JPH0276601A - Structure of headstock of machine tool - Google Patents

Abstract

PURPOSE:To improve processing precision of a work by limiting a main heating source to only a head where a tool main shaft is set up, decreasing an amount of thermal deformation of a headstock having the head, and making the direction of its deformation simple. CONSTITUTION:A head drive means such as a head turning device 10 is installed on a body 9 and a head 17 is rotatably set up through the head drive means. A tool main shaft 23 is rotatably set up on the head 17 and also a main shaft drive motor 26, etc., are installed to drive the tool main shaft 23 in rotation. Thus it is possible to limit a heating source of the drive motor, etc., to the head 17, to decrease an amount of thermal deformation of the whole headstock 7, and to make the direction of its deformation simple. As the result, it becomes easy to make correction according to thermal deformation resulting in possibility to precisely process a work 30.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention limits the main heat source to only the head provided with the tool spindle, and prevents thermal deformation of the entire headstock including the head. Assuming that the deformation direction is small and the deformation direction is simple,
This invention relates to a headstock structure for a machine tool that can improve the machining accuracy of a workpiece.

(b), Prior Art FIG. 5 is a front view showing how a conventional machine tool undergoes thermal displacement during processing of a workpiece.

FIG. 6 is a left side view of FIG. 5.

Conventionally, the headstock of a machine tool, for example, as shown in Fig. 5,
A headstock 4 that can rotate the head 41 by 180° in the directions of arrows E and F to make the axis CT 4 of the tool spindle 42 horizontal and vertical.
3, a motor 4 for rotationally driving the main shaft 42;
6 was not installed on the head 41 side, but on the main body 45 side of the headstock 43 that drives the head 41 in rotation.

The power is transmitted from the motor 46 to the tool main shaft 42 through a number of transmission shafts 49 equipped with gears such as a bevel gear 47.
This is done via a power transmission mechanism 51 consisting of a bearing 50 and the like that supports the shaft 49.

(C) 0 Problems to be Solved by the Invention However, in this case, the motor 46. It has many heat generating sources such as a large number of gears and bearings 50, and these heat generating sources generate heat when processing a workpiece. Then, during machining, the main body 45 and head 41 of the headstock 43 are thermally deformed, and the peripheral parts of the headstock 43, for example, the sixth
The column 52 shown in the figure is connected to the center CT of the column 52 via a ball screw 53 etc. screwed into the main body 45 of the headstock 43.
2, the part on the right side in the figure is pressed and thermally deformed. As a result, during workpiece machining, the headstock 43 of the machine tool 40 undergoes complex thermal displacement as shown in the imaginary lines in FIGS. 5 and 6, and it is difficult to make corrections according to the displacement. .

In view of the circumstances described above, the present invention has been devised to reduce the amount of thermal deformation of the headstock and to simplify the direction of the deformation by limiting the heat generation source to the head having the tool spindle. The purpose is to provide a platform structure.

(d) Means for determining zero problems The present invention has a main body (9), the main body (9) is provided with a head driving means (10), and the main body (9) is provided with:
A head (17) is rotatably provided via the head driving means (10), and a tool spindle (
23) is rotatably provided, and the tool main shaft (23)
A drive motor (26) is provided to rotationally drive the.

Note that a heat insulating member (21, 22) may be provided between the head driving means (10) and the head (17).

Note that the numbers in parentheses are for convenience and indicate corresponding elements in the drawings, and therefore, this description is not limited to the descriptions on the drawings. r (e) below
The same applies to the column ``, action''.

(e) 0 effect With the above-described configuration, the present invention provides a head driving means (10
), the head (17) moves to the main body (9).
The drive motor (26) of the head (17)
By driving the tool spindle (23), the tool spindle (23) is rotated.

(f), Example Hereinafter, the present invention will be described in detail based on the drawings.

FIG. 1 is a front view showing an example of a machine tool to which an embodiment of the machine tool headstock structure according to the present invention is applied, and FIG. 2 is a left side view of FIG. 1.

FIG. 3 is a sectional view showing the main parts of the headstock shown in FIG. 1.

FIG. 4 is a diagram showing the main parts of a machine tool headstock to which another embodiment of the machine tool headstock structure according to the present invention is applied.

A machine tool 1 such as a machining center has a bed 2, as shown in FIG. ) and in the direction perpendicular to the plane of the paper in the figure, that is, in the direction @arrow J in figure 2 (X-axis direction). At the center of the column 3 shown in FIG.
As shown in FIG. (center of 3) is provided in a form that coincides with CT2.

Further, in the headstock movement space 5 of the column 3, as shown in FIG. 1, the headstock 7 has its main body 9 threadedly engaged with the vertical feed screw 6, and the headstock 7 is provided with arrows C in the vertical direction in FIG. It is provided so as to be freely movable and driven in the D direction (namely, the Z-axis direction), and a support portion is formed at the right end of the main body 9 in the figure. The support section is provided with a head turning device 10 for turning and driving a head 17, which will be described later. Head rotation device 1
0, as shown in FIG. 3, the engaging body 11 and the moving mechanism 1
5, etc., and the engaging body 11 has an engaging shaft 12 . gear 1
3 and a connecting cylinder 16B.

That is, a support portion 11A is formed at the right end of the main body 9 shown in FIG. 3, and a cylindrical engagement hole lid is formed through the support portion 11A. In the engagement hole lid, an engagement shaft 12 has its axis (hereinafter referred to as a turning center CT3) inclined by a predetermined angle θ with respect to the directions of arrows A and B (Y-axis direction).

The engaging shaft 12 is provided with a through hole 1, which is rotatable in the directions of arrows E and F about the pivot center CT3.
2h is penetrated in the directions of arrows P and Q along the turning center CT3. In addition, at the lower end of the engagement shaft 12 in the figure,
A flange-shaped connecting portion 12A is formed perpendicular to the turning center CT3, and a connecting surface 12f is formed at the lower end of the connecting portion 12A in the drawing. Further, a gear 13 is attached to the upper end of the engagement shaft 12 shown in FIG.
are meshing. Note that the rack 15a includes a drive mechanism 1.
A drive cylinder (not shown) constituting the rack 1
5a is connected in such a way that it can move in a direction perpendicular to the plane of the drawing.

Further, a connecting cylinder 16B is provided between the gear 13 and the connecting portion 12A, and the connecting cylinder 16B includes a cylinder 16c, a piston 16d, and the like. That is,
The cylinder 16c is inserted into the engagement hole lid.
It is perforated in an annular shape along the inner circumference of the cylinder 1.
6c, a piston 16 fixed to the outer periphery of the engagement shaft 12;
d is provided so as to be movable in the directions of arrows P and Q.

Note that the lower end surface 11 of the support portion 11A shown in FIG.
An annular engagement groove 11b is formed in a,
A coupler 16f is fitted into the engagement groove 11b.

By the way, as shown in FIG. 3, the head 17 is attached to the support portion 11A of the headstock 7 through the engagement body 11 of the head rotation device 10 described above, and rotates around the rotation center CT3 in the direction of the arrow E.
, is mounted so as to be able to rotate freely in the F direction, and the head 17
has a casing 19. The casing 19 is made of a material with a low thermal expansion ratio, and a mounting portion 20 is formed at the left end of the casing 19 in the figure. A connection hole 20b is bored in the upper end surface 20a of the attachment part 20 in the figure along the rotation center CT3.
A first connecting surface 20d is formed in an annular shape at the bottom. Note that a second connecting surface 20e formed in an annular shape is formed on the end surface 20a so as to be perpendicular to the turning center CT3.

Further, a coupler 16e is fixed to the second connection surface 20e of the mounting portion 20 shown in FIG. They engage freely. On the other hand, the connection hole 20b
A connecting portion 12A of the engagement shaft 12 is connected to the first heat insulating member 21 via fastening means such as bolts.

Further, as shown in FIG. 3, the casing 19 of the head 17 has a motor housing space 19A formed therein, and the motor housing space 19A includes a tool main shaft 23 and an earth shaft egg movement directly connected to the main shaft 23. A motor 26 and the like are provided. That is, in the motor housing space 19A, the tool spindle 23 is centered around the center CT4 via a plurality of bearings 25.
It is provided in such a way that it can be freely rotated in the direction of arrow G and 11.
A rotor 26a constituting a main shaft drive motor 26 is attached to the tool main shaft 23 so as to surround the main shaft 23. Further, on the inner wall 19b of the casing 19, a stator 26b constituting the main shaft drive motor 26 is attached to the rotor 2.
6a, and the tool spindle 23
A tool holding surface 23a is formed in a tapered shape. Furthermore, a through hole 23b is formed through the tool spindle 23 in the directions of arrows C and D in a manner that connects to the tool holding surface 23a. A drawer (not shown) and the like are provided.

Furthermore, a table 27 is placed on the bed 2 shown in FIG.
It can be freely moved and driven in the direction perpendicular to the plane of the paper in the figure (i.e., in the direction of arrow J in Figure 2), and in the direction of arrow M with center CT5 as the center.
The table 27 is provided in such a manner that it can freely turn in any direction, and a workpiece mounting surface 27a is formed on the upper part of the table 27.

Since the machine tool 1 has one or more configurations, in order to process a workpiece using the machine tool 1, the workpiece 30 to be processed is placed on the workpiece mounting surface of the table 27 as shown in FIG. Install it on 27a. Next, on the tool spindle 23,
A tool 31 (for example, a rotary tool such as an end mill) used for machining is attached so as to be brought into close contact with the tool holding surface 23a shown in FIG. In this state, the table 27 shown in FIG. 1 is placed along with the workpiece 30 in a direction perpendicular to the plane of the paper in the figure.

Drive it to move in the direction of arrow J in Figure 2 (X-axis direction),
Further, index and rotate in the direction of arrow M in FIG. Further, the column 3 is appropriately moved and driven together with the axle base 7 in the directions of arrows A and B (Y-axis direction) and in the directions of arrows C and D (Z-axis direction) to position the tool 31 at a predetermined machining start position.

Next, drive the spindle drive motor 26 to move the tool spindle 23.
It is rotated together with the tool 31 in the direction of arrow G or H in FIG.

In this state, the table 27 is moved in the X-axis direction, and the column 3 and the headstock 7 are moved in the Y-axis and Z-axis directions as appropriate.

The upper surface 30a of the workpiece 3o on the table 27 is cut using the tool 31. At this time, the head 17 connects to the support portion 11A of the headstock 7 via couplers 16e, 16f, etc.
Since it is securely fixed against the arrow E,
There is no turning in the F direction, and the workpiece 30
is processed smoothly.

Next, in order to process the side surface 30b of the workpiece 30 shown in FIG. 1, the head 17 is turned by 90 degrees in the directions of arrows E and F in FIG. There is a need. To do this, first the connecting cylinder 16B
Pressure oil is supplied to the cylinder 16c, and the piston 16d is moved in the direction of arrow P within the cylinder 16c. Then, the engagement shaft 12 moves in the direction of arrow P while being pushed by the piston 16d. Then, the engagement state between the coupler 16e on the head 17 side and the coupler 16f on the headstock 7 side is released, and the head 17 enters a free state in which it can freely rotate in the directions of arrows E and F.

In this manner, when the head 17 is in a free state, the rack 15a of the drive mechanism 15 shown in FIG. and move around the turning center CT3 with arrow E.
, rotate by 180° in the F direction. Then head 1
7 is connected to the position shown in FIG.
180° in the direction of arrows E and F from the position where T4 is vertical)
The tool spindle 23 (therefore, the tool 31) becomes horizontal.

In this way, when the tool 31 becomes horizontal, the piston 16d of the connecting cylinder 16B is moved in the direction of the arrow Q. Then, the head 17 is pushed by the piston L6d via the engagement shaft 12 and the gear 13, and moves in the direction of the arrow Q, and the coupler 16e on the head 17 side is moved against the headstock 7.
It engages with the side coupler 16f. As a result, the head 17 is fixed to the main body 9 side of the headstock 7 via the couplers 16e, 16f, etc.

When the head 17 is fixed in this way, the main shaft moving motor 26 is driven to move the tool main shaft 23.

It is rotated together with the tool 31 in the direction of arrow G or H.

At the same time, the column 3 is moved and driven in the Y-axis and Z-axis directions to create the table 27J shown in FIG.

The side surface 30b of the workpiece 30 is cut into a predetermined shape using the tool 31.

As described above, when the spindle drive motor 26 built into the head 17 is driven to rotate the tool spindle 23 together with the tool 31 and process the workpieces 30 one after another, the movable part of the head 17, i.e. The main shaft drive motor 26, the bear link 25, etc. that rotationally drive the main shaft 23 generate heat. However, since the casing 19 of the head 17 is made of a material with a low coefficient of thermal expansion, even if the heat 32 generated from the motor 26 is transmitted through the inner wall 19b etc. of the casing 19 of the head 17 and the temperature rises,
It does not undergo excessive thermal expansion, and is only displaced by a minute length (hereinafter referred to as thermal displacement amount) ΔY1 in the direction of arrow B (negative direction of the Y-axis) with respect to the main body 9.

On the other hand, between the mounting part 20 of the head 17 and the engagement shaft 12 and between the mounting part 20 and the support part 11A of the headstock 7, first and second heat insulating members are provided, respectively, as shown in FIG. 21.
22, it is difficult for the heat 32 to be transmitted from the head 17 side to the main body 9 side of the headstock 7. Also, if heat 3
2 is transmitted to the main body 9 of the headstock 7 shown in FIG. Press the column 3 outward along CT2. Then column 3
is displaced by a small length ΔZ1 in the direction of arrow C (positive direction of the Z axis) without bending in the directions of arrows C and D, and the front surface 3b of the column 3 is at a small angle Δ with respect to the rear surface 3c.
The head 17 of the headstock 7 is displaced by θ1 in the positive direction of the Z axis, but the amount of displacement is equal to the amount of displacement ΔY described above.
It is smaller than 1 and can be ignored. Moreover, the column 3 does not have a heat source that can generate a large amount of heat, such as the main shaft drive motor 26, and does not expand due to heat other than the heat 32 from the head 17 side.

As a result, during workpiece machining, the total displacement amount Δ゛■゛ of the head 17 (therefore, the tool 31 attached to the tool spindle 23) with respect to the workpiece 30 is the displacement amount in the Y-axis direction due to thermal expansion of the head 17 (i.e., Since it is equal to the minute length ΔYl) and is displaced only in a single direction, it is easy to correct, and since the amount of displacement is minute, the workpiece 30 can be processed with high precision.

In the above embodiment, the navel 1-17 is attached to the rack 15a via the engagement shaft 12 of the head rotation device 10.
A case has been described in which the drive mechanism 15 having the following is used to turn in the directions of arrows E and F. However, the means for turning the head 17 is not limited to this, and it goes without saying that any means can be used as long as the head 17 can be accurately indexed and turned in the directions of the arrows 1ζ and . For example, the head 17 is driven by a drive mechanism 15A shown in FIG.
It is also possible to index and rotate using . The machine tool 1 having the drive mechanism 15A will be described below. Note that the same parts as those explained in FIG. 3 are given the same reference numerals, and the explanation of those parts will be omitted.

That is, the support part IL of the headstock 7 of the machine tool 1 shown in FIG.
At A, the engagement shaft 12 is supported via bearings 36a, 36b, etc. so as to be able to pivot in the directions of arrows E and F about the pivot center CT3, and the engagement shaft 12 is supported by a worm wheel. A drive mechanism 15A consisting of a worm 33, a worm 35, etc. is connected thereto. That is, at the upper end of the engagement shaft 12 in the figure.

A worm wheel 33 is attached to the worm wheel 33, and a worm 35 provided with a rotary door so as to be movable is attached to the worm wheel 33.
are meshing.

Next, a case will be described in which a workpiece is machined using the machine tool 1 described above. Note that, except for the turning operation of the head 17 in the directions of arrows E and F, it is the same as when processing a workpiece using the machine tool 1 described above, so only the turning operation of the head 17 will be described. That is, in order to turn the head 17 shown in FIG. 4 in the directions of arrows E and F, the worm 35 is
drive the rotation. Then, the engagement shaft 12 is driven by the worm 35 via the worm wheel 33 and rotates by a predetermined angle in the directions of arrows E and I-'.

(g) Effects of the 1st Invention As explained above, the present invention has a main body 9, the main body 9 is provided with a head driving means such as a turning device 10, and the main body 9, a head 17 is provided rotatably via the head driving means, and the head 17 is rotatably provided via the head driving means.
7, the tool spindle 23 is rotatably provided and a drive motor such as a spindle drive motor 26 for rotationally driving the tool spindle 23 is provided, so that the heat generation source such as the drive motor can be limited to the head 17. It is possible to reduce the amount of thermal deformation of the entire headstock 7 and to simplify the direction of deformation. As a result, correction according to the thermal deformation becomes easy, and the workpiece 30 can be processed with high precision.

Note that between the head pulsating means and the head 17.

1st. Providing heat insulating members such as the second heat insulating members 21 and 22 prevents the heat 32 generated from the heat source from propagating from the head 17 to the main body 9 side of the headstock 7.

Furthermore, the amount of thermal deformation of the headstock 7 is reduced by effectively preventing it.
Moreover, the direction of deformation can be made simple.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an example of a machine tool to which an embodiment of the machine tool headstock structure according to the present invention is applied, FIG. 2 is a left side view of FIG. 1, and FIG. 3 is a view similar to that of FIG. FIG. 4 is a sectional view showing the main parts of the headstock of a machine tool to which another embodiment of the headstock structure of a machine tool according to the present invention is applied; FIG. is a front view showing how a conventional machine tool undergoes thermal displacement when machining a workpiece. FIG. 6 is a left side view of FIG. 5. 1... Machine tool 7... Headstock 9... Main body 10... Head driving means (head rotating device) 1
7... Head 21... Heat insulation member (first heat insulation member) 22...
...Insulating member (second heat insulating member) 23...Tool spindle 26...Drive motor (spindle drive motor) Applicant Yamazaki Mazak Co., Ltd. Agent Patent attorney Phase 1) Shinji ( and 2 others) Q◆-佽O 4-4-O 沫 (J -0 紫--N Rinaka groan O

Claims (2)

[Claims] (1) having a main body, a head driving means provided on the main body, a head rotatably provided on the main body via the head driving means, and a tool spindle rotatably provided on the head; and a drive motor for rotationally driving the tool spindle.
Machine tool headstock structure. (2) A headstock structure for a machine tool according to claim 1, wherein a heat insulating member is provided between the head driving means and the head.