JP2001287109A - Machining method by machine tool and machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly guide a toll spindle to a predetermined machining position of a workpiece while enabling the high-speed rotation of the tool spindle. SOLUTION: This machining method using a machine tool is provided, where the machine tool is provided with a cylindrical guide member 44 into which the tool spindle 22 held by a main spindle head 20 is inserted, and sends the tool spindle 22 to the predetermined machining position of the workpiece 30 while guiding it by the guide member 44. The guide member 44 is rotatably supported on a guide support member 38, and is rotated in the same direction as that of the rotation of the tool spindle 22. More preferably, the guide member 44 is rotated at a speed nearly equal to the rotation speed of the tool spindle 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a machining method using a machine tool provided with means for guiding a tool to a workpiece machining position and a machine tool.

[0002]

2. Description of the Related Art Some conventional machine tools are provided with a means for supporting a long tool shaft in the middle thereof and guiding the same to a work processing position (for example, Japanese Patent Publication No. 8-25081).
No.). As an example, a drilling device provided with a long drill bit is shown in FIG.

In FIG. 1, a table 2 is placed on a fixed bed 1, and the table 2 is driven to be fed back and forth (left and right in the drawing) by a motor and a feeding mechanism (not shown). The table 2 is provided with a processing head 3 and a plurality (two in the figure) of guide cylinders 4.

[0004] The processing head 3 holds a drill bit 3a at the front end thereof, and at the rear upper portion (upper left of FIG. 7).
A motor for rotating the drill bit 3a is provided. A pilot bar 5 is inserted through each guide tube 4 in the front-rear direction, and is relatively movable in the same direction.

Reference numeral 6 denotes an auxiliary guide cylinder fixed to the front end of the guide cylinder 4.

A positioning pin 7 with a flange is fixed to the tip of each pilot bar 5, and a guide support plate 8 is fixed to the positioning pin 7 such that the positioning pins 7 are connected to each other. This guide support plate 8
Is provided with a guide bush (guide member) 9 through which the drill bit 3a is inserted in the axial direction. In the inserted state, the drill bit 3a is guided along the axial direction to the processing position.

The positioning pin 7 penetrates the guide support plate 8, and its end protrudes forward. The projecting end of the positioning pin 7 is
The guide support plate 8 and the guide bush 9 are positioned at regular positions by fitting into the bush 31 of the receiving member 32a provided in the second member 2.

A coil spring 5a is interposed between the auxiliary guide cylinder 6 and the flange of the positioning pin 7 in a compressed state. The resilient force of the coil spring 5a causes the pilot bar 5, the positioning pin 7, and the guide. The moving body including the support plate 8 and the guide bush 9 is urged forward (to the right in FIG. 7).

The processing procedure by this machine tool is as follows.

The processing head 3 and the guide cylinder 4 are advanced together with the table 2. Then, when the front end of the positioning pin 7 is fitted into the bush 31 on the work support 32 side, the advance is stopped once. By this fitting, the relative positions of the positioning pin 7, the guide support plate 8, and the guide bush 9 with respect to the work 30 and the position of the drill bit 3a are accurately determined, and the bending of the pilot bar 5 due to its own weight of the guide support plate 8 and the like. This prevents the position of the drill bit 3a from shifting downward.

The motor of the processing head 3 is operated to rotate the drill bit 3a. In this state, the advance of the table 2 is restarted. At this time, since the positioning pin 7 has already been fitted into the bush 12 and the pilot bar 5 and the guide support plate 8 cannot advance any further, only the processing head 3 and the guide cylinder 4 are subjected to compression deformation of the coil spring 5a. Moves forward, and the drill bit 3a is
The workpiece 30 accurately reaches the processing position of the workpiece 30 while being guided and held.

[0012]

In the above device, the drill bit 3a is driven to rotate while the drill bit 3a is inserted into the guide bush 9 fixed to the guide support plate 8, so that the drill bit 3a is rotated. If the rotation speed of the motor is increased, seizure may occur with the guide bush 9. Therefore, there is a disadvantage that the rotation speed of the drill bit 3a is severely restricted.

As a means for avoiding the seizure, it is conceivable to increase the clearance between the drill bit 3a and the guide bush 9. However, as the clearance increases, the deflection of the drill bit 3a also increases, and the processing accuracy decreases. Inconvenience occurs.

It is also conceivable that a key is provided on the outer peripheral surface of the drill bit 3a, and a key groove corresponding to the key is formed in the guide bush 9 so that the two rotate together. If a key is protruded, the balance in the circumferential direction is deteriorated, so that high-speed rotation becomes difficult as in the conventional device. Furthermore, when performing processing with low support rigidity relying on self-centering by self-guide such as reamer processing, there is a possibility that the diameter of the processing hole is increased due to the constraint of the tool by the key and the key groove.

The problem described above is not limited to the case where the guide bush 9 is sent to the work 30 together with the drill bit 3a as shown in FIG. 7, but also the case where the guide bush 9 is fixed to the bed side and does not move. It can happen as well.

In view of such circumstances, the present invention provides a machining method using a machine tool and a machine tool capable of accurately guiding the tool axis to a predetermined machining position on a workpiece while enabling high-speed rotation of the tool axis. The purpose is to provide.

[0017]

As means for solving the above-mentioned problems, the present invention provides a tool shaft, a tool holder for rotatably holding the tool shaft, and a tool driving means for rotating the tool shaft. And a work supporting portion for supporting the work, and a feeding means for feeding the tool shaft and the tool holding portion to the work supported by the work supporting portion in the axial direction thereof, the machine tool comprising: A cylindrical guide member for guiding the tool shaft to the work position of the work is arranged between the tool holding portion and the work support portion, and the tool shaft is inserted through the guide member, and The tool shaft is sent toward the workpiece while rotating the guide member in the same direction as the rotation direction of the tool shaft.

The present invention also provides a tool shaft, a tool holding portion for rotatably holding the tool shaft, tool driving means for rotating the tool shaft, and a work supporting portion for supporting a work.
In a machine tool provided with feed means for feeding the tool shaft and the tool holder in the axial direction with respect to the work supported by the work support, the tool is provided between the tool holder and the work support. A tool guide portion having a guide member through which the shaft is inserted and a guide support member that rotatably supports the guide member around the center axis of the tool shaft is provided,
A guide member driving means for rotating the guide member in the same direction as the rotation direction of the tool shaft is provided.

According to the machining method and the machine tool, the guide member guides the workpiece accurately to a predetermined machining position while the tool shaft is inserted through the guide member. Moreover,
Since the guide member is driven to rotate in the same direction as the rotation direction of the tool shaft, the relative speed between the guide member and the tool shaft is reduced by the rotation speed. Therefore, even when the tool shaft is rotated at a high speed, the guide member is driven to rotate in accordance therewith, thereby preventing the burn-in between the tool shaft and the guide member.

Further, if the guide member is rotated at a speed substantially equal to the rotation speed of the tool shaft, the relative rotation speed can be made almost zero, and the image sticking is more reliably prevented. .

In the present invention, the specific structure of the guide member driving means can be variously set.

For example, if the guide member drive means is provided in the tool guide portion, the drive source can be arranged near the guide member, so that the configuration of the guide member drive means can be reduced in size and simplified.

In this case, the guide member driving means includes a guide member drive source fixed to the guide support member, and a drive transmission mechanism for transmitting an output of the guide member drive source to the guide member. Alternatively, a rotor may be provided on an outer peripheral portion of the guide member, a stator facing the rotor may be fixed to the guide support member side, and a motor (a so-called built-in motor) that rotates the guide member by the rotor and the stator ) May be configured. In the latter case, the structure of the tool guide itself can be made smaller and lighter.

The guide support member may be fixed directly to the bed of the machine tool, for example. However, if the guide member is provided with the guide member driving means as described above, the guide support member may be a tool. It is possible to adopt a configuration in which the tool is supported by the holding part so as to be relatively movable in a direction parallel to the feed direction with respect to the tool holding part, and is urged toward the work supporting part. . According to this configuration, the tool guide is fed and driven to the work support together with the tool holder until the tool guide reaches the work support. Therefore, the tool guide is particularly suitable for guiding a long tool axis. is there.

Further, in this structure, if the structure of the built-in motor is adopted for the guide member driving means,
By reducing the weight of the guide member driving means, the burden on the support structure of the guide support member is reduced, and it is possible to suppress, for example, bending due to its own weight.

Further, the guide member driving means includes a drive distribution mechanism for distributing a driving force output from a drive source of the tool driving means to the guide member. It is also preferable that both of the rotational drives are performed in synchronization with each other. According to this configuration, with a simple configuration using a single drive source, both the tool shaft and the guide member can be reliably driven to rotate synchronously.

Specifically, a drive source of the tool driving means is provided on the tool holding section side, and the drive distribution mechanism is rotatably supported on the tool holding section side and the tool guide section side, and A transmission shaft that can be extended and contracted in the feed direction of the tool holding unit, a tool-side transmission mechanism that transmits a driving force output by a drive source of the tool driving unit to the transmission shaft, and a guide member that transmits a rotational force of the transmission shaft to the guide member. And a guide-side transmission mechanism for transmitting the power to the vehicle.

According to this configuration, even if the distance between the tool holder and the tool guide changes due to the feed driving of the tool holder, the distance from the drive source to the guide member is absorbed while expanding and contracting the transmission shaft. Can be transmitted without any trouble.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. In the following embodiments, an example in which the present invention is applied to a boring machine will be described. However, in the present invention, the present invention is applied to various machine tools such as a drill, a reamer, a milling machine, and an end mill regardless of the type of a tool shaft. Is applicable.

First Embodiment (FIGS. 1 and 2) The illustrated machine tool includes a bed 10 on which a slide table 14 is provided via a slide base 12 in a predetermined direction (left-right direction in FIG. 1). It is installed so that it can slide.
A nut 15 is provided at a lower portion of the slide table 14, while a feed motor 16 and a feed screw 18 connected to an output shaft thereof are provided on the slide base 12, and the feed screw 18 and the nut 15 are provided. It is screwed. Therefore, the feed screw 18 by the feed motor 16 is used.
The slide table 14 is slidably driven by the rotational drive of. That is, the feed motor 16 and the feed screw 18 constitute feed means.

On the slide table 14, a spindle head 20 is installed. A horizontal spindle (not shown) is rotatably supported by the spindle head 20, and a long tool shaft 22 is mounted coaxially with a tip side (right side in FIG. 1) of the spindle. A boring tool 23 is mounted on the tip of the tool shaft 22. That is, the slide table 14 and the spindle head 20 constitute a tool supporting portion that rotatably supports the tool shaft 22.

On the slide table 14, a tool driving motor 25 is installed via a motor support 21 at a position behind the spindle head 20. The output shaft of the tool drive motor 25 and the rear end of the main shaft are each provided with a toothed pulley (hereinafter, all of the toothed pulleys are "pulleys").
Abbreviated. ) 26, 24 are fixed, and both pulleys 26,
A toothed belt (hereinafter, all the toothed belts are abbreviated as “belts”) 28 is stretched around 24. Therefore,
A driving force output from an output shaft of a tool driving motor 25 as a driving source is output from a pulley 26, a belt 28, and a pulley 24.
The drive shaft is transmitted to the main shaft of the main shaft head 20 through a drive transmission mechanism, whereby the main shaft and the tool shaft 22 are integrally rotated.

On the bed 10, the spindle head 2 is provided.
The work 30 is supported at a position away from the zero in the feed direction (the slide direction of the slide table 14). In the illustrated example, the work 30 is supported from below by a work support (work support portion) 32 fixed on the bed 10. The workpiece 30 is provided with a machining hole 34 to be subjected to boring by the tool shaft 22.
The work 30 is supported at a position where the machining hole 34 opens toward the tip of the tool shaft 22.

A tool guide 36 is provided between the spindle head 20 and the work support 32.
The tool guide portion 36 supports a middle portion of the long tool shaft 22 to form a processing hole 34 (processing position) of the workpiece 30.
It is to guide to.

More specifically, the tool guide section 36 includes a guide support member 38 erected on the bed 10. In place of the guide support member 38, the tool support 22
A bush storage hole 40 penetrating in the axial direction is provided, and a cylindrical guide bush (guide member) 44 is supported inside the bush storage hole 40 via a pair of front and rear bearings 42 so as to be rotatable around its central axis. Have been.

As shown in FIG. 2, the guide bush 44 has an inside diameter through which the tool shaft 22 is inserted with an extremely small clearance, and is arranged in order from the front end side (the work 30 side; right side in FIG. 2). , A main body 46, a step 47 having a slightly larger outer diameter than the main body 46, and a pulley 48. And the main body 4
6, the inner ring of the bearings 42 is fixed to the outer peripheral surface, and the retaining ring 45 fixed to the distal end side of the main body 46 and the step portion 47 sandwich the bearings 42 from the front and rear. I have.

At the upper end of the guide support member 38, a mounting plate 50
Has been fixed. The mounting plate 50 is used for the guide support member 3.
8 from the upper end to the rear side (spindle head 20 side; left side in FIG. 2)
And a bush drive motor (guide member drive source) 52 is fixed to the end thereof. A pulley 54 is fixed to the output shaft of the bush drive motor 52, and a belt 56 is stretched between the pulley 54 and the pulley portion 48 of the guide bush 44. Therefore, the rotation driving force output from the bush drive motor 52 is transmitted to the guide bush 44 by a drive transmission mechanism including the pulley 54, the belt 56, and the pulley portion 48. The bush drive motor 52 and the drive transmission mechanism are designed so that the guide bush 44 is driven to rotate in the direction and speed equal to the direction and speed of rotation of the tool shaft 22 by the transmission of the drive force. I have.

Next, a processing method using this machine tool will be described.

1) At the stage before machining, the tool shaft 22 is inserted through the guide bush 44 as shown in FIG. 1, but is retracted from the machining hole 34 of the work 30.

2) The tool shaft 22 is driven to rotate by operating the tool drive motor 25. Further, in synchronization with this, the guide bush 44 is rotationally driven by operating the bush drive motor 52. Since the rotation direction and speed of the guide bush 44 are equivalent to the rotation direction and speed of the tool shaft 22, no relative rotation occurs between the guide bush 44 and the tool shaft 22. Therefore, even if the tool shaft 22 is rotated at a high speed, no seizure occurs between the outer peripheral surface and the inner peripheral surface of the guide bush 44.

3) The feed motor 16 is operated to advance the slide table 14 and the spindle head 20 integrally (slide toward the work support 32). At this time, the long tool shaft 22 is rotated by the guide bush 4
4 accurately guides the workpiece 30 to the machining hole 34,
With the boring tool 23 of the tool shaft 22, high-precision machining is performed on the machining hole 34.

Second Embodiment (FIGS. 3 and 4) The illustrated machine tool has a bed 10 on which a slide table 14 is placed via a slide base 12 in a predetermined direction (left-right direction in FIG. 3). It is installed so that it can slide.
A nut 15 is provided at a lower portion of the slide table 14, while a feed motor 16 and a feed screw 18 connected to an output shaft thereof are provided on the slide base 12, and the feed screw 18 and the nut 15 are provided. It is screwed. Therefore, the feed screw 18 by the feed motor 16 is used.
The slide table 14 is slidably driven by the rotational drive of. That is, the feed motor 16 and the feed screw 18 constitute feed means.

On the slide table 14, a spindle head 20 is installed. A horizontal main shaft (not shown) is rotatably supported on the main shaft head 20, and a long tool shaft 22 is mounted coaxially with a front end side (right side in FIG. 3) of the main shaft. A boring tool 23 is mounted on the tip of the tool shaft 22. That is, the slide table 14 and the spindle head 20 constitute a tool supporting portion that rotatably supports the tool shaft 22.

On the slide table 14, a tool drive motor 25 is installed via a motor support 21 at a position behind the spindle head 20. A pulley 26 is fixed to the output shaft of the tool drive motor 25, and a front pulley 24 and a rear pulley 70 are fixed side by side at the rear end of the main shaft. And a belt 28 is stretched between them. Therefore, the driving force output from the output shaft of the tool driving motor 25 as a driving source is
The drive shaft is transmitted to the main shaft of the main shaft head 20 via a drive transmission mechanism including the drive shaft 8 and the pulley 24, whereby the main shaft and the tool shaft 22 are integrally rotated.

On the bed 10, the spindle head 2 is provided.
The work 30 is supported at a position away from the zero in the feed direction (the slide direction of the slide table 14). In the illustrated example, the work 30 is supported from below by a work support (work support portion) 32 fixed on the bed 10. The workpiece 30 is provided with a machining hole 34 to be subjected to boring by the tool shaft 22.
The work 30 is supported at a position where the machining hole 34 opens toward the tip of the tool shaft 22.

Further, a tool guide 36 is provided between the spindle head 20 and the work support 32.
The tool guide portion 36 supports a middle portion of the long tool shaft 22 to form a processing hole 34 (processing position) of the workpiece 30.
It is to guide to.

More specifically, the tool guide section 36 includes a guide support member 38 erected on the bed 10. In place of the guide support member 38, the tool support 22
A bush storage hole 40 penetrating in the axial direction is provided, and a cylindrical guide bush (guide member) 44 is supported inside the bush storage hole 40 via a pair of front and rear bearings 42 so as to be rotatable around its central axis. Have been.

As shown in FIG. 4, the guide bush 44 has an inner diameter through which the tool shaft 22 is inserted with a very small clearance, and is arranged in order from the front end side (the work 30 side; right side in FIG. 4). , A main body 46, a step 47 having a slightly larger outer diameter than the main body 46, and a pulley 48. And the main body 4
6, the inner ring of the bearings 42 is fixed to the outer peripheral surface, and the retaining ring 45 fixed to the distal end side of the main body 46 and the step portion 47 sandwich the bearings 42 from the front and rear. I have.

Further, in this embodiment, a drive distribution mechanism for distributing the driving force output from the tool driving motor 25 to the guide bush 44 is provided.

The drive distribution mechanism includes a slide table 1
4 is provided with a transmission shaft 60 extending toward the tool guide portion 36. The transmission shaft 60 includes a front shaft 62 and a rear sleeve 64 into which the front shaft 62 is inserted from the front side, and the entire transmission shaft 60 can expand and contract in the insertion direction. Further, splines 62a and 64a are formed on the outer peripheral surface of the rear half of the front shaft 62 and the inner peripheral surface of the rear sleeve 64, and the front shaft 62 and the rear sleeve 64 are fitted by the splines. Relative rotation is restricted. That is, torque transmission from the rear sleeve 64 to the front shaft 62 is possible.

The rear sleeve 64 includes a pair of front and rear bearings 66.
And is supported on the slide table 14 side via the sleeve so as to be rotatable around the central axis of the sleeve. A pulley 68 is formed at the rear end of the rear sleeve 64.
A belt 72 is stretched between the main shaft and the rear pulley 70 of the main shaft.

On the other hand, the front end of the front shaft 62 is rotatably supported on a predetermined portion (a portion below the guide bush 44 in the illustrated example) of the bush support member 38 via a pair of front and rear bearings 74 so as to be rotatable around the central axis. Have been. In the front shaft 62, a pulley 76 is fixed to a portion immediately behind the portion supported by the bearing 74, and a step portion 77 formed on the pulley 76 and a flange formed on a front end of the front shaft 62. With the portion 63, the two bearings 74 are sandwiched from the front and rear. A belt 78 is stretched between the pulley 76 and the pulley portion 48 of the guide bush 44.

Accordingly, the rotational force of the main shaft supported by the main shaft head 20 is controlled by the tool-side transmission mechanism including the rear pulley 70, the belt 72, and the pulley 68, the transmission shaft 60, the pulley 76, and the belt 78. , And a guide-side transmission mechanism including a pulley portion 48, and are sequentially distributed to the guide bush 44. The tool-side transmission mechanism and the guide-side transmission mechanism are designed so that the guide bush 44 is driven to rotate in the direction and speed equal to the direction and speed of rotation of the tool shaft 22 by the distribution of the driving force. ing.

Next, a processing method using this machine tool will be described.

1) At the stage before machining, the tool shaft 22 is inserted through the guide bush 44 as shown in FIG. 3, but is retracted from the machining hole 34 of the work 30.

2) The tool drive motor 25 is operated. The driving force is transmitted to the main shaft via the pulley 26, the belt 28, and the pulley 24, and the tool shaft 22 is driven to rotate integrally with the main shaft. Further, the rotational force of the main shaft is transmitted to the guide bush 44 via the tool-side transmission mechanism, the transmission shaft 60, and the guide-side transmission mechanism, and the guide bush 44 is also driven to rotate. That is, the synchronous rotation of the tool shaft 22 and the guide bush 44 is realized with a simple configuration using a single drive source (tool drive motor 25).

Since the direction and speed of rotation of the guide bush 44 at this time are equivalent to the direction and speed of rotation of the tool shaft 22, the relative rotation between the guide bush 44 and the tool shaft 22 is limited. Does not occur. Therefore, even if the tool shaft 22 is rotated at a high speed, no seizure occurs between the outer peripheral surface and the inner peripheral surface of the guide bush 44.

3) The feed motor 16 is operated to advance the slide table 14 and the spindle head 20 integrally (slide toward the work support 32). At this time, the long tool shaft 22 is rotated by the guide bush 4
4 accurately guides the workpiece 30 to the machining hole 34,
With the boring tool 23 of the tool shaft 22, high-precision machining is performed on the machining hole 34.

In the second embodiment, the drive transmission path from the tool drive motor 25 to the main shaft is common to the tool shaft 22 and the guide bush 44, and the driving force is distributed from the main shaft to the guide bush 44. What to do,
The drive distribution mechanism according to the present invention is not limited to this. For example, the drive force may be directly distributed from the output shaft of the tool drive motor 25 to the guide bush 44 without passing through the main shaft.

Third Embodiment (FIGS. 5 and 6) The illustrated machine tool includes a bed 10 on which a slide table 14 is provided via a slide base 12 in a predetermined direction (left-right direction in FIG. 5). It is installed so that it can slide.
A nut 15 is provided at a lower portion of the slide table 14, while a feed motor 16 and a feed screw 18 connected to an output shaft thereof are provided on the slide base 12, and the feed screw 18 and the nut 15 are provided. It is screwed. Therefore, the feed screw 18 by the feed motor 16 is used.
The slide table 14 is slidably driven by the rotational drive of. That is, the feed motor 16 and the feed screw 18 constitute feed means.

On the slide table 14, a spindle head 20 is installed. A horizontal spindle (not shown) is rotatably supported on the spindle head 20, and a long tool shaft 22 is mounted coaxially with a tip side (right side in FIG. 5) of the spindle. A boring tool 23 is mounted on the tip of the tool shaft 22. That is, the slide table 14 and the spindle head 20 constitute a tool supporting portion that rotatably supports the tool shaft 22.

A tool drive motor 25 is mounted on the slide table 14 at a position behind the spindle head 20 via a motor support 21. A pulley 26 is fixed to the output shaft of the tool drive motor 25, and a pulley 24 is fixed to the rear end of the main shaft.
8 have been bridged. Therefore, the driving force output from the output shaft of the tool driving motor 25 as a driving source is
The power is transmitted to the main shaft of the main shaft head 20 via a drive transmission mechanism including the belt 6, the belt 28, and the pulley 24, whereby the main shaft and the tool shaft 22 are integrally rotated.

On the bed 10, the spindle head 2
The work 30 is supported at a position away from the zero in the feed direction (the slide direction of the slide table 14). In the illustrated example, a work support (work support portion) 32 having a cavity 33 opening forward is fixed on the bed 10, and the work 30 is supported in the cavity 33 from below.
The work 30 is provided with a machining hole 34 to be subjected to boring by the tool shaft 22, and the work 30 is supported at a position where the machining hole 34 opens toward the tip of the tool shaft 22. ing.

Further, a tool guide 36 is provided between the spindle head 20 and the work support 32.
The tool guide portion 36 supports a middle portion of the long tool shaft 22 to form a processing hole 34 (processing position) of the workpiece 30.
It is to guide to. Moreover, the tool guide 36
Is supported on the main spindle head 20 side so as to be relatively movable in a direction parallel to the feed direction, and the main spindle head 20
And is driven for feeding.

More specifically, the tool guide section 36 has a guide support member 38 as shown in FIG. A plurality of through holes 39 are provided in a peripheral portion of the guide support member 38,
The front end of the pilot bar 82 is fixed to each through hole 39. Each of the pilot bars 82 has a flange 83 at a position slightly behind the front end thereof, and is inserted into the through hole 39 of the guide support member 38 until the flange 83 hits the rear side surface of the guide support member 38. It is fixed to the guide support member 38 in a state of being inserted from the rear, and a portion on the rear side thereof is extended rearward from the guide support member 38 to be long. The rear part is the main spindle head 20.
Are held slidably in the front-rear direction within a cylinder portion 80 provided at the front end. Further, a compression coil spring 84 is interposed between the flange portion 83 and the front end of the cylinder portion 80, and the entire guide support member 38 is urged forward by its elastic force.

At the front end of each pilot bar 82, a positioning pin 85 projecting forward is formed. on the other hand,
The front surface of the work support 32 (the surface facing the guide support member 38; the left side in FIG. 5) is provided with the positioning pin 8.
A positioning hole 35 into which the guide support member 38 can be fitted is provided, and the guide support member 38 is positioned with respect to the work support 32 by the fitting.

A cylindrical portion 86 extending forward from the central portion is formed at the center of the guide support member 38, and a ring-shaped support member 88 is fixed to the rear end of the cylindrical portion 86. A bush housing hole 40 is formed inside 86. A cylindrical guide bush (guide member) is provided inside the bush housing hole 40 via a pair of front and rear bearings 90.
44 is rotatably supported about its central axis.

The guide bush 44 is connected to the tool shaft 2
2 has an inner diameter through which a very small clearance is inserted, and an outer diameter which keeps a sufficient gap between the inner surface of the cylindrical portion 86 and the front end and the rear end through the bearing 90, respectively. The front end of the tubular portion 86 and the support member 8
8 and rotatably supported.

A bush drive motor 92 for rotating and driving the guide bush 44 is incorporated in the cylindrical portion 86 of the guide support member 38. Specifically, a rotor 93 is fixed to an outer peripheral portion of the guide bush 44, and a stator 94 is fixed to an inner peripheral portion of the cylindrical portion 86 so as to surround the rotor 93. A so-called built-in motor is configured. That is, when the stator 94 is energized, the guide bush 44 is driven to rotate by a magnetic field formed between the stator 94 and the rotor 93. In addition, the bush drive motor 92 is designed to rotate the guide bush 44 in the direction and speed equal to the direction and speed of rotation of the tool shaft 22.

Next, a processing method using this machine tool will be described.

1) At the stage before machining, the tool shaft 22 is inserted through the guide bush 44 as shown in FIG. 5, but is retracted from the machining hole 34 of the work 30. At this time, the guide support member 38 is held at the foremost end position by the resilient force of the compression coil spring 84, but the positioning pin 85 is separated rearward from the positioning hole of the work support 38.

2) The tool drive motor 25 is operated to rotate the tool shaft 22. At the same time, the guide support member 38
By operating the bush drive motor 92 inside, the guide bush 44 is also driven to rotate. Guide bush 44 at this time
The rotation direction and speed of the guide bush 44 are the same as the rotation direction and speed of the tool shaft 22.
No relative rotation occurs between the tool shaft 22 and the tool shaft 22. Therefore, even if the tool shaft 22 is rotated at a high speed, no seizure occurs between the outer peripheral surface and the inner peripheral surface of the guide bush 44.

3) The feed motor 16 is operated to advance the slide table 14 and the spindle head 20 integrally (slide toward the work support 32). At first, the guide support member 38 also advances integrally with the main spindle head 20, but the positioning pin 85 is fitted into the positioning hole 35 on the work support tool 32 side so that the peripheral edge of the guide support member 38 works. The guide support member 38 is prevented from advancing from the point of contact with the front end surface of the support tool 32, and only the main shaft head 20 advances with the compression deformation of the coil spring 84. Thus, the tool shaft 22 advances inside the guide bush 44 and is guided to the machining hole 34 of the work 30. Therefore, high precision machining is performed on the machining hole 34 by the boring tool 23 of the tool shaft 22.

In the machine tool according to this embodiment, since the guide support member 38 advances integrally with the main spindle head 20 until the guide support member 38 comes into contact with the work support 32 side, especially the long tool shaft 2
2 is suitable for the guidance. Moreover, the bush drive motor 9
Reference numeral 2 denotes a so-called built-in motor which is integrated into the guide support member 38, and is lighter than the bush drive motor 52 shown in FIG. 1, for example. Also in the structure supported on the side of the pad 20, the weight of the bush drive motor 92 does not add much strength, and for example, the pilot bar 82 bends due to the weight and the like so that the guide support member 38 is lower than the normal position. Is suppressed.

In addition, the present invention can take the following embodiments, for example.

In each of the above-described embodiments, a winding transmission mechanism using a belt and a pulley is used for the drive transmission mechanism and the drive distribution mechanism. However, the present invention is not limited to this, and for example, a gear mechanism and other various mechanisms are used. Is applicable.

In each of the above embodiments, the direction and speed of the rotational drive of the tool shaft 22 and the guide bush (guide member) 44
Although the direction and speed of the rotational drive are completely matched, the two speeds may be slightly shifted. Further, even when the rotation speed of the guide bush 44 is clearly lower than the rotation speed of the tool shaft 22, if the rotation directions of the guide bush 44 and the tool shaft 22 are the same, the rotation speed of the guide bush 44 is the same. The relative rotation speed between the guide bush 44 and the tool shaft 22 can be reduced, which is effective.

[0078]

As described above, the present invention is provided with a guide member for guiding a tool shaft to a workpiece machining position, and feeds the tool shaft while rotating the guide member in the same direction as the rotation direction of the tool shaft. So that
By reducing the relative rotation speed between the guide member and the tool shaft, there is an effect that the tool shaft can be accurately guided to a predetermined workpiece processing position while enabling high-speed rotation of the tool shaft.

[Brief description of the drawings]

FIG. 1 is a cross-sectional front view illustrating an entire configuration of a machine tool according to a first embodiment of the present invention.

FIG. 2 is a sectional front view showing a main part of the machine tool of FIG.

FIG. 3 is a cross-sectional front view illustrating an entire configuration of a machine tool according to a second embodiment of the present invention.

FIG. 4 is a sectional front view showing a main part of the machine tool of FIG. 3;

FIG. 5 is a cross-sectional front view showing the entire configuration of a machine tool according to a third embodiment of the present invention.

FIG. 6 is a sectional front view showing a main part of the machine tool shown in FIG. 5;

FIG. 7 is an overall side view of a conventional machine tool.

[Explanation of symbols]

Reference Signs List 14 slide table (tool holding unit) 20 spindle head (tool holding unit) 22 tool shaft 25 tool driving motor (drive source of tool driving means) 30 work 32 work support (work support) 36 tool guide 38 guide support Reference Signs List 40 bush storage hole (guide member storage hole) 44 guide bush (guide member) 48 pulley portion (configures drive transmission mechanism or guide side transmission mechanism) 52 bush drive motor (guide member drive source) 54 pulley (configures drive transmission mechanism) ) 56 Belt (configures a drive transmission mechanism) 60 Transmission shaft 68 Pulley section (configures a tool-side transmission mechanism) 70 Pulley (configures a tool-side transmission mechanism) 72 Belt (configures a tool-side transmission mechanism) 76 Pulley (guide-side transmission) (Construction mechanism) 78 Belt (Construction of guide-side transmission mechanism) 82 Pilot bar 84 Compression coil spring 92 Interview drive motor 93 rotor 94 stator

Claims (10)

[Claims] 1. A tool shaft, a tool holding portion for rotatably holding the tool shaft, tool driving means for rotating the tool shaft, a work support portion for supporting a work, and a work support portion supported by the work support portion. And a feed means for feeding the tool axis and the tool holding portion in the axial direction with respect to the workpiece, wherein the tool axis is provided between the tool holding portion and the work support portion. A cylindrical guide member for guiding the workpiece to the processing position is provided, the tool shaft is inserted through the guide member, and the guide member is rotated while being driven in the same direction as the rotation of the tool shaft. A machining method using a machine tool, wherein a tool axis is sent toward the workpiece. 2. The machining method according to claim 1, wherein the guide member is rotated at a speed substantially equal to a rotation speed of the tool shaft. 3. A tool shaft, a tool holding portion for rotatably holding the tool shaft, tool driving means for rotating the tool shaft, a work support portion for supporting a work, and a work support portion supported by the work support portion. A feeding member for feeding the tool axis and the tool holding portion in the axial direction with respect to the workpiece, wherein a guide member through which the tool shaft is inserted between the tool holding portion and the work supporting portion. A tool guide portion having a guide support member rotatably supporting the guide member around the center axis of the tool shaft, and rotating the guide member in the same direction as the rotation direction of the tool shaft. A machine tool comprising guide member driving means. 4. The machine tool according to claim 3, wherein said guide member driving means rotates said guide member at a speed substantially equal to a rotation speed of said tool shaft. 5. The machine tool according to claim 3, wherein said guide member driving means is provided in said tool guide portion. 6. The machine tool according to claim 5, wherein said guide member drive means includes a guide member drive source fixed to said guide support member, and a drive for transmitting an output of said guide member drive source to said guide member. A machine tool comprising a transmission mechanism. 7. The machine tool according to claim 5, wherein a rotor is provided on an outer peripheral portion of the guide member, and a stator facing the rotor is fixed to a guide support member side, and the guide member is formed by the rotor and the stator. A machine tool comprising a motor configured to rotate a motor. 8. The machine tool according to claim 5, wherein the guide support member is relatively movable with respect to the tool holding unit in a direction parallel to a feed direction of the tool holding unit. A machine tool characterized in that the machine tool is supported so as to be biased toward the work supporting portion. 9. The machine tool according to claim 3, wherein the guide member drive unit includes a drive distribution mechanism that distributes a driving force output by a drive source of the tool drive unit to the guide member. A machine tool characterized in that both the rotational drive of the tool shaft and the rotational drive of the guide member are performed synchronously by the source. 10. The machine tool according to claim 9, wherein a drive source of the tool driving means is provided on the tool holding section side, and the drive distribution mechanism rotates to the tool holding section side and the tool guide section side. A transmission shaft that is supported so as to be able to extend and contract in the feed direction of the tool holding unit, a tool-side transmission mechanism that transmits a driving force output by a drive source of the tool driving unit to the transmission shaft, A machine tool comprising: a guide-side transmission mechanism that transmits torque to the guide member.