JP4900366B2 - Temperature increase control method for autonomous inverter drive hydraulic unit and temperature increase control device for autonomous inverter drive hydraulic unit - Google Patents

Description

  TECHNICAL FIELD The present invention relates to an autonomous inverter-driven hydraulic unit temperature increase control method and apparatus, and more particularly, to a fixed displacement pump connected to a motor in a hydraulic drive apparatus such as a machine tool using pressure oil as a power source. The present invention relates to an autonomous inverter-driven hydraulic unit that can control hydraulic pressure and flow rate by controlling the hydraulic pressure.

  For example, as shown in FIG. 1, a conventional hydraulic unit employs a configuration in which a hydraulic pump directly connected to a motor is started and stopped by turning on / off a power source. In order to simplify the control, the radiator fan is linked to the start and stop.

  It is also conceivable to increase the flow rate by increasing the rotational speed, return the oil from the relief valve or the hydraulic drive device to the tank, and increase the oil temperature by pressure loss.

JP 2002-61611 A Microfilm of Japanese Utility Model No. 59-51741 (Japanese Utility Model Application No. 60-165558) Microfilm of Japanese Utility Model No. 52-120925 (Japanese Utility Model Publication No. 54-46990)

  When the former configuration is adopted, when the power is turned on, the radiator fan starts unconditionally, so even if the oil temperature is low and you want to raise the oil temperature quickly, The required time will be significantly longer.

  In addition, when the latter configuration is adopted and the hydraulic pump is of a variable displacement type, the flow rate automatically changes according to the load pressure, so a separate hydraulic circuit for increasing the temperature is required. In addition, because of the characteristics of the variable displacement pump, the flow rate decreases when the load pressure increases, and the pressure setting value of the relief valve of the temperature raising circuit cannot be increased. As a result, the synergistic effect with the radiator fan increases the time required to increase the oil temperature. Further, the number of components such as a temperature sensor increases, resulting in an increase in cost.

  Further, when the latter configuration is adopted and the hydraulic pump is of a fixed displacement type, if the hydraulic pump is driven by a motor having a permanent magnet attached to the rotor, the speed electromotive force is supplied from the power source. If the voltage exceeds the voltage, the motor current cannot be supplied and it becomes difficult to operate at high speed, so the oil temperature cannot be expected to rise due to pressure loss at the relief valve. In addition, the synergistic effect with the radiator fan increases the time required to increase the oil temperature.

  The present invention has been made in view of the above problems, and quickly raises the temperature to an oil temperature at which the hydraulic unit using a hydraulic pump as a drive source can operate in an optimum state without providing an oil temperature sensor. It is an object of the present invention to provide a temperature increase control method for an autonomous inverter-driven hydraulic unit and a temperature increase control device for an autonomous inverter-driven hydraulic unit.

  In the temperature rising control method for an autonomous inverter-driven hydraulic unit according to the present invention, a fixed displacement hydraulic pump (3) is driven by a motor (11) controlled by an inverter (10) and discharged by a fixed displacement hydraulic pump (3). In an autonomous inverter-driven hydraulic unit provided with a heat dissipating means (6) at a predetermined position of the oil circulation flow path, the temperature of the oil flowing through the circulation flow path is detected, and the detected oil temperature is a predetermined reference temperature In response to determining that the oil temperature is equal to or lower than a predetermined reference temperature, the temperature of the heat dissipating means is raised.

The detection of the oil temperature is performed by estimating from the rotational speed of the motor (11) at the time of pressure control in the first mode and by estimating from the pressure at the time of flow rate control in the second mode.

  A third aspect of the temperature rising control method for an autonomous inverter-driven hydraulic unit according to the present invention is any one of the first to second aspects, and the heat dissipating means (6) is a radiator (6). The temperature of the heat dissipating means is increased by controlling the radiator fan (7) to reduce the heat dissipating efficiency of the radiator (6).

  The temperature increase control device for an autonomous inverter-driven hydraulic unit according to the present invention drives a fixed displacement hydraulic pump (3) by a motor (11) controlled by an inverter (10) and discharges by a fixed displacement hydraulic pump (3). An oil temperature detecting means for detecting the temperature of oil flowing through a circulation flow path, which is a temperature rise control device for an autonomous inverter-driven hydraulic unit provided with a heat dissipating means (6) at a predetermined position of the oil circulation flow path (15), determination means (15) for determining whether or not the detected oil temperature is equal to or lower than a predetermined reference temperature, and determination by the determination means (15) that the oil temperature is equal to or lower than a predetermined reference temperature In response to this, a temperature raising means (16) for raising the temperature of the heat radiating means (6) is included.

The detection of the oil temperature is performed by estimating from the rotational speed of the motor (11) at the time of pressure control in the first mode and by estimating from the pressure at the time of flow rate control in the second mode.

  A third aspect of the temperature increase control device for an autonomous inverter-driven hydraulic unit according to the present invention is any one of the first to second aspects, and the heat dissipating means (6) is a radiator (6). The temperature raising means (16) is a radiator fan control means (16) for controlling the radiator fan (7), and the judging means (15) has determined that the oil temperature is equal to or lower than a predetermined reference temperature. In response to this, the radiator fan (7) is controlled to reduce the heat radiation efficiency of the radiator (6).

  According to the first aspect and the second aspect of the temperature increase control method for the autonomous inverter-driven hydraulic unit according to the present invention, the oil temperature can be quickly increased by increasing the temperature of the heat dissipating means without providing the oil temperature sensor. The temperature can be raised.

  According to the third aspect of the temperature increase control method for an autonomous inverter-driven hydraulic unit according to the present invention, the same control as the first and second aspects can be performed by performing simple control for controlling the radiator fan. The action can be achieved.

  According to the first aspect and the second aspect of the temperature increase control device for an autonomous inverter-driven hydraulic unit according to the present invention, the oil temperature can be quickly increased by increasing the temperature of the heat dissipating means without providing the oil temperature sensor. The temperature can be raised.

  According to the third aspect of the temperature increase control device for an autonomous inverter-driven hydraulic unit according to the present invention, by performing simple control for controlling the radiator fan, the same as the first aspect and the second aspect. The action can be achieved.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an autonomous inverter drive hydraulic unit temperature increase control method and apparatus according to the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 2 is a schematic diagram showing the configuration of an autonomous inverter-driven hydraulic unit to which an embodiment of the temperature raising control method of the present invention is applied.

  This autonomous inverter-driven hydraulic unit sucks oil from a tank 1 through an oil filter 2 through a fixed capacity pump 3 and discharges pressure oil through a discharge port. A relief valve 4 is provided so that the discharge pressure does not exceed a predetermined pressure, and part of the discharged pressure oil is returned to the tank 1 through the throttle 5 and the radiator 6. Further, a radiator fan 7 is provided in the radiator 6 for promoting cooling of the oil. Reference numeral 7 a denotes a fan motor that drives the radiator fan 7.

  Also, a PQ control unit 8 that outputs a speed command based on the discharge pressure-discharge flow rate characteristic (PQ characteristic), a speed at which a speed command is calculated by inputting the speed command and the current speed, and a current command is output. A control unit 9; an inverter unit 10 which receives a power supply and operates based on a current command; a motor 11 which operates by receiving an AC voltage from the inverter unit 10 and drives the fixed capacity pump 3; 11, a pulse generator 12 that outputs a pulse signal, and a speed detector 13 that detects the speed of the motor 11 by measuring the interval between the pulse signals by using the pulse signal output from the pulse generator 12 as an input; A pressure sensor 14 for detecting the pressure of the discharged pressure oil, and performing a predetermined process with the current speed and the current pressure as inputs and performing a first process. A pitch command Atsushi Nobori control unit 15 for outputting, is controlled by a first switch command and a switch unit 16 for controlling the ON / OFF of the power supply to the fan motor 7a.

  FIG. 3 is a block diagram showing in detail the configuration of the temperature rise control unit 15.

  The temperature raising control unit 15 receives the current speed as an input, the first oil temperature estimating unit 21 that estimates the temperature of the oil under the constant pressure control, and the current pressure as the input, the oil temperature under the constant flow rate control. A second oil temperature estimating unit 22 for estimating the temperature, a current pressure as an input, determining whether the pressure is in a constant pressure control state or a constant flow rate control state based on the PQ characteristic, and a second switch corresponding to the determination result The pressure control mode determination unit 23 that outputs a command and the estimated oil temperature from the first oil temperature estimation unit 21 or the estimated oil temperature from the second oil temperature estimation unit 22 operated by the second switch command. A switch unit 24 to be selected, and a temperature increase control determination unit 25 that receives the selected oil temperature as an input, determines the magnitude of the reference temperature, and outputs a first switch command according to the determination result. .

  The operation of the first oil temperature estimation unit 21 is as follows.

  When controlling the hydraulic pressure to a constant pressure, if the state of the hydraulic circuit of the load does not change, the rotation speed of the fixed displacement pump 3 is controlled so that the pressure becomes the set pressure. Further, when the oil temperature is lowered, the viscosity of the oil is also lowered and the pump efficiency is increased, so that the rotational speed is lowered. Therefore, it is possible to estimate the oil temperature from the number of rotations in a state where the engine is operated at a constant pressure.

  The operation of the second oil temperature estimation unit 22 is as follows.

  When the hydraulic pressure is controlled to a constant flow rate, if the state of the hydraulic circuit of the load does not change, the rotation speed of the fixed displacement pump 3 is controlled so that the flow rate becomes the set flow rate. Further, when the oil temperature is lowered, the viscosity of the oil is also lowered and the pump efficiency is increased, so that the pressure is increased. Therefore, it is possible to estimate the oil temperature from the pressure in a state where the engine is operated at a constant flow rate.

  The operation of the autonomous inverter-driven hydraulic unit configured as described above is as follows.

  Based on the difference between the speed command output from the PQ control unit 8 that retains the PQ characteristic and the current speed, the speed control unit 9 performs speed control and outputs a current command to control the inverter unit 10. . The AC voltage output from the inverter unit 10 is supplied to the motor 11, and the fixed displacement pump 3 is driven by the motor 11.

  The fixed displacement pump 3 sucks and discharges oil from the tank 1 through the oil filter 2. A part of the oil flows through a series circuit of the throttle 5 and the radiator 6.

  The temperature increase control unit 15 is supplied with the current speed and the current pressure. The pressure control mode determination unit 23 determines whether the pressure is in a constant pressure control state or a constant flow rate control state, and a second switch corresponding to the determination result. Since the command is output, the estimated oil temperature from the first oil temperature estimating unit 21 or the estimated oil temperature from the second oil temperature estimating unit 22 is selected by the switch unit 24.

  If the selected estimated oil temperature is higher than the reference temperature, a first switch command for instructing to turn on the switch unit 16 is output from the temperature increase control determination unit 25. Therefore, in this case, the radiator fan 7 operates to promote heat dissipation from the radiator 6.

  On the other hand, if the selected estimated oil temperature is lower than the reference temperature, a first switch command for instructing to turn off the switch unit 16 is output from the temperature increase control determination unit 25. Therefore, in this case, the radiator fan 7 stops and suppresses heat radiation from the radiator 6. As a result, the temperature of the oil can be increased quickly. In other words, the time required for raising the temperature to the predetermined temperature can be shortened.

  However, when the required temperature increase time may be somewhat longer, the rotational speed may be lowered instead of stopping the radiator fan 7.

  FIG. 4 is a schematic diagram showing the configuration of an autonomous inverter-driven hydraulic unit to which another embodiment of the temperature raising control method of the present invention is applied.

  This autonomous inverter-driven hydraulic unit includes a converter unit 31 that outputs an AC voltage from an AC power source, an inverter unit 32 that outputs an AC voltage from an input DC voltage and supplies the AC voltage to a brushless DC motor 33, and a brushless DC motor. 33 and a fixed displacement pump 34 that is driven by a brushless DC motor 33. The brushless DC motor 33 is integrated with the fixed capacity pump 34.

  Then, PQ control that generates a discharge pressure-discharge flow rate characteristic (PQ characteristic) with the set pressure, set flow rate, and set horsepower as inputs, and outputs a rotation speed command with the current discharge pressure and current speed as inputs. Unit 35, rotation speed control unit 36 for performing rotation speed control calculation with the rotation speed command and current speed as input, and outputting current command, current control calculation with current command and current phase command as input, and duty command A current control unit 37 for outputting, a phase map unit 38 for holding a current phase map with respect to the number of revolutions for each current command, and outputting a corresponding map current phase with the current command and current speed as inputs, and a current command and current speed Is used as an input to output a temperature-raising current phase to be set for temperature rise (current phase deviated from the map current phase to some extent). The third switch unit 40 that selects one of the map current phase or the current-raising current phase and outputs it as a current phase command, the pressure sensor 41 that detects the discharge pressure from the pump 2, and the motor 33 are connected. A pulse generator 42, a pulse detection unit 43 that receives a pulse from the pulse generator 42 and detects a current speed based on a pulse interval; an oil temperature that is estimated by inputting the current speed and the current pressure; A temperature increase control unit 44 that determines the magnitude of the predetermined reference temperature, generates a switch command according to the determination result, and supplies the switch command to the third switch unit 40 is provided.

  The configuration of the temperature rise control unit 44 is the same as that of the temperature rise control unit 15 described above. Further, the temperature-raising current phase output unit 39 may output a preset current phase according to the current command and the current speed, but performs a predetermined calculation based on the current command and the current speed. The current phase may be calculated and output.

  The operation of the autonomous inverter-driven hydraulic unit configured as described above is as follows.

  A rotation speed command is output from the PQ control unit 35 according to the current pressure and current speed, a rotation speed control calculation is performed by the rotation speed control unit 36 based on the rotation speed command and the current speed, and a current command is output. Based on the current command and the current phase command, the current control unit 37 performs a current control calculation to supply the duty command to the inverter unit 32, and the brushless DC motor 33 is driven by the output from the inverter unit 32. It can be driven to discharge pressure oil.

  In this case, if the oil temperature is higher than the reference temperature, the third switch unit 40 is operated so that the map current phase becomes the current phase command. Therefore, the brushless DC motor 33 is driven so as to optimize the efficiency. Thus, motor heat generation can be greatly suppressed.

  On the contrary, if the oil temperature is lower than the reference temperature, the third switch unit 40 is operated to set the current phase for temperature increase as the current phase command, so that the reactive current increases, thereby increasing the motor heat generation. The oil temperature is transmitted to the fixed displacement pump 34, and the oil temperature can be quickly raised.

  In addition, the motor current phase can be advanced and shifted to the phase side with respect to the speed electromotive force. In this case, the rotor magnetic flux of the brushless DC motor is controlled to be weakened by the magnetic flux generated by the motor coil. An increase in speed electromotive force can be suppressed and high-speed rotation can be achieved. As a result, the flow rate increases, a part of oil is returned to the tank through a relief valve or the like, and the oil temperature can be quickly raised by pressure loss.

  Of course, it is possible to add control of a radiator fan to this embodiment, and in this case, the oil temperature can be raised more rapidly.

  Further, the same processing as in the above embodiment can be achieved by a computer program or the like.

It is the schematic which shows the structure of the conventional hydraulic unit. It is the schematic which shows the structure of the autonomous type inverter drive hydraulic unit to which one Embodiment of the temperature rising control method of this invention is applied. It is a block diagram which shows the structure of a temperature rising control part in detail. It is the schematic which shows the structure of the autonomous type inverter drive hydraulic unit to which other embodiment of the temperature rising control method of this invention is applied.

Explanation of symbols

3, 34 Fixed displacement pump 6 Radiator 7 Radiator fan 10, 32 Inverter part 11, 33 Motor 15, 44 Temperature rise control part 16 Switch part

Claims (6)

The fixed displacement hydraulic pump (3) is driven by the motor (11) controlled by the inverter (10), and the heat dissipating means (6) is placed at a predetermined position in the circulation path of the oil discharged by the fixed displacement hydraulic pump (3). In the autonomous inverter drive hydraulic unit provided,
Detecting the temperature of the oil flowing through the circulation channel by estimating the temperature of the oil from the number of rotations of the motor (11) during pressure control;
Determine whether the detected oil temperature is below a predetermined reference temperature,
A temperature increase control method for an autonomous inverter-driven hydraulic unit, wherein the temperature of the heat dissipating means is increased in response to determining that the oil temperature is equal to or lower than a predetermined reference temperature. The fixed displacement hydraulic pump (3) is driven by the motor (11) controlled by the inverter (10), and the heat dissipating means (6) is placed at a predetermined position in the circulation path of the oil discharged by the fixed displacement hydraulic pump (3). In the autonomous inverter drive hydraulic unit provided,
The temperature of the oil flowing through the circulation channel is detected by estimating the oil temperature from the pressure during flow control,
Determine whether the detected oil temperature is below a predetermined reference temperature,
A temperature increase control method for an autonomous inverter-driven hydraulic unit, wherein the temperature of the heat dissipating means is increased in response to determining that the oil temperature is equal to or lower than a predetermined reference temperature.   The heat radiating means (6) is a radiator (6), and the temperature of the heat radiating means is increased by controlling a radiator fan (7) to reduce the heat radiating efficiency of the radiator (6). 3. A temperature increase control method for an autonomous inverter-driven hydraulic unit according to 2. The fixed displacement hydraulic pump (3) is driven by the motor (11) controlled by the inverter (10), and the heat dissipating means (6) is placed at a predetermined position in the circulation path of the oil discharged by the fixed displacement hydraulic pump (3). A temperature rising control device for an autonomous inverter-driven hydraulic unit provided,
An oil temperature detecting means (15) for detecting the temperature of the oil flowing through the circulation channel from the number of rotations of the motor (11) during pressure control;
Determination means (15) for determining whether or not the detected oil temperature is equal to or lower than a predetermined reference temperature;
And a temperature raising means (16) for raising the temperature of the heat dissipating means (6) in response to the oil temperature being judged to be equal to or lower than a predetermined reference temperature by the judging means (15). Temperature rising control device for autonomous inverter driven hydraulic unit. The fixed displacement hydraulic pump (3) is driven by the motor (11) controlled by the inverter (10), and the heat dissipating means (6) is placed at a predetermined position in the circulation path of the oil discharged by the fixed displacement hydraulic pump (3). A temperature rising control device for an autonomous inverter-driven hydraulic unit provided,
Oil temperature detecting means (15) for detecting the temperature of the oil flowing through the circulation flow path from the pressure at the time of flow rate control;
Determination means (15) for determining whether or not the detected oil temperature is equal to or lower than a predetermined reference temperature;
And a temperature raising means (16) for raising the temperature of the heat dissipating means (6) in response to the oil temperature being judged to be equal to or lower than a predetermined reference temperature by the judging means (15). Temperature rising control device for autonomous inverter driven hydraulic unit. The heat dissipation means (6) is a radiator (6),
The temperature raising means (16) is a radiator fan control means (16) for controlling the radiator fan (7),
The radiator fan (7) is controlled to reduce the heat radiation efficiency of the radiator (6) in response to the fact that the oil temperature is determined to be equal to or lower than a predetermined reference temperature by the determination means (15). The temperature increase control device for an autonomous inverter-driven hydraulic unit according to claim 5.

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