JPH11188506A - Multi-task machine tools - Google Patents

Abstract

(57) [Problem] To provide a multi-tasking machine tool capable of reducing the cost by performing machining using the same tool with the same tool even if the process is different, eliminating the need to prepare a tool for each process. provide. A first indexing mechanism for a tool spindle is provided.
A first fixed side coupling 23 fixed to the tool headstock 12, a first rotation side coupling 24 fixed to the tool spindle 14, and the first headset 12 provided on the tool headstock 12 side. A first coupling coupling 25 capable of meshing with both the fixed-side and rotation-side couplings 23 and 24 is provided, and a second indexing mechanism 130 for the tool headstock 12 is provided.
To the second fixed-side coupling 1 fixed to the tool rest 10.
23, a second rotation-side coupling 124 fixed to the tool headstock 12, and a second coupling cup provided on the tool rest 10 and capable of meshing with the second fixed-side and rotation-side couplings 123, 124. A ring 125 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool rest which is provided with a tool spindle so as to be capable of rotating index positioning, a tool spindle is provided on the tool spindle so as to be indexable for rotation, and a spindle is provided with two spindles.
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-tasking machine tool provided with a set and capable of performing turning on both sides of a work.

[0002]

2. Description of the Related Art Conventionally, there is an NC lathe 53 shown in FIG. 9 as a multi-tasking machine tool having one tool post and two spindles and capable of performing turning on the front and back of a work.

In the conventional NC lathe 53, two tools 54 and 55 are attached to one tool post 50, and two spindles 5
1, 52 are provided so as to face each other on the Z axis. In the NC lathe 53, first, the work W is rotated by the left main shaft 51 to perform the first step of turning with the left tool 54, and when the machining is completed, the work W
Is gripped by the right main shaft 52, and the turning process in the second step is performed by the right tool 55.

[0004]

However, in the conventional multi-task machine tool described above, even if the tools used in the first and second steps are the same, it is necessary to prepare different tools for each step. Therefore, there is a problem that a large number of tools are required and the cost is high.

The present invention has been made in view of the above-mentioned conventional problems, and machining using the same tool is performed with the same tool even if the process is different, so that it is not necessary to prepare a tool for each process. It is an object of the present invention to provide a multi-tasking machine tool capable of reducing the number of times.

[0006]

According to the first aspect of the present invention, FIG.
As shown in FIG. 2, a tool headstock 12 is arranged on the tool rest 10 in the X-axis direction, and a tool spindle 14 is provided on the tool headstock 12 so as to be indexable around the X axis and can be positioned. 4 are provided so as to face each other on the Z axis, and a turning tool T is mounted on the tool spindle 14, and the tool spindle 14 is
Is fixed to the tool headstock 12 and the workpiece W is rotated by the spindles 3 and 4 to perform turning on the front and back of the workpiece W.
As shown in FIG. 3, a first indexing mechanism 30 for indexing and positioning the tool spindle 14 is connected to a first fixed side coupling 2 having a large number of meshing teeth 23a on the tool spindle base 12.
3 and a first rotating side coupling 24 having a large number of meshing teeth 24a on the tool spindle 14 is coaxial with the first fixed side coupling 23, and both couplings 2
3 and 24 are fixed so that the meshing teeth 23a and 24a are on the same plane, and a large number of meshing teeth 25a are provided on the tool headstock 12 side.
The first coupling coupling 25 having the first fixed side,
The coupling teeth 25a of the first coupling 25 are provided so as to advance and retreat toward the rotation-side couplings 23 and 24.
The tool spindle 14 is fixed to the tool headstock 12 by engaging or disengaging both the meshing teeth 23a, 24a of the fixed-side and rotation-side couplings 23, 24, or the fixing is released. It is characterized in that the tool spindle 14 is rotated by 180 degrees around the X axis when machining the work of the one spindle 4 and when machining the work of the other spindle 3.

According to a second aspect of the present invention, as shown in FIGS. 5 to 7, a tool headstock 12 is provided on a tool rest 10 so as to be indexable around a Y axis in an XZ axis plane.
The tool spindle 14 is provided around the tool spindle so as to be indexable and positionable, and two sets of spindles 3 and 4 for rotationally driving the work W are provided so as to face each other on the Z-axis, and a turning tool T is mounted on the tool spindle 14. The tool spindle 14 is fixed to the tool spindle 12, and the tool spindle 12 is fixed to the tool rest 10. As shown in FIG. 3, in the multi-tasking machine tool 1 which performs turning on the tool spindle 14, a first indexing mechanism 30 for indexing and positioning the tool spindle 14 is attached to the tool spindle base 12 by a large number of meshing teeth 23a.
The first fixed-side coupling 23 having a plurality of meshing teeth 24a is fixed to the tool spindle 14, and the first fixed-side coupling 23 is coaxial with the first fixed-side coupling 23. Meshing teeth 2 of rings 23 and 24
3a, 24a are fixed so as to form the same plane, and the first coupling coupling 25 having a large number of meshing teeth 25a on the tool headstock 12 side is directed toward the first fixed side, rotation side couplings 23, 24. The tool spindle 14 is provided so as to be able to advance and retreat, and by engaging or disengaging the engagement teeth 25a of the first coupling 25 with the engagement teeth 23a, 24a of both the first fixed side and the rotation side couplings 23, 24. A second tool for fixing or releasing the fixation to the tool headstock 12 and indexing and positioning the tool headstock 12
As shown in FIG. 4, the indexing mechanism 130 has a second fixed side coupling 123 having a large number of meshing teeth 123a fixed to the tool rest 10 and a second fixed coupling 123 having a large number of meshing teeth 124a provided to the tool headstock 12. Rotation side coupling 124
Is coaxial with the second fixed side coupling 123,
And the meshing teeth 123a of both couplings 123, 124,
The second coupling 125 having a large number of meshing teeth 125a on the tool headstock 12 side can move forward and backward toward the second fixed side and the rotation side couplings 123 and 124. And the meshing teeth 125a of the second coupling coupling 125 are connected to the meshing teeth 123 of both the second fixed-side and rotation-side couplings 123 and 124.
When the tool spindle 12 is fixed to the tool rest 10 by releasing or engaging with the tool spindles 12a and 124a, or when the workpiece W is turned, the work W of the one spindle 4 is turned. The tool spindle 14 is opposed to one spindle 4 on the Z axis (see FIG. 5), and the workpiece W of the other spindle 3 is
When turning is performed on the tool spindle, the tool spindle 14 is opposed to the other spindle 3 on the Z axis (see FIG. 6), and is rotated 180 degrees around the tool spindle (see FIG. 7). I have.

[0008]

According to the multi-tasking machine tool according to the first aspect of the present invention, as shown in FIG. 8, when turning the work W to the front (right portion), the tool spindle 14 is moved to the state shown in FIG. The work W is gripped by the left main shaft 4 and the work W is rotated by the main shaft 4. Also,
In turning on the back (left part) of the work W, the work W is gripped by the right main spindle 3 and the tool spindle 14 is rotated by 180 ° around the tool main spindle so as to reverse the tool T, and indexed and positioned. This is performed by turning the work W around the right spindle 3.

Thus, in the multi-tasking machine tool 1 according to the first aspect of the present invention, when the turning in the first step is completed, the tool T
Is rotated around the tool spindle by 180 °, and the second process of turning is performed with the same tool T, so that the same tool can be used for turning on the front and back of the work W, and a separate process is performed for each process. There is no need to prepare tools, so that the total number of tools to be prepared is small and the cost can be reduced.

In the indexing and positioning of the tool spindle 14, a common coupling is engaged with both the fixed coupling provided on the fixed body and the rotary coupling provided on the rotating body. Since the side and rotation side couplings are connected by meshing of a large number of meshing teeth, the clamping strength of the tool spindle 14 can be improved, and the clamping position accuracy in the rotating direction can be greatly improved, resulting in improved machining accuracy. effective.

According to the multi-tasking machine tool according to the second aspect of the present invention, the turning of the work W to the front (right portion) is performed by gripping the work W with the left main spindle 4 as shown in FIG. The tool headstock 1 is arranged such that the tool spindle 14 faces the spindle 4 on the left side.
This is performed by indexing and positioning 2 and rotating the work W with the main shaft 4. As shown in FIG. 6, the turning of the work W to the back (left portion) is performed by grasping the work W with the right spindle 3 and rotating the tool headstock 12 by 180 ° about the Y axis. 14 is indexed and positioned so as to face the main spindle 3 on the right side, and as shown in FIG.
This is performed by rotating the tool spindle 14 by 180 ° about the tool spindle so as to be indexed and positioned so that the workpiece W is turned upside down in the figure, and the workpiece W is turned by the spindle 3 on the right side.

As described above, in the multi-tasking machine tool 1 according to the second aspect of the present invention, when the turning in the first step is completed, the tool headstock 12 is turned by 180 ° and the tool spindle 14 is moved by one.
Since the turning in the second step is performed with the same tool T by rotating by 80 °, the turning can be performed on the front and back of the work W with the same tool, and it is necessary to prepare a separate tool for each step. Therefore, the total number of tools to be prepared is small, and the cost can be reduced.

Further, the tool headstock 12 and the tool spindle 1
In the indexing positioning of 4, the common coupling is engaged with both the fixed side coupling provided on the fixed body side and the rotation side coupling provided on the rotating body side. The tool headstock 1 is connected by the meshing of a large number of meshing teeth.
2. There is an effect that the clamping strength of the tool spindle 14 can be improved, the clamping position accuracy in the rotating direction can be greatly improved, and as a result, the processing accuracy can be improved.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 7 are views for explaining a composite lathe (composite machining machine tool) according to an embodiment of the first and second aspects of the present invention, and FIGS. 1 and 2 are perspective views of the composite lathe, and FIGS. Is a sectional view of a main part of the lathe, and FIGS. 5 to 7 are schematic views for explaining the operation of the lathe.

In FIG. 1, reference numeral 1 denotes a composite lathe capable of performing both turning and turning of a workpiece W on the front and back sides and a rotary tool. The composite lathe 1 is located on the right side when viewed from the front of the bed 2. A headstock (spindle) 3 for gripping the work is provided so as to be movable in the Z-axis direction (left-right direction), a headstock (spindle) 4 for holding the work is fixedly provided on the left side, and a carriage 5 is provided on the back side. It has a schematic structure movably provided in the axial direction.

The headstocks 3 and 4 are provided with a chuck 6 for gripping a work with a claw 6a.
Is driven to rotate by a built-in spindle motor. A pedestal 9 is mounted movably in the X-axis direction on an inclined surface 5a of the reciprocating platform 5 which is lowered forward. A tool rest 12 provided on the pedestal 9 causes a tool headstock 12 to move in the XZ-axis plane. And is rotatably indexable about the Y axis. In the tool headstock 12, a tool spindle 14 is disposed so as to be rotatable around the Z axis and to be rotatable and indexable.

A tool changer 22 provided with a tool magazine 21 for holding a number of turning tools and rotary tools 20 is provided on the carriage 5. The tool T mounted on 14 is replaced with a required turning tool or rotating tool.

The turning shaft 12a of the tool headstock 12 is supported by the tool post 10 via a bearing 115 so as to be freely rotatable. Between the tool rest 10 and the tool headstock 12,
A second indexing mechanism 130 for indexing and positioning the tool headstock 12 about the Y axis in the XZ axis plane is provided, and the tool headstock 12 is turned by an index motor (not shown).

In FIG. 4 showing the second indexing mechanism 130, a portion on the right side of the turning axis B of the tool headstock 12 shows a clamped (fixed) state, and a portion on the left side shows an unclamped (unfixed) state. The second indexing mechanism 130 is a three-piece coupling type, and includes a second fixed-side coupling 123 fixed to the upper end surface 112a of the tool rest 10 by a bolt 127 so as not to rotate and move in the axial direction. Flange 114 of tool headstock 12
a second rotation-side coupling 124 fixed with bolts 128 to rotate together with the tool headstock 12, and a second coupling coupling opposed to the couplings 124 and 123 and arranged to be movable in the axial direction. 125.

The second fixed side coupling 123, the second
The rotation-side coupling 124 is formed by forming a large number of meshing teeth 123a, 124a radially and at equal angular intervals on the upper surface of an annular plate. The second rotation-side coupling 124 is located inside the second fixed-side coupling 123, the two couplings 123, 124 and the tool headstock 12 are coaxial, and the plurality of meshing teeth 123a, 1 are provided.
The distal end face of 24a forms the same plane.

The second coupling 125 is in the shape of an annular piston.
A meshing tooth 125a that can mesh with the meshing teeth 123a, 124a is formed on a surface facing the gear 124. This second coupling 125 is connected to a cylinder member 126.
Is inserted into the sliding groove 126a so as to be able to advance and retreat, and is urged in a retreating direction (fixing releasing direction) by an urging spring 126c.

When hydraulic oil is supplied into the oil chamber 126b formed by the coupling coupling 125 and the sliding groove 126a, the coupling coupling 125 moves downward in the figure to move its meshing tooth 125a to the second fixed side. The meshing teeth 123a and 124a of the rotation-side couplings 123 and 124 are meshed with each other.
The fixed-side and rotary-side couplings 123 and 124 are positioned with high precision in the rotational direction, and are firmly connected. In addition, the lower end surface of the outer peripheral edge of the cylinder member 126 is the second end.
It is superimposed on the fixed side coupling 123 and the bolt 12
7, it is fastened and fixed to the tool rest 10 together. Reference numeral 128a denotes a labyrinth groove for sealing between the tool headstock 12 and the tool rest 10.

The tool spindle 14 is used for the tool headstock 1.
2 rotatably supported via a bearing 15.
A first indexing mechanism 30 for indexing and rotating the tool spindle 14 around the tool spindle is provided between the tool spindle head 12 and the tool spindle 14.
4 is rotationally driven by a drive motor (not shown).

In FIG. 3 showing the first indexing mechanism 30, a portion above the rotation axis A of the tool spindle 14 shows a clamped state, and a lower portion shows an unclamped state. The first indexing mechanism 30 is of a three-piece coupling type, and has a tip end surface 1 of the tool headstock 12.
A first fixed side coupling 23 fixed to the 2a by a bolt 27 so as not to be rotatable and axially movable;
The first rotation-side coupling 24 fixed to the flange portion 14 a of the fourth member 14 with bolts 28 and rotated together with the tool spindle 14.
And a first coupling coupling 25 which is opposed to the couplings 24 and 23 and is arranged to be movable in the axial direction.

The first fixed side coupling 23 and the first rotating side coupling 24 are formed by forming a large number of meshing teeth 23a, 24a radially and at equal angular intervals on the front surface of an annular plate. is there. First rotation side coupling 24
Is located in the first fixed side coupling 23, the couplings 23 and 24 and the tool spindle 14 are coaxial,
The tip surfaces of the plurality of meshing teeth 23a and 24a are flush with each other.

The first coupling 25 is in the form of an annular piston.
And a meshing tooth 25a that can mesh with the meshing teeth 23a and 24a. The first coupling 25 is inserted into the sliding groove 26a of the cylinder member 26 so as to be able to advance and retreat, and is urged in a retreating direction by an urging spring 26c.

When hydraulic oil is supplied into an oil chamber 26b formed by the coupling coupling 25 and a sliding groove 26a, the coupling coupling 25 moves rightward in the drawing to move its meshing tooth 25a to the first position.
Meshing teeth 23 of fixed side and rotating side couplings 23, 24
a, 24a, whereby the first fixed-side and rotary-side couplings 23, 24 are positioned with high precision in the rotational direction and are firmly connected. The cylinder member 26
The right end face of the outer peripheral edge is the first fixed side coupling 2
3 and are fixedly fastened to the headstock 12 by bolts 27.

A seal ring 31 is fixed to the front end face of the tool spindle 14 together with the tool holder receiving portion 32 by bolts 29. A labyrinth groove 28a for sealing is formed between the seal ring 31 and the cylinder 26.

Next, the operation and effect of the combined lathe 1 of the present embodiment will be described. The following description relates to the inner diameter processing.

When turning is performed on the front (right portion) of the work W, as shown in FIG. 5, the work W is gripped by the chuck 6 of the spindle 4 on the left side, and the turning tool T is mounted on the tool spindle 14. At the same time, the tool headstock 12 is opposed to the spindle 4 on the left side.

In this state, in the second indexing mechanism 130, an oil chamber 126b formed by the sliding groove 126a of the cylinder member 126 and the end face of the second coupling 125 is formed.
And the oil supply passage is opened, the second coupling 125 moves downward in the drawing, and the meshing teeth 125a of the second coupling 125 rotate to the second fixed side and rotate. Side coupling 123,1
The tool head 12 is non-rotatably fixed to the tool rest 10 by engaging with both of the 24 meshing teeth 123a and 124a.

Further, in the first indexing mechanism 30, the return passage of the hydraulic oil communicating with the oil chamber 26b formed by the sliding groove 26a of the cylinder member 26 and the end face of the first coupling 25 is closed as described above. And the oil supply passage is opened, so that the first coupling 25 is moved rightward in the figure, and the meshing teeth 25a of the first coupling 25 are changed to the meshing teeth of the first fixed-side and rotation-side couplings 23, 24. 23
a, 24a, and thereby the tool spindle 14
Is non-rotatably fixed to the tool headstock 12.

With the tool spindle 12 and the tool spindle 14 fixed, the carriage 5 is moved in the Z-axis direction while the work W is being rotated by the headstock 4, and the tool rest 10 is moved in the X-axis direction. Turning is performed on the work W.

When the rotary tool is to be machined, a rotary tool is mounted on the tool spindle 14 and the tool spindle 14 is released while the tool headstock 12 is fixed. In this case, in the first indexing mechanism 30, the supply passage of the hydraulic oil communicating with the oil chamber 26b is closed and the return passage is opened, and the first coupling 25 is moved leftward in the figure by the urging force of the spring 26c. The first coupling 25 is disengaged from the first fixed coupling 25 and the first coupling coupling 25 is disengaged from the first coupling coupling 25 and the rotational couplings 23 and 24. As a result, the tool spindle 14 becomes the tool headstock 1
2 is freely rotatable.

The tool headstock 12 is fixed, and the tool spindle 1
In a state where the fixing of the spindle 4 is released and the rotation of the headstock 4 is stopped, the tool rest 10 is moved in the X-axis direction while the tool spindle 14 is rotationally driven by the drive motor, and the carriage 5 is moved in the Z-axis direction. By doing so, the rotary tool processing is performed on the workpiece W.

When performing turning on the back (left part) of the work W, as shown in FIG. 6, the work W is gripped by the chuck 6 of the right headstock 3 and the tool headstock 12 is moved. Y
The tool head 12 is fixed to the tool rest 10 by the second indexing mechanism 130 by rotating the tool head 180 around the axis by 180 ° to face the right head stock 3. Then, as shown in FIG. 7, the tool spindle 14 is rotated by 180 ° around the tool spindle so that the tool T is turned upside down in the figure, and in this state, the tool spindle 14 is moved to the tool spindle base 12 by the first indexing mechanism 30. Then, the back surface of the work W is turned.

As described above, in the present embodiment, when the turning of the workpiece of the left headstock 4 is completed, the tool headstock 12 is rotated by 180 degrees so that the tool T faces the right headstock 3, and is positioned. Further, since the tool spindle 14 is rotated by 180 ° and positioned so that the cutting edge of the tool T is at the proper position, the front and back surfaces of the work W can be subjected to turning by the same tool T. Does not require another tool, the number of tools to be prepared is small, and the cost can be reduced.

In the present embodiment, the indexing and positioning of the tool headstock 12 includes the second fixed side coupling 123 provided on the fixed body (tool post) and the second fixed coupling 123 provided on the rotating body (tool headstock). Since the common second coupling 125 is engaged with both of the rotation-side couplings 124, the indexing and positioning of the tool spindle 14 is performed by the first fixed-side cup provided on the fixed body (tool headstock) side. The common first coupling 25 is engaged with both the ring 23 and the first rotary coupling 24 provided on the rotating body (tool spindle) side. Since the ring is connected by meshing of a large number of meshing teeth, the tool headstock 12 and the tool spindle 1
4, the clamp strength can be improved, and the clamp position accuracy in the rotation direction can be greatly improved. As a result, the processing accuracy can be improved.

Here, in the above-described embodiment, the case where the inner diameter machining of the work W is performed has been described. However, in the above-described lathe 1, the outer diameter machining of the work W can be performed. When performing external machining, as shown in FIG. 8, the tool headstock 12 is indexed and positioned in the X-axis direction by the second indexing mechanism 130, and the tool spindle 14 is indexed by the first indexing mechanism 30 to the state shown in FIG. The workpiece W held by the left main spindle 4 is processed in the first step in this state. Subsequently, the workpiece W is gripped by the right spindle 3, and the tool spindle 14 is rotated by 180 ° by the first indexing mechanism 30 so that the tool T is turned left and right, and is indexed and positioned. Should be performed.

In the case of the outer diameter machining, similarly to the above, the cost can be reduced by eliminating the necessity of another tool for each process, and the machining accuracy can be improved.

In the above embodiment, the case where both the first and second indexing mechanisms 30 and 130 are provided has been described.
Need not necessarily be provided, and the tool headstock 12 may be fixed in the state shown in FIG.

[Brief description of the drawings]

FIG. 1 is a perspective view of a case where a work on a left spindle of a combined lathe according to an embodiment of the present invention is processed.

FIG. 2 is a perspective view showing an indexing operation of a tool headstock of the combined lathe.

FIG. 3 is a sectional view of a first indexing mechanism portion of the composite lathe.

FIG. 4 is a sectional view of a second indexing mechanism portion of the composite lathe.

FIG. 5 is a schematic diagram for explaining the operation of the composite lathe.

FIG. 6 is a schematic diagram for explaining the operation of the composite lathe.

FIG. 7 is a schematic diagram for explaining the operation of the composite lathe.

FIG. 8 is a schematic diagram for explaining the operation of the composite lathe.

FIG. 9 is a schematic diagram for explaining a problem of a conventional combined lathe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Combined lathe (compound machine tool) 3, 4 Spindle 10 Turret 12 Tool spindle stand 14 Tool spindle 23 First fixed side coupling 23a Mesh teeth 24 First rotation side coupling 24a Mesh teeth 25 First coupling 25a Meshing teeth 30 first indexing and positioning mechanism 123 second fixed side coupling 123a meshing teeth 124 second rotating side coupling 124a meshing teeth 125 second coupling coupling 125a meshing teeth 130 second indexing and positioning mechanism T turning tool W work

Claims (2)

[Claims] 1. A tool spindle is arranged on a tool rest in the X-axis direction, a tool spindle is provided on the tool spindle so as to be indexable around the X-axis, and a spindle for rotating a workpiece is opposed on a Z-axis. In this way, two sets are provided so that a turning tool is mounted on the tool spindle, the tool spindle is fixed to the tool spindle head, and the workpiece is turned on the front and back by rotating the work with the spindle. In the combined machining machine tool, a first indexing mechanism for indexing and positioning the tool spindle is fixed to a first fixed side coupling having a large number of meshing teeth on the tool spindle base, and a large number of meshing teeth are fixed to the tool spindle. A first rotating side coupling having the same configuration as the first fixed side coupling, and fixing such that the meshing teeth of both couplings are on the same plane, and providing a large number of meshing teeth on the tool headstock side. Have A first coupling is provided so as to be able to advance and retreat toward the first fixed side and the rotation side coupling, and the meshing teeth of the first coupling coupling are meshed with both the meshing teeth of the first fixed side and the rotation side coupling. Or the tool spindle is fixed to the tool spindle base by releasing or releasing the tool spindle, and the tool spindle is processed at the time of machining the work of the one spindle and the work of the work of the other spindle. A multi-tasking machine tool characterized in that is rotated 180 degrees around the X axis. 2. A tool spindle is mounted on a tool rest in a Y-axis direction in an XZ-axis plane.
The tool spindle is provided so as to be indexable around the axis, the tool spindle is provided so as to be indexable around the tool spindle, and two sets of spindles for driving and rotating the work are provided so as to face each other on the Z axis. A turning tool is mounted on the tool spindle, the tool spindle is fixed to the tool spindle, the tool spindle is fixed to the tool rest, and the workpiece is rotated by the spindle so that the front and back of the workpiece are turned. A first indexing mechanism for indexing and positioning the tool spindle, a first fixed side coupling having a large number of meshing teeth fixed to the tool spindle base, and a plurality of indexing mechanisms fixed to the tool spindle. The first rotating side coupling having the meshing teeth is fixed so that the first rotating side coupling is coaxial with the first fixed side coupling and the meshing teeth of both couplings are on the same plane. A first coupling having a plurality of meshing teeth is provided on the tool headstock side so as to be able to advance and retreat toward the first fixed side and the rotation side coupling, and the meshing teeth of the first coupling coupling are arranged on the first fixed side and the first fixed side. The tool spindle is fixed to or released from the tool spindle by engaging or disengaging both meshing teeth of the rotation-side coupling, and the second indexing for indexing and positioning the tool spindle is described. The mechanism fixes a second fixed-side coupling having a large number of meshing teeth to the tool post, and a second rotation-side coupling having a large number of meshing teeth to the tool headstock, and the second fixed-side coupling. The second coupling coupling, which is coaxial and has a plurality of meshing teeth on the tool headstock side, is fixed to the second fixed side and the rotation side coupling. The tool headstock is fixed to the tool rest by engaging or disengaging the meshing teeth of the second coupling coupling with the meshing teeth of both the second fixed side and the rotating side coupling, Or, when the turning is performed on the work of one of the main spindles, the tool main spindle is opposed to one of the main spindles on the Z axis, and the turning of the work on the other main spindle is performed. A multi-tasking machine tool characterized in that the tool spindle is opposed to the other spindle on the Z axis and is rotated by 180 degrees around the tool spindle.