JP2017118695A - Abnormality judgment system - Google Patents

Abstract

It is possible to determine both clogging of a filter and refrigerant leakage on a cooling circuit through which refrigerant flows. An inflow pressure sensor (12) for detecting an inflow pressure (PB) of a refrigerant flowing into a pump (5) interposed on a feed flow path of a refrigerant cooling circuit (4) for cooling a rotating electrical machine (2, 3), The clogging of the filter 8 and the cooling circuit 4 based on the outflow pressure sensor 13 for detecting the outflow pressure PC of the refrigerant flowing out from the filter 8 interposed on the flow path, and the detection results by the inflow pressure sensor 12 and the outflow pressure sensor 13. And a determination device 10 for determining leakage of refrigerant from the apparatus. [Selection] Figure 1

Description

  The present invention relates to an abnormality determination system that determines clogging of a filter and leakage of a refrigerant as an abnormality of a refrigerant cooling circuit that cools a rotating electrical machine.

  Conventionally, as one of the methods for cooling a rotating electric machine such as an electric motor or a generator, a pump and a cooler are interposed on a cooling circuit (circulation circuit) including the rotating electric machine, and the refrigerant pumped by the pump is placed in the cooling circuit. It is known that the refrigerant is cooled by a cooler. Since this refrigerant is also used for lubrication of the bearing of the rotating electrical machine, if the circulation of the refrigerant stops for some reason, the bearing may be seized. Therefore, a technique for determining whether or not the refrigerant can be circulated reliably has been proposed. For example, Patent Document 1 discloses a cooling device that detects the pressure in an oil passage through which oil (refrigerant) flows and determines that the oil passage is damaged and leaks when a pressure drop is detected. ing.

JP 2011-148378 A

  By the way, a filter for removing foreign substances in the refrigerant is often interposed in the refrigerant cooling circuit described above, and the refrigerant cannot flow through the cooling circuit even when the filter is clogged. Therefore, in order to correctly determine whether or not the refrigerant can be circulated reliably, it is desirable to be able to determine the clogging of the filter in addition to the leakage of the refrigerant.

  The present invention has been devised in view of such problems, and an object thereof is to provide an abnormality determination system capable of determining both clogging of a filter and leakage of refrigerant on a cooling circuit through which refrigerant flows. One of them. The present invention is not limited to this purpose, and is a function and effect derived from each configuration shown in the embodiment for carrying out the invention described later, and has another function and effect that cannot be obtained by conventional techniques. is there.

  (1) An abnormality determination system disclosed herein includes an inflow pressure sensor that detects an inflow pressure of refrigerant flowing into a pump interposed on a feed flow path of a refrigerant cooling circuit that cools a rotating electrical machine, An outflow pressure sensor for detecting the outflow pressure of the refrigerant flowing out from the filter disposed on the return flow path, and the clogging of the filter based on the detection result by the inflow pressure sensor and the outflow pressure sensor when the pump is operated. And a determination device that determines leakage of refrigerant from the cooling circuit.

(2) It is preferable that the determination device determines that the clogging has occurred when the outflow pressure is a value within a negative pressure range that is less than a lower limit value of a range in which atmospheric pressure can fluctuate.
(3) It is preferable that the determination device determines that the leakage has occurred when both the inflow pressure and the outflow pressure are values within a range in which atmospheric pressure can vary.
(4) It is preferable that the abnormality determination system includes an atmospheric pressure sensor that detects atmospheric pressure. In this case, when the inflow pressure and the outflow pressure are both atmospheric pressures detected by the atmospheric pressure sensor, the determination device preferably determines that there is no refrigerant in the cooling circuit due to the leakage. .

  Both clogging of the filter on the cooling circuit through which the refrigerant flows and leakage of the refrigerant can be determined.

It is a schematic diagram of the cooling device to which the abnormality determination system according to the embodiment is applied. It is a figure for demonstrating a pressure range according to a pressure range and the state of a cooling device.

  An abnormality determination system as an embodiment will be described with reference to the drawings. Each embodiment shown below is only an example, and there is no intention of excluding various modifications and application of technology that are not clearly shown in each of the following embodiments. Each configuration of the present embodiment can be implemented with various modifications without departing from the spirit thereof. Further, they can be selected as necessary, or can be appropriately combined.

[1. Constitution]
FIG. 1 is a schematic diagram showing a cooling device 1 to which the abnormality determination system of the present embodiment is applied. The cooling device 1 is a device including a cooling circuit 4 through which a refrigerant flows in order to cool a motor 2 and a generator 3 (both rotating electrical machines), and is mounted on a vehicle, for example. In the present embodiment, oil is exemplified as the refrigerant.

  On the cooling circuit 4, a pump 5 that circulates oil in the cooling circuit 4 and a cooler 6 that cools the oil are interposed. The pump 5 is interposed on the feed flow path of the cooling circuit 4. In the cooling circuit 4, oil cooled by passing through the cooler 5 flows into the pump 5, is discharged from the pump 5, and is supplied to the motor 2 and the generator 3. This oil also has a function as a lubricating oil for lubricating the bearings of the motor 2 and the generator 3.

  The oil that has cooled and lubricated the motor 2 and the generator 3 accumulates in an oil pan 7 provided in the lower part of the generator 3. The oil pan 7 is open to the atmosphere, and a discharge port 7 a for discharging the oil in the oil pan 7 to the cooling circuit 4 is provided on the side surface thereof. The cooling circuit 4 is connected to the discharge port 7a from the outside of the oil pan 7. On the other hand, a filter 8 is attached to the discharge port 7a from the inside of the oil pan 7. The filter 8 removes foreign matters in the oil, and is disposed near the bottom surface of the oil pan 7 and is located on the return flow path of the cooling circuit 4. The oil in the oil pan 7 flows out of the oil pan 7 after passing through the filter 8 to remove foreign matter, flows through the cooling circuit 4 and flows to the cooler 5. As the oil circulates through the cooling circuit 4 in this way, the motor 2 and the generator 3 are cooled.

The cooling device 1 according to the present embodiment includes three pressure sensors 11 to 13 that detect the pressure P (refrigerant pressure P) of oil flowing through the cooling circuit 4, and an atmospheric pressure sensor 14 that detects the atmospheric pressure P _ATM. Is provided. The first pressure sensor 11 (hereinafter referred to as "discharge pressure sensor 11") detects the pressure P of the oil discharged from the pump 5 as a discharge pressure P _A. The second pressure sensor 12 (hereinafter also referred to as “inflow pressure sensor 12”) detects the pressure P of oil flowing into the pump 5 as the inflow pressure P _B. The third pressure sensor 13 (hereinafter referred to as "outlet pressure sensor 13") detects the pressure P of the oil flowing out from the filter 8 as the outflow pressure P _C. Values detected by the pressure sensors 11 to 13 and the atmospheric pressure sensor 14 are transmitted to the ECU 10.

  The ECU 10 (determination device) is an electronic control unit (Electronic Control Unit) configured as, for example, an LSI device in which a microprocessor, ROM, RAM, or the like is integrated, or an embedded electronic device. The ECU 10 of the present embodiment has a function as a determination device that determines whether the cooling device 1 is normal or abnormal by using values transmitted from the pressure sensors 11 to 13 and the atmospheric pressure sensor 14. That is, the abnormality determination system of the cooling device 1 is configured by the pressure sensors 11 to 13 and the atmospheric pressure sensor 14 and the ECU 10.

The ECU 10 according to the present embodiment detects “clogged filter 8” and “oil leakage (refrigerant refrigerant)” as abnormalities in the cooling device 1 based on the detection results of the inflow pressure sensor 12 and the outflow pressure sensor 13 when the pump 5 is operated. Is determined.
First, the discharge pressure P _A in the case the cooling device 1 is normal, the inflow pressure P _B, the relationship between the outflow pressure P _C in Table 1 below. Note that when the temperature of the oil is low (low temperature), the viscosity increases, so that the oil is not easily circulated in the cooling circuit 4. Therefore, since the detected pressure value also varies depending on the temperature state of the oil, the following Table 1 shows the case of normal temperature and the case of low temperature.

The atmospheric pressure range Ra, positive pressure range Rp, and negative pressure range Rn in Table 1 will be described with reference to FIG. As shown in FIG. 2, the atmospheric pressure range Ra is a predetermined pressure range including the atmospheric pressure P _ATM detected by the atmospheric pressure sensor 14, and the environment (elevation and climate) where the vehicle on which the cooling device 1 is mounted exists. Etc.) is a range in which the atmospheric pressure P _ATM can fluctuate. The atmospheric pressure range Ra is a range of pressure P that is not less than the lower limit value P ₁ and less than the upper limit value P ₂ (P ₁ ≦ P <P ₂ ). The lower limit value P ₁ and the upper limit value P ₂ may be preset as upper and lower limits of the range in which the atmospheric pressure P _ATM can vary, or the atmospheric pressure P detected by the atmospheric pressure sensor 14. from the _ATM to a predetermined value subtracted value and the atmospheric pressure P _ATM to X or it may be set as the value obtained by adding a predetermined value X.

The positive pressure range Rp is a range of pressure P that is equal to or higher than the upper limit value P ₂ of the atmospheric pressure range Ra (P ₂ ≦ P). If the detected pressure value is within this positive pressure range Rp, the oil pressure Means that the pressure is higher than the atmospheric pressure _ATM (positive pressure state). On the other hand, the negative pressure range Rn is a range of pressure P less than the lower limit value P ₁ of the atmospheric pressure range Ra (P <P ₁ ), and when the detected pressure value is within this negative pressure range Rn, This means that the oil is at a lower pressure (negative pressure) than the atmospheric pressure _ATM .

When the cooling device 1 is normal and the oil is at room temperature, the pressure P of the oil discharged from the pump 5 increases, and conversely, the pressure P of the oil flowing (sucked) into the pump 5 decreases. Therefore, as shown in FIG. 2 and Table 1, the discharge pressure P _A is the value of the positive pressure range Rp, the inflow pressure P _B becomes a value within the negative pressure range Rn. On the other hand, when the cooling device 1 is normal and the oil is at a low temperature, the discharge pressure P _A is lower than that at room temperature and the inflow pressure P _B is higher than that at room temperature. Atmospheric pressure P Value close to _ATM . That is, as shown in Table 1, the discharge pressure P _A is a value within the positive pressure range Rp from atmospheric range Ra (except the atmospheric pressure P _ATM or higher). The inflow pressure P _B is a value within the negative pressure range Rn to the atmospheric pressure range Ra (but less than the atmospheric pressure P _ATM ).

In the present embodiment, when the cooling device 1 is normal, a high pressure threshold value P _H and a low pressure threshold value P _L are set as threshold values for determining whether the oil is at a normal temperature or a low temperature. Pressure threshold P _H, in case the cooling device 1 is normal, a following values discharge pressure P _A at the normal temperature, and is higher than the discharge pressure P _A at low temperature. Similarly, when the cooling device 1 is normal, the low pressure threshold value P _L is a value higher than the inflow pressure P _B at the normal temperature and a value equal to or lower than the inflow pressure P _B at the low temperature. By providing such threshold values P _H and P _L , it is possible to more precisely determine the pressure state, and it is possible to determine the temperature state of the oil when the cooling device 1 is abnormal. When the cooling device 1 is normal, the pressure P on the downstream side of the filter 8 is substantially the same as the pressure value in the oil pan 7 (atmospheric pressure P _ATM ). not, as shown in Table 1, the outflow pressure P _C is a value within the atmospheric pressure range Ra.

In summary, as shown in FIG. 2, when the cooling device 1 is normal and the oil is at room temperature, the discharge pressure P _A fluctuates in a range equal to or higher than the high pressure threshold P _H , and the inflow pressure P _B is varies in a range of less than the low pressure threshold P _L, outflow pressure P _C varies at the lower limit value P ₁ or more and a range of less than the upper limit value P _2. Further, when the cooling device 1 is normal and the oil is at a low temperature, the discharge pressure P _A fluctuates in a range not less than the atmospheric pressure P _ATM and less than the high pressure threshold P _H , and the inflow pressure P _B is the low pressure threshold P _L. or more and varies with the atmospheric pressure P _ATM following range, outflow pressure P _C varies at the lower limit value P ₁ or more and a range of less than the upper limit value P _2.

Therefore, ECU 10 determines that at least the discharge pressure P _A is in the case where more pressure threshold P _H, the cooling apparatus 1 (refrigeration circuit 4) is normal oil is cold. Further, ECU 10, when the discharge pressure P _A is smaller than pressure threshold P _H is the inflow pressure P _B is below the atmospheric pressure P _ATM, and the outflow pressure P _C is the lower limit value P ₁ or more and the upper limit value P If it is less than ₂ , it determines with the cooling device 1 (cooling circuit 4) being normal, and oil being low temperature. Incidentally, described later in Table 2 shows the discharge pressure P _A for the temperature condition of the cooling device 1 of the state and the oil inflow pressure P _B, the relationship between the outflow pressure P _C.

In contrast to the normal state described above, when the filter 8 is clogged, it is difficult for the oil to flow out (or hardly flows out) from the oil pan 7, so that the pump 5 continues to suck the oil. The oil pressure P on the downstream side of the filter 8 decreases. Therefore, ECU 10, when the outflow pressure P _C which is detected by the outflow pressure sensor 13 is a value within the negative pressure range Rn, that is, when outlet pressure P _C is less than the lower limit value P ₁ (Pc <P ₁₎ Then, it is determined that the filter 8 is clogged.

ECU10 in the present embodiment, when the outlet pressure P _C is the value of the negative pressure range Rn (if clogging occurs) further outflow pressure P _C and the temperature of the low pressure threshold P _L and compared with the oil Determine the state. When the oil is at a low temperature (when the viscosity is high), it is difficult for the oil to flow in the first place. Therefore, the oil pressure P is close to the atmospheric pressure P _ATM as compared with the normal temperature. Therefore, as shown in FIG. 2 and Table 2, if the outflow pressure P _C is lower than the low pressure threshold P _L (P _C <P _L ), the ECU 10 determines that the oil is at room temperature (room temperature and filter clogging). If the outflow pressure P _C is equal to or higher than the low pressure threshold P _L (P _L ≦ P _C <P ₁ ), it is determined that the oil is at a low temperature (low temperature and filter clogged).

In the case where the oil occurs clogging of a cold filter 8, as shown in FIG. 2 and Table 2, the discharge pressure P _A is the positive pressure range Rp from atmospheric range Ra (except high pressure threshold P It fluctuates at a lower pressure than _H , that is, P ₁ ≦ P _A <P _H. Further, the inflow pressure P _B when the oil is at room temperature and the filter 8 is clogged fluctuates within the negative pressure range Rn (but lower than the low pressure threshold value P _L , that is, P _B <P _L ). Since these two pressure values P _A and P _B overlap with the fluctuation range of the pressure value at the normal time, in order to appropriately determine whether or not the filter 8 is clogged, the detected value of the outflow pressure sensor 13 ( it is effective to use the outflow pressure P _C). The discharge pressure P _A and the inflow pressure P _B when the oil is low temperature and the filter 8 is clogged are as shown in FIG. 2 and Table 2.

In addition, when oil leakage occurs, the oil that should circulate in the cooling circuit 4 is reduced or does not exist, so that oil and air or only air circulates in the cooling circuit 4. Then, the pump 5 sucks air in the cooling circuit 4. That is, if the oil leakage occurs, as shown in FIG. 2 and Table 2, the discharge pressure P _A, the inflow pressure P _B, none of the outflow pressure P _C varies within atmospheric pressure range Ra. Therefore, it is determined ECU10, when the inflow pressure P _B and the outlet pressure P _C are both at atmospheric pressure range Ra, and oil leakage has occurred.

In the case where the oil is completely gone from the cooling circuit within 4, the discharge pressure P _A, the inflow pressure P _B, and the same value as the atmospheric pressure P _ATM both detected by the atmospheric pressure sensor 14 of the outlet pressure P _C Become. Therefore, ECU 10 determines if the inflow pressure P _B and the outlet pressure P _C are both atmospheric P _ATM, the oil is not present in the cooling circuit 4 due to the leakage and (complete oil leakage has occurred).

[2. Action, effect]
(1) In the above-described abnormality determination system, “clogged filter 8” and “oil leakage” are determined as abnormalities in the cooling device 1 based on detection results by the inflow pressure sensor 12 and the outflow pressure sensor 13. Thus, by using the two pressure sensors 12 and 13, the difference from the pressure value when the cooling device 1 is normal can be used, and the filter 8 on the cooling circuit 4 through which the oil flows is clogged and the oil leaks. Can be determined. Thereby, it is possible to reliably detect and determine whether oil is flowing through the cooling circuit 4.

(2) determines that the above-described abnormality determination system, the outflow pressure P _C is clogging of the filter 8 when the value of the negative pressure range Rn occurs. Thus, since the presence or absence of clogging can be determined by checking the pressure (outflow pressure P _C ) on the downstream side of the filter 8, it is possible to reliably detect whether or not oil is flowing through the cooling circuit 4. it can.

(3) In the above-described abnormality determination system determines when the inflow pressure P _B and the outlet pressure P _C are both values within the atmospheric pressure range Ra, and oil leakage has occurred. In this manner, the inflow pressure P _B and the outlet pressure P _C is checked whether or not the atmospheric pressure range Ra, can be reliably detected, determining the occurrence of oil leakage of the cooling circuit 4.
(4) Further, in the above-described abnormality determination system, when the inflow pressure P _B and the outlet pressure P _C is the atmospheric pressure P _ATM detected both at atmospheric pressure sensor 14, the oil in the cooling circuit 4 is not present judge. Thus, by comparing with the detection value of the atmospheric pressure sensor 14, it can be reliably detected and determined whether or not the oil in the cooling circuit 4 has completely leaked.

(5) In the abnormality determination system of the present embodiment, since the high pressure threshold value P _H and the low pressure threshold value P _L are set, the pressure state can be more finely determined, and the oil in the case where the cooling device 1 is abnormal is determined. The temperature state can be determined. For example, when the outflow pressure P _C is a value within the negative pressure range Rn (clogging occurs), the outflow pressure P _C is compared with the low pressure threshold P _L, and if the former is lower than the latter (P _{If C} <P _L, it can be determined that the oil is at room temperature, and if the former is greater than the latter (P _C ≧ P _L ), it can be determined that the oil is cold.

(6) Further, in the abnormality determination system of the present embodiment, by providing the discharge pressure sensor 11 and sets the pressure threshold P _H, the cooling device 1 is normal discharge pressure P _A is equal to or greater than the high pressure threshold P _H Therefore, it can be determined that the oil is at room temperature (that is, the cooling device 1 is in an optimal state). Alternatively, it is acceptable to set the low threshold P _L, the discharge pressure P _A, the inflow pressure P _B, by checking the pressure range of the outlet pressure P _C, also oil cooling apparatus 1 is normal is low Can be determined.

[3. Modified example]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
The configuration of the cooling device 1 described above is an example, and is not limited to the above. The cooling device 1 only needs to include a pump 5 and a filter 8 on at least a refrigerant cooling circuit 4 that cools the rotating electrical machine. The shape of the cooling circuit 4, the arrangement of the devices to be interposed, and the like are as follows. There is no particular limitation. The refrigerant may be a fluid other than oil.

In the embodiment described above, the high pressure threshold value P _H and the low pressure threshold value P _L are set, but these threshold values may not be provided. Further, the value (atmospheric pressure P _ATM ) detected by the atmospheric pressure sensor 14 and the discharge pressure P _A , the inflow pressure P _B , and the outflow pressure are provided without providing the atmospheric pressure range Ra (range in which the atmospheric pressure P _ATM can vary). Each of P _C may be compared.

1 Cooling device 2 Motor (rotary electric machine)
3 Generator (Rotating electric machine)
4 Cooling Circuit 5 Pump 6 Cooler 7 Oil Pan 7a Discharge Port 8 Filter 10 ECU (Evaluation Device)
11 Discharge pressure sensor 12 Inflow pressure sensor 13 Outflow pressure sensor 14 Atmospheric pressure sensor
P _A discharge pressure
P _B inlet pressure
P _C outflow pressure
P _ATM atmospheric pressure
P _H high pressure threshold
P _L Low pressure threshold
Ra Atmospheric pressure range (range)
Rp Positive pressure range
Rn Negative pressure range

Claims (4)

An inflow pressure sensor for detecting the inflow pressure of the refrigerant flowing into the pump interposed on the feed flow path of the refrigerant cooling circuit for cooling the rotating electrical machine;
An outflow pressure sensor for detecting an outflow pressure of the refrigerant flowing out from the filter interposed on the return flow path of the cooling circuit;
A determination device for determining clogging of the filter and leakage of refrigerant from the cooling circuit based on detection results by the inflow pressure sensor and the outflow pressure sensor during operation of the pump;
An abnormality determination system comprising: 2. The determination device according to claim 1, wherein the determination device determines that the clogging has occurred when the outflow pressure is a value within a negative pressure range that is less than a lower limit value of a range in which atmospheric pressure can vary. Abnormality judgment system. 3. The cooling according to claim 1, wherein the determination device determines that the leakage has occurred when both the inflow pressure and the outflow pressure are values within a range in which atmospheric pressure can fluctuate. Circuit abnormality determination device. It has an atmospheric pressure sensor that detects atmospheric pressure,
The determination device determines that there is no refrigerant in the cooling circuit due to the leakage when both the inflow pressure and the outflow pressure are atmospheric pressures detected by the atmospheric pressure sensor. The cooling circuit abnormality determination device according to claim 3.

Images