JPH0994728A - Automatic tool change device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conduct tool change operation at a high speed by fitting a drive means which performs oscillating movement of approaching and separating a grip to/from a main spindle top end, interlocking with the indexing movement of a magazine and the straight movement of a main spindle head. SOLUTION: Based on a tool change command, when a main spindle head 16 moves upwards, the roller of a grip 34 moves relatively along the Z-axis cam at the side surface of the main spindle head 16. When the roller moves from the flat part of the Z-axis cam to a curved part, the grip 34 oscillates toward the top end of a main spindle 22, namely, a tool change position. When the grip 34 engages with a tool holder 24a mounted on the top of a main spindle 22 and starts clamping movement of a tool holder 24a, the tool clamping device of a main spindle starts unclamping movement of the tool holder 24a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic tool changer for machine tools.

[0002]

2. Description of the Related Art Recently, in the field of machine tools, machine tools equipped with an automatic tool changer, particularly so-called CNC drills, have been widely used. A tool changing device used for such a CNC drill generally includes a tool magazine accommodating a plurality of tools on its circumference. For example, in the automatic tool changer for machine tools disclosed in Japanese Patent Laid-Open No. 64-45540, when a tool change is instructed, first, in FIG. 1 of the same publication, a tool holder (not shown) is used. The orientation of the spindle X on which the tool is mounted is carried out. Then, the spindle head 5 moves upward. The upward movement of the spindle head 5 is performed by the link mechanism 3,
2 is transmitted to the tool magazine 1 through the tool magazine 1
Is converted into a swinging motion that approaches the main axis X. Of the grips 22 arranged on the outer circumference of the tool magazine 1, a grip that does not grip the tool reaches the tip of the spindle X by the swinging motion, approaches the tool holder at the tip of the spindle X, and grips the tool holder. Then, in order to remove the tool holder from the spindle, the spindle head 5 moves further upward.

When the tool holder is removed from the spindle X,
The tool magazine gear 21 is engaged with the spindle gear 71 and the tool magazine 1 provided at the tip peripheral portion of the spindle X, and the spindle X rotates to perform the indexing operation of the tool magazine 1. As a result, a desired tool on the circumference of the tool magazine 1 is selected. Then, the spindle head 5 moves downward, and the tool holder held by the grip swinging toward the spindle X moves to the spindle X.
It is attached to the taper hole at the tip of the. When the spindle head 5 is further moved downward, the downward movement is transmitted to the tool magazine 1 via the link mechanisms 3 and 2, and the tool magazine 1 is converted into a swinging movement away from the spindle X. The tool magazine 1 is separated from the tip of the spindle X, and the tool exchange operation ends.

[0004]

In the conventional automatic tool changer, not only is it difficult to increase the speed of the tool magazine because the entire tool magazine having a large mass performs the swinging motion for the tool change. A device such as a link mechanism for performing the swinging motion of the tool magazine must be upsized. Further, since the mass of the tool magazine is large, there is a problem that a large impact occurs at the end of the swing motion of the tool magazine.

The present invention has as a technical problem to solve the above-mentioned problems of the prior art, and realizes the tool exchange without rocking the entire tool magazine, thereby increasing the speed of the tool exchange operation. To provide a tool changer.

[0006]

According to the present invention, there is provided a spindle head which is reciprocally movable along a predetermined axis, and a tool holder which is rotatably supported by the spindle head around the axis and is attached to a tip end portion of the tool holder. In an automatic tool changer for a machine tool having a spindle for holding a tool via a tool magazine, which is rotatably supported around an axis line substantially perpendicular to the axis of rotation of the spindle, and stores tools on its circumference. And a grip for holding the tool, which is swingable between a tool exchange position immediately below the spindle and a storage position where the tool is arranged and stored on the circumference of the magazine in the tool magazine. The grip attached to the tool magazine and the grip arranged at the indexing position by the indexing operation of the tool magazine are linked with the indexing operation of the tool magazine and the linear movement of the spindle head to move the spindle. It approaches the end, a gist of the automatic tool changer having a drive means for causing the rocking operation of separating.

[0007]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. In the following description, the case where the automatic tool changer of the present invention is applied to a vertical CNC drill will be described as an example of an embodiment of the present invention, but the present invention is not limited to this and a machine tool of another type. May be

The CNC drill 10 as a machine tool comprises a column 14 and a spindle head 16 slidably supported in the vertical direction along a pair of linear guides 14a extending in the column 14 in the vertical direction. are doing. That is, the spindle head 16
Has a pair of arms 30, and a sliding member 30a that is slidably engaged with the distal ends of the pair of arms 30 along the linear guide 14a is provided. The spindle head 16 moves up and down in the vertical direction by a drive device (not shown) that is a combination of a ball screw and a motor.

A spindle 22 is supported on the spindle head 16 so as to be rotatable about a substantially vertical axis. The main shaft 22 is driven by a motor 28. A taper hole is formed at the tip of the main shaft 16. The tapered hole has a complementary fitting shape with the tapered portion of the tool holder 24a attached to the tip of the main shaft 16. A tool 26a selected for use in a machining process is mounted on the tip of the spindle 22 via a tool holder 24a.

A support arm 18 for an automatic tool changer extends substantially horizontally from the side surface of the column 14 to the side of the spindle head 16 (see FIGS. 2 and 3). The base end side of the support arm 18 is attached to the side surface of the column 14 in a cantilever manner by a plurality of bolts 18a. A rotary shaft 32 for the tool magazine 20 of the automatic tool changer is fixed to the tip of the support arm 18 by a plurality of bolts 18b (see FIG. 3). The rotary shaft 32 extends along a substantially horizontal axis.

The tool magazine 20 has a cover 20a shown by a chain double-dashed line in FIG. 1 (the cover 20a is omitted in other FIGS. 3 and 5). The tools 26 mounted on the plural tool holders 24 are arranged and housed inside the cover 20a via grips 34 (see FIG. 5). In this embodiment, the tool magazine 20 is, for example, 1
Can store zero tools. The rotary shaft 32 has
A ring-shaped rotation support member 38 is rotatably supported via a pair of bearings 32a. A ring-shaped worm gear 50 is fixed to the rotation support member 38 with bolts 46a. Worm gear 50 is worm shaft 52
The bevel gear 53 coaxially provided with the worm shaft 52 and the bevel gear 54 are rotationally driven by the indexing motor 56. (Although the bevel gear 54 is not shown coaxially with the indexing motor 56 in FIG. 5, it is attached to the rotating shaft of the indexing motor 56.)

The support member 38 has a cylinder bore formed of a plurality of through holes extending substantially parallel to the central axis. A rod-shaped plunger 36 is axially slidably disposed in each of the cylinder bores. A coil spring 36c is arranged between the cylinder bore and the plunger 36. The coil spring 36c causes the plunger 36 to move
It is biased in a direction away from the spindle head 16. A ball 36b is rotatably held at the end of the plunger 36 on the opposite side of the spindle head 16. At the end of the plunger 36 opposite to the ball 36b, the rack gear 3
6a are formed. The rack gear 36a engages with a fan-shaped pinion gear 34a formed on the grip 34. Through the engagement of the rack gear 36a and the pinion gear 34a, the grip 34 is biased by the coil spring 36c in the direction of approaching the spindle head 16.

The grip 34a (34) is a coil spring 34.
By f, the two arms 34d (see FIG. 4) are urged toward each other, and the engaging roller 34e provided at the tip of the arm 34d is engaged with the engaging groove (not shown) of the tool holder 24a (24). Tool holder 24a (2
4) Hold. Tool magazine 20 via pin 34c
It is supported swingably. More specifically, the grip 34 is rotatably attached to the bracket 48 via a pin 34c at the end opposite to the side where the tool holder is gripped. The pins 34c are arranged at equal intervals on the circumference centered on the central axis of the rotary shaft 32, and extend in the tangential direction. The bracket 48 is a bolt 48a
It is fixed to the flange 46 by. The flange 46 is fixed to the rotation support member 36 by an embedded bolt 46a.

A fan-shaped pinion gear 34a, which is concentric with the pin 34c, is formed on the grip 34 at the end opposite to the end for gripping the tool holder 24. The pinion gear 34 a engages with the rack gear 36 a of the plunger 36. As a result, the movement of the plunger 36 in the axial direction is converted into the swing motion of the grip 34. As shown in FIG.
When the plunger 36 is at the most right side, that is, at the position closest to the spindle head 16, the grip 34 is at the storage position in the tool magazine 20 and the tool holder 2 gripped at the tip thereof.
4 and the tool 26 are placed on the circumference of the tool magazine 20 (see grip shown on the upper side in FIG. 5). When the plunger is at the leftmost position, that is, at the position farthest from the spindle head 16, the grip 34 is held by the tool magazine 20.
Rocks outside of.

A cylinder bore formed as a blind hole is provided at the end of the rotary shaft 32 on the spindle head 16 side. A piston 42 is axially slidably disposed in the cylinder bore. The piston 42 is urged in a direction away from the spindle head 16 by a coil spring arranged between the cylinder bore and the piston 42. Piston 4
An abutting portion 42a is attached to the end portion of the second spindle head 16 side. The piston 42 is moved toward and away from the spindle head 16 in the axial direction by the lever 40. The lever 40 has a pin 38 attached to a bracket 38 fixed to the end surface of the rotary shaft 32.
It is attached rotatably in the direction of arrow A by b. The lever 40 is connected to the end of the piston 42 via a link 40b. Link 40 at lever 40
A roller 40a is rotatably attached to the opposite end of b. The roller 40a is provided so as to be engageable with the block 44 attached to the side surface of the spindle head 16.

The rack gear 36a in the plunger 36
On the back of the roller 36d, the contact portion 42a of the piston 42
It is arranged so that it can come into contact with. When the spindle head 16 moves upward and the block 44 engages with the roller 40a, the link 40 rotates in the counterclockwise direction, and the piston 42 moves in the direction approaching the spindle head 16. As a result, the abutting portion of the piston 42 abuts on the roller 36d of the grip 34 arranged at the lowermost side in the tool magazine 20, and the plunger 36 is pulled out in the direction approaching the spindle head 16. As a result, the rack gear 36a and the pinion gear 3
Through the engagement of 4c, the grip 34 performs a swinging motion to approach the tip end of the main shaft 22.

A Z-axis cam 60 extends on the side surface of the spindle head 16. On the other hand, the grip 34 is provided with a cam roller 34 which is provided so as to be engageable with the Z-axis cam 60. The Z-axis cam 60 is attached to the main shaft 22 along the side surface of the main spindle head 16.
Has a flat portion extending substantially parallel to the central axis of the Z axis cam, and a curved portion 60a provided at the lower end of the Z-axis cam 60. When the cam roller 3b engages with the tip of the curved portion 60a, the grip 34 is held in the tool changing position. When the spindle head 16 moves downward and the cam roller 34b moves from the curved portion 60a to the flat portion, the grip 34 is held at a position away from the tool replacement position.

The rotary shaft 32 is further provided with an annular end surface cam 5
8 is fixed by a plurality of bolts 18c. A cam surface is formed on the end surface of the end surface cam 58 that faces the side surface of the spindle head 16. Plunger 36 is coil spring 3
6a, the ball 36b of the plunger 36 engages with the cam surface as described above. The cam surface of the end surface cam 58 has a curved portion formed by one concave portion 58a and a substantially flat portion continuously connected to the curved portion (see FIG. 4). The recess 58a is formed symmetrically, and is formed deepest at the position where the central axis or the axis of symmetry passes. In this embodiment, the angular position of the axis of symmetry with respect to the central axis of the rotary shaft 32 is defined as the index position of 0 °. As is apparent from FIG. 4, the end face cam 58
Is fixed to the rotary shaft 32 so that the symmetry axis of the recess 58a passing through the angular position of 0 ° passes through the central axis of the main shaft 22.

When the ball 36b provided at the tip of the plunger 36 is engaged with the flat portion of the end cam 58, the plunger 36 is held at a position closest to the spindle head 16. At this time, the grip 34 is attached to the rack gear 36a.
And the pinion gear 34a are engaged with each other to be held at the grip standby position. The ball 36b of the plunger 36 is at the center of the recess 58a, that is, the plunger 36 is at an angular position of 0 °
When it is in the indexing position of the
It is held at a position away from 6. At this time, the grip 34 is held at the grip tool exchange position by the engagement of the rack gear 36a and the pinion gear 34a. In the present embodiment, ten tools are held on the circumference of the tool magazine 20, so that they are connected to the flat portion at + 36 ° or −36 °.

The operation of the automatic tool changer according to this embodiment will be described below. While the CNC drill 10 is performing the cutting process, the grip 34a is the cover 20a of the tool magazine 20.
It is in the standby position that protrudes downward from. When the predetermined cutting process is completed and the control unit of the automatic tool changer generates a tool change command, the spindle 22 executes the orientation for positioning the drive key.
At the same time, the spindle head 16 moves upward. When the spindle head 16 moves upward, the roller 34b of the grip 34 moves
Relatively moves along the Z-axis cam 60 on the side surface of the. When the roller 34b moves from the flat portion of the Z-axis cam 60 to the curved portion, the grip 34 swings toward the tip portion of the main shaft 22, that is, toward the tool exchange position. When the grip 34 engages with the tool holder 24a attached to the tip of the main shaft 22 and starts the gripping operation of the tool holder 24a, the tool clamping device of the main shaft starts the unclamping operation of the tool holder 24a.

The curved portion 60a of the Z-axis cam 60 and the roller 3
When the grip 34 starts to swing to the tool exchange position due to the engagement with the gear 4a, the plunger 36 moves to the rack gear 3
6a and the pinion gear 34a are engaged with each other to form the recess 58a.
And moves toward the bottom of the recess 58a along the axis of symmetry. The ball 36b at the tip of the plunger 36 has a recess 58a.
When the bottom surface of the plunger is contacted, the translational movement of the plunger 36 stops, and the grip 34 stops at the tool exchange position. At this time, the gripping operation of the tool holder 24a by the grip 34 is completed. At the same time when the gripping operation by the grip 34 is completed, the unclamping operation of the spindle 22 is completed. From this point onward, when the spindle head 16 moves further upward, the spindle 22
The tool holder 24a is separated from the tip of the tool holder.

Immediately after this, the block 44 engages the roller 40a of the lever 40. This causes the lever 40 to rotate in the counterclockwise direction about the pin 38b.
This rotational movement is converted into an approaching movement of the piston 42 to the spindle head 16 via the link 40b. When the piston 42 moves toward the spindle head 16, the roller 36d provided at the end of the plunger 36 at the indexing position (0 °).
Engage with. As a result, the plunger 36 approaches the spindle head 16. The operation of this plunger 36 is performed by the rack gear 36.
The swing motion of the grip 34 is converted via a and the pinion gear 34a, and the grip 34 starts the separating operation from the tool exchange position to the tool storage position (P1 in FIG. 6).
At this time, the roller 34b of the grip 34 is moved by the Z-axis cam 6
Move away from zero.

When the tool holder 24a is removed from the taper hole at the tip of the main shaft 22, the tool magazine indexing motor 5
6 starts rotating. (PP1 in FIG. 6) Indexing motor 56
Rotation of the rotation support member 38 via the bevel gears 54, 53, the worm shaft 52, and the worm gear 50.
Is transmitted to A desired tool is selected by the rotation operation of the rotation support member 38. That is, the grip 34 holding the desired tool 26 is indexed to the above-described indexing position (0 °). During the indexing operation of the tool magazine, the plunger that engages with the grip that holds the tool holder removed from the spindle 22 moves from the index position 0 ° to the angular position + 36 °.
Or it moves relatively toward −36 °. At this time, the engagement between the ball 36b and the end surface cam 58 causes the plunger 36 to perform a translational motion away from the spindle head 16 while performing a rotational motion about the central axis of the rotary shaft 32. Thus, the plunger 36 continues the backward swinging motion of the grip 34 by the piston 42 (P2 in FIG. 6).
In order to smoothly perform the transition from the swinging movement of the grip 34 due to the upward movement of the spindle head 16 to the indexing movement of the tool magazine 20, that is, the swinging movement of the grip 34 due to the rotation of the rotation support member 38, The control of the upward movement of the spindle head 16 and the indexing movement of the tool magazine 20 is adjusted.

After this, the upward movement of the spindle head 16 is stopped (PP2 in FIG. 6), and the spindle head 16 is held in its vertical position. This also holds the piston 42 in the corresponding position. Further, the rotation support member 32 rotates to rotate the main shaft 2
The grip 34 for gripping the tool and the tool holder removed from 2 is moved to the tool storage position (P3 in FIG. 6). At this time, the ball 34a of the plunger 34 moves from the index position 0 ° to the angular position of + 36 ° or −36 °, and holds the plunger 34 at the position closest to the spindle head 16.

When the rotation support member 32 further rotates, the grip adjacent to the grip that has been swung back to the tool holding position approaches the indexing position 0 °. Plunger 3 at this time
The engagement of the ball 36b of No. 6 with the recess 58a of the end cam 58 causes the plunger 36 to start a translational movement away from the spindle head 16 (P4 in FIG. 6). This translational movement is converted into a swinging movement of the grip 34 toward the tool exchange position via the rack 36a and the pinion 34a.

While the plunger 36 continues to translate,
The engaging portion 42a of the piston 42, which is pulled out during the upward movement of the spindle head 16 described above, engages with the roller 36d of the plunger 36. When the grip 34 does not grip the tool used in the next machining process, the spindle head 16 does not move downward and the piston 42 is held in the above position. Therefore, the plunger 36 is the roller 36d.
The engagement of the engagement portion 42a with the engagement portion 42a prevents further translational movement. The rotation support member 32 continues to rotate without stopping. Therefore, the ball 36b of the plunger 36
Does not engage the deepest bottom of the recess 50a, but engages the opposite slope of the recess 58a to move the plunger 36 in the opposite direction. Therefore, the grip 34 swings again toward the tool holding position.

The above process is repeated until the grip 34 holding the desired tool approaches the recess 58a.
After the grip 34 for gripping the desired tool starts approaching the recess 58a (P4 in FIG. 6), that is, after passing through the angular position + 36 ° or −36 ° position in FIG.
6 starts moving downward (PP2 in Fig. 6). When the spindle head 16 moves downward, the lever 40 rotates in the clockwise direction around the pin 38b and moves the piston 42 in the direction away from the spindle head 16. Then, the roller 36d engages with the engaging portion 42a of the piston 42 (P5 in FIG. 6). As a result, the swing motion of the grip 34 to the tool replacement position by the indexing motion of the tool magazine 20 is succeeded by the swing motion by the translational motion of the piston 42. After that, the indexing motor 56 is stopped and the indexing operation of the tool magazine 20 ends (PP4 in FIG. 6).

When the spindle head 16 moves further downward, the lever 40
Continues the clockwise rotation to swing the grip 34 toward the tool exchange position. When the ball 34b of the plunger 36 reaches the bottom of the recess 58a (P6 in FIG. 6), the grip 34 is in the tool exchange position just below the main shaft 22. At this time, the taper portion of the tool holder gripped by the grip 34 is fitted into the taper hole of the spindle 22, and the tool clamping device in the spindle 22 engages with the pull stud of the tool holder to clamp the tool holder. .

When the spindle head 16 continues to move downward, the roller 34b of the grip 34 engages with the Z-axis cam 60 and the roller 40a of the lever 40 disengages from the block 44 of the spindle head 16. It When the spindle head 16 continues to move further downward, the grip 34 moves to the Z-axis cam 60 and the grip 3.
4 engages with the roller 34b to move away from the tool replacement position along the curved portion 60a of the Z-axis cam 60. When the roller 34b comes into engagement with the flat portion of the Z-axis cam 60, the grip 34 is locked by the cover 20a of the tool magazine 20.
It is held in the state of protruding from and hanging downwards, completing the tool change process.

As is apparent from the above description, the grip 34 is driven by the plunger 36. More specifically, the Z-axis cam 60 and the roller 34b are engaged to swing between the tool replacement position and the standby position, and the end surface cam 58 and the ball 36b of the plunger 36 are engaged to move to the storage position and the standby position. It is configured to rock between positions. Further, the engaging portion 42a of the piston 42 and the plunger 3
The engagement of the roller 6 with the roller 36d prevents the unselected grip 34 from moving beyond the standby position to the tool changing position. Further, by the piston 42, the lever 40, the link member 40b, and the block 44, the rocking motion of the grip 34 in association with the motion of the spindle head 16 causes the engagement between the ball 36b and the end face cam 58 near the standby position. From the combined drive to the engagement of the roller 34b and the Z-axis 60 is continuously connected.

The present invention can be implemented with the following features. a. The grip is swingably provided between the storage position and the tool exchange position, passing through a standby position protruding downward from the tool magazine, and the grip driving means is A first swinging grip between the storage position and the standby position
2. The driving means of claim 1, and a second driving means for swinging between the standby position and the tool changing position.
The automatic tool changer described in. b. The automatic tool changer according to the feature (a), further comprising a restriction unit that restricts swing of an unselected grip beyond the standby position toward the tool change position. apparatus. c. The automatic tool changer includes a third driving unit that smoothly connects the swinging motion of the grip by the first driving unit and the swinging motion of the grip by the second driving unit. The automatic tool changer described in.

[0032]

According to the automatic tool changer of the present invention, unlike the conventional automatic tool changer, the drive mechanism is simplified because only the lightweight grip is rocked without rocking the entire tool magazine having a large mass. At the same time, it is possible to speed up the tool changing operation.

In the conventional automatic tool changer, the tool holders housed in the tool magazine and the tools mounted on the tool holders are arranged conically or radially around the circumference of the tool magazine. The rotation moment of the tool magazine including the tool becomes large, which prevents the tool magazine from speeding up the rotation operation for indexing the tool. On the other hand, in the automatic tool changer of the present invention, since the tools in the tool magazine are arranged substantially parallel to the rotation axis of the tool magazine, the tool magazine can be formed into a substantially columnar shape. Therefore, it is possible to reduce the rotation moment of the tool magazine itself as compared with the conical or radial tool magazine of the related art, and it is easy to speed up the indexing operation of the tool magazine.

Further, in the conventional automatic tool changer, the tools are arranged conically or radially around the circumference of the tool magazine, so that the tool magazine occupies a very large space. On the other hand, in the automatic tool changer of the present invention, the tools in the tool magazine are arranged substantially parallel to the rotation axis of the tool magazine, so that the tool magazine can be made compact.

Further, in the conventional automatic tool changer, since the tool magazine is arranged in the front part of the machine tool such as the CNC drill, the above-mentioned tool magazine occupies a large space and the spindle is Although there is a problem that the accessibility of the worker to the lower part is poor, since the tool magazine is fixed to the side part of the machine tool in the automatic tool changing device of the present invention,
An operator can easily access the space below the spindle. Further, since no tool is arranged near the worker who approaches the space below the main spindle, especially above the head, the safety of the worker can be ensured.

Furthermore, in the conventional automatic tool changer, the indexing operation of the tool magazine cannot be started until the spindle gear and the tool magazine gear are completely engaged, which causes a problem of a long tool change time. is there. On the other hand, in the automatic tool changer of the present invention, since the tool magazine can execute the indexing operation without engaging with the spindle, the tool can be indexed simultaneously with the vertical movement of the spindle head. Therefore, the tool change time is shortened. Further, since the spindle is not related to the indexing operation of the tool magazine, it is not necessary to execute the orientation of the spindle again when mounting a new tool on the spindle. Therefore, it becomes possible to shorten the tool exchange time.

[Brief description of drawings]

FIG. 1 is an elevational view of a preferred embodiment of the automatic tool changer of the present invention shown in partial cross section.

2 is a side view of the automatic tool changer of FIG. 1. FIG.

3 is a plan view of the automatic tool changer of FIG. 1. FIG.

FIG. 4 is a partial bottom view of the automatic tool changer of FIG. 1 as seen from below.

5 is an enlarged view of the automatic tool changer of FIG.

6 is a diagram illustrating a tool changing process of the automatic tool changing apparatus of FIG. 1. FIG.

[Explanation of symbols]

 10 ... CNC drill 16 ... Spindle head 20 ... Tool magazine 22 ... Spindle 24 ... Tool holder 26 ... Tool 34 ... Grip 36 ... Plunger 58 ... End face cam 38 ... Rotation support member 60 ... Z-axis cam

Claims (1)

[Claims] 1. A spindle head provided so as to be capable of reciprocating along a predetermined axis, and a spindle for rotatably supported by the spindle head around the axis and holding a tool at a tip end thereof via a tool holder. In an automatic tool changer for a machine tool including: a tool magazine, which is rotatably supported around an axis substantially perpendicular to the axis of rotation of the spindle, and stores a tool on its circumference; and a grip for holding the tool. And is attached to the tool magazine so as to be swingable between a tool exchange position immediately below the spindle and a storage position in which the tool is arranged and stored on the circumference of the magazine in the tool magazine. The grip and the grip arranged at the indexing position by the indexing operation of the tool magazine are swayed toward and away from the tip of the spindle in conjunction with the indexing operation of the tool magazine and the linear movement of the spindle head. An automatic tool changer comprising a driving means for performing an operation.