JP2014014883A - Spindle device, machine tool including the same, and tool holder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spindle device which reduces the weight of a spindle and achieves high rigidity of the spindle, and to provide a machine tool including the spindle device and a tool holder.SOLUTION: A spindle device 60 includes: a bearing body 71; a spindle 61 rotatably supported by the bearing body 71; a grind stone 67 which is attached to the spindle 61 through a tool holder 66 and serves as a tool; and a rotation driving mechanism 101 which rotates the spindle 61. The spindle 61 and the tool holder 66 are formed by carbon fiber reinforced plastic.

Description

  The present invention relates to a spindle device, a machine tool including the spindle device, and a tool holder. Specifically, a spindle device comprising a bearing body, a spindle rotatably supported by the bearing body, a tool attached to the spindle via a tool holder, and a rotation drive mechanism for rotating the spindle, And a tool holder.

In recent years, there has been an increasing demand for higher speeds in machine tools due to demands for improving productivity.
In order to meet this demand, some machine tools are made of carbon fiber reinforced plastic (CFRP) that is partly molded with carbon fiber reinforced plastic (CFRP) for the purpose of weight reduction and high rigidity. It is known (see Patent Document 1).

JP 2000-263356 A

  As described above, some of the conventional parts are made of carbon fiber reinforced plastic (CFRP) to reduce the weight, but the spindle is mainly made of stainless steel so far. Therefore, it is not sufficient in terms of weight reduction, and further weight reduction is required.

  SUMMARY OF THE INVENTION An object of the present invention is to respond to such a demand and to provide a spindle device that is reduced in weight while maintaining the rigidity of the spindle itself, and a machine tool and a tool holder provided with the spindle device.

A spindle apparatus according to the present invention includes a bearing body, a spindle rotatably supported by the bearing body, a tool attached to the spindle via a tool holder, and a rotation drive mechanism that rotates the spindle. In the spindle apparatus, the spindle is made of carbon fiber reinforced plastic.
Here, the carbon fiber reinforced plastic may be either a bread system obtained by firing polyacrylonitrile fiber or a pitch system obtained by firing a pitch produced as a coal / petrochemical residue after melt spinning.
According to this configuration, since the spindle is made of carbon fiber reinforced plastic, it is possible to reduce the weight while increasing the natural frequency and rigidity. Therefore, the spindle can be rotated at a high speed, which can contribute to the improvement of productivity.

In the spindle apparatus of the present invention, it is preferable that the spindle is formed in a cylindrical shape having a hollow portion therein.
According to this configuration, since the spindle is formed in a cylindrical shape having a hollow portion inside, the weight can be reduced structurally in addition to the weight reduction of the material by the carbon fiber reinforced plastic.

In the spindle apparatus of the present invention, it is preferable that a plating layer is formed on the surface of the spindle.
Here, the plating layer is preferably a hard plating layer, and examples thereof include electroless nickel plating.
According to this configuration, since the plating layer is formed on the surface of the spindle, the surface roughness and wear resistance are excellent. Accordingly, since the wear between the bearing body and the bearing main body that rotatably supports it can be reduced, the rotational performance of the spindle can be maintained over a long period of time.

In the spindle apparatus of the present invention, it is preferable that the tool holder is also made of carbon fiber reinforced plastic.
According to this structure, since the tool holder attached to this spindle with the rotating spindle is also comprised by the carbon fiber reinforced plastic, the weight of the rotating part can be further reduced. As a result, the spindle can be rotated at a high speed, which in turn can contribute to an improvement in productivity.

A machine tool according to the present invention includes a table on which a workpiece is placed, the spindle device described in any of the above, and a relative movement mechanism that relatively moves the table and the spindle device.
According to this configuration, it is possible to realize a machine tool that can expect the above-described effects.

The tool holder of the present invention is a tool holder that is detachably provided on a rotatable spindle and holds a tool, wherein the tool holder is made of carbon fiber reinforced plastic.
According to this configuration, since the tool holder attached to the spindle is made of carbon fiber reinforced plastic, the weight of the rotating portion can be further reduced. As a result, the spindle can be rotated at a high speed, which in turn can contribute to an improvement in productivity.

The perspective view which shows the machine tool which concerns on embodiment of this invention. The figure which shows a main shaft apparatus and its peripheral part in the said embodiment. Sectional drawing which shows a spindle apparatus in the said embodiment. The figure which shows the structure of a table in the said embodiment. The figure which shows the structure of a saddle in the said embodiment. The figure which shows the structure of a spindle head main body in the said embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<Configuration of Embodiment>
As shown in FIG. 1, the machine tool according to the present embodiment is provided with a base 1 and a base 1 that is movable in the X-axis direction via an X-axis guide mechanism 11 and an X-axis linear motor mechanism 12. A table 13 on which W is placed, a portal column 20 provided across the table 13, and a horizontal beam 20 A of the portal column 20 via a Y-axis guide mechanism 21 and a Y-axis linear motor mechanism 22. The spindle device 30 is provided so as to be movable in the axial direction.

The X-axis guide mechanism 11 includes a guide rail 11A disposed on the upper surface of the base 1 in parallel along the X-axis direction, and a slide member 11B provided on the lower surface of the table 13 so as to be slidable along the guide rail 11A. It is comprised including.
The X-axis linear motor mechanism 12 includes a magnet 12A arranged in parallel with the guide rail 11A on the upper surface of the base 1, and a coil 12B attached to the lower surface of the table 13 with a gap between the magnet 12A. It is comprised by the linear motor containing.

The Y-axis guide mechanism 21 is slidable along the guide rail 21A on the upper surface of the horizontal beam 20A of the portal column 20 and parallel to each other along the Y-axis direction, and on the lower surface of the spindle device 30. And a provided slide member 21B.
The Y-axis linear motor mechanism 22 includes a magnet 22A arranged in parallel with the guide rail 21A on the upper surface of the horizontal beam 20A of the portal column 20, and a lower surface of the spindle device 30 with a gap between the magnet 22A. It is comprised by the linear motor containing the attached coil 22B.

(Description of spindle device: see FIG. 2)
As shown in FIG. 2, the spindle device 30 is provided with a spindle head support member provided on the horizontal beam 20 </ b> A of the portal column 20 so as to be movable in the Y axis direction via a Y axis guide mechanism 21 and a Y axis linear motor mechanism 22. , A spindle head 43 provided on the saddle 33 through a Z-axis guide mechanism 41 and a Z-axis linear motor mechanism 42 as an elevating mechanism, and at least a part of the weight of the spindle head 43 And a balance cylinder 44 for generating an urging force for supporting

The Z-axis guide mechanism 41 includes a guide rail 41A arranged parallel to each other along the Z-axis direction on the back surface of the spindle head 43, and a slide member 41B fixed to the front surface of the saddle 33 and slidably guiding the guide rail 41A. It is comprised including.
The Z-axis linear motor mechanism 42 includes a magnet 42A arranged in parallel with the guide rail 41A on the back surface of the spindle head 43, and a coil 42B attached to the front surface of the saddle 33 with a gap between the magnet 42A. It is comprised by the linear motor containing.
Here, the periphery of the coil 42B is covered with a heat shield member 42C. The heat shield member 42C is formed in a box shape from a material such as aluminum or plastics.

  As shown in FIG. 1, the spindle head 43 includes a spindle head main body 51 and a spindle device 60 attached to the spindle head main body 51.

  The balance cylinders 44 are provided on both sides of the spindle head 43, respectively. Each balance cylinder 44 has a cylinder main body 44 </ b> A whose upper end is supported by the saddle 33 via a bracket 52, and a piston which is slidably housed in the cylinder main body 44 </ b> A at its upper end, and its lower end is at the lower end of the spindle head 43. The piston rod 44B is connected to the piston rod 44B. Air from an air supply source (not shown) is supplied to the lower chamber of the cylinder body 44A partitioned by the piston via a pressure regulator or the like. As a result, an urging force that balances the weight of the spindle head 43 is applied upward to the spindle head 43 by the balance cylinder 44.

(Description of spindle device: see FIG. 3)
As shown in FIG. 3, the spindle device 60 includes a spindle 61 having a grindstone 67 as a tool attached to a tip via a tool holder 66, a bearing body 71 having a storage hole 72 for storing the spindle 61, and the bearing Bearing members 81 and 82 fixed in the housing hole 72 of the main body 71 and rotatably supporting the spindle 61 via an air layer, air supply means 91 for supplying air to the bearing members 81 and 82, and the spindle 61 And a rotation driving mechanism 101 for rotating.

  The spindle 61 includes a shaft portion 63 formed in a cylindrical shape with a predetermined length having a hollow portion 62 inside, and a flange portion 64 provided in the middle of the shaft portion 63 and having a diameter larger than the diameter of the shaft portion 63. It is formed in the shape to have. An air turbine blade 102 is attached to the base end side of the spindle 61.

  The tool holder 66 includes a spindle mounting portion 66A having a screw structure that is detachably attached to the tip of the spindle 61, a flange portion 66B formed larger in diameter than the spindle mounting portion 66A, and heading from the flange portion 66B toward the tip. Accordingly, the taper portion 66C having a gradually reduced diameter is formed. A cup-shaped grindstone 67 as a tool is integrally held at the tip of the taper portion 66C by a fastening bolt 68 or adhesion.

In the present embodiment, the spindle 61 and the tool holder 66 are made of carbon fiber reinforced plastic (CFRP). The carbon fiber reinforced plastic may be either a bread system obtained by firing polyacrylonitrile fiber or a pitch system obtained by firing a pitch produced as a coal / petrochemical residue after melt spinning.
A plating layer, for example, an electroless nickel plating layer is formed on the surface of the spindle 61.

  The bearing members 81 and 82 include radial bearing members 81A and 82A having an inner diameter having a predetermined radial gap 83 between the outer peripheral surface of the shaft portion 63 and an air ejection hole 84 for blowing air into the radial gap 83, and these radials. The thrust bearing members 81B and 82B are formed integrally with the bearing members 81A and 82A and have a predetermined thrust gap 85 and an air ejection hole 86 for ejecting air into the thrust gap 85 between the end face of the flange portion 64. ing.

  The bearing body 71 is formed with a storage hole 72 for storing the spindle 61 in the central axis direction, and two air supply ports 73 and 74 are formed outside. In addition, an air supply path 77 that communicates from the air supply port 73 to the air ejection holes 84 and 86 of the bearing members 81 and 82 and an air supply path that faces the outer periphery of the air turbine blade 102 from the air supply port 74 are provided inside. An air nozzle 103 is formed.

  The air supply means 91 includes a compressor 92 as an air supply source, a pressure regulator 94 provided between the compressor 92 and the air supply port 73, and a pressure provided between the compressor 92 and the air supply port 74. And a regulator 95.

  The rotation drive mechanism 101 includes an air turbine blade 102 fixed to the base end side of the spindle 61 and an air nozzle 103 formed on the bearing body 71. Thereby, when the air from the air supply means 91 is supplied to the air turbine blade 102 through the air nozzle 103, the air turbine blade 102 is rotated, and the spindle 61 is rotated together therewith.

(Description of table 13, saddle 33 and spindle head main body 51: see FIGS. 4 to 6)
In the present embodiment, among the relative movement mechanisms that move the table 13 and the spindle device 60 relative to each other, the movable-side member has a plurality of different types of basic shapes that are previously made of carbon fiber reinforced plastic (CFRP). It is composed of a combination of materials. Here, among the components constituting the machine tool, the table 13, the saddle 33, and the spindle head main body 51 are made of a plurality of types of different shapes formed of carbon fiber reinforced plastic (hereinafter also referred to as CFRP). It is composed of a combination of structural materials. Next, these manufacturing methods and structures will be described.

(About the manufacturing method of the table 13)
As shown in FIG. 4, the table 13 is formed between a CFRP structural member 13A having a C-shaped cross section disposed on four sides of the rectangular table 13 and the front and rear structural members 13A surrounded by the structural member 13A. A CFRP reinforcing structural member 13B having an I-shaped cross section, a rectangular CFRP surface member 13C disposed on the upper and lower surfaces of the structural members 13A and 13B, and a CFRP reinforcing surface bonded to the lower surface It is comprised from material 13D.

(About the manufacturing method of the saddle 33)
As shown in FIG. 5, the saddle 33 includes a CFRP structural member 33A having an L-shaped cross section disposed at the four corners of the box-shaped saddle 33, and a rectangular CFRP side surface bonded between the structural members 33A. It is composed of a material 33B, a rectangular CFRP upper surface material 33C bonded to the upper surface, and a CFRP lower surface material 33D bonded to the bottom surface.

(About the manufacturing method of the spindle head main body 51)
As shown in FIG. 6, the spindle head main body 51 includes a CFRP side member 51A arranged in parallel to each other, a CFRP back member 51B bonded to the back surface of the side member 51A, and an upper surface of the side member 51A. The CFRP upper surface material 51C and the lower surface material 51D bonded to the bottom surface, the CFRP reinforcing surface material 51E inserted in the middle of the side surface material 51A, the lower end portion of the side surface material 51A and the front surface portion of the lower surface material 51D. The reinforcing surface material 51F is made of bonded CFRP. That is, it is formed in a vertically long box shape in which the front half and the front half of the upper surface are opened. A hole 51G for inserting the spindle device 60 is formed at the center of the lower surface material 51D.

<Operation and Effect of Embodiment>
In the machine tool having such a configuration, in order to process the workpiece W, after setting the workpiece W on the table 13, the table 13 is set in the X-axis direction, the saddle 33 is set in the Y-axis direction, and the spindle head 43 is set in the Z-axis. The workpiece W is processed by the grindstone 67 while moving in the direction.
In this embodiment, since the spindle 61 and the tool holder 66 of the spindle device 60 are made of carbon fiber reinforced plastic, the spindle 61 and the tool holder 66 can be reduced in weight. Therefore, since the spindle 61 can be rotated at a high speed, an improvement in productivity can be expected.

Moreover, since the spindle 61 has a cylindrical shape having a hollow portion 62 inside, the weight can be further reduced as compared with a solid spindle.
Moreover, since the plating layer is formed on the surface of the spindle 61, the wear resistance is excellent. Accordingly, the wear between the bearing body 71 and the bearing body 71 that rotatably supports it can be reduced, so that the rotational performance of the spindle 61 can be maintained over a long period of time.

  In the present embodiment, the movable side members, that is, the spindle head main body 51 constituting the table 13, the saddle 33, and the spindle head 43 are made of carbon fiber reinforced plastic. it can. Therefore, since the moving speed of these members can be increased, an improvement in productivity can be expected.

  In addition, the spindle head main body 51 constituting the table 13, the saddle 33, and the spindle head 43 is manufactured by combining a plurality of different types of structural materials made of carbon fiber reinforced plastic, so that it can be manufactured at low cost.

The elevating mechanism for elevating the spindle head 43 includes a magnet 42A provided on the spindle head 43 along the elevating direction of the spindle head 43, and a coil 42B disposed on the saddle 33 so as to face the magnet 42A. Since the shaft linear motor mechanism 42 is included, the spindle head 43 can be moved up and down at high speed, smoothly and with high accuracy.
In addition, since the periphery of the coil 42B constituting the Z-axis linear motor mechanism 42 is covered with the heat shield member 42C, it is possible to prevent the spindle head main body 51 and the like from being thermally deformed by heat generated from the coil. Therefore, high accuracy can be maintained.

<Modification>
It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
In the embodiment, the spindle 61 has a shaft portion 63 having a predetermined length having a hollow portion 62 inside, and a flange portion 64 provided in the middle of the shaft portion 63 and having a diameter larger than the diameter of the shaft portion 63. The shape is not limited to this. For example, it may be a solid cylindrical shape. The spindle 61 has a structure that is rotatably supported by an air bearing, but may have a structure that is rotatably supported by a ball bearing or the like.

In the embodiment, the tool holder 66 is detachably attached to the tip of the spindle 61 with a threaded spindle mounting portion 66A, a flange portion 66B formed larger in diameter than the spindle mounting portion 66A, and the flange portion. Although it was formed in the shape provided with the taper part 66C gradually diameter-reduced as it goes to the front-end | tip from 66B, it is not restricted to this. For example, the spindle mounting portion 66A is not limited to a screw structure, and may be formed in a taper shank, and this taper shank engages with the tip tapered hole of the spindle.
In addition, the grindstone 67 is integrally held at the tip of the tapered portion 66C by a fastening bolt 68 or adhesion, but the grindstone 67 can be attached to and detached from the tip of the tapered portion 66C by a chuck or the like. It may be.
The tool is not limited to the grindstone 67, and any tool that performs cutting or grinding while rotating, such as a drill or an end mill, may be used.

In the above-described embodiment, as the structural material of the table 13, the saddle 33, and the spindle head main body 51, the cross-sectional C-shaped, I-shaped, L-shaped profile and the face material are used. For example, in addition to C-shaped, I-shaped, and L-shaped profiles and face materials, structural materials such as H-shaped, T-shaped, triangular, round, and quadrangular are prepared, and these are necessary. A structural material may be selected to constitute a machine part.
In addition, in order to manufacture these structural materials in advance, a molding method suitable for the cross-sectional shape of the structural materials is performed. For example, in the case of a structural material such as a triangle, a circle, or a quadrangle, it is preferable that a continuous carbon fiber impregnated with a resin is wound around a metal core and formed into a cylindrical shape.

In the said embodiment, among the relative movement mechanisms which move the table 13 and the grindstone 67 relatively, about the movable side member, it comprised by the combination of the multiple types of structural material of the different shape comprised by the carbon fiber reinforced plastic previously. Not limited to this.
For example, the horizontal beam 20A of the portal column 20 may be configured by combining a plurality of types of structural materials having different shapes made of carbon fiber reinforced plastic, or the main structural material of a machine tool including the base 1 All of these may be configured by combining a plurality of types of structural materials having different shapes formed of carbon fiber reinforced plastic.

  In the embodiment, the table 13 is movable in the X-axis direction and the spindle head 43 is movable in the Y-axis direction and the Z-axis direction as a machine tool. However, the present invention is not limited to this. In short, any structure may be used as long as the table 13 and the spindle head 43 can move relative to each other in two dimensions (two-axis direction) or three dimensions (three-axis direction).

Further, in the above-described embodiment, each axis moving mechanism is configured by the linear motor mechanism, that is, the X-axis linear motor mechanism 12, the Y-axis linear motor mechanism 22, and the Z-axis linear motor mechanism 42, but is not necessarily a linear motor mechanism. May be. A feed mechanism using a ball screw may be used.
In the above embodiment, an air turbine mechanism is used as the rotation drive mechanism 101 of the spindle 61. However, the present invention is not limited to this, and may be a motor, for example.

  In the embodiment, the urging force that balances the weight of the spindle head 43 is generated by the balance cylinder 44. However, the urging force that balances the weight of the spindle head 43 is not necessarily required. The structure which generate | occur | produces the biasing force which supports at least one part of the weight of may be sufficient.

  The present invention can be applied not only to general machine tools but also to ultraprecision machine tools such as ultraprecision aspherical machines.

11 ... X-axis guide mechanism (relative movement mechanism),
12 ... X-axis linear motor mechanism (relative movement mechanism),
13 ... Table,
21 ... Y-axis guide mechanism (relative movement mechanism),
22 ... Y-axis linear motor mechanism (relative movement mechanism),
41 ... Z-axis guide mechanism (relative movement mechanism),
42 ... Z-axis linear motor mechanism (relative movement mechanism),
60 ... Spindle device,
61 ... Spindle,
66 ... Tool holder,
67 ... Whetstone (tool),
71 ... bearing body,
101 ... Rotation drive mechanism,
W ... Work.

Claims (6)

In a spindle apparatus comprising a bearing body, a spindle rotatably supported by the bearing body, a tool attached to the spindle via a tool holder, and a rotation drive mechanism that rotates the spindle.
The spindle device is characterized in that the spindle is made of carbon fiber reinforced plastic. The spindle device according to claim 1,
The spindle device is characterized in that the spindle is formed in a cylindrical shape having a hollow portion therein. The spindle apparatus according to claim 1 or 2,
A spindle device, wherein a plating layer is formed on a surface of the spindle. In the spindle device according to any one of claims 1 to 3,
The spindle device, wherein the tool holder is also made of carbon fiber reinforced plastic. A table on which the workpiece W is placed;
The spindle device according to any one of claims 1 to 4,
A machine tool comprising: a relative movement mechanism that relatively moves the table and the spindle device. A tool holder that is detachably provided on a rotatable spindle and holds a tool,
The tool holder is made of carbon fiber reinforced plastic.

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