JP2003266259A - Machine tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a machine tool capable of achieving compactness, and high speed machining by composing movable parts light. <P>SOLUTION: A housing 4 including a built-in motor and a Z-axis motor 16 are fixed to a base body 3, and a movable block 9 is supported to be movable along a rail 7 provided on the base body 3. A spindle 6 driven and rotated by the built-in motor in the housing 4 to be movable in the rotation axis direction to a bearing means provided in the housing 4 is rotatably journaled to the movable block 9. A screw shaft body 13 engaged with the movable block 9 is rotated by the Z-axis motor 16 to feed the spindle to a workpiece 1. A pressure foot 21 on the tip side of the spindle 6 is movably connected through an air cylinder 19 provided on a fork part 9b of the movable block 9. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle (machining main shaft) for mounting a tool such as a drill at its tip, which is rotatably driven by a built-in motor so as to be movable in the axial direction, and only this spindle can reciprocate. The present invention relates to the configuration of the machine tool as described above.

[0002]

2. Description of the Related Art Conventionally, a spindle unit for a machine tool, which has a spindle rotatably driven by a built-in motor and a housing having a bearing for supporting the spindle, is fixed to a head block (support frame), This head block is arranged so that it can be moved up and down along a vertical guide rail provided on a column with respect to a table on which a work (workpiece) below is placed, and a Z-axis motor provided at the upper end of the column is used. The head block is connected to the lower end of the screw shaft body in the Z-axis direction to be driven so that the head block can be moved up and down.

Air cylinders are arranged on both left and right sides of the ascending / descending head block, and a pressure foot for pressing against the surface of the work on the table is provided at the lower end of a piston rod which projects downward of the air cylinders. Link. In the center of the pressure foot, there is a hole through which a tool such as a drill attached to the lower end of the spindle of the spindle unit is inserted vertically, and the chips generated by cutting the work with the tool are removed by suction air. The one configured to do is known.

[0004]

However, in the above-mentioned conventional configuration, the Z-axis motor causes the heavy object such as the housing having the built-in motor to be moved together with the spindle together with the work piece together with the head block. Since it is necessary to drive the Z-axis motor with a large driving force, the size becomes large,
There was a problem that the cost would be high. Further, since the heavy housing and head block have a large moment of inertia in the moving direction, when they are rapidly approached toward the workpiece at the beginning of processing, the inertia force causes
Since the tool collides with the surface of the object to be processed, it has to be approached at a low speed, which requires a long time until the start of processing, resulting in poor work efficiency.

The present invention has been made to solve these conventional problems, and to provide a machine tool which can be downsized and made possible at high speed by reducing the weight of a moving part. It is intended.

[0006]

In order to achieve the above object, a machine tool according to a first aspect of the present invention is rotationally driven by a built-in motor in a housing whose position is fixed,
A spindle that is movable in the direction of the rotation axis with respect to the bearing means provided in the housing, and has a tool mountable tip and a base end of the spindle that is rotatably supported and reciprocates in the direction of the rotation axis. It is provided with a movable block which is movable, and a first drive means for reciprocating the movable block along the axial direction.

According to a second aspect of the present invention, in the machine tool according to the first aspect, the housing and the first drive means are fixed to a common base body, and along a rail provided on the base body. A moving block is supported so as to be capable of reciprocating, and the first driving means and the moving block are connected via a screw shaft, and the screw shaft is rotationally driven to reciprocate the moving block. It is configured in.

The invention described in claim 3 is the same as claim 1
Alternatively, in the machine tool described in item 2, the moving block is screwed onto the screw shaft body, and the axis line of the screw shaft body and the axis line of the spindle are arranged on the same line.

According to a fourth aspect of the present invention, in the machine tool according to any one of the first to third aspects, the moving block is formed in a bifurcated shape that sandwiches a location where the housing is arranged, The pressure foot on the tip end side of the spindle is movably connected via a second drive means provided at the bifurcated portion.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described. 1 is a partial sectional front view of a machine tool according to the present invention, FIG. 2A is a side view taken along the line IIa-IIa in FIG. 1, and FIG. 2B is a side view taken along the line IIb-IIb in FIG. 3 is a sectional view taken along the line III-III of FIG. 1, FIG. 4 is a sectional view taken along the line IV-IV of FIG. 1, and FIG. 5 is a bottom view taken along the line VV of FIG.

The machine tool according to the present invention is for rotating a tool such as a drill or a milling cutter to perform a cutting process such as drilling a workpiece, and a horizontal machining table 2 on which the workpiece 1 is placed is placed. On the other hand, a vertical cylindrical housing 4 having a built-in motor (not shown) is installed at a height position at a lower position near the processing table 2 on the vertical surface of the vertically elongated base body 3 which is vertically installed. A support portion 5 for fixing is provided. A cylindrical spindle 6 is arranged in the inner diameter portion (vertical center axis portion) of the housing 4 so as to vertically project. The outer circumference of the spindle 6 is rotatably supported by a radial air bearing (not shown), and the spindle 6 is axially movably supported by a thrust air bearing as bearing means. It is supported. Further, the spindle 6 is rotationally driven by a built-in motor (not shown) in which a stator fixed in the housing 4 surrounds a rotor provided on the outer periphery of the spindle 6.

A movable block 9 which is arranged parallel to the vertical surface of the base body 3 and which is vertically movable on a pair of left and right vertically long guide rails 7, 7 is arranged via a linear guide 8 so as not to come off. ing. As shown in FIG. 1, the moving block 9 is formed in a U shape in a downward direction in a front view. The mounting piece 1 is attached to the upper piece 9a of the moving block 9.
The bearing 11 is attached via 0, and the upper end (base end) of the spindle 6 is rotatably supported by the bearing 11 so as not to move in the axial direction. A female screw portion 12 is provided on the upper piece 9a of the moving block 9, and a vertically long screw shaft body 13 is screwed into the female screw portion 12. The screw shaft body 13 and the spindle 6 are arranged so that their rotation axes are on the same line. The lower end of the screw shaft body 13 is rotatably supported by a bearing provided on a bracket 18 protruding from the surface of the base body 3.

An upper portion of the screw shaft body 13 is rotatably supported by a bearing 14 provided on a support block 3a on an upper portion of the base body 3, and an upper end of the screw shaft body 13 is connected via a coupling 15. And is mounted on the Z-axis motor 16 as the first drive means.

A tool 17 such as a drill is detachably attached to the tip (lower end) of the spindle 6.
Further, in the moving block 9, the left and right forked portions 9b,
9b includes an air cylinder 19 as a second driving means,
19 are mounted so that the respective piston rods 19a move downward and forward, and the left and right piston rods 19a, 19a
A pressure foot 20 is attached to the lower end of the via a lifting shaft 22. The pressure foot 20 is provided with a hollow portion at the center of both the left and right sides through which the tool 17 at the lower end of the spindle 6 can be inserted vertically, and the lower surface of the pressure foot 20 is a presser for pressing the surface of the workpiece 1. Board 21
Is installed. The lifting shafts 22 are movable blocks 9
It is supported by slide bearings 23 provided on the left and right bifurcated portions 9b, 9b so as to be only movable up and down.

In the above structure, when the workpiece 1 on the processing table 2 is cut, the Z-axis motor 16 which is the first driving means is rotated in the reverse direction (for example, left rotation),
The moving block 9 rises along the guide rail 7 by the reverse rotation of the screw shaft body 13. Therefore, this moving block 9
The spindle 6 mounted on the upper part of the housing rises with respect to the housing 4 fixed in the height position. The pressure foot 20 is also raised simultaneously with the moving block 9 via the air cylinder 19.

The work piece 1 is placed at a predetermined position on the work table 2.
Is fixed, and then the Z-axis motor 16 is rotated in the normal direction (for example, right rotation), the movable block 9 descends due to the normal rotation of the screw shaft body 13. As a result, the spindle 6 is rotatably and rotatably supported by the air bearing (thrust air bearing and radial air shaft) in the housing 4 in the height position fixed state, so that the spindle 6 can descend smoothly.
The tool 17 at the lower end is temporarily stopped at a height close to the surface of the workpiece. In this state, the pair of air cylinders 19, 19, which are the second driving means, are driven to lower the pressure foot 20 and hold the surface of the work piece in a pressed state by the pressing plate 21 at the lower end thereof. Then the housing 4
When the built-in motor therein is driven, a rotational force is applied to the spindle 6, and the spindle 6 descends at a predetermined machining speed (feed speed) by the normal rotation of the Z-axis motor 14, so that the workpiece 1 is moved by the tool 17. It can be cut appropriately.

Since the upper end of the hollow portion of the pressure foot 20 is covered by the lower end of the housing 4, the air generated in the hollow portion is sucked by a vacuum device (not shown) to process the generated cutting chips. It can be effectively removed from the surface of the object 1.

FIG. 6 shows a second embodiment. In this embodiment, a thrust air bearing portion 31 is provided at a lower end portion of a suspension support body 30 fixed to a moving block 9 that is raised and lowered by the rotation of the screw shaft body 13, and the thrust air bearing portion 31 can move up and down in the housing 4. The supported portion 6a at the upper end of the spindle 6 arranged at is pivotally supported. The housing 4 is fixed at a height position via a support portion 5 provided on the processing table 2 as in the above embodiment. The suspension support 30 is fitted in a large diameter hole 32 on the upper end side of the housing 4 so as to be able to move up and down. The spindle 6 is rotatably supported by a radial air bearing 33 in the housing 4, and is rotationally driven by a built-in motor 34 built in the housing 4. Since other configurations are the same as those in the first embodiment, the same reference numerals are given and detailed description will be omitted. Also in this embodiment, the same operational effect as that of the first embodiment can be obtained.

In the machine tool of the present invention, it is not necessary to raise and lower the spindle with the Z-axis motor together with the heavy housing having the built-in stator of the built-in motor, and the spindle 6 having a small weight and the rotor around the spindle are raised and lowered. Since it is driven, the first drive means Z
The load on the axis motor 16 is small, and the Z-axis motor 1
6 is small in size, and the weight of the object to be moved up and down including the spindle 6 and the moving block 9 can be reduced. Therefore, the rigidity of the base body 3 on the supporting side can be sufficiently small, This has the effect of making the entire machine tool compact and lightweight. When the weight of the object to be moved up and down is light as described above, the vertical feed rate can be increased during cutting and the speed can be easily adjusted.

In the machine tool according to the present invention, the screw shaft body 13
Since the rotation axes of the spindle 6 and the spindle 6 are designed to be on the same straight line, even if the moving block 9 is shaken when the screw shaft body 13 is rotated, the rotation of the spindle 6 is shaken and the tool is rotated. There is an effect that the shake can be suppressed to a minimum and high-precision processing can be realized.

The spindle 6 and the moving block 9 of the present invention may be a machine tool that reciprocates horizontally instead of reciprocating vertically (vertically).

[0022]

As described above in detail, the machine tool according to the invention described in claim 1 is rotationally driven by the built-in motor in the housing whose position is fixed, and the bearing means provided in the housing. And a movable block that is configured to be movable in the rotation axis direction and has a tool attached to the tip thereof, a movable block that rotatably supports the base end of the spindle, and that can reciprocate in the rotation axis direction, and the movable block. And a first drive means for reciprocating along the axial direction, compared with a conventional feed mechanism for reciprocating a spindle with a built-in housing with a large weight along a rotation axis as in the prior art. As a result, the weight is reduced, and the effect is that a compact machine tool can be obtained. Further, since the weight of the reciprocating portion is light, it is easy to increase the spindle feed speed.

According to a second aspect of the present invention, in the machine tool according to the first aspect, the housing and the first driving means are fixed to a common base body, and along a rail provided on the base body. Since the moving block is supported so as to be capable of reciprocating, the structure of the base body can be simplified.
The first drive means and the moving block are connected to each other via a screw shaft body, and the screw shaft body is rotationally driven to reciprocate the moving block. Since the moving block can reciprocate by the length of the screw portion, the effect that the spindle feed speed can be easily adjusted only by adjusting the rotation speed of the screw shaft body by the first drive means.

The invention described in claim 3 is the same as claim 1
Alternatively, in the machine tool described in item 2, the moving block is screwed onto the screw shaft body, and the axis line of the screw shaft body and the axis line of the spindle are arranged on the same line.

Therefore, even if the movement block is shaken when the screw shaft is rotated, it is possible to minimize the rotational runout of the spindle and thus the rotary runout of the tool, and to realize highly accurate machining. Produce an effect.

According to a fourth aspect of the present invention, in the machine tool according to any one of the first to third aspects, the moving block is formed in a bifurcated shape sandwiching the location of the housing, and the pair of the pair of moving blocks is formed. Since the pressure foot on the tip end side of the spindle is movably connected via the second drive means provided in the bifurcated portion, only the pressure foot is brought into contact with the workpiece during cutting. The effect is that they can be separated, and work such as replacement of the work piece can be easily performed.

[Brief description of drawings]

FIG. 1 is a partially sectional front view of a machine tool of the present invention.

2A is a side view taken along the line IIa-IIa of FIG.
(B) is a side view taken along the line IIb-IIb of FIG. 1.

3 is a sectional view taken along line III-III in FIG.

4 is a sectional view taken along line IV-IV in FIG.

5 is a bottom view taken along the line VV of FIG.

FIG. 6 is a side sectional view of a second embodiment.

[Explanation of symbols]

1 Workpiece 2 processing table 3 base body 4 housing 5 Support 6 spindles 6a Bearing part 7 Guide rail 9 moving blocks 10 Mounting piece 11 bearings 12 Female thread 13 screw shaft 14 screw shaft 16 Z-axis motor as first driving means 17 tools 19 Air cylinder 20 Pressure foot 30 suspended supports 31 Thrust air bearing 32 large hole 33 radial bearing

Claims (4)

[Claims] 1. A spindle which is rotatably driven by a built-in motor in a positionally fixed housing and is movable in a rotation axis direction with respect to a bearing means provided in the housing, and a tool can be attached to a tip thereof. A machine provided with a movable block that rotatably supports the base end of the spindle and is capable of reciprocating in the rotation axis direction; and a first driving means that reciprocates the moving block along the axis direction. machine. 2. The housing and the first drive means are fixed to a common base body, and a moving block is reciprocally supported along a rail provided on the base body,
The first driving means and the moving block are connected via a screw shaft body, and the screw shaft body is rotationally driven to reciprocate the moving block. Machine tool described in. 3. The work according to claim 1, wherein the moving block is screwed onto the screw shaft body, and the axis line of the screw shaft body and the axis line of the spindle are arranged on the same line. machine. 4. The movable block is formed in a bifurcated shape that sandwiches the location of the housing, and a pressure foot on the tip side of the spindle can be moved through a second drive means provided in the pair of bifurcated portions. The machine tool according to any one of claims 1 to 3, wherein the machine tool is connected to the machine tool.