JP6642033B2 - Power supply for vacuum pump - Google Patents

Description

  The present invention relates to a power supply device for a vacuum pump.

  Since a power supply device of a vacuum pump includes a circuit that generates relatively large heat, such as a motor drive unit that supplies power to a motor, a power supply housing may include a cooling fan (for example, see Patent Document 1). ). Some of the cooling fans for cooling the inside of the housing have a function of outputting a signal when the fan stops abnormally.

JP-A-10-131887

  However, when a cooling fan with an abnormal signal output function is used, the cost of the cooling fan increases, and it is necessary to add a circuit for detecting an abnormal signal, which raises a problem of an increase in the cost of the power supply device.

A power supply device for a vacuum pump according to a preferred embodiment of the present invention includes a motor drive unit that is housed in a power supply housing and supplies current to a motor of the vacuum pump, a cooling fan that cools the motor drive unit, and a power supply housing. A temperature sensor that detects an internal temperature of the temperature sensor, and an abnormality determination unit that determines that the cooling fan is stopped when a temperature increase rate of the temperature detected by the temperature sensor is equal to or greater than a set determination value. The determination value is set in accordance with a motor current value supplied to the motor from the motor drive unit, such that the determination value increases as the motor current value increases, and the abnormality determination unit includes The determination is performed based on the determination value according to the motor current value and the temperature increase rate .
In a further preferred embodiment, the determination value is set such that the determination value is smaller for a plurality of temperature ranges of the temperature detected by the temperature sensor, the higher the temperature range, the smaller the determination value. Performs a determination based on the determination value for the temperature range that includes the temperature detected by the temperature sensor and the temperature increase rate.
A power supply device for a vacuum pump according to a preferred embodiment of the present invention includes a motor drive unit that is housed in a power supply housing and supplies current to a motor of the vacuum pump, a cooling fan that cools the motor drive unit, and a power supply housing. A temperature sensor that detects an internal temperature of the temperature sensor, and an abnormality determination unit that determines that the cooling fan is stopped when a temperature increase rate of the temperature detected by the temperature sensor is equal to or greater than a predetermined determination value. The determination value is set for each of a plurality of temperature ranges of the temperature detected by the temperature sensor, such that the determination value decreases as the temperature range increases, and the abnormality determination unit includes: The determination is performed based on the determination value for the temperature range including the temperature detected by the temperature sensor and the temperature increase rate.
In a further preferred embodiment, the cooling fan has an abnormal signal output function of outputting an abnormal signal at the time of abnormal stop, and the abnormality determining unit determines whether the temperature rise rate is equal to or more than the determination value, and If any one of the signal outputs occurs, it is determined that the cooling fan has stopped.
In a further preferred embodiment, the temperature sensor is for detecting the temperature of the motor drive unit, and when the temperature detected by the temperature sensor exceeds a preset high temperature abnormality threshold, the motor drive unit The apparatus further includes a second abnormality determination unit that determines that the temperature is abnormal.
In a further preferred embodiment, the motor drive section reduces the current supplied to the motor when the second abnormality determination section determines that the motor drive section has a high temperature abnormality .

  ADVANTAGE OF THE INVENTION According to this invention, a stop of a cooling fan can be detected, suppressing cost.

FIG. 1 is a block diagram showing a schematic configuration of the vacuum pump device. FIG. 2 is a diagram illustrating an example of a temporal change in the detected temperature during the operation of the cooling fan. FIG. 3 is a diagram illustrating an example of the determination value. FIG. 4 is a flowchart illustrating an example of the procedure of the high temperature abnormality detection and the fan stop determination. FIG. 5 is a diagram illustrating the second embodiment.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
-1st Embodiment-
FIG. 1 is a block diagram showing a schematic configuration of the vacuum pump device. The vacuum pump device includes a pump unit 1 for evacuating and a power supply device 2 for controlling the pump unit 1. The pump unit 1 is provided with a motor 10 that rotationally drives a pump rotor (not shown). In the example shown in FIG. 1, the power supply device 2 is provided separately from the pump unit 1. However, the pump unit 1 and the power supply device 2 may be integrated.

  The housing 20 of the power supply device 2 includes a motor drive unit 21 that supplies a motor current to the motor 10, a control unit 22 that controls the entire power supply device 2, a motor drive unit 21, a control unit 22, and the like. A cooling fan 24 for cooling the housing 20, a temperature sensor 23 for detecting the temperature inside the housing 20, and a temperature detection circuit 25 to which a sensor signal of the temperature sensor 23 is input. The control unit 22 includes a CPU, a ROM, a RAM, and the like, and has a function of the abnormality determination unit 221 by software. The software is stored in the storage unit 222.

  The motor drive unit 21 includes an inverter having a switching element and the like. A desired motor current is supplied to the motor 10 by turning on / off the switching element provided in the inverter according to a control command from the control unit 22. The temperature detection circuit 25 reads the temperature based on the sensor signal of the temperature sensor 23.

  The temperature sensor 23 is provided as a temperature sensor for detecting a high-temperature abnormality of the motor drive unit 21 that generates a large amount of heat. The abnormality determination unit 221 detects a high-temperature abnormality based on the temperature detected by the temperature sensor 23 and performs a fan stop determination as described later. The storage unit 222 of the control unit 22 stores software, data, and the like necessary for the control operation.

  As described above, in the power supply device 2 of the present embodiment, based on the temperature detected by the temperature sensor 23, the control to limit the motor current by detecting the high temperature abnormality of the motor drive unit 21 and the abnormal stop of the cooling fan 24 are detected. Control is performed.

  2 and 3 are diagrams illustrating an example of a method of detecting the stop of the cooling fan 24 using the temperature detected by the temperature sensor 23. FIG. 2 shows an example of a temporal change in the temperature detected by the temperature sensor 23 during the operation of the cooling fan. The curves L0, L1, and L2 have different gas loads of the pump unit 1, respectively. FIG. 2 shows a temperature rise from the reference temperature T0, for example, a temperature rise from the point of no load. A curve L0 represents a temperature change when there is no load, and shows a temperature change when the no-load state is maintained from the reference temperature T0. A curve L1 indicates a temperature change after switching from the no-load state of the reference temperature T0 to the light load. A curve L2 shows a temperature change after switching from the no-load state of the reference temperature T0 to the large load.

  In order to maintain the motor 10 at a predetermined rotation speed (for example, a rated rotation speed), it is necessary to change the motor current value according to the gas load to be exhausted. Therefore, the motor current value increases as the gas load increases, and the heat generation of the motor drive unit 21 also increases, so that the temperature also increases. In the case of no load indicated by the curve L0, the motor current value Im satisfies Im ≦ 2A. In the case of a light load indicated by the curve L1, the motor current value Im is in the range of 2A <Im ≦ 7A. In the case of a large load indicated by the curve L2, the motor current value Im is Im> 7A.

  In each case, the environmental temperature at which the power supply device 2 is arranged is assumed to be the same. Further, the current range and the temperature rising tendency under no load, light load, and large load differ depending on the pump model.

  In the present embodiment, the stop of the fan is determined by comparing the temperature rise rate, which is the temperature rise value during the predetermined time, with the determination value ΔTth for determining whether to stop the fan. In the following, the temperature rise rate (° C./min) when the predetermined time is 1 minute will be described as an example. As shown in FIG. 2, the tendency of the temperature rise varies depending on the load condition of the pump unit 1 and also varies depending on the temperature range. FIG. 3 shows an example of the determination value ΔTth (° C./min), but the determination value ΔTth is set according to the load and the temperature range.

  Here, the determination temperature of the high temperature abnormality of the motor drive unit 21 is T = 80 ° C., and two temperature ranges A (T ≦ 60 ° C.) and B (60 ° C. <T ≦ 80 ° C.) are set as shown in FIG. did. In the case of FIG. 2 in which the cooling fan operates normally, the temperature rise rate (° C./min) is 3 (° C./min) in the temperature range A and 3 ° C./min. 0.5 (° C./min). When the cooling fan 24 is stopped, the temperature change becomes larger, so the determination value ΔTth is set to a value larger than these temperature rise rates. For example, the temperature range A is set such that ΔTth (A, L2) = 5 (° C./min), and the temperature range B is set such that ΔTth (B, L2) = 1 (° C./min).

  If the temperature rise rate ΔT (° C./min) in the temperature range A is ΔTth (A, L2) = 5 (° C./min) or more during operation with a large load, the cooling fan 24 Is determined to have stopped. As shown in FIG. 3, the judgment value is set similarly in the case of light load (curve L1) and no load (curve L0).

  In the present embodiment, the predetermined time for setting the temperature rise rate is set to 1 (min). However, the present invention is not limited to this, and any time interval at which the temperature rise rate can be easily detected is 1 (sec) or 10 (min). sec). Further, in order to improve the measurement accuracy, the temperature rise rate may be obtained a plurality of times, and the data of the plurality of times may be compared with the determination value. The calculation of the temperature rise rate and the determination of the stop of the fan are performed by the abnormality determination unit 221 based on the temperature detected by the temperature sensor 23 in FIG. Each determination value illustrated in FIG. 3 is stored in the storage unit 222.

  FIG. 4 is a flowchart illustrating an example of the procedure of the above-described high temperature abnormality detection and fan stop determination. A series of processing shown in the flowchart is executed by the abnormality determination unit 221 in FIG. A series of processing shown in FIG. 4 is repeatedly executed at a constant cycle (for example, a cycle of 1 second or 10 seconds).

  In step S10, the abnormality determination unit 221 acquires the detected temperature T from the temperature detection circuit 25 and stores it in the storage unit 222. In step S20, the abnormality determination unit 221 acquires the value of the current output to the motor 10 (that is, the motor current value) from the motor drive unit 21 and stores it in the storage unit 222. In step S30, the abnormality determination unit 221 determines whether or not the detected temperature T acquired in step S10 is equal to or lower than a high temperature abnormality threshold of 80 ° C. If it is determined in step S30 that T ≦ 80 ° C., the process proceeds to step S40, and if it is determined that T> 80 ° C., the process proceeds to step S32.

  When the process proceeds from step S30 to step S32, the motor current is reduced as a protection operation in the case of a high temperature abnormality. Then, in step S34, a high-temperature abnormality notification operation is performed, and the abnormality determination operation in FIG. 4 ends. The notification operation in step S34 includes, for example, lighting of an abnormal lamp (not shown) provided in the power supply device 2, output of a high temperature abnormality signal from the power supply device 2, and the like.

  On the other hand, when it is determined in step S30 that T ≦ 80 ° C. and the process proceeds to step S40, the calculation of the temperature rise rate ΔT (° C./min) is performed in step S40. This calculation is performed based on the detected temperature acquired in step S10 and the history of the detected temperature stored in the storage unit 222. Next, in step S50, the abnormality determination unit 221 determines whether the detected temperature T acquired in step S10 is equal to or lower than 60 ° C., that is, whether the current detected temperature is the temperature range A or the temperature range B shown in FIG. judge. When the detected temperature T is T ≦ 60 ° C., the process proceeds to step S60, and when T> 60 ° C., the process proceeds to step S52.

  In step S60, the determination value ΔTth (A) for the temperature range A is set as the determination value ΔTth. Note that the determination value ΔTth (A) is based on the motor current value acquired in step S20, and the determination value ΔTth (A, L2) for large load, the determination value ΔTth (A, L1) for light load and One of the no-load determination values ΔTth (A, L0) is used.

  In step S52, the determination value ΔTth (B) for the temperature range B is set as the determination value ΔTth. The determination value ΔTth (B) is based on the motor current value acquired in step S20, and the large load determination value ΔTth (B, L2), the light load determination value ΔTth (B, L1), One of the use determination values ΔTth (B, L0) is used.

  In step S70, the abnormality determination unit 221 determines whether the temperature rise rate ΔT calculated in step S40 is equal to or greater than a determination value ΔTth. If it is determined in step S70 that ΔT ≧ ΔTth, the process proceeds to step S80, in which an operation for notifying that the cooling fan 24 is stopped is performed, and a series of abnormality determination operations is ended. The notification operation in step S80 includes turning on a fan stop lamp (not shown) provided in the power supply device 2, outputting a fan stop signal from the power supply device 2, and the like.

  On the other hand, if ΔT <ΔTth is determined in step S70, the cooling fan 24 is operating normally, and the series of abnormality determination operations illustrated in FIG.

  As described above, the power supply device 2 for a vacuum pump in the present embodiment is housed in the housing 20 and cools the motor drive unit 21 that supplies current to the motor 10 of the pump unit 1 and the motor drive unit 21. It includes a cooling fan 24, a temperature sensor 23 that detects the temperature inside the housing 20, and an abnormality determination unit 221 that determines whether the cooling fan 24 is stopped. The abnormality determination unit 221 determines that the cooling fan 24 has stopped when the temperature increase rate of the temperature detected by the temperature sensor 23 is equal to or greater than the determination value ΔTth. As a result, the stop of the cooling fan 24 can be detected by software based on the detection result of the temperature sensor 23 for detecting the temperature inside the housing.

  By the way, when the cooling fan 24 is functioning normally, the temperature rise of the motor drive unit 21 which is a power unit can be suppressed, but other circuit units (for example, circuit components provided in the control unit 22) are also required. Temperature is low. On the other hand, when the cooling fan 24 stops, the temperature of the motor drive unit 21 also increases, but the temperatures of other circuit units also increase. Since the semiconductor element used in the control unit 22 has a lower allowable temperature than the semiconductor element in the motor drive unit 21, the temperature rise when the cooling fan 24 stops and the reliability of the semiconductor element used in the control unit 22 increases. May decrease. However, in the present embodiment, since the stop of the cooling fan 24 is detected, such a decrease in reliability can be prevented.

  Further, the temperature sensor 23 is originally provided for detecting a high temperature abnormality of the motor drive unit 21, and it is not necessary to add hardware for judging the stop of the cooling fan. be able to.

  As shown in FIG. 2, the temperature change (that is, the temperature rise rate) of the motor drive unit 21 changes according to the load of the pump, that is, the motor current value supplied to the motor 10 from the motor drive unit 21. Therefore, as shown in FIG. 3, by setting a plurality of determination values according to the motor current value, it is possible to more accurately determine whether the fan has stopped.

  Further, as shown in FIG. 2, the slopes of the curves L0, L1, L2 related to the temperature rise rate also differ depending on the level of the temperature detected by the temperature sensor 23. Therefore, the fan stop can be more accurately determined by setting the determination values ΔTth for a plurality of temperature ranges as in the temperature ranges A and B in FIG.

  The reference temperature T0 shown in FIG. 2 fluctuates depending on the environmental temperature in which the power supply device 2 is arranged. That is, when the environmental temperature is 5 ° C. higher than that in FIG. 2, the curves L0, L1, and L2 are substantially equal to the curves L0, L1, and L2 shown in FIG. 2 shifted upward by 5 ° C. . In this case, the temperature range A is replaced by T ≦ 65 ° C., the temperature range B is replaced by 65 ° C. <T ≦ 85 ° C., and the data of FIG. The correction may be performed so as to shift to. The environmental temperature may be the temperature detected by the temperature sensor 23 when the power of the power supply device 2 is turned on.

  By the way, in FIG. 3, the determination value ΔTth is set to 0.3 (° C./min) even in the case of no temperature and the temperature range B, for the following reason. For example, consider a case in which the system is operated with a large load (curve L2) in FIG. 2 and the temperature is in a rising process (for example, 70 ° C.). Here, when switching from a large load to no load, the temperature does not immediately start to decrease, and the temperature rising tendency continues for a certain time after the switching. In this case, the detected temperature is about 70 ° C. even when there is no load. Therefore, 0.3 (° C./min) is used as the determination value ΔTth in such a situation.

  The setting of the temperature range and the setting of the load shown in FIG. 3 are merely examples, and the number of setting of the temperature range may be smaller or larger than two, and the setting of the load may be set to four or more. The greater the set number, the more accurately the fan stop can be determined.

  In general, since the power unit generates a large amount of heat, the temperature sensor 23 detects the temperature of the motor drive unit 21 as the power unit in the above-described embodiment. However, the present invention is not limited to this. You may make it detect the temperature of a low circuit component.

-2nd Embodiment-
FIG. 5 is a block diagram illustrating the second embodiment. In FIG. 5, the cooling fan 24 has an abnormal signal output function of outputting an abnormal signal when abnormally stopped. The abnormal signal is input to the fan abnormal signal detection circuit 30, and a signal indicating whether the cooling fan 24 is abnormal is input from the fan abnormal signal detection circuit 30 to the control unit 22.

  In the case of the present embodiment, similarly to the case of the first embodiment, the abnormality determination unit 221 performs the fan stop determination based on the temperature detected by the temperature sensor 23, and the cooling fan 24 by the fan abnormality signal detection circuit 30. An abnormal stop of the vehicle is also detected. The abnormality determination unit 221 determines that the cooling fan 24 has stopped when the temperature rise value is equal to or greater than the determination value or when an abnormal signal is output. Thus, by providing the fan stop detection function in duplicate, the fan stop detection can be performed more reliably. For example, even when the abnormal signal of the cooling fan 24 is not output or the fan abnormal signal detection circuit 30 fails and the stop of the cooling fan 24 cannot be detected, the fan stop using the temperature detected by the temperature sensor 23 is performed. By the determination, it is possible to appropriately cope with the stop of the fan.

  In the case of the above-described first embodiment, the cooling fan 24 may or may not have the abnormality signal output function. Even if the cooling fan 24 has an abnormal signal output function, the power supply device 2 does not include the fan abnormal signal detection circuit 30 as shown in FIG. Therefore, the configuration of the first embodiment is inferior to the configuration of the second embodiment in the redundancy of the fan stop detection function, but is superior in cost.

  Although various embodiments and modified examples have been described above, the present invention is not limited to these contents. Other embodiments that can be considered within the scope of the technical concept of the present invention are also included in the scope of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Pump unit, 2 ... Power supply device, 10 ... Motor, 20 ... Housing, 21 ... Motor drive part, 22 ... Control part, 23 ... Temperature sensor, 24 ... Cooling fan, 25 ... Temperature detection circuit, 30 ... Fan abnormality Signal detection circuit, 221: abnormality determination unit, 222: storage unit

Claims (6)

A motor drive unit housed in the power supply housing and supplying current to the motor of the vacuum pump;
A cooling fan for cooling the motor drive unit,
A temperature sensor for detecting the temperature inside the power supply housing,
When the temperature rise rate of the temperature detected by the temperature sensor is equal to or greater than a predetermined determination value, an abnormality determination unit that determines that the cooling fan has stopped ,
The plurality of determination values are set according to a motor current value supplied to the motor from the motor driving unit, such that the determination value increases as the motor current value increases,
The power supply device for a vacuum pump , wherein the abnormality determination unit performs a determination based on the determination value according to the motor current value and the temperature rise rate .   The power supply device for a vacuum pump according to claim 1,
  The determination value is set for each of a plurality of temperature ranges of the temperature detected by the temperature sensor, such that the determination value decreases as the temperature range increases.
  The power supply device for a vacuum pump, wherein the abnormality determination unit performs a determination based on the determination value with respect to the temperature range including the temperature detected by the temperature sensor and the temperature increase rate. A motor drive unit housed in the power supply housing and supplying current to the motor of the vacuum pump;
A cooling fan for cooling the motor drive unit,
A temperature sensor for detecting the temperature inside the power supply housing,
When the temperature rise rate of the temperature detected by the temperature sensor is equal to or greater than a predetermined determination value, an abnormality determination unit that determines that the cooling fan has stopped,
The determination value is set for each of a plurality of temperature ranges of the temperature detected by the temperature sensor, such that the determination value decreases as the temperature range increases .
The power supply device for a vacuum pump, wherein the abnormality determination unit performs a determination based on the determination value with respect to the temperature range including the temperature detected by the temperature sensor and the temperature increase rate. The power supply device for a vacuum pump according to any one of claims 1 to 3,
The cooling fan has an abnormal signal output function of outputting an abnormal signal at the time of abnormal stop,
The abnormality determination unit determines that the cooling fan is stopped when the temperature rise rate is equal to or greater than the determination value, and when any one of the output of the abnormality signal is generated, Power supply for pump. The power supply device for a vacuum pump according to any one of claims 1 to 4,
  The temperature sensor is for detecting the temperature of the motor drive unit,
  A vacuum pump power supply device further comprising a second abnormality determination unit that determines that the motor drive unit has a high temperature abnormality when the temperature detected by the temperature sensor exceeds a preset high temperature abnormality threshold. The power supply device for a vacuum pump according to claim 5 ,
The power supply device for a vacuum pump, wherein the motor drive unit reduces the current supplied to the motor when the second abnormality determination unit determines that the motor drive unit has a high temperature abnormality .

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