JP2010023158A - Cooling system for machine tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling device for a machine tool capable of varying cooling ability according to speed variation of the revolution speed of a main shaft and certainly removing the generation heat. <P>SOLUTION: In the cooling device 1 for the machine tool 2, thermal deformation of the machine tool 2 is prevented by circulating a main shaft cooling oil to the inside of the main shaft 28. The cooling device is provided with: a speed information receiving part 41 for receiving rotation speed information V<SB>θ</SB>of the main shaft 28; a temperature data memory part 42 provided with a main shaft speed-temperature table in which a range capable of taking a rotation speed is stepwisely divided to a plurality of speed areas and a temperature setting value corresponding to a calorific power is determined in every speed area; a comparison operation part 43 for reading the rotation speed information V<SB>θ</SB>and the main shaft speed-temperature table, discriminating the speed area to which the rotation speed information V<SB>θ</SB>belongs and making the temperature setting value corresponding to the speed area as a setting temperature of the main shaft cooling oil; and a main shaft cooling device 35 for applying temperature adjustment to the main shaft cooling oil based on the set temperature and performing feeding of the oil. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a machine for preventing thermal deformation of a machine tool by circulating cooling oil through a spindle cooling path formed inside a spindle or a feed axis cooling path formed inside a feed shaft that moves the spindle relative to a workpiece. The present invention relates to a cooling device for a machine.

  In a machine tool such as a machining center, heat is generally generated according to machining conditions such as the rotation speed of the main shaft, the feed speed of the feed shaft, and machining resistance, and the main shaft and the feed shaft may be thermally deformed. In order to cope with this, particularly as a means for removing heat from the main shaft, for example, Patent Documents 1 and 2 disclose a cooling device that circulates cooling oil inside the main shaft to remove heat.

Patent Document 1 describes an invention in which the main shaft is cooled by controlling the flow rate of the cooling oil in accordance with the heat generation amount and the rotational speed of the main shaft.
Further, Patent Document 2 stores in advance a necessary amount of cooling heat corresponding to the main shaft rotational speed, detects that the main shaft rotational speed is changed from a low speed to a high speed, and sets the high speed main shaft rotational speed prior to the speed change. An invention is described in which the temperature is controlled by being confused with the lubricating oil that discharges the return lubricating oil from the main shaft when discharging the corresponding lubricating oil having the required cooling heat quantity. In the present invention, the temperature of the discharged lubricating oil is adjusted to a temperature difference determined with respect to a reference temperature of a machine tool base or the like.
JP 2005-230955 A Japanese Patent No. 3119768

By the way, the above cooling apparatus has the following problems.
That is, if the heat transfer area of the cooling path in the main shaft is increased, the cooling capacity is improved. However, the heat transfer area cannot be increased beyond a certain level due to space limitations in terms of design. Therefore, there has been a problem that a machine tool having a large calorific value accompanying the recent high speed and high output cannot obtain a sufficient cooling capacity for removing the calorific value by the conventional method.

  Further, in the case of the method of controlling the flow rate of the cooling liquid according to the calorific value as in the invention described in Patent Document 1, there is a limit to increasing the heat transfer area of the cooling liquid circulation path as described above. Furthermore, in order to increase the flow rate, it is necessary to increase the pressure of the pump, so that the cooling oil is heated by the heat generated from the pump itself, and sufficient cooling performance can be obtained. There was a problem that I could not.

On the other hand, in the invention described in Patent Document 2, since the temperature of the discharged lubricating oil is adjusted to a constant temperature difference with respect to the reference temperature, it cannot be said that it follows the change in the speed of the main shaft, but has a cooling capacity. There was a shortage. In addition, since the return lubricating oil whose temperature changes depending on the use conditions is mixed, there is a drawback that the temperature of the lubricating oil supplied to the main shaft tends to become unstable.
In general, the spindle speed frequently changes in such a machine tool, so even if a slight change in the spindle speed occurs, if the cooling capacity is changed accordingly, the adjustment of the cooling capacity is not possible. There arises a problem that the cooling is performed in an unstable manner and the proper cooling cannot be performed.

  Further, when cooling the main shaft and the feed shaft, it is desired to supply cooling oil having a cooling performance suitable for the amount of heat generated in order to reliably remove generated heat and prevent overcooling.

  The present invention has been made in view of such problems, and can appropriately change the cooling capacity in response to changes in the rotation speed of the main shaft and the feed speed of the feed shaft, thereby reliably generating generated heat. It is an object of the present invention to provide a machine tool cooling device that can be removed.

In order to solve the above problems, the present invention proposes the following means.
That is, a cooling system for a machine tool according to the present invention is a speed information for receiving rotational speed information of the spindle in a machine tool cooling apparatus that circulates spindle cooling oil inside the spindle to prevent thermal deformation of the machine tool. A spindle speed and temperature table in which a temperature setting value corresponding to a heat generation amount is determined for each speed region by dividing a range that can be taken by the receiver and the rotational speed of the spindle into a plurality of speed regions. The temperature data storage section provided, the rotational speed information and the spindle speed / temperature table are read to determine the speed region to which the rotational speed information belongs, and the temperature setting value corresponding to the speed region is A comparison calculation unit for setting a temperature of the main spindle cooling oil, and a main spindle cooling device for adjusting the temperature of the main spindle cooling oil based on the set temperature and feeding oil are provided.

According to the cooling system for machine tools having such characteristics, the temperature is adjusted using the temperature setting value of the speed region to which the rotation speed information of the spindle belongs as the setting temperature of the spindle cooling oil, so that the cooling corresponding to the speed change of the spindle is performed. It becomes possible to feed the main spindle cooling oil to the main spindle.
Further, the spindle cooling oil can be stably adjusted by dividing the speed region stepwise and circulating the spindle cooling oil having the cooling capacity corresponding to the division.

  In the machine tool cooling system according to the present invention, when the speed region to which the rotational speed information belongs is changed, the spindle cooling device corresponds to the original speed region within 10 seconds to 1 minute. The temperature of the spindle cooling oil is adjusted based on a set temperature, and the temperature of the spindle cooling oil is adjusted based on the set temperature corresponding to the new speed region after the elapse of 10 seconds to 1 minute. To do.

  As a result, when the rotational speed of the main shaft changes and the speed region is changed, the set temperature of the main spindle cooling oil is not changed unless a certain time elapses. For example, the boundary between the two speed regions Even when the rotational speed of the main shaft is not stable, the set temperature is maintained at a value corresponding to the original speed region, and the temperature control of the main shaft cooling oil can be prevented from being performed unstablely.

Furthermore, the cooling system for a machine tool according to the present invention is characterized in that the spindle cooling device stops feeding the spindle cooling oil after 10 to 30 minutes have elapsed since the rotation of the spindle has stopped. To do.
Thereby, it is possible to prevent overcooling of the main shaft and to save energy.

  Furthermore, in the machine tool cooling system according to the present invention, when the rotation of the spindle stops, the spindle cooling device sets the temperature higher than the base temperature of the machine tool as the set temperature. The temperature is adjusted.

  In a machine tool, the temperature of the spindle is slightly higher during steady operation where machining accuracy is stable than when the machine is stopped for a long time. Therefore, if the cooling is continued even after the operation is stopped, the temperature in the stable state is lowered, and the accuracy immediately after resuming the machining is lowered. Therefore, as described above, by adjusting the temperature of the cooling oil after stopping the spindle higher than the base temperature of the machine tool, it is possible to stabilize the machining accuracy when the machining is resumed.

Further, in the machine tool cooling system according to the present invention, the comparison operation unit calculates 1 minute to 10 minutes based on the rotation speed information instead of determining the speed region to which the rotation speed information belongs. The speed region to which the average rotational speed belongs is discriminated, and the temperature set value corresponding to the speed region is set as the set temperature of the spindle cooling oil.
Also by this, it becomes possible to feed the spindle cooling oil having the cooling capacity corresponding to the speed change of the spindle to the spindle.

  A cooling system for a machine tool according to the present invention includes: a feed shaft cooling oil that circulates inside a feed shaft that moves a main shaft relative to a workpiece to prevent thermal deformation of the machine tool. A speed information receiving unit that receives the feed speed information of the shaft, and a range that can be taken by the feed speed of the feed shaft is divided into a plurality of speed regions step by step, and temperature setting corresponding to the heat generation amount for each speed region A temperature data storage unit having a feed axis speed / temperature table with a predetermined value, the feed speed information and the feed axis speed / temperature table are read, and the speed region to which the feed speed information belongs is determined. A comparison calculation unit that sets the temperature setting value corresponding to the speed region as a set temperature of the feed shaft cooling oil, and a feed shaft that performs oil supply by adjusting the temperature of the feed shaft cooling oil based on the set temperature. With cooling device Wherein the eclipse was.

By adjusting the temperature using the temperature setting value of the speed region to which the feed speed information of the feed axis belongs as the set temperature of the feed shaft cooling oil, feed shaft cooling oil with cooling capacity corresponding to the feed shaft speed change is sent to the feed shaft. It becomes possible to oil.
In addition, it is possible to stably adjust the feed shaft cooling oil by dividing the speed region step by step and circulating the feed shaft cooling oil having a cooling capacity corresponding to this division. .

  In the machine tool cooling system according to the present invention, when the speed region to which the feed speed information belongs is changed, the feed shaft cooling device corresponds to the original speed region within 10 seconds to 1 minute. The temperature of the feed shaft cooling oil is adjusted based on the set temperature, and the temperature of the feed shaft cooling oil is adjusted based on the set temperature corresponding to the new speed region after the elapse of 10 seconds to 1 minute. It is characterized by that.

  Thereby, when the rotational speed of the feed shaft changes and the speed region is changed, the set temperature of the feed shaft cooling oil is not changed unless a certain time has elapsed. Therefore, for example, even when the rotational speed of the feed shaft is not stable at the boundary between the two speed regions, the set temperature is maintained at a value corresponding to the original speed region, and temperature adjustment of the feed shaft cooling oil is not possible. It is possible to prevent the stable operation.

Further, in the machine tool cooling system according to the present invention, the feed shaft cooling device stops feeding the feed shaft cooling oil after 10 to 30 minutes have elapsed since the feed shaft feed stopped. It is characterized by.
This makes it possible to prevent overcooling of the feed shaft and to save energy.

In the machine tool cooling system according to the present invention, when the rotation of the feed shaft is stopped, the feed shaft cooling device sets the feed shaft to a temperature higher than the base temperature of the machine tool as the set temperature. The temperature of the cooling oil is adjusted.
This makes it possible to stabilize the machining accuracy at the time of resuming the machining, similar to the above spindle.

Furthermore, in the machine tool cooling system according to the present invention, the comparison calculation unit calculates 1 minute to 10 based on the feed speed information instead of determining the speed region to which the feed speed information belongs. The speed region to which the average feed speed per minute belongs is determined, and the temperature set value corresponding to the speed region is set as the set temperature of the feed shaft cooling oil.
This also makes it possible to feed feed shaft cooling oil having a cooling capacity corresponding to the speed change of the feed shaft to the feed shaft.

  According to the cooling system of the machine tool of the present invention, the temperature of the main spindle cooling oil or the feed shaft cooling oil is adjusted based on the temperature setting value for each speed region, so that the cooling suitable for the heat generation corresponding to the speed change. It becomes possible to supply performance spindle or feed shaft cooling oil. Therefore, since the generated heat can be removed accurately according to the processing conditions, it is possible to reliably suppress thermal deformation of the machine tool and improve processing accuracy.

Embodiments of a machine tool cooling apparatus according to the present invention will be described below in detail with reference to the drawings.
1 is a perspective view showing a schematic configuration of a machine tool to which a cooling system for a machine tool is applied, FIG. 2 is a schematic configuration diagram of a cooling device for a machine tool according to an embodiment, and FIG. 3 is (a) spindle speed / temperature. FIG. 4 is a flowchart illustrating the operation of the machine tool cooling device, and FIG. 5 is a diagram illustrating the relationship between the speed value in the speed region and the temperature setting value. .

The cooling system 1 is applied to a machine tool 2 which is a horizontal machining center as shown in FIG.
As shown in FIG. 1, the machine tool 2 includes a base 3, a column portion 4 erected on the base 3, and a table 5 that is disposed on the base 3 and holds the pallet P in the same manner as the column portion 4. And an automatic pallet changer (APC) 6 for automatically changing the pallet P.

  The column portion 4 includes a gate-type column 11 erected on the base 3, a pair of X-axis guide rails 12 disposed above and below the column 11 along the X-axis direction x, and the X-axis guide A saddle 13 supported so as to be movable in the X-axis direction via the rail 12, a pair of Y-axis guide rails 14 disposed along the Y-axis direction y on both sides of the saddle 13 in the X-axis direction, The head 15 is configured to be movable in the Y-axis direction via the Y-axis guide rail 14, and the spindle cylinder 16 provided on the head 15 and extending toward the table 5 along the Z-axis direction z.

The saddle 13 is movable in the X-axis direction via an X-axis feed shaft 24 that is rotated by an X-axis motor 21. Similarly to the saddle 13, the head 15 is also movable in the Y-axis direction y via a Y-axis feed shaft 25 that is rotated by a Y-axis motor 22.
A cutting tool (not shown) is attached to the spindle cylinder 16 at its tip so as to be rotatable around the axis line in the Z-axis direction z, and is rotated around the axis line parallel to the Z-axis direction z by a spindle motor 27 as shown in FIG. The spindle 28 and the spindle motor 27 constitute a spindle 28.

  In addition, an automatic tool changer (ATC) 19 is provided at the upper part of the column portion 4 so that the cutting tool is automatically changed.

  The table 5 is supported so as to be movable in the Z-axis direction z via a Z-axis guide rail 20 provided in parallel along the Z-axis direction z on the base 3. A pallet P to which a work is attached via an scale or a jig is provided.

The automatic pallet exchanging device 6 is provided on the base 3 at a position opposite to the column portion 4 when viewed from the table 5, is supported rotatably around the vertical direction, extends in the horizontal direction, and has one end on the table side. 5 and a set-up table 18 positioned on the other end side of the turning support arm 17.
The automatic pallet changing device 6 is configured such that when the table 5 is moved to the pallet changing position, the turning support arm 17 receives the pallet P on the table 5 and the pallet P on the setup table 18 and turns, thereby turning the table. 5 and the new workpiece (standby workpiece) W on the setup table 18 are exchanged with each other (the workpiece W is transferred to the table 5).

In the machine tool 2 as described above, the saddle 13 of the column portion 4 can move in the X-axis direction x, the head 15 can move in the Y-axis direction y, and the table 5 can move in the Z-axis direction z. Thus, the spindle cylinder 16 can be arbitrarily moved relative to the workpiece on the pallet P disposed on the table in the XYZ directions.
In machining, an NC device 30 (see FIG. 2) installed outside the machine tool 2 is used to send a rotational speed command to the spindle motor 27, an X-axis motor 21, a Y-axis motor 22, and a Z-axis motor 23. The main shaft 28 and the feed shafts 24, 25, and 26 are driven by the feed speed command. The NC device 30 transmits rotational speed information _Vθ and feed speed information _VXYZ corresponding to the rotational speed command and the feed speed command to a speed information receiving unit 41 described later.

Next, the configuration of the cooling system 1 applied to the machine tool 2 will be described with reference to FIG.
The cooling system 1 includes a main shaft cooling path 50 that passes through the main shaft 28, a feed shaft cooling path 60 that passes through the X-axis feed shaft 24, the Y-axis feed shaft 25, and the Z-axis feed shaft 26, respectively, and a main shaft cooling path. 50, a spindle cooling device 35 that feeds the spindle cooling oil whose temperature is adjusted, a feed shaft cooling device 36 that feeds the feeding shaft cooling oil whose temperature is adjusted to the feed shaft cooling path 60, and these spindle cooling devices 35 and a temperature control device 40 for controlling the set temperature of the cooling oil of the feed shaft cooling device 36.

  The main shaft cooling device 35 and the feed shaft cooling device 36 adjust the temperatures of the tanks 35a and 36a for storing the cooling oil and the cooling oil in the tanks 35a and 36a based on the temperature set by the temperature control device 40, respectively. It is comprised from the temperature control parts 35b and 36b.

The main shaft cooling path 50 is connected to the temperature adjusting unit 35 b of the main shaft cooling device 35, passes through the main shaft 28, and is then connected to the tank 35 a of the main shaft cooling device 35. Specifically, the main flow path 51 extends from the temperature adjustment unit 35 b and branches into the rotating body cooling path 52 and the fixed body cooling path 53 on the way. The rotary body cooling path 52 is provided with a pressurizing pump 54 in the middle thereof, and passes through the main shaft motor 27 and main shaft cylinder 16 in the main shaft 28 so as to reciprocate along the axial direction, and then the tank 35a. To form a circulation passage.
After the stationary body cooling path 53 is further branched into two flow paths 53a and 53b, one flow path 53a is formed in a coil shape inside the main shaft cylinder 16, and the other flow path 53b is formed in a coil shape inside the main shaft motor 27. After passing, they merge together and are connected to the tank 35a to form a circulation channel.

  The feed shaft cooling path 60 is connected to the temperature adjusting unit 36b of the feed shaft cooling device 36, passes through the X-axis feed shaft 24, the Y-axis feed shaft 25, and the Z-axis feed shaft 26, and then the feed shaft cooling device 36. The tank 36a is connected. Specifically, the main flow path 61 extending from the temperature adjustment unit 36b is divided into three axial flow paths 62a, 62b, and 62c that pass through the X-axis feed shaft 24, the Y-axis feed shaft 25, and the Z-axis feed shaft 26 along the way. It branches, merges after passing through the feed shafts 24, 25, and 26, and is connected to the tank 36b to form a circulation flow path.

The temperature control units 35b and 36b of the main spindle cooling device 35 and the feed shaft cooling device 36 perform feedback control by measuring the temperature of the cooling oil passing through the main flow paths 51 and 61 with the temperature sensors 38 and 38, respectively. The temperature of the main spindle cooling oil and feed shaft cooling path is adjusted respectively.
Furthermore, temperature information from temperature sensors 39 and 39 provided in the base 3 of the machine tool 2 is input to the temperature adjusting units 35b and 36b.

Next, the temperature control device 40 that sets the temperature of the cooling oil in the cooling system 1 will be described with reference to the upper left block diagram of FIG.
The temperature control device 40 includes a speed information receiving unit 41, a temperature data storage unit 42, a comparison calculation unit 43, and two transmission / reception units 44 and 44.

The speed information receiving unit 41 receives the rotation speed information _Vθ and the feed speed information _VXYZ from the NC device 30 and outputs them to the comparison calculation unit.

The temperature data storage unit 42 stores the temperature setting value of the cooling oil corresponding to the rotational speed of the main shaft 28 and the feed speeds of the feed shafts 24, 25, and 26.
More specifically, the temperature data storage unit 42 owns a speed / temperature table as shown in FIG. 3 for each of the main shaft 28 and the feed shafts 24, 25, and 26, for example.

The speed / temperature table for the main shaft 28 shown in FIG. 3A (hereinafter referred to as the main shaft speed / temperature table) is, for example, as shown in the upper column, for example, the rotation stoppage of the rotation speed of the main shaft 28. , Velocity region A _θ , velocity region B _θ , velocity region C _θ , and velocity region D _θ are divided into five velocity regions in total. The speed regions A _{θ to} D _θ are arranged in order from the smallest speed value to the largest value, and the temperature setting values T _{θ1 to} T _θ5 are determined for each of the five speed regions. It has been. It should be noted that these temperature setting value T _.theta.1 through T _.theta.5 is temperature is defined needed to remove the heat generated of the main shaft 28 in each speed region, the relationship between the temperature setting value and the speed region in FIG. 5, for example As shown, the larger the speed value in the speed region, the lower the temperature set value.

Similarly, the speed / temperature table (hereinafter referred to as “feed axis speed / temperature table”) for the feed axes 24, 25, and 26 shown in FIG. possible range, for example, feed stop, speed range _{a XYZ,} speed range _{B XYZ,} speed range _{C XYZ,} are divided into a total of five speed ranges of the speed range _{D XYZ,} each of these speed ranges _a XYZ _{to D XYZ} In addition, temperature setting values T _{XYZ1 to} T _XYZ5 of the cooling oil are determined.

The comparison calculation unit 43 is based on the rotational speed information _Vθ and the feed speed information _VXYZ input from the speed information receiver 41 and the spindle speed / temperature table and the feed axis speed / temperature table owned by the temperature data storage unit 42. Thus, the set temperatures of the spindle cooling device 35 and the feed shaft cooling device 36 are determined.

Specifically, for the main shaft 28, the speed region to which the rotational speed information _Vθ belongs is determined from the five speed regions A _{θ to} D _θ , and the temperature setting value corresponding to this speed region is determined as the main shaft cooling path 50. Determine as the set temperature. For example, when it is determined that the rotational speed information V _θ of the main shaft 28 falls within the speed region A among the five speed regions, the temperature set value T _θ1 corresponding to the speed region A becomes the set temperature of the main shaft cooling oil.

Similarly for each feed shaft 24, 25, 26, to determine the speed areas belonging feedrate information _{V XYZ} among the five speed regions _A XYZ _{to D XYZ,} sends the temperature setting value corresponding to the speed range shaft It is determined as the set temperature of the cooling path 60. For example, when it is determined that the feed speed information V _XYZ of each feed shaft 24, 25, 26 falls within the speed area A among the five speed areas, the temperature set value T _XZY1 corresponding to the speed area A is the spindle cooling oil. Set temperature.

The set temperature determined in this way is output to the transmission / reception unit 44 after 10 seconds to 1 minute has elapsed since the speed region to which the rotational speed information _Vθ and the feed speed information _VXYZ belong is changed.
Specifically, when the rotational speed information _Vθ or the feed speed information _VXYZ changes according to the processing conditions and the speed region is changed, the set temperature is transmitted to the transmission / reception unit 44 within 10 seconds to 1 minute from the change. Only after 10 seconds to 1 minute has elapsed, the set temperature corresponding to the new speed range is output to the transmission / reception unit 44.
That is, the comparison operation unit 43 when the speed range speed information V _theta and feed rate information V _XYZ belongs has changed, become a new set temperature after a predetermined delay time to output to the transceiver 44 ing.

Further, the comparison calculation unit 43 is provided with an energy saving mode. Specifically, when the main shaft 28 and the feed shafts 24, 25, and 26 are stopped and the rotational speed information _Vθ or the feed speed information _VXYZ input from the speed information receiving unit 41 becomes 0, A signal for stopping the feeding of the main spindle cooling oil and the feed shaft cooling oil is sent to the transmission / reception unit 44 after the zero state has elapsed from 10 minutes to 30 minutes.

  The transmission / reception units 44 and 44 transmit the set temperatures of the main spindle cooling oil and the feed shaft cooling oil input from the comparison calculation unit 43 to the main spindle cooling device 35 and the feed shaft cooling device 36, respectively, as set temperature change commands.

The cooling system 1 according to the present embodiment has the above-described configuration, and the operation thereof will be described along the flowchart shown in FIG.
First, it is confirmed whether or not the effective switch of the temperature control device 40 is ON (step S1). When this effective switch is OFF, the temperature control device 40 does not operate.

Next, comparison operation unit 43, reads the rotational speed information V _theta and feed rate information V _XYZ sent from the NC device 30 to the speed information receiving unit 41 (step S2), and determines whether the speed has changed However, if there is a speed change, the spindle speed / temperature table and the feed axis speed / temperature table are read from the temperature data storage unit 42. (Step S4).

Then, the comparison calculation unit 43 determines whether the rotation speed information _Vθ and the feed speed information _VXYZ have deviated from the current speed area and entered another speed area. (Step S5).

  If it is determined that another speed range has been entered, a timer count is performed (step S6), and then it is determined whether or not a fixed time T1 (10 seconds to 1 minute in the present embodiment) has elapsed (step S7). If it has elapsed, it is confirmed whether or not the energy saving mode is ON (step S8).

When the energy saving mode is OFF, the transmission / reception unit 44 sends a set temperature change command to the temperature control units 35b and 36b of the spindle cooling device 35 and the feed shaft cooling device 36 based on the set temperature determined by the comparison calculation unit 43. Thereafter, the set temperatures of the main spindle cooling device 35 and the feed shaft cooling device 36 are confirmed (step S10), and it is confirmed whether or not the set temperature has been changed normally (step S11). If not normal, an abnormal display is performed (step S12).
The spindle cooling device 35 and the feed shaft cooling device 36 adjust the temperature of the spindle cooling oil and the feed shaft cooling oil, respectively, based on the set temperature.

On the other hand, when the energy saving mode is ON, it is confirmed whether or not the rotational speed information _Vθ and the feed speed information _VXYZ are 0, that is, whether or not the speed is stopped (step S13). If the oil supply is continued (step S14) and stopped, a timer count is performed (step S15), and then a fixed time T2 (10 to 30 minutes in this embodiment) has elapsed. (Step S16), if it has elapsed, a signal for stopping the feeding of the main spindle cooling oil and the feed shaft cooling oil is sent to the main spindle cooling device and the feed shaft cooling apparatus (step S17).

As described above, according to the cooling device of the present embodiment, the comparison calculation unit 43 has the rotation speed information V _θ and the feed speed information V _XYZ input from the speed information reception unit 41 and the temperature data storage unit 42. Based on the main shaft speed / temperature table and the feed shaft speed / temperature table, the main shaft cooling oil and the set temperature are determined.
Therefore, the cooling oil having the cooling capacity corresponding to the rotational speed of the main shaft 28 and the speed changes of the feed shafts 24, 25, 26 can be supplied to the main shaft cooling passage 50 and the feed shaft cooling passage 60, respectively. Therefore, since the generated heat can be removed accurately according to the processing conditions, it is possible to reliably suppress thermal deformation of the machine tool and improve processing accuracy.

Further, when the speed region to which the rotation speed information _Vθ and the feed speed information _VXYZ belong is changed, the temperature is set until a certain time (10 seconds to 1 minute in the present embodiment) elapses after the timer is counted. The change command is not sent to the spindle cooling device 35 and the feed shaft cooling device 36.
Accordingly, in order for the temperature adjusting units 35b and 36b to start the temperature adjustment of the cooling oil based on the set temperature corresponding to the new speed region after the lapse of the predetermined time, for example, the rotational speed and the feed at the boundary between the two speed regions. Even when the speed is not stable, the set temperature is maintained corresponding to the original speed range, and it is possible to prevent the temperature adjustment of the spindle cooling oil and the feed shaft cooling oil from being unstable. .

  Further, in the energy saving mode described above, the cooling oil feed of the main spindle cooling passage 50 and the feed shaft cooling passage 60 is performed after a certain time (10 to 30 minutes in the present embodiment) has elapsed since the rotation speed and the feed speed were stopped. When the oil is stopped, the cooling is not performed more than necessary, so that it is possible to prevent the main shaft 28 and the feed shafts 24, 25, 26 from being overcooled and to save energy.

The embodiment of the present invention has been described above, but the present invention is not limited to this, and can be appropriately changed without departing from the technical idea of the present invention.
For example, as a modification, a processing preparation mode may be provided instead of the energy saving mode.
According to this machining preparation mode, when the main shaft 28 and the feed shafts 24, 25, 26 are stopped, the temperature adjusting units 35 a, 35 b adjust the cooling oil in the main shaft cooling path 50 and the feed shaft cooling path 60. The temperature is set to a temperature higher than the temperature of the base 3 of the machine tool 2 obtained by the temperature sensor 39.

  Here, in the machine tool 2, the temperature of the main shaft 28 and each of the feed shafts 24, 25, and 26 is slightly higher during steady operation with stable machining accuracy than when stopped for a long time. Therefore, if cooling is continued even after the machine tool 2 is stopped, the temperature in the stable state is lowered, and the accuracy immediately after resuming the machining is lowered. Therefore, as described above, after the main shaft 28 and the feed shafts 24, 25, and 26 are stopped, the temperature is adjusted to be higher than the base 3 temperature of the machine tool 2 so as to be in a machining preparation state. Can be stabilized.

Further, instead of determining the speed region to which the rotation speed information _Vθ or the feed speed information _VXYZ belongs, the comparison calculation unit 43 calculates one minute based on the rotation speed information _Vθ or the feed speed information _VXYZ. A speed region to which the average rotational speed for 10 minutes belongs is determined, and the temperature set value corresponding to this speed region may be set as the set temperature of the main spindle cooling oil and the feed shaft cooling oil.

It is a perspective view which shows schematic structure of the machine tool to which the cooling device of a machine tool is applied. It is a schematic block diagram of the cooling device of the machine tool which concerns on embodiment. It is a figure which shows a speed and temperature table. It is a flowchart explaining operation | movement of the cooling device of a machine tool. It is a figure which shows the relationship between the speed value of a speed area | region, and a temperature setting value.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cooling system 2 Machine tool 3 Base 16 Spindle cylinder 21 X-axis motor 22 Y-axis motor 23 Z-axis motor 24 X-axis feed shaft 25 Y-axis feed shaft 26 Z-axis feed shaft 27 Spindle motor 28 Spindle 30 NC device 35 Spindle cooling device 35b Temperature control unit 36 Feed shaft cooling device 36b Temperature control unit 40 Temperature control device 41 Speed information receiving unit 42 Temperature data storage unit 43 Comparison calculation unit 44 Transmission / reception unit 50 Spindle cooling path 60 Feed shaft cooling path

Claims (10)

In the machine tool cooling device that circulates the spindle cooling oil inside the spindle to prevent thermal deformation of the machine tool,
A speed information receiver for receiving rotation speed information of the spindle;
Temperature data provided with a spindle speed / temperature table in which the range that the rotation speed of the spindle can take is stepwise divided into a plurality of speed areas, and a temperature setting value corresponding to the heat generation amount is determined for each speed area. A storage unit;
The rotational speed information and the spindle speed / temperature table are read to determine the speed region to which the rotational speed information belongs, and the temperature setting value corresponding to the speed region is set as the set temperature of the spindle cooling oil. A comparison operation unit;
A cooling system for a machine tool, comprising: a spindle cooling device that feeds oil by adjusting the temperature of the spindle cooling oil based on the set temperature.   When the speed region to which the rotational speed information belongs is changed, the spindle cooling device adjusts the temperature of the spindle cooling oil based on the set temperature corresponding to the original speed region within 10 seconds to 1 minute. 2. The cooling system for a machine tool according to claim 1, wherein the temperature of the spindle cooling oil is adjusted based on the set temperature corresponding to the new speed region after the elapse of 10 seconds to 1 minute.   The cooling of the machine tool according to claim 1 or 2, wherein the spindle cooling device stops feeding the spindle cooling oil after 10 to 30 minutes have elapsed since the rotation of the spindle stopped. system.   3. The temperature of the cooling oil is adjusted by the spindle cooling device using the temperature higher than the base temperature of the machine tool as the set temperature when the rotation of the spindle is stopped. The cooling system for machine tools described in 1.   Instead of determining the speed region to which the rotational speed information belongs, the comparison operation unit determines the speed region to which the average rotational speed of 1 to 10 minutes calculated based on the rotational speed information belongs. 5. The machine tool cooling system according to claim 1, wherein the temperature setting value corresponding to the speed region is set as a setting temperature of the spindle cooling oil. 6. In a machine tool cooling device that circulates feed shaft cooling oil inside the feed shaft that moves the spindle relative to the workpiece to prevent thermal deformation of the machine tool,
A speed information receiver for receiving feed speed information of the feed shaft;
A range in which the feed rate of the feed shaft can be taken is divided into a plurality of speed regions step by step, and a feed shaft speed / temperature table in which a temperature setting value corresponding to the heat generation amount is determined for each speed region. A temperature data storage unit;
The feed speed information and the feed axis speed / temperature table are read to determine the speed area to which the feed speed information belongs, and the temperature setting value corresponding to the speed area is set to the set temperature of the feed axis cooling oil. A comparison operation unit and
A cooling system for a machine tool, comprising: a feed shaft cooling device that feeds oil by adjusting the temperature of the feed shaft cooling oil based on the set temperature.   When the speed region to which the feed speed information belongs is changed, the feed shaft cooling device is heated to the feed shaft cooling oil based on the set temperature corresponding to the original speed region within 10 seconds to 1 minute. The machine tool according to claim 6, wherein the adjustment is performed and the temperature of the feed shaft cooling oil is adjusted based on the set temperature corresponding to the new speed region after the elapse of 10 seconds to 1 minute. Cooling system.   The work according to claim 6 or 7, wherein the feed shaft cooling device stops feeding the feed shaft cooling oil after 10 to 30 minutes have passed since the feed shaft stopped. Mechanical cooling system.   When the rotation of the feed shaft is stopped, the feed shaft cooling device adjusts the temperature of the feed shaft cooling oil with the temperature higher than the base temperature of the machine tool as the set temperature. Item 8. The machine tool cooling system according to Item 6 or 7.   Instead of determining the speed region to which the feed speed information belongs, the comparison calculation unit determines the speed region to which the average feed speed of 1 minute to 10 minutes calculated based on the feed speed information belongs. The machine tool cooling system according to any one of claims 6 to 9, wherein the temperature set value corresponding to the speed region is set to a set temperature of the feed shaft cooling oil.

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