JP2015200618A - Temperature measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately measure a temperature of a moving body.SOLUTION: A temperature measurement device measures a temperature of a rotor 4 of a motor 1 that has the rotor 4 and a stator 6 adjacent to the rotor 4 and formed of the same material as the rotor 4. The temperature measurement device includes: a first non-contact temperature sensor 11 that is installed separately from the rotor 4 and measures a first temperature Tra to be the temperature of the rotor 4; a second non-contact temperature sensor 12 that measures a second temperature Tsa to be the temperature of the stator 6; a thermocouple 13 that is installed on the stator 6 and measures a third temperature Tsb to be the temperature of the stator 6; and a motor temperature measurement unit 21 that integrates a correction coefficient K(Tsb/Tsa) to be a ratio between the second temperature Tsa and the third temperature Tsb to the first temperature Tra, and calculates a temperature Tr of the rotor 4.

Description

  The present invention relates to a technique for measuring the temperature of a moving body.

As a measuring device that measures the temperature of an object, for example, a contact temperature measuring instrument that measures the temperature by contacting the object such as a thermocouple, and a temperature that does not contact the object such as a radiation thermometer. Non-contact temperature measuring instruments are known.
The contact temperature measuring instrument is relatively inexpensive and can have high measurement accuracy.
On the other hand, although the non-contact temperature measuring device is excellent in installation property, it is generally inferior in measurement accuracy than the contact temperature measuring device.

  Furthermore, in order to improve the accuracy of the temperature measured by the non-contact temperature measuring device, a contact temperature measuring device is further provided, and the same location other than the object is measured by the non-contact temperature measuring device and the contact temperature measuring device, and the difference between them is measured. Has been proposed as a correction value, and the correction value is subtracted from the temperature of the object measured by a non-contact temperature measuring instrument to correct it (Patent Document 1).

Japanese Patent Laid-Open No. 6-235562

By the way, when measuring the temperature of an object that moves (rotates) like a rotor of a motor, it is difficult to measure the temperature with a contact temperature measuring instrument. It is done.
However, the non-contact temperature measuring instrument may have low measurement accuracy as described above. Then, using a contact temperature measuring device like the said patent document 1, a different location from the target object which measures temperature is measured with a non-contact temperature measuring device and a contact temperature measuring device, and the non-contact is performed using the difference. It is conceivable to correct the measured temperature of the object measured by the temperature measuring instrument. However, even with this correction, the temperature difference between the location where the temperature is measured by both the non-contact temperature measuring instrument and the contact temperature measuring instrument and the object whose temperature is measured is not always constant, and the measurement accuracy is sufficiently high. There is a risk that it will not be secured.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a temperature measurement device capable of accurately measuring the temperature of a moving body.

  In order to achieve the above object, a temperature measuring apparatus according to claim 1 is provided separately from a moving body, the first temperature being the temperature of the moving body, and the moving body disposed adjacent to the moving body. A non-contact temperature measuring instrument that measures the second temperature, which is the temperature of the stationary body formed of the same material as the first, and a contact that is installed on the stationary body and that measures the third temperature, which is the temperature of the stationary body. A temperature measuring device; and a calculation unit that calculates a temperature of the moving body by adding a correction coefficient that is a ratio of the second temperature and the third temperature to the first temperature. Features.

According to a second aspect of the present invention, there is provided the temperature measuring device according to the first aspect, wherein the calculation unit calculates and stores the correction coefficient at each of the plurality of second temperatures, and corresponds to the first temperature. The correction coefficient is added to the first temperature to calculate the temperature of the moving body.
The temperature measuring device according to claim 3 is the temperature measuring device according to claim 1, wherein the non-contact temperature measuring device is configured to measure a temperature of the movable body, a first non-contact temperature measuring device that measures the temperature of the moving body, and the temperature of the stationary body. It has the 2nd non-contact temperature measuring device to measure, It is characterized by the above-mentioned.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the moving body is a rotor of a motor, and the fixed body is a stator of the motor.

  According to the temperature measuring device of claim 1, since the movable body and the fixed body are arranged adjacent to each other and are formed of the same material, the temperature and the contact measured by the non-contact temperature measuring device in a wide temperature range. The ratio of the temperature measured by the temperature measuring device is substantially the same between the fixed body and the moving body. Since the correction coefficient, which is the temperature ratio calculated by the fixed body, is added to the temperature of the moving body measured by the non-contact temperature measuring device and corrected, the temperature of the moving body is the temperature measured by the non-contact temperature measuring device. The measurement accuracy can be increased to the same level.

According to the temperature measuring device of claim 2, the correction coefficient is calculated and stored at each of the plurality of second temperatures, and the correction coefficient corresponding to the first temperature is used when obtaining the temperature of the moving body. Since the calculation is performed, the correction coefficient can be appropriately set at a plurality of temperatures, and the temperature of the moving body can be accurately obtained at each temperature.
According to the temperature measuring device of the third aspect, the first non-contact temperature measuring device may measure the temperature of the moving body, and the second non-contact temperature measuring device may measure the temperature of the stationary body. The non-contact temperature measuring instrument and the second non-contact temperature measuring instrument can be made narrow in the measurement area, and control such as signal processing during temperature measurement by the non-contact temperature measuring instrument can be simplified. Can do.

  According to the temperature measuring device of the fourth aspect, the temperature measured by the non-contact temperature measuring device and the contact temperature measuring device is obtained using the stator that is arranged adjacent to the rotor of the motor and is formed of the same material. Based on this, the temperature of the rotor measured by the non-contact temperature measuring device can be corrected, and the temperature of the rotor of the motor can be accurately measured.

It is a lineblock diagram of the inside of a motor concerning one embodiment of the present invention, and a temperature measuring device. It is a flowchart which shows the procedure of the temperature measurement control in the motor temperature measurement unit which concerns on this embodiment. It is a figure which shows an example of a correction table.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram of the inside of a motor 1 and a temperature measuring device according to an embodiment of the present invention. In addition, in this figure, the internal structure of the motor 1 is shown with sectional drawing.
The temperature measuring device 20 of the present embodiment is applied to, for example, a motor 1 that is mounted on a plug-in hybrid vehicle or a hybrid vehicle for driving driving.

As shown in FIG. 1, the motor 1 has an output shaft 3 rotatably supported in a housing 2, and a columnar rotor 4 (moving body) is fixed to the output shaft 3. The rotor 4 contains a permanent magnet 5.
A stator 6 (fixed body) is fixed to the outer periphery of the rotor 4 at the inner peripheral portion of the housing 2. The stator 6 incorporates a coil 7.

The rotor 4 and the stator 6 of this embodiment are formed of the same material such as iron.
When electric power is supplied to the coil 7 from the outside via the three-phase wire 8, a magnetic field is generated around the stator 6, and the rotor 4 disposed adjacent to the inside of the stator 6 rotates.
Since the motor 1 of the present embodiment is used for driving the vehicle, it requires a large output and generates a large amount of heat, so that a cooling water passage 9 is provided in the housing 2. The stator 6 can be cooled via the housing 2 by circulating a heat medium such as cooling water through the cooling water passage 9.

The motor 1 of this embodiment includes a first non-contact temperature sensor 11 (first non-contact temperature measuring instrument), a second non-contact temperature sensor 12 (second non-contact temperature measuring instrument), and a thermocouple 13. (Contact temperature measuring device) is provided.
The first non-contact temperature sensor 11 and the second non-contact temperature sensor 12 are radiation thermometers that measure thermal radiation such as infrared rays and visible light, and can measure the temperature of a separated object.

The first non-contact temperature sensor 11 faces the measurement position A that is the side surface of the rotor 4 and is installed in the housing 2, and measures the temperature at the measurement position A on the side surface of the rotor 4 (first temperature Tra).
The second non-contact temperature sensor 12 is installed in the housing 2 adjacent to the first non-contact temperature sensor 11 and facing the measurement position B on the side surface of the stator 6 close to the measurement position A. The measurement position of the stator 6 The temperature of B (second temperature Tsa) is measured.

The thermocouple 13 is disposed in contact with the stator 6 in the vicinity of the temperature measurement position B by the second non-contact temperature sensor 12, and measures the temperature of the stator 6 (third temperature Tsb).
The first non-contact temperature sensor 11, the second non-contact temperature sensor 12, and the thermocouple 13 output the measured temperature to the motor temperature measurement unit 21 (calculation unit).
The motor temperature measurement unit 21 includes a storage device (ROM, RAM, nonvolatile RAM, etc.), a central processing unit (CPU), etc., and includes a first non-contact temperature sensor 11 and a second non-contact temperature sensor 12. And the output signal from the thermocouple 13 is input, and the temperature Tr of the rotor 4 is measured. The motor temperature measurement unit 21 outputs the temperature Tr of the rotor 4 to the motor control unit 22 that controls the operation of the motor 1 and outputs an operation control signal for the motor 1.

FIG. 2 is a flowchart showing a procedure of temperature measurement control in the motor temperature measurement unit 21 according to the present embodiment.
The motor temperature measurement unit 21 repeatedly executes this control when the vehicle power is turned on.
As shown in FIG. 2, in step S10, it is determined whether or not it is time to execute the sensor correction mode. The sensor correction mode is a mode for creating a correction table, which will be described later, and is set to be executed when the vehicle power is turned on at a predetermined time (for example, every six months). If it is time to execute the sensor correction mode, the process proceeds to step S20. If it is not time to execute the sensor correction mode, the process proceeds to step S130.

In step S20, the sensor correction mode is started. Then, the process proceeds to step S30.
In step S30, a correction temperature upper limit value Th is set. The correction temperature upper limit Th is set to how many times the temperature of the stator 6 of the motor 1 is raised in the sensor correction mode. For example, the second non-contact temperature sensor 12 within the usable temperature range of the motor. May be set in advance to a value in the vicinity of the upper limit value of the temperature estimated to reach the second temperature Tsa measured by the above. Then, the process proceeds to step S40.

In step S40, driving of the motor 1 is started. Then, the process proceeds to step S50.
In step S50, the second non-contact temperature sensor 12 measures the second temperature Tsa, and the thermocouple 13 measures the third temperature Tsb. Then, the process proceeds to step S60.
In step S60, the correction coefficient K is calculated. The correction coefficient K is a ratio of the second temperature Tsa measured by the second non-contact temperature sensor 12 and the third temperature Tsb measured by the thermocouple 13 measured in step S40, and is obtained by K = Tsb / Tsa. Then, the process proceeds to step S70.

  In step S70, the correction coefficient K calculated in step S60 is stored in association with the second temperature Tsa, and a correction table is created. As shown in FIG. 3, for example, this correction table shows a correction coefficient K every time the second temperature Tsa rises by a predetermined temperature T1 (for example, 5 degrees) (for example, 20 degrees, 25 degrees,... 75 degrees). Remember. For example, in the correction table shown in FIG. 3, the correction coefficient K is set to increase stepwise as the second temperature Tsa increases. Then, the process proceeds to step S80.

  In step S80, the saturation determination of the second temperature Tsa measured by the second non-contact temperature sensor 12 in step S50 is performed. The saturation determination of the second temperature Tsa is determined to be a saturation determination if the second temperature Tsa changes below the predetermined temperature T2 even after the predetermined time Ti1 has elapsed. For example, the predetermined temperature T2 may be set to a temperature lower than the predetermined temperature T1. The predetermined time Ti1 may be appropriately set to a time at which it can be determined that the motor 1 will not change greatly even if the operation of the motor 1 is continued. If the determination is saturation, that is, if the change is not more than the predetermined temperature T2 even after the predetermined time Ti1 has elapsed, the process proceeds to step S90. If it is not the saturation determination, that is, if the change is greater than the predetermined temperature T2 after a predetermined time Ti1, the process proceeds to step S100. Even when the second temperature Tsa changes more than the predetermined temperature T2 before the predetermined time Ti1 has elapsed, it is determined that the saturation determination is not made at that time.

In step S90, the correction temperature upper limit Th stored in step S30 is changed to the second temperature Tsa measured in step S50, that is, the saturation temperature of the stator 6. Then, the process proceeds to step S100.
In step S100, it is determined whether or not the second temperature Tsa measured by the second non-contact temperature sensor 12 is higher than the correction temperature upper limit value Th. If the second temperature Tsa is higher than the corrected temperature upper limit value Th, the process proceeds to step S110. If the second temperature Tsa is equal to or lower than the corrected temperature upper limit value Th, the process returns to step S50.

In step S110, the correction table is completed and the motor 1 is stopped. Then, the process proceeds to step S120.
In step S120, the sensor correction mode is terminated. Then, this routine ends.
In step S130, the normal temperature measurement mode is started. Then, this routine ends.

  The normal temperature measurement mode is executed when the vehicle power supply is turned on and in a mode other than the sensor correction mode. In the normal temperature measurement mode, the first non-contact temperature sensor 11 measures the first temperature Tra, and reads the correction coefficient K corresponding to the second temperature Tsa that is the same as the first temperature Tra from the correction table. Then, the first temperature Tra and the correction coefficient K are integrated to obtain the rotor temperature Tr (Tr = Tra × K).

When the first temperature Tra does not coincide with the second temperature Tsa stored in the correction table, interpolation is performed with the correction coefficient K at the second temperature Tsa before and after the first temperature Tra. Thus, the correction coefficient K may be set.
For example, in the correction table shown in FIG. 3, when the first temperature Tra is 28 degrees, the correction coefficient K1 at the second temperature Tsa before and after the first temperature Tra (correction coefficient K1 at 25 degrees = 1.6). And the correction coefficient K2 (correction coefficient K2 at 30 degrees = 1.65) is read from the correction table, and the correction coefficient K is calculated by the following equation (1).
K = (K2−K1) / (30−25) × (Tra−25) + K1 (1)
As described above, in the present embodiment, the rotating rotor 4 is measured by the first non-contact temperature sensor 11, and the correction coefficient K is added to the first temperature Tra that is the measured temperature of the rotor 4 for correction. Then, the rotor temperature Tr is obtained.

The correction coefficient K is a ratio Tsb / a ratio between the second temperature Tsa that is the temperature of the stator 6 measured by the second non-contact temperature sensor 12 and the third temperature Tsb that is the temperature of the stator 6 measured by the thermocouple 13. Tsa.
By the way, since the stator 6 and the rotor 4 are located in the vicinity of each other and are made of the same material, the temperature ratio (Tsb / Tsa) in the stator 6 and the temperature ratio (Tr / Tra) in the rotor 4 are approximately in a wide temperature range. Be the same. Therefore, the correction coefficient K is integrated with the first temperature Tra, which is the temperature of the rotor 4 measured by the first non-contact temperature sensor 11, and the rotor temperature Tr is obtained by the thermocouple 13. It can be measured accurately with the same accuracy as the measured value.

  Note that the temperature measurement by the non-contact temperature measuring instrument such as the first non-contact temperature sensor 11 and the second non-contact temperature sensor 12 is performed based on the far-infrared radiation amount radiated from the measurement target part, This amount of radiation depends on the emissivity of the part to be measured. Emissivity refers to the substance that emits the maximum far-infrared radiation among all substances, and the radiation that a substance radiates at the same predetermined temperature with respect to the maximum radiation that the assumed substance radiates at the predetermined temperature. Say quantity ratio. Therefore, the emissivity varies from substance to substance and varies depending on the surface state of the substance. That is, correcting the measured temperature of the first non-contact temperature sensor 11 as described above is equivalent to correcting the emissivity of the measurement target part. In the present embodiment, as described above, since the temperature ratio suitable for correction of emissivity is used as the correction coefficient K of the measurement temperature, for example, the correction of the measurement temperature is performed in comparison with the correction coefficient K using a temperature difference. Accuracy can be increased.

Further, since the correction coefficient K is calculated and stored at each of the plurality of second temperatures Tsa and the rotor temperature Tr is calculated using the correction coefficient K corresponding to the first temperature Tra, the first temperature Tra Thus, the rotor temperature Tr of the motor 1 can be accurately calculated over a wide temperature range.
Therefore, it is possible to accurately measure the temperature of the object that rotates and moves like the rotor 4 of the motor 1, and to control the upper limit value of the driving power supplied to the motor 1 in the motor control unit 22, for example, using this temperature. As a result, the motor 1 can be protected.

  For example, in the motor 1 of the present embodiment, heat is generated from the coil 7 by driving the motor 1, and the temperature of the stator 6 rises. Along with this, the temperature of the rotor 4 also rises. Moreover, since the cooling water channel 9 is provided in the housing 2, the stator 6 is cooled. Therefore, the temperature of the rotor 4 may be higher than that of the stator 6. By accurately measuring not only the temperature of the stator 6 but also the temperature of the rotor 4 as in this embodiment, the motor 1 can be further protected.

  In the present embodiment, the first non-contact temperature sensor 11 and the second non-contact temperature sensor 12 are provided independently, and the first non-contact temperature sensor 11 measures the temperature at the measurement position A. Since the second non-contact temperature sensor 12 only needs to measure the temperature at the measurement position B, the non-contact temperature sensors 11 and 12 can be easily installed, and the non-contact temperature sensors 11 and 12 The parts cost can be reduced because the measurement area is narrow. Further, as compared with the case where one non-contact temperature measuring instrument having a wide measurement area is provided, the process of extracting the measurement values at the measurement positions A and B is not required. Can be a thing.

In addition, this invention is not limited to the said embodiment. For example, for the temperature ratio stored in the correction table, the temperature range or temperature interval to be measured may be changed as appropriate.
In the present embodiment, in the example of the correction table shown in FIG. 3, the correction coefficient K is set to increase as the first temperature Tra rises. This is a measurement object such as iron. This is because it has been confirmed that the temperature measured by the non-contact temperature sensor tends to be measured slightly lower than the actual temperature of the measurement object as the temperature of the object rises. However, the present invention is not limited to the numerical value or the increasing tendency of the correction coefficient K shown in FIG.

  The first non-contact temperature sensor 11 and the second non-contact temperature sensor 12 may be one non-contact temperature measuring instrument. In this case, the temperature at the measurement position A of the rotor 4 and the temperature at the measurement position B of the stator 6 are extracted from the data in the measurement region, and the temperature of the measurement position A of the rotor 4 and the temperature of the measurement position B of the stator 6 are. Can be measured individually. Thus, if the 1st non-contact temperature sensor 11 and the 2nd non-contact temperature sensor 12 are made into one non-contact temperature measuring instrument, the number of parts can be reduced.

  Further, in the present embodiment, the present invention is applied to the temperature measurement of the rotor 4 of the motor 1 for driving driving in the plug-in hybrid vehicle or the hybrid vehicle. However, the present invention can be widely applied to motors for other uses. . Also, the present invention can be widely applied when measuring the temperature of a moving body other than a motor.

1 Motor 4 Rotor (moving body)
6 Stator (fixed body)
11 First non-contact temperature sensor (first non-contact temperature measuring device)
12 Second non-contact temperature sensor (second non-contact temperature measuring instrument)
13 Thermocouple (Contact temperature measuring instrument)
21 Motor temperature measurement unit (calculation unit)

Claims (4)

A first temperature which is set apart from the moving body and which is the temperature of the moving body, and a second temperature which is the temperature of a fixed body which is arranged adjacent to the moving body and formed of the same material as the moving body. A non-contact temperature measuring instrument to measure the temperature;
A contact temperature measuring device installed on the fixed body and measuring a third temperature which is a temperature of the fixed body;
A calculation unit that calculates a temperature of the moving body by adding a correction coefficient that is a ratio between the second temperature and the third temperature to the first temperature;
A temperature measuring device comprising:   The calculation unit calculates and stores the correction coefficient at each of the plurality of second temperatures, integrates the correction coefficient corresponding to the first temperature to the first temperature, and moves the moving body. The temperature measuring device according to claim 1, wherein the temperature is calculated.   The non-contact temperature measuring device includes a first non-contact temperature measuring device that measures the temperature of the moving body, and a second non-contact temperature measuring device that measures the temperature of the stationary body. The temperature measuring device according to claim 1 or 2.   The temperature measuring device according to any one of claims 1 to 3, wherein the moving body is a rotor of a motor, and the fixed body is a stator of the motor.

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