JPH0794099B2 - Spindle cooling device oil temperature adjusting method and device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil temperature adjusting method and device for a cooling device that cools the periphery of a main shaft bearing portion of a machine tool or the like.

2. Description of the Related Art Conventionally, as shown in FIG. 3, a cooling oil temperature adjusting mechanism of a spindle cooling device has a control temperature difference TD selected by a rotary switch or the like in a control temperature difference setting unit 101 to determine whether the machine temperature or the room temperature is changed. The reference temperature TB is detected by the reference temperature sensor 102, the cooling oil temperature TO in the oil tank is detected by the temperature sensor 103, and it is sent to the comparison calculation unit 104. The comparison calculation unit 104 has an upper limit T.
A constant temperature range that defines H and the lower limit TL is input and stored, and a comparison is made here by calculation. When TO-TB> TD + TH, the refrigerator 106 is operated via the on / off control unit 105. ,
Further, when TO-TB <TD-TL, the method of adjusting the oil temperature is generally performed by a cycle in which the operation of the refrigerator 106 is stopped.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The oil temperature adjusting method described in the prior art adjusts the temperature difference of the cooling oil in the oil tank with respect to the reference temperature to a constant temperature range centered on the set management temperature difference. Therefore, the temperature adjustment of the cooling oil is delayed with respect to the temperature rise around the bearing portion. The amount of heat that can be carried by circulating the cooling oil is determined by the temperature difference and the flow rate of the cooling oil around the bearing portion, but there is a limit to the amount of heat that can be carried without a means for changing the temperature difference. Therefore, in the case of a large amount of heat generated during high-speed rotation, the amount of heat generated exceeds the amount of heat transferred and reaches the equilibrium temperature at the same high temperature, which causes a difference from the equilibrium temperature during low-speed rotation. ing.

The present invention has been made in view of such problems of the conventional technology, and the object thereof is to perform oil temperature adjustment capable of carrying an optimum amount of heat corresponding to the spindle speed, An object of the present invention is to provide an oil temperature adjusting method and device capable of suppressing a temperature increase around the bearing portion at high speed.

Means for Solving the Problems In order to achieve the above object, an oil temperature adjusting method and device for a spindle cooling device according to the present invention, a temperature difference with respect to a reference temperature of cooling oil, a constant temperature range centered on a management temperature difference. By the normal operation cycle of turning on / off the refrigerator,
In the method of adjusting the oil temperature of the spindle cooling device that manages the oil temperature,
In an oil temperature adjusting method of a spindle cooling device for performing oil temperature management by a normal operation cycle in which a refrigerator is turned on / off so that a temperature difference with respect to a reference temperature of cooling oil has a constant temperature range centered around a predetermined management temperature difference, Parameters that set the on / off pattern of the refrigerator according to the rotation speed of the spindle and the duration of that pattern are stored in advance, and the on / off pattern and the duration corresponding to the rotation speed are set by the spindle rotation command to freeze. After the initial operation of the machine, the normal operation cycle is switched to.

In addition, the comparison operation unit compares the constant temperature range centered on the control temperature difference with the temperature difference with respect to the reference temperature of the cooling oil, and normal operation is performed to turn on / off the refrigerator so that the oil temperature becomes the constant temperature range. In a spindle cooling device that manages oil temperature in a cycle, a first parameter that sets a refrigerating machine on / off pattern and a duration of the pattern in advance according to the rotational speed of the spindle, and a second parameter that sets a temperature control difference. And a means for storing a condition corresponding to the rotation speed from the first parameter and the second parameter according to a spindle rotation command and storing the condition, and after performing an initial operation under the condition determined from the first parameter. And a switching timer unit for switching to a normal operation cycle according to the condition determined from the second parameter.

Action After initializing the refrigerator by selecting the refrigerator on / off pattern and its duration corresponding to the rotation speed from the first parameter stored by the spindle rotation command, the oil temperature (temperature difference from the reference temperature) The normal operating cycle is switched to ON when exceeding the upper limit value of a constant width centered on the control temperature difference corresponding to the rotation speed selected from the second parameter stored by, and OFF when falling below the lower limit value.

In addition, after selecting the on / off pattern of the refrigerator corresponding to the rotation speed and its duration from the operating parameters stored by the spindle rotation command, and after performing the initial operation of the refrigerator, the oil temperature (temperature relative to the reference temperature It is also possible to switch to a normal operation cycle in which when the difference) exceeds an upper limit value of a certain width centered on a predetermined control temperature difference, it is turned on, and when it falls below a lower limit value, it is turned off.

First Embodiment A first embodiment will be described with reference to FIG.

A spindle 3 is rotatably supported by a plurality of bearings 2 on a headstock 1 of a machine tool, and the rotation of the spindle 3 is controlled by an NC device 4. Oil jackets 5 and 6 having radiating fins are provided around the bearing portion of the headstock 1, and a cooling device for circulating cooling oil is provided in the oil jackets 5 and 6. In this cooling device, a pump 8 provided on the oil tank 7 sends cooling oil to the oil jackets 5 and 6 through a pipe 9 and returns it to the oil tank through a pipe 10.
During this return, the refrigerator 12 cools the cooling oil.

As shown in the block diagram of FIG. 1, the control mechanism of the refrigerator 12 has such a value that the higher the rotation speed set from the related material that can predict the bearing peripheral temperature with respect to the spindle rotation speed, the lower the value. Temperature difference parameter storage unit 13 for storing the management temperature difference parameter, from the parameter in the spindle rotation command of the NC, the management temperature difference determination unit 14 for determining the corresponding management temperature difference, the longer the rotation speed in advance, the longer the entering time, On the other hand, an operation parameter storage unit 15 that stores an operation parameter that sets an on / off pattern cycle that shortens the off time and the duration of the cycle.
In the conventional NC device 4, an ON / OFF pattern and duration determining unit 16 for determining and storing an ON / OFF pattern corresponding to the spindle rotation speed and its duration by an NC spindle rotation command is newly provided. There is. Further, a control temperature difference storage unit 17 that stores the control temperature difference TD corresponding to the determined rotation speed, an upper limit value TD + TH and a lower limit value TD of the control temperature difference TD depending on the stored temperature width.
-TL is obtained, and the temperature difference TO-TB is obtained from the output TB of the reference temperature sensor 18 that detects the environmental temperature of the airframe or the room and the output TO of the oil temperature sensor 19 that detects the temperature of the cooling oil in the oil tank 7. Further, there is provided a comparison operation unit 20 which compares the both and outputs a signal to enter the refrigerator when TO-TB> TD + TH, and outputs a signal to turn off the refrigerator when TO-TB <TD-HL.

The switching timer unit 22 preferentially sends the signal from the on / off pattern determination unit 16 to the on / off control unit 23 until the duration from the on / off pattern and duration determination storage unit 16 ends.
When the continuation time ends, a signal from the comparison calculation section 20 is sent to the on / off control section 23 to switch the on / off cycle of the refrigerator 12.

The temperature parameter storage unit 13, the management temperature difference determination unit 14, the operation parameter storage unit 15, the on / off pattern and duration determination storage unit 16 are not limited to those provided in the NC device 4, and are separate. It can also be installed independently as a unit.

Next, the operation of the first embodiment will be described.

When the spindle 3 is rotated by the NC rotation command, the spindle rotation speed S is simultaneously sent to the control temperature difference determination unit 14 and the on / off pattern and duration determination storage unit 16 in the NC device 4. The control temperature difference corresponding to the spindle rotational speed is read and determined from the parameters stored in the temperature difference parameter storage unit 13, stored in the management temperature difference storage unit 17, and stored in the operation parameter storage unit 15. The on / off pattern cycle corresponding to the spindle rotation speed and the duration of this cycle are read, determined, and stored from the parameters.
Then, the difference between the oil temperature and the reference temperature TO-TB
And the control temperature difference upper limit value TD + TH and lower limit value TD-TL are compared. When TO-TB> TD + TH, the refrigerator input signal is output, and when TO-TB <TD-TL, the refrigerator shutdown signal is output. Is output to the switching timer unit 22. However, this output signal is circuit-interrupted by the signal sent from the on / off pattern and duration determination storage unit 16 to the switching timer unit 22, and the on / off control unit
It does not reach 23. Therefore, the initial operation of the refrigerator 12 is controlled through the on / off control unit 23 by the on / off pattern cycle sent from the on / off pattern and duration determination storage unit 16, and the temperature around the bearing unit is controlled. The oil temperature control that is optimal and without delay with respect to the rise is performed until the determined duration ends.

When the duration is over, the timer is activated to switch the circuit, and the refrigerator is controlled via the on / off control unit 23 by the on / off signal from the comparison calculation unit 20 to control the temperature difference corresponding to the rotation speed. The cooling oil temperature is managed within a fixed temperature range centered on.

The duration of the initial operation is not limited to being set to a different time corresponding to the rotation speed, and it goes without saying that it can be set to a fixed time.

Next, a second embodiment will be described with reference to FIG.

The difference from the first embodiment is that the temperature difference parameter storage unit
13 and the management temperature difference determination unit 14 is not provided, and the management temperature difference storage unit 17
In place of the control temperature difference setting unit 24, the other parts are the same, the same reference numerals are given to avoid duplication, and the description thereof is omitted. The operation of the second embodiment will be described directly.

When the spindle 3 is rotated by the NC rotation command, the spindle rotation speed S is sent to the ON / OFF pattern and duration determination storage unit 16 in the NC device 4, where the operation parameter storage unit 15
On / off pattern cycle corresponding to the spindle rotation speed and the duration of this cycle are read, determined and stored from the operating parameters stored in. Then, a code is sent to the switching timer unit 22 to switch the circuit, and the on / off pattern cycle signal is preferentially sent to the on / off control unit 23 to turn on / off the refrigerator. The control by this ON / OFF pattern cycle is continued for the determined duration, and when the duration is over, the circuit is disconnected and the signal from the comparison operation unit 20 is sent to the ON / OFF control unit 23. From the control temperature difference TD selected by the rotary switch, etc. in the control temperature difference setting section 24, the comparison calculation section 20 calculates the cooling oil temperature difference TO.
-TB is compared with the upper limit value TD + TH and the lower limit value TD-TL of the control temperature difference, and when TO-TB> TD + TH, the refrigerator input signal is output and the refrigerator 12 operates via the on / off control unit 23. However, if the oil temperature drops due to this and TO-TB <TD-TL, the comparison calculation unit
A signal for turning off the refrigerator is output from 20, and the operation of the refrigerator 12 is stopped.

EFFECTS OF THE INVENTION Since the present invention is configured as described above, it has the following effects.

After repeating the on / off pattern and duration of the refrigerator corresponding to the rotation speed of the spindle and the control temperature difference by the rotation command automatically, and repeating the on / off pattern cycle for the determined duration. , Oil temperature (temperature difference from the reference temperature)
When the temperature exceeds the upper limit value centered on the control temperature difference, the refrigerator is turned on, and when it becomes less than the lower limit value, the control method is switched to off to adjust the oil temperature. By setting the set temperature difference to a value lower than that at low speed, it is possible to raise the carrying heat amount to the full refrigeration capacity,
It is possible to lower the equilibrium temperature, and even during the initial operation in which the bearing temperature is in the process of rising, it is possible to positively suppress the temperature increase by executing the operation cycle corresponding to the temperature increase predicted in advance. Therefore, even a refrigerator having a relatively small capacity can exhibit the same effect as the conventional one.

[Brief description of drawings]

1 is an explanatory view of a spindle cooling device of a first embodiment including a partial block diagram, FIG. 2 is an explanatory diagram of a spindle cooling device of a second embodiment including a partial block diagram, and FIG. 3 is It is a block diagram of the control mechanism of the conventional refrigerator. 3 ... Spindle, 13 ... Temperature difference parameter storage unit, 14 ... Control temperature difference determination unit, 15 ... Operation parameter storage unit, 16 ...
ON / OFF pattern and duration determination storage unit, 17 ... management temperature difference storage unit, 20 ... comparison calculation unit, 22 ... switching timer unit

Claims (2)

[Claims] 1. A refrigerator (12) is turned on / off so that a temperature difference (TO-TB) with respect to a reference temperature (TB) of cooling oil has a constant temperature range centered on a predetermined control temperature difference (TD). In the oil temperature adjusting method for a spindle cooling device that manages oil temperature by a normal operation cycle, a parameter in which a refrigerator on / off pattern and a duration of the pattern are set in advance according to the rotation speed (S) of the spindle (3). The oil temperature of the spindle cooling device is characterized in that the on / off pattern corresponding to the rotation speed and the continuation time are selected by the spindle rotation command to perform the initial operation of the refrigerator and then switch to the normal operation cycle. Adjustment method. 2. A temperature difference (TO-) with respect to a reference temperature (TB) of the cooling oil and a constant temperature range (TD + TH), (TD-TL) centered on the control temperature difference (TD) in the comparison calculation unit (20). TB) in the spindle cooling device that manages the oil temperature in a normal operation cycle in which the refrigerator (12) is turned on / off so that the oil temperature has a constant temperature range, the rotation speed of the spindle (3) ( S) means for storing the first parameter for setting the on / off pattern of the refrigerator and the continuation time of the pattern and the second parameter for setting the temperature control difference, and the spindle rotation command for the above Means for determining and storing a condition corresponding to the rotation speed from the first parameter and the second parameter (14, 16, 17)
And a switching timer section (22) for performing an initial operation under the condition determined by the first parameter and then switching to a normal operation cycle under the condition determined by the second parameter. apparatus.