JP2003005836A - Driving device with self-protection function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving device with a self-protection function which can continue to operate while being protected by adjusting an output of the driving device in accordance with a high value of temperature of the driving device so as to prevent the driving device from being heated furthermore. SOLUTION: This driving device 1 with a self-protection function comprises a driving part 2 for driving a load, a temperature sensor 12 for detecting the temperature of the driving part 2, and a controller 3 for making the driving part 2 continuously operate with an output of driving part 2 lowered in response to a situation that a detection temperature detected by the temperature sensor 12 becomes equal to or higher than a preset temperature. When the detection temperature of the temperature sensor 12 becomes equal to or higher than the preset temperature, an interpolation processing part 8 interpolates an actual acceleration on the basis of low acceleration determined by an acceleration determining part 10. The output of the driving part 2 is not immediately stopped even though the output is lowered, and the driving device 1 is made to continuously operate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive device with a self-protection function, which is provided with a protection function so as not to damage the drive device itself when the drive device falls into a heating state due to overload or the like.

[0002]

2. Description of the Related Art Conventionally, in a machine tool, the operating state of the machine tool is changed according to the load applied to the machine tool. For example, Japanese Utility Model Publication No. 59-192710 discloses a controller for positioning a numerically controlled machine tool, in which the acceleration / deceleration rate and the maximum feed rate during positioning control of the workpiece are changed according to the weight of the workpiece to be processed. By doing so, there is disclosed a positioning controller capable of performing positioning according to the weight of a work without difficulty and at the highest possible speed.

Further, Japanese Patent Laid-Open No. 12407/1990 discloses that
A numerical control device for controlling the drive of a motor by a numerical control program, which automatically estimates and calculates a load weight based on a motor drive current that is constantly detected, and determines the motor load according to the estimated and calculated load weight. A numerical controller that automatically determines an acceleration / deceleration time constant is disclosed. According to this numerical control device, the rate of acceleration / deceleration of the motor is changed according to the degree of load, so an unnecessarily long time constant is applied to lengthen the machining time even if the load is light, Alternatively, it is possible to avoid a situation in which a short time constant is applied despite the heavy load and an excessive load is applied to the motor, which adversely affects the machining accuracy.

Further, Japanese Patent Laid-Open No. 4-100123 discloses a method of setting an acceleration / deceleration time constant of a numerical control device for automatically setting an acceleration / deceleration time constant, by performing model operation with a work placed on a table. By obtaining the load on the motor and setting the acceleration / deceleration time constant for the work weight from the motor load, it is possible to perform optimum optimal machining corresponding to the weight of the workpiece, and obtain the optimal machining time and machining accuracy. To be

As described above, in a numerical controller such as that found in a machine tool, when the load of the drive unit is the weight of the work, the weight of the work preset or automatically estimated is used. Accordingly, the operating state of the motor, which is the drive device, is automatically changed and set. However, it is obvious that the operating condition of the drive device is not limited to the weight of the work as a load. For example, the operating conditions change depending on the material of the work and the operating frequency of the driving device, and such changes in the operating conditions also change the driving characteristics of the driving device and affect the processing accuracy and processing speed when processing the work. There is. In other words, where heavy cutting has been the mainstream in the past, in recent years light cutting has been performed at high speeds.
High acceleration / deceleration reduces machining time. For this reason, there is also a circumstance in which the load ratio increases due to high acceleration / deceleration that is more frequent than the cutting load.

[0006]

The influence of the load applied to the drive unit appears in the temperature of the drive unit of the drive unit, that is,
It is known that the larger the load applied to the drive device, the higher the temperature of the drive unit. Conventionally, when a drive device overheats, it is common to issue an alarm to that effect and stop the operation of the drive device, so that the drive device is not damaged by heat. Protects. The drive device is restarted after it is confirmed that the drive device has cooled down to the allowable temperature. Since the drive device has a corresponding heat capacity and it takes a considerable time after the drive device is stopped to decrease in temperature, it cannot be restarted immediately. Further, when the drive device heats up during unmanned operation at night, the processing is stopped the next morning until the stoppage of the device is discovered, resulting in a situation where the product is not completed.

Therefore, paying attention to the fact that stopping the drive device immediately when the temperature of the drive device rises has a great effect on processing and production, and the drive device is driven in accordance with the temperature of the drive device. There is a problem to be solved in that the drive device is protected from further heating by controlling the output of the device so as to protect the drive device and continue the operation of the drive device.

An object of the present invention is to continue the operation of the drive unit within a range in which the temperature of the drive unit does not rise even when the temperature of the drive unit rises due to overheating of the drive unit and immediately stop the drive unit. An object of the present invention is to provide a drive device having a self-protection function that can avoid the inconvenience that occurs.

[0009]

In a drive device with a self-protection function according to the present invention, a drive unit for driving a load, a temperature sensor for detecting the temperature of the drive unit, and a detection temperature detected by the temperature sensor are preset. The controller is configured to continuously operate the drive unit in a state where the output of the drive unit is reduced in response to the temperature being equal to or higher than the above temperature.

According to the present invention, when the detected temperature detected by the temperature sensor becomes equal to or higher than the preset temperature, the controller continuously operates the drive unit in a state in which the output of the drive unit is reduced. , The output is reduced, but it is not stopped immediately and it is operated continuously.

In this drive device with self-protection function,
The driving unit may include a motor and a servo driver for the motor, and the temperature sensor may be a sensor that detects the temperature of the motor or the temperature of the servo driver. As the drive unit, a motor is the most easily available and easy to use. The position for detecting the temperature may be the motor itself or a servo driver having a motor control circuit where the influence of heat is most concerned. By detecting the temperature of the part most susceptible to the heat, the output control of the drive device can be quickly dealt with in response to the temperature rise, and the self-protection function of the drive device can be surely exhibited.

Further, the controller can reduce the output of the drive section by limiting the acceleration exerted by the drive section on the load. That is, when the temperature becomes equal to or higher than the preset temperature, the acceleration of the load is prevented from being rapidly accelerated or decelerated by limiting the acceleration of the drive unit in the state before that. As a result, the output of the drive unit is suppressed, and overheating of the drive unit is prevented.

Further, the controller sets the acceleration to the normal acceleration in response to the detection temperature lowering and falling below the first temperature, and the detection temperature is set as the preset temperature from the first temperature. It is preferable to perform control such that the acceleration is set to a light acceleration smaller than the normal acceleration in response to the second temperature being set to a high value. That is, when the detected temperature rises and exceeds the second temperature, the acceleration is set to a light acceleration that is smaller than the normal acceleration, so that the drive device drives the load at an unreasonable acceleration / deceleration that accompanies the temperature rise. , The temperature of the drive device does not rise further,
It usually starts to descend. In addition, the detected temperature drops and the first
When the temperature falls below the temperature, since there is a margin in the temperature of the driving unit, the acceleration is set to the normal acceleration, and the driving device can be quickly driven. At this time, the temperature of the drive device may exceed the second temperature again, but the above control is repeated in the operation of the drive device.

Further, the controller is based on a machining program analyzing section for analyzing a machining program installed for machining the workpiece as the load, the temperature detected by the temperature sensor and the preset temperature. An acceleration determining unit that determines the acceleration based on the analysis result performed by the machining program analyzing unit and the acceleration of the driving unit determined by the acceleration determining unit, and determines the actual acceleration to be taken by the driving unit by interpolation. An interpolation processing unit and a servo control unit that servo-controls the drive unit based on the processing result of the interpolation processing unit are provided. By configuring the controller in this way, the acceleration determined by the acceleration determining unit based on the temperature detected by the temperature sensor and the preset temperature is used as the actual load by the machining program analyzing unit in the interpolation processing unit. Interpolation is performed according to the analysis result of the machining program for machining the workpiece, and the acceleration obtained by the interpolation is output to the drive unit via the servo control unit as the acceleration that should be actually taken.

Further, the drive device with the self-protection function is
It is applied to drive the feed axis or spindle of machine tools. For the feed axis and spindle of the machine tool, the weight of the work, operating environment,
Loads of different sizes are applied depending on operating conditions. Therefore, by applying this drive device with self-protection function to drive the feed axis or spindle of a machine tool,
Even if various conditions such as the weight of the work change, by detecting the temperature of the drive unit, it is possible to continue the drive with a gentle output without causing an unreasonable operation and without stopping.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a drive device with a self-protection function according to the present invention will be described below with reference to the drawings.
1 is a block diagram showing an embodiment of a drive unit with a self-protection function according to the present invention, FIG. 2 is a flow chart showing a control procedure of the drive unit with a self-protection function shown in FIG. 1, and FIG. 3 is shown in FIG. It is a graph which shows the relationship of the temperature of a drive device and acceleration which are performed based on a flowchart.

The drive device 1 with a self-protection function comprises a drive unit 2 for driving a feed shaft and a spindle of a machine tool for machining a work, and a controller 3 for controlling the operation of the drive unit 2. . The drive unit 2 includes a motor 4 and a motor 4
And a servo driver 5 that directly controls the drive of the motor 4. Further, the controller 3 receives a signal from the machining program analysis unit 7 that analyzes the machining program 6 when the machining program 6 is installed, and an interpolation process provided for a feedback process described later. Unit 8, a servo control unit 9 that receives a processing result of the interpolation processing unit 8 and outputs a control signal to the servo driver 5, and an acceleration determination unit 10 that determines acceleration as information for performing interpolation on the interpolation processing unit 8. have.

In this embodiment, the drive device 1 with a self-protection function has a temperature sensor 12 attached to the power device 11 of the servo driver 5. The temperature sensor may be attached to the motor 4 as indicated by reference numeral 12a. The temperature sensor 12 can be attached to either the motor 4 or the servo driver 5, whichever is more thermally restricted. Information on the detected temperature detected by the temperature sensor 12 is A /
The digital signal is input to the acceleration determining unit 9 via the D converter 13. The A / D converter 13 may be included in the controller 3 side, but the A / D converter 13 may be incorporated in the temperature sensor 12 so that the sensor directly outputs a digital signal.

The acceleration determining section 10 includes a servo driver 5
Regarding the temperature of (or the motor 4), a threshold parameter as a predetermined temperature such as the first temperature or the second temperature is input. The threshold parameter is input manually, for example. The acceleration determination unit 10 outputs the acceleration to the interpolation processing unit 8 based on the threshold parameter and the temperature detected by the temperature sensor 11 so that the driving unit 2 does not overheat. Since the acceleration determining unit 10 only determines an appropriate value of the two accelerations, for example, the interpolation processing unit 8 is based on the acceleration determined by the acceleration determining unit 10 and the result analyzed by the machining program analyzing unit 7. Then, the acceleration that the drive unit 2 should actually take is determined by interpolation. Since the driving unit 2 is driven with the acceleration that should be actually obtained by the interpolation processing unit 8, the acceleration signal obtained by interpolation by the interpolation processing unit 8 is input to the servo control unit 9.

In the drive device with a self-protection function (hereinafter abbreviated as drive device) 1 shown in FIG. 1, actual control is performed based on the flow chart shown in FIG. As shown in FIG. 2, when the control of the driving device 1 is started, the acceleration of the driving device 1 is set to the normal acceleration αn (step S1). It is determined whether the temperature of the driving device 1 is lower than the first temperature T ₁ which is one threshold value (step S2). When it is determined Yes in step S2, that is, when the temperature of the drive device 1 is determined to be lower than the first temperature T _{1, the} temperature of the drive device 1 is sufficiently low and the acceleration is maintained at the normal acceleration αn. (Step S3),
Then, the determination of step S2 is repeated. If the temperature of the driving device 1 is equal to or higher than the first temperature T ₁ in the determination of step S2, it is determined as No in step S2 and the process proceeds to step S4. In step S4, the temperature of the driving device 1 is the first temperature. It is determined whether the temperature is higher than the second temperature T ₂ which is the other threshold value higher than T ₁ .

Although the temperature of the driving device 1 is equal to or higher than the first temperature T ₁ , the temperature of the driving device 1 is not higher than the second temperature T ₂ in the judgment of step S4 (that is, the second temperature T _2).
(The following is true), the determination in step S4 is No, the process returns to step S2 and the loop with step S4 is continued. Therefore, the acceleration remains at the normal acceleration αn. When the temperature of the driving device 1 is higher than the second temperature T ₂ and it is determined Yes in step S4, the acceleration is set to the light acceleration α1 which is a value smaller than the normal acceleration αn (step S5), and thereafter, The control flow returns to step S2. The temperature of the driving device 1 is the second temperature T
_As long as the time higher than ₂ continues, the determination in step S2 is N.
The determination of step S4 is Yes, the state of Yes continues.

The manner of this temperature change is shown in FIG. That is, initially, when the temperature T of the drive device 1 rises, the acceleration is set to the normal acceleration αn according to the determination in step S2. Drive at a time _{t 1 1}
Even if the temperature T of the driving device 1 is equal to or higher than the first temperature T ₁ and the determination in step S2 is No, the temperature T of the driving device 1 is equal to the second temperature T 1.
_Since it is not higher than ₂ , the determination in step S4 is No, and the acceleration is still set to the normal acceleration αn. At time t ₂ , the temperature T of the drive device is the second temperature T
_When it reaches ₂ , the determination in step S4 turns to Yes, and the acceleration is set to the light acceleration αl in step S5.

Since the light acceleration αl is determined so that the temperature of the drive unit 1 is lowered even if it is continuously operated at the acceleration, the temperature T of the drive unit 1 is set after the acceleration is set to the light acceleration αl. Usually continues to fall. When the temperature T of the driving device 1 drops to a temperature lower than the first temperature T _{1 at} time t ₃ , the determination in step S2 turns to Yes, and the acceleration is set to the normal acceleration αn in step S3. After that, the temperature T of the driving device 1 starts to rise,
After that, the above-mentioned behavior is repeated for setting the temperature T and the acceleration of the driving device 1. In this way, the drive device 1 continues to operate without stopping. When the drive device 1 is applied to, for example, the feed shaft or the main spindle of a machine tool, the machine tool continues to operate without stopping due to the temperature rise even during nighttime operation, so that the processing of the product is interrupted. Never.

In the temperature-acceleration control of the drive unit 1, it is preferable that the second temperature T ₂ is set to the same temperature as or lower than the temperature at which the conventional drive unit is stopped. In addition, the acceleration is, as seen in the linear motion that the machine tool feed axis gives to the work that is a load,
Obviously, it may be acceleration for linear movement, or it may be rotational acceleration when the main shaft rotates to process a workpiece. Furthermore, the acceleration can be treated as a negative value, that is, an absolute value so as to include the case of deceleration. Also, in the above example, the acceleration was controlled to one of two values,
Even if the maximum value of acceleration is limited to two levels and the acceleration up to the maximum value at that time is allowed, arbitrary acceleration is not limited to normal acceleration and light acceleration, depending on the situation. Good.

As described above, the temperature-acceleration control can be performed according to various situations by setting the temperature to be detected as the characteristic of the drive unit 2. For example, it is known that even if the weight of the work as a load is constant, the driving characteristics of the drive unit 2 change depending on the temperature of the load. That is, the temperature of the drive unit 2 not only changes depending on the frequency of use of the drive machine and the size of the load, but also the seasonal change of temperature, the change of date and time,
It also changes depending on the ambient environment temperature, the radiant heat from the ambient equipment, the elapsed time of continuous operation, and the like. By performing the acceleration control according to the temperature detected by the drive unit 2, the drive unit can be controlled in a state in which the resulting temperature change including these factors is captured.

[0026]

In the drive device with the self-protection function according to the present invention, the controller drives the load in response to the temperature detected by the temperature sensor detected by the drive unit being equal to or higher than a preset temperature. Since the drive unit is continuously operated in a state where the output of is decreased, when the drive device overheats and the detected temperature becomes equal to or higher than the preset temperature,
The drive unit does not immediately stop, and the drive unit is continuously operated in a range in which the temperature of the drive device does not further increase with the output reduced. Therefore, the drive with self-protection function is
When the drive section overheats, the alarm is stopped by stopping the operation of the drive unit by issuing an alarm to that effect.Unlike the case where the alarm is stopped by reducing the load before stopping the alarm, the alarm can be stopped. It is possible to continue the operation without damaging the heat and within a range where it is not damaged by heat. Also, in continuous operation, constructing a highly reliable system that achieves processing to the end while protecting the drive device without stopping operation and minimizing the influence on processing and production as much as possible. In particular, even if the temperature of the drive device rises during unmanned operation at night, the processing can be continued until the product is completed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a drive device with a self-protection function according to the present invention.

2 is a flowchart showing a control procedure of the drive device with the self-protection function shown in FIG.

FIG. 3 is a graph showing a relationship between temperature and acceleration of a driving device, which is performed based on the flowchart shown in FIG.

[Explanation of symbols]

1 Drive Device with Self-Protection Function 2 Drive Unit 3 Controller 4 Motor 5 Servo Driver 6 Machining Program 7 Machining Program Analysis Unit 8 Interpolation Processing Unit 9 Servo Control Unit 10 Acceleration Determination Unit 11 Power Device 12 Temperature Sensor T ₁ First Temperature T ₂ Second temperature αn Normal acceleration αl Light acceleration

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G05B 19/19 G05B 19/19 W 19/404 19/404 K (72) Inventor Yasuhiko Suzuki Niwa-gun, Aichi prefecture Yamaguchi Mazak Corporation Headquarters Factory F-term (reference) 3C001 KA06 KB10 SA00 TB10 5H209 AA06 BB02 BB08 BB09 CC01 DD05 DD14 GG05 HH15 HH35 SS01 SS04 SS07 TT03 5H269 AB01 BB03 BB05 MM05FF06 BB05 MM06FF06 BB05 MM05FF06 BB06 MM05FF06 FF05 BB05 MM05FF06 FF05 BB06 MM FF05 BB05 MM FF06 BB05 MM FF06 BB05 MM FF05 BB05 MM FF05 FF05 FF05 WH AA01 BB01 BB02 BB06 BB07 BB11 BB12 CC03 DD01 EE03 JJ08 KK08

Claims (6)

[Claims] 1. A drive unit for driving a load, a temperature sensor for detecting a temperature of the drive unit, and an output of the drive unit in response to a detected temperature detected by the temperature sensor being equal to or higher than a preset temperature. A drive device with a self-protection function, which comprises a controller that continuously operates the drive unit in a state where 2. The self drive according to claim 1, wherein the drive unit comprises a motor and a servo driver for the motor, and the temperature sensor is a sensor for detecting the temperature of the motor or the temperature of the servo driver. Drive device with protection function. 3. The drive device with a self-protection function according to claim 1, wherein the controller reduces the output of the drive unit by limiting the acceleration exerted by the drive unit on the load. 4. The controller sets the acceleration to a normal acceleration in response to the detected temperature lowering and falling below a first temperature, and the detected temperature is set as the preset temperature from the first temperature. Second set to a higher value
4. The drive device with self-protection function according to claim 3, wherein the acceleration is set to a light acceleration smaller than the normal acceleration in response to the temperature being exceeded. 5. The controller is based on a machining program analysis unit that analyzes a machining program installed to machine a work as the load, the detected temperature from the temperature sensor, and the preset temperature. An acceleration determining unit that determines the acceleration based on the analysis result performed by the machining program analyzing unit and the acceleration of the driving unit determined by the acceleration determining unit, and determines the actual acceleration to be taken by the driving unit by interpolation. The drive device with a self-protection function according to claim 3 or 4, further comprising: an interpolation processing unit and a servo control unit that servo-controls the driving unit based on a processing result of the interpolation processing unit. 6. The drive device with self-protection function according to claim 1, which is applied to drive a feed shaft or a spindle of a machine tool.