JPH08243870A - Tool changer device for machine tool - Google Patents

Abstract

PURPOSE: To prevent occurrence of an error in positioning a tool when it is changed, by conforming a temperature of a spindle at machining time to a temperature of a tool held in a tool magazine to be intended in use for the next machining. CONSTITUTION: Based on an output from a contactless temperature measurig device provided in a spindle head and an output from a temperature measuring device 19 provided in a magazine pot 8, heating value of a heating unit 20 necessary for equalizing a temperature of a spindle to that of a tool in the magazine pot 8 is calculated in a heating value calculating part 22 in a numerical control mechanism 21, and based on a calculated result of the heating value calculating part 22, the heating value of the heating unit 20 is controlled by a heating unit control part 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool changer for accurately positioning a rotary tool in a numerically controlled machine tool having a function of automatically changing a rotary tool such as a machining center or a combined machining lathe.

[0002]

2. Description of the Related Art In recent years, numerically controlled machine tools such as machining centers and multi-tasking lathes generally have a function of automatically changing tools. Especially, in the case of rotating tools, concentricity with the spindle is ensured. At the same time, in order to improve the positioning accuracy in the axial direction, a taper hole corresponding to a taper shank formed in the holder portion of the tool is provided in the main shaft, and the tool is used in a state in which the tool is pulled rearward.

FIG. 6 is a typical sectional view of a spindle head of such a numerically controlled machine tool. The spindle head 10 has bearings 11 and 11.
A spindle hole 12a corresponding to the taper shank Ha formed in the holder portion H of the tool T is provided at the tip of the main shaft 12 which is rotatably supported via the motor 13 and is pulled by the tip of the taper shank Ha. The tool T is mounted by clamping the stud 14 with a collet 15 and urging the disk spring 17 via a draw bar 16 toward the rear of the main shaft.

[0004]

When a workpiece is machined with such an apparatus, the spindle 12 is heated by frictional heat generated in the tool T during machining, heat generated by the rotation of the bearing 11, heat generated by the motor 13, and the like. Temperature rises. Due to this temperature rise, the main shaft 12 expands and the diameter of the tapered hole 12a increases. In this case, the mounted tool T also expands the taper shank Ha due to the temperature rise, so that the position of the tool T does not change. However, if the tool is replaced with the taper hole 12a widened, the temperature of the tool newly mounted on the spindle is close to room temperature. Therefore, the disc spring 17 pulls the tool to the rear of the spindle to position it behind the spindle as compared to room temperature. Will be done. FIG. 7 illustrates the effect, where a indicates the case where the spindle is at room temperature and b indicates the case where the temperature rises. Comparing these, the effect of the temperature rise is that the tip position of the tool T is L
However, there is a problem that the machining accuracy is deteriorated by only changing the value.

Further, when the amount of heat generated by the next mounted tool is small as compared with the processing up to that point, the temperature of the spindle, which has once increased, will decrease, and the tapered hole 12a Attempts to shrink to the position shown in phantom in FIG. 7b. As a result, the taper shank Ha is
The tool is tightly tightened in the taper hole 12a, and even if the biasing of the disc spring toward the rear of the spindle for releasing the tool is released, the tool does not separate from the spindle. There was a problem that the machine tool stopped alarming.

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel tool changer for accurately positioning a tool to be used next and preventing biting with respect to a spindle whose temperature has risen due to machining up to that point. .

[0007]

In order to solve the above-mentioned problems, the tool changing device of the present invention takes out a designated tool from a magazine accommodating a plurality of tools and tapers the tool rotating spindle. Fit the taper shank formed on the holder part of the tool into the hole and position it in the axial direction and urge the tool toward the back of the spindle, or vice versa, remove the tool from the spindle. A tool exchanging device for exchanging tools between the magazine and the spindle such as returning to the magazine, a spindle temperature measuring means for measuring the temperature of the spindle, and a tool temperature measuring means for measuring at least the temperature of the tool to be exchanged. A cooling / heating means for heating / cooling the tool and a temperature control means for controlling the cooling / heating device based on the outputs of the spindle temperature measuring means and the tool temperature measuring means are provided.
Further, a spindle temperature calculating means for calculating an estimated value of the spindle temperature from a machining program, a tool temperature measuring means for measuring at least the temperature of a tool to be replaced, a cooling / heating means for heating / cooling the tool, and the spindle temperature. It is provided with temperature control means for controlling the cooling / heating device based on the outputs of the calculating means and the tool temperature measuring means.

[0008]

According to the tool changer of the present invention, the temperature of the spindle during machining and the temperature of the tool used for the next machining are measured or calculated respectively, and the tool is heated or cooled according to the spindle temperature. However, since the spindle temperature and the tool temperature are controlled to be substantially the same, it is possible to prevent the positioning error of the tool when the tool is replaced. Further, when the temperature of the spindle decreases after the tool is replaced, the tool also contracts due to the same temperature change as the spindle, so that the biting phenomenon of the tool with respect to the spindle can be prevented.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. 1 to 4 for a gate type machining center. FIG.
1 is a front view of a machining center, in which a bed 1 is arranged on a floor surface, and a table 2 which is movable and positioned in the front-rear direction of the drawing is provided on the bed 1. Columns 3 and 3 are fixed to the left and right of the bed 1, and a cross rail 5 is provided on a vertical sliding surface 3a provided on the front surface of each column 3,3.
Is provided so that it can be moved and positioned via the ball screw 4 by a motor (not shown). A spindle ram 6, a tool magazine 7, and a tool changing mechanism 9 are integrally provided on a horizontal sliding surface 5a provided on the front surface of the cross rail 5 so as to be movable in the horizontal direction. The spindle ram 6 is provided with a spindle head 10 capable of moving and positioning in the vertical direction, and at the lower end of the tool changing mechanism 9, a tool can be gripped and vertically moved and positioned, and can be rotated around the axis of the movement. A tool changing arm 9a is provided. The tool magazine 7 is covered with a cover 7a shown by a virtual line in the figure, and a magazine pot 8 for holding the tool in a horizontal posture is provided inside the tool magazine 7 so as to be movable and positioned in an annular shape. It is possible to turn vertically.

FIG. 2 is a sectional view of the spindle head 10 according to the embodiment of the present invention. The same parts as those of the prior art are designated by the same reference numerals and the description thereof will be omitted. A temperature measuring device 18 as temperature measuring means is provided near the tip of the spindle 12 of the spindle head 10. The temperature measuring device 18 is preferably a non-contact type.

FIG. 3 is a sectional view of the magazine pots 8. The pull studs 1 projecting from the tip of the taper shank Ha in the holder portion H of the tool T are located in the back of each magazine pot 8.
There is provided a holding mechanism that engages with No. 4 and holds the tool T. The magazine pot 8 has a heating element 20 formed in a shape corresponding to the tapered shank Ha formed on the holder portion H of the held tool T, and a temperature for penetrating the heating element 20 and measuring the temperature of the tool. A temperature measuring device 19 as a measuring means is built in.

FIG. 4 is a block diagram showing a control means for controlling the heating element 20, and the block diagram and FIG.
A control example will be described with reference to FIGS. 3 to 3. The numerical control mechanism 21 as a temperature control means includes a non-contact temperature measuring device 18 provided in the spindle head 10 and a temperature provided in the magazine pot 8. A heating amount for inputting signals from the measuring device 19 and calculating the heating amount of the heating element 20 necessary to make the temperature of the tool T in the spindle 12 equal to the temperature of the tool T in the magazine pot 8 based on these data. A calculation unit 22 and a heating element control unit 23 that controls the heat generation amount of the heating element based on the calculation result of the heating amount calculation unit 22 are provided.

Next, the operation of the control means will be described. Spindle 1
When machining is carried out by the tool T attached to No. 2, the temperature of the spindle rises due to machining heat, heat generation of the bearing and heat generation of the motor. The temperature of the spindle is detected by the temperature measuring device 18, and the temperature of the tool T in the magazine pot 8 of the tool magazine is detected by the temperature measuring device 19, and the detected values are the heating amount calculation unit 22 of the numerical control mechanism 21. Sent to. The heating amount calculation unit 22 calculates the heating amount of the heating element required to eliminate the temperature difference between the spindle temperature and the tool temperature, and the heating element control unit 23 controls the heating element 20 based on the calculation result.

FIG. 5 is a block diagram showing a modified example of the control means. The same components as those in FIG. 4 are designated by the same reference numerals and the description thereof will be omitted. The difference from the above-described embodiment is that the temperature measuring device 18 in the spindle head 10 is omitted, and a machining program storage unit 24 and a spindle temperature calculating unit 25 are added in the numerical control mechanism 21.

The operation of this modification will be described. The machining content of the spindle (main spindle rotation speed, cut amount, etc.) is stored in the machining program storage unit 24 in advance, and the spindle temperature calculation unit 25 estimates the temperature rise amount of the spindle from the machining content. The amount of heat applied to the tool is obtained from this estimated spindle temperature value and the output of the temperature measuring device 19 in the magazine pot 8.

In the above embodiment, a heating element is provided in the tool pot to heat the tool. However, a cooling means is provided together with the heating element or in place of the heating element, and the tool magazine is more suitable. In the case of a temperature higher than that of the spindle, it is possible to cool the tool so that the temperatures of the tool and the spindle match. Further, since the tool for temperature control is intended for the tool to be used next, it is not necessary to provide the heating element in all magazine pots, and in FIG. 1, the tool exchange is the lowest end of the annular magazine pots. It is desirable to provide it at one position and minimize the amount of energy. When it is provided for all magazine pots, only one heating element can generate heat, and it can be used for preheating other tools.

Further, in the case of automatic operation by the machining program, the tool to be used next can be estimated, but if the operator directly operates, any tool may be used next, so that the tool magazine 7 can be used. The temperature of the entire cover 7a can be controlled. In that case, one heating element may be provided in the cover or all the heating elements provided in each magazine pot may be controlled.

The gate type machining center shown in the embodiment is
The distance between the spindle and the tool magazine is relatively short, but there are also those in which the magazine is installed at a different position in order to prepare more tools.In such a machining center, the tool replacement time is shortened. Therefore, it is common to have a ready station pot that takes out the tool to be used next from the tool magazine in advance, moves it to the vicinity of the tool exchange arm, and stands by. Therefore, in a machine tool having such a ready station pot, a heating element may be provided in this ready station pot. The present invention is also applicable to machine tools other than machining centers, such as multi-tasking lathes.

[0019]

As described above in detail, according to the first aspect of the invention, the tool temperature control device for eliminating the temperature difference between the spindle and the tool to be mounted next to the spindle is mounted on the spindle of the tool. The positioning accuracy is stable during the machining, and high processing accuracy is secured. Further, even when the temperature of the spindle which has once risen decreases, the temperature of the tool also changes, so that the amount of shrinkage also becomes the same, and so-called biting phenomenon of the tool can be prevented in advance.

According to the invention of claim 2, the invention of claim 1 can be dealt with only by changing the control program, and since it is not necessary to measure the temperature of the spindle, the temperature measuring device is not required, and the invention of claim 1 is eliminated. Compared with the invention of 1, the cost is reduced, and it is more easily applied to existing equipment.

[Brief description of drawings]

FIG. 1 is a front view of a machining center to which the present invention is applied.

FIG. 2 is a sectional view of a main shaft of the machining center shown in FIG.

FIG. 3 is a sectional view of a magazine pot of the tool magazine of the present invention.

FIG. 4 is a block diagram showing the configuration of the first exemplary embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 6 is a sectional view of a spindle of a conventional machine tool.

FIG. 7 is a diagram showing the spread of the taper shank and the retraction of the tool as the temperature of the spindle increases.

[Explanation of symbols]

7 ・ ・ Magazine, 8 ・ ・ Magazine pot, 10 ・ ・ Spindle head, 12 ・ ・ Spindle, 12a ・ ・ Tapered hole, 18 ・ ・ Non-contact temperature measuring instrument, 19 ・ ・ Temperature measuring instrument, 20 ・ ・ Heating element , 22 ... Heating amount calculation unit, 23 ... Heating element control unit, T
..Tools, H..holders, Ha..taper shanks

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] March 15, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction content]

[Document name] Statement

Title of machine tool tool changer

[Claims]

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool changer for accurately positioning a rotary tool in a numerically controlled machine tool having a function of automatically changing a rotary tool such as a machining center or a combined machining lathe.

[0002]

2. Description of the Related Art In recent years, numerically controlled machine tools such as machining centers and multi-tasking lathes generally have a function of automatically changing tools. Especially, in the case of rotating tools, concentricity with the spindle is ensured. At the same time, in order to improve the positioning accuracy in the axial direction, a taper hole corresponding to a taper shank formed in the holder portion of the tool is provided in the main shaft, and the tool is used in a state in which the tool is pulled rearward.

FIG. 6 is a typical sectional view of a spindle head of such a numerically controlled machine tool. The spindle head 10 has bearings 11 and 11.
A spindle hole 12a corresponding to the taper shank Ha formed in the holder portion H of the tool T is provided at the tip of the main shaft 12 which is rotatably supported via the motor 13 and is pulled by the tip of the taper shank Ha. The tool T is mounted by clamping the stud 14 with a collet 15 and urging the disk spring 17 via a draw bar 16 toward the rear of the main shaft.

[0004]

When a workpiece is machined with such an apparatus, the spindle 12 is heated by frictional heat generated in the tool T during machining, heat generated by the rotation of the bearing 11, heat generated by the motor 13, and the like. Temperature rises. Due to this temperature rise, the main shaft 12 expands and the diameter of the tapered hole 12a increases. In this case, the mounted tool T also expands the taper shank Ha due to the temperature rise, so that the position of the tool T does not change. However, if the tool is replaced with the taper hole 12a widened, the temperature of the tool newly mounted on the spindle is close to room temperature. Therefore, the disc spring 17 pulls the tool to the rear of the spindle to position it behind the spindle as compared to room temperature. Will be done. FIG. 7 illustrates the effect, where a indicates the case where the spindle is at room temperature and b indicates the case where the temperature rises. Comparing these, the effect of the temperature rise is that the tip position of the tool T is L
However, there is a problem that the machining accuracy is deteriorated by only changing the value.

Further, when the amount of heat generated by the next mounted tool is small as compared with the processing up to that point, the temperature of the spindle, which has once increased, will decrease, and the tapered hole 12a Attempts to shrink to the position shown in phantom in FIG. 7b. As a result, the taper shank Ha is
The tool is tightly tightened in the taper hole 12a, and even if the biasing of the disc spring toward the rear of the spindle for releasing the tool is released, the tool does not separate from the spindle. There was a problem that the machine tool stopped alarming.

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel tool changer for accurately positioning a tool to be used next and preventing biting with respect to a spindle whose temperature has risen due to machining up to that point. .

[0007]

In order to solve the above-mentioned problems, the tool changing device of the present invention takes out a designated tool from a magazine accommodating a plurality of tools and tapers the tool rotating spindle. Fit the taper shank formed on the holder part of the tool into the hole and position it in the axial direction and urge the tool toward the back of the spindle, or vice versa, remove the tool from the spindle. A tool exchanging device for exchanging tools between the magazine and the spindle such as returning to the magazine, a spindle temperature measuring means for measuring the temperature of the spindle, and a tool temperature measuring means for measuring at least the temperature of the tool to be exchanged. A cooling / heating means for heating / cooling the tool and a temperature control means for controlling the cooling / heating device based on the outputs of the spindle temperature measuring means and the tool temperature measuring means are provided.
Further, a spindle temperature calculating means for calculating an estimated value of the spindle temperature from a machining program, a tool temperature measuring means for measuring at least the temperature of a tool to be replaced, a cooling / heating means for heating / cooling the tool, and the spindle temperature. It is provided with temperature control means for controlling the cooling / heating device based on the outputs of the calculating means and the tool temperature measuring means.

[0008]

According to the tool changer of the present invention, the temperature of the spindle during machining and the temperature of the tool used for the next machining are measured or calculated respectively, and the tool is heated or cooled according to the spindle temperature. However, since the spindle temperature and the tool temperature are controlled to be substantially the same, it is possible to prevent the positioning error of the tool when the tool is replaced. Further, when the temperature of the spindle decreases after the tool is replaced, the tool also contracts due to the same temperature change as the spindle, so that the biting phenomenon of the tool with respect to the spindle can be prevented.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. 1 to 4 for a gate type machining center. FIG.
1 is a front view of a machining center, in which a bed 1 is arranged on a floor surface, and a table 2 which is movable and positioned in the front-rear direction of the drawing is provided on the bed 1. Columns 3 and 3 are fixed to the left and right of the bed 1, and a cross rail 5 is provided on a vertical sliding surface 3a provided on the front surface of each column 3,3.
Is provided so that it can be moved and positioned via the ball screw 4 by a motor (not shown). A spindle ram 6, a tool magazine 7, and a tool changing mechanism 9 are integrally provided on a horizontal sliding surface 5a provided on the front surface of the cross rail 5 so as to be movable in the horizontal direction. A spindle head 10 is provided on the spindle ram 6 so that the spindle ram 6 can be moved and positioned in the vertical direction, and a tool changing mechanism 9 can hold a tool and vertically move and position the spindle, and can rotate around the axis of the movement. A tool changing arm 9a is provided. The tool magazine 7 is covered with a cover 7a shown by imaginary lines in the figure, and a magazine pot 8 for holding the tool in a horizontal posture is provided inside the tool magazine 7 so as to be movable and positioned in an annular shape. It is possible to turn vertically.

FIG. 2 is a sectional view of the spindle head 10 according to the embodiment of the present invention. The same parts as those of the prior art are designated by the same reference numerals and the description thereof will be omitted. A temperature measuring device 18 as temperature measuring means is provided near the tip of the spindle 12 of the spindle head 10. The temperature measuring device 18 is preferably a non-contact type.

FIG. 3 is a sectional view of the magazine pots 8. The pull studs 1 projecting from the tip of the taper shank Ha in the holder portion H of the tool T are located in the back of each magazine pot 8.
There is provided a holding mechanism that engages with No. 4 and holds the tool T. The magazine pot 8 has a heating element 20 formed in a shape corresponding to the tapered shank Ha formed on the holder portion H of the held tool T, and a temperature for penetrating the heating element 20 and measuring the temperature of the tool. A temperature measuring device 19 as a measuring means is built in.

FIG. 4 is a block diagram showing a control means for controlling the heating element 20, and the block diagram and FIG.
A control example will be described with reference to FIGS. 3 to 3. The numerical control mechanism 21 as a temperature control means includes a non-contact temperature measuring device 18 provided in the spindle head 10 and a temperature provided in the magazine pot 8. A heating amount for inputting signals from the measuring device 19 and calculating the heating amount of the heating element 20 necessary to make the temperature of the tool T in the spindle 12 equal to the temperature of the tool T in the magazine pot 8 based on these data. A calculation unit 22 and a heating element control unit 23 that controls the heat generation amount of the heating element based on the calculation result of the heating amount calculation unit 22 are provided.

Next, the operation of the control means will be described. Spindle 1
When machining is carried out by the tool T attached to No. 2, the temperature of the spindle rises due to machining heat, heat generation of the bearing and heat generation of the motor. The temperature of the spindle is detected by the temperature measuring device 18, and the temperature of the tool T in the magazine pot 8 of the tool magazine is detected by the temperature measuring device 19, and the detected values are the heating amount calculation unit 22 of the numerical control mechanism 21. Sent to. The heating amount calculation unit 22 calculates the heating amount of the heating element required to eliminate the temperature difference between the spindle temperature and the tool temperature, and the heating element control unit 23 controls the heating element 20 based on the calculation result.

FIG. 5 is a block diagram showing a modified example of the control means. The same components as those in FIG. 4 are designated by the same reference numerals and the description thereof will be omitted. The difference from the above-described embodiment is that the temperature measuring device 18 in the spindle head 10 is omitted, and a machining program storage unit 24 and a spindle temperature calculating unit 25 are added in the numerical control mechanism 21.

The operation of this modification will be described. The machining content of the spindle (main spindle rotation speed, cut amount, etc.) is stored in the machining program storage unit 24 in advance, and the spindle temperature calculation unit 25 estimates the temperature rise amount of the spindle from the machining content. The amount of heat applied to the tool is obtained from this estimated spindle temperature value and the output of the temperature measuring device 19 in the magazine pot 8.

In the above embodiment, a heating element is provided in the tool pot to heat the tool. However, a cooling means is provided together with the heating element or in place of the heating element, and the tool magazine is more suitable. In the case of a temperature higher than that of the spindle, it is possible to cool the tool so that the temperatures of the tool and the spindle match. Further, since the tool for temperature control is intended for the tool to be used next, it is not necessary to provide the heating element in all magazine pots, and in FIG. 1, the tool exchange is the lowest end of the annular magazine pots. It is desirable to provide it at one position and minimize the amount of energy. When it is provided for all magazine pots, only one heating element can generate heat, and it can be used for preheating other tools.

Further, in the case of automatic operation by the machining program, the tool to be used next can be estimated, but if the operator directly operates, any tool may be used next, so that the tool magazine 7 can be used. The temperature of the entire cover 7a can be controlled. In that case, one heating element may be provided in the cover or all the heating elements provided in each magazine pot may be controlled.

The gate type machining center shown in the embodiment is
The distance between the spindle and the tool magazine is relatively short, but there are also those in which the magazine is installed at a different position in order to prepare more tools.In such a machining center, the tool replacement time is shortened. Therefore, it is common to have a ready station pot that takes out the tool to be used next from the tool magazine in advance, moves it to the vicinity of the tool exchange arm, and stands by. Therefore, in a machine tool having such a ready station pot, a heating element may be provided in this ready station pot. The present invention is also applicable to machine tools other than machining centers, such as multi-tasking lathes.

[0019]

As described above in detail, according to the first aspect of the invention, the tool temperature control device for eliminating the temperature difference between the spindle and the tool to be mounted next to the spindle is mounted on the spindle of the tool. The positioning accuracy is stable during the machining, and high processing accuracy is secured. Further, even when the temperature of the spindle which has once risen decreases, the temperature of the tool also changes, so that the amount of shrinkage also becomes the same, and so-called biting phenomenon of the tool can be prevented in advance.

According to the invention of claim 2, the invention of claim 1 can be dealt with only by changing the control program, and since it is not necessary to measure the temperature of the spindle, the temperature measuring device is not required, and the invention of claim 1 is eliminated. Compared with the invention of 1, the cost is reduced, and it is more easily applied to existing equipment.

[Brief description of drawings]

FIG. 1 is a front view of a machining center to which the present invention is applied.

FIG. 2 is a sectional view of a main shaft of the machining center shown in FIG.

FIG. 3 is a sectional view of a magazine pot of the tool magazine of the present invention.

FIG. 4 is a block diagram showing the configuration of the first exemplary embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 6 is a sectional view of a spindle of a conventional machine tool.

FIG. 7 is a diagram showing the spread of the taper shank and the retraction of the tool as the temperature of the spindle increases.

[Explanation of code] 7 ・ ・ Magazine, 8 ・ ・ Magazine pot, 10 ・ ・ Spindle head, 12 ・ ・ Spindle, 12a ・ ・ Tapered hole, 18 ・ ・ Non-contact temperature measuring instrument, 19 ・ ・ Temperature measuring instrument, 20 ... Heating element, 22 ... Heating amount calculation section, 23 ... Heating element control section, T
..Tools, H..holders, Ha..taper shanks

Claims (2)

[Claims] 1. A specified tool is taken out from a magazine accommodating a plurality of tools, and a taper shank formed in a holder portion of the tool is fitted in a taper hole provided in a tool rotation spindle in an axial direction. Positioning and mounting the tool in a state of being urged to the rear of the spindle, or vice versa, a tool exchange function to exchange tools between the magazine and the spindle, such as removing the tool from the spindle and returning it to the magazine In the machine tool having the spindle temperature measuring means for measuring the temperature of the spindle,
At least a tool temperature measuring means for measuring the temperature of the tool to be replaced, and a cooling / heating means for heating / cooling the tool,
A tool changing device for a machine tool, comprising: a spindle temperature measuring means and a temperature control means for controlling a cooling / heating device based on outputs of the tool temperature measuring means. 2. A specified tool is taken out from a magazine accommodating a plurality of tools, and a taper shank formed in a holder part of the tool is fitted in a taper hole provided in a tool rotation spindle in an axial direction. Positioning and mounting the tool in a state of being urged to the rear of the spindle, or vice versa, a tool exchange function to exchange tools between the magazine and the spindle, such as removing the tool from the spindle and returning it to the magazine In the machine tool having, a spindle temperature calculating means for calculating an estimated value of the spindle temperature from a machining program, a tool temperature measuring means for measuring at least the temperature of a tool to be replaced, and a cooling / heating means for heating / cooling the tool. A tool changer for a machine tool, comprising: a spindle temperature calculation means and a temperature control means for controlling a cooling / heating device based on outputs of the tool temperature measurement means.