shown in FIG. 2, the first current lower limit IL1 is a current value lower than the current upper limit IH, and the second current lower limit IL2 is a current value lower than the first current lower limit IL1. These current upper limit IH, first current lower limit IL1, and second current lower limit IL2 are diagnostic thresholds according to the oil temperature T, and are stored in the memory unit 13 as a map of current values ​​divided into a plurality of regions (regions A to D).

[0017] The determination unit 14 retrieves a map of diagnostic thresholds stored in the memory unit 13, and compares the diagnostic thresholds with the drive current value I that drives the electric pump 10. Then, the determination unit 14 notifies various determination results as necessary based on the comparison results.

[0018] Next, a procedure for diagnosing the electric pump 10 by the diagnosing device 11 will be described. FIG. 3 is a flowchart illustrating the procedure of the diagnosis.

[0019] When the electric pump 10 is in a driving state, the determination unit 14 obtains the oil temperature T from the oil temperature sensor 12 (step S01), and further obtains the drive current value I of the electric pump 10 (step S02). The determination unit 14 retrieves a map of diagnostic thresholds stored in the memory unit 13, and compares the diagnostic thresholds with the obtained drive current value I (step S03). The determination unit 14 compares the diagnostic thresholds with the drive current value I as follows to diagnose the electric pump 10.

[0020] (normal) When the determination unit 14 determines that the drive current value I is in the range from the current upper limit value IH to the first current lower limit value IL1 (area B) (step S04), it diagnoses that the electric pump 10 is normal and does not notify of an abnormality (step S05). Specifically, it diagnoses that the electric pump 10 is performing sufficiently and that there is no change in the oil quality or shortage.

[0021] (Abnormality 1) When the determination unit 14 determines that the drive current value I is equal to or greater than the upper current limit value IH (area A) (step S06), it diagnoses that an abnormality has occurred and notifies the user of the abnormality (step S07). Specifically, it diagnoses that a change in the oil characteristics or a deterioration in the performance of the electric pump 10 has occurred and notifies the user of the abnormality.

[0022] (Abnormality 2) When the determination unit 14 determines that the drive current value I is in the range from the first current lower limit value IL to the second current lower limit value IL2 (area C) (step S08), it diagnoses that an abnormality has occurred and notifies the user of the abnormality (step S09). Specifically, it diagnoses that a change in the oil characteristics has occurred and notifies the user of the abnormality.

[0023] (Abnormality 3) When the determination unit 14 determines that the drive current value I is equal to or less than the second current lower limit value IL2 (area D) (step S10), it diagnoses that an abnormality has occurred and notifies the user of the abnormality (step S11). Specifically, it diagnoses that there is a shortage of oil and notifies the user of the abnormality.

[0024] As described above, according to the diagnostic device 11 for the electric pump 10 of this embodiment, the condition of the electric pump 10 can be easily and accurately diagnosed, and abnormalities can be determined and notified using the drive current value I that drives the electric pump 10.

[0025] Based on the diagnosis results from the diagnosing device 11, the signs of performance degradation of the electric pump 10 and the estimated causes of abnormalities such as changes in the oil properties can be grasped before they occur, allowing prompt countermeasures to be taken.

[0026] In the above embodiment, the electric pump 10 consisting of an electric oil pump that pumps oil has been described as an example, but the present invention is applicable to diagnosing various electric pumps, such as an electric water pump that circulates fluids such as cooling water for an engine, an inverter, or a fuel cell. [Explanation of symbols]

[0027] 10 Electric Pump 11 Diagnostic equipment 13 Storage section 14 Judgment section I Drive current value IH current upper limit (diagnosis threshold) IL1 First current lower limit (diagnosis threshold) IL2 Second current lower limit (diagnosis threshold)

Claims

[Claim 1] An electric pump diagnostic device for diagnosing an electric pump that pumps a fluid, comprising: A storage unit that stores a diagnostic threshold value; a determination unit that compares the diagnostic threshold value of the storage unit with a drive current value that drives the electric pump; Equipped with the storage unit stores, as the diagnostic thresholds, a current upper limit value, a first current lower limit value lower than the current upper limit value, and a second current lower limit value lower than the first current lower limit value; The determination unit is when it is determined that the drive current value is equal to or greater than a current upper limit value, a change in the nature of the fluid or a deterioration in performance of the electric pump is notified; notifying a change in the nature of the fluid when it is determined that the drive current value is within a range from the first current lower limit value to the second current lower limit value; when it is determined that the drive current value is equal to or less than the second current lower limit value, a shortage of the fluid is notified. Diagnostic device for electric pumps.

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