JPH08126934A - Dust protective device for two-plane constrained type tool shank mounting end face of main spindle - Google Patents

Abstract

PURPOSE: To prevent a decrease in tool mounting accuracy due to the entry of dust such as chips in tool replacement on a tool holder and the tool holder mounting end face of a main spindle in the main spindle which can be mounted with the tool holder having a two-plane constrained type tool shank part. CONSTITUTION: Part of air supplied to an air pocket 1c for air sealing provided engraved in the outer surface of a main shaft 1 at its tip is exhausted from a nozzle 1f opened to a main shaft tip face 1b through an air path 1d in the main spindle 1. Cleaning is applied to a tool holder 5 and the tool holder mounting face of the main shaft, using part of the air and air exhausted in a main shaft tapered hole 1a from the slit part of a collet 7. Thus, the entry of dust such as chips is prevented in tool replacement to enhance tool mounting accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing dust such as cutting chips from adhering to a two-face restraint type tool shank attachment end face of a spindle of a machine tool such as a machining center.

[0002]

2. Description of the Related Art Conventionally, a tool holder mounted on a spindle of a machine tool such as a machining center usually has a BT type shank portion 101 as shown in FIG. 3, and is supported by a tapered hole 103a of a spindle 103 only by a tapered portion. It has become so. Therefore, since there is a gap δ between the main shaft side end surface 102a of the flange portion 102 and the main shaft 103 front end surface 103b, it is only necessary to clean the main shaft taper hole with air at the time of automatic tool replacement. Nozzle 105
More air is ejected to clean the tapered hole 103a.

[0003]

In the method of cleaning only the taper hole at the time of automatic tool change described in the prior art, both the taper and the flange end surface, which have recently been used, are brought into close contact with the main shaft. When using a tool holder having a two-face restraint type tool shank, there is a problem that it is insufficient to remove dust such as fine chips adhering to the flange end surface and the spindle tip surface of the tool holder.
The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to prevent dust and other dust from adhering to the two-face constraining type tool shank mounting end surface, An object of the present invention is to provide a dustproof device that improves the accuracy of tool attachment during automatic tool replacement.

[0004]

In order to achieve the above object, a dustproof device for a two-face restraint type tool shank mounting end face of a spindle according to the present invention is a spindle in which a two-face restraint type tool shank can be attached and detached. An air flow path is provided to supply the air supplied from the outer circumference of the tool shank to the nozzle that opens on the tool shank mounting end face, and the air supplied from the spindle head to the spindle is ejected from the nozzle to attach dust such as cutting chips to the tool shank. It is to prevent adhesion to the end face.

Further, the dustproof device for the mounting end face of the two-face restraint type tool shank of the main spindle of the present invention is such that the two-face restraint type tool shank is attachable and detachable and has an air pocket for forming an air seal on the outer periphery of the tip end. An air flow path communicating with the air pocket in the main shaft and having a nozzle opening at the tool shank mounting end surface is provided, and a part of the air supplied to the pocket is ejected from the nozzle so that dust such as cutting chips is used as a tool. It is intended to prevent the shank from being attached to the mounting end surface.

[0006]

[Operation] In addition to cleaning the conventional spindle taper hole by ejecting air from the nozzle that opens on the spindle tip surface, the contact surface between the spindle tip surface and the flange end surface of the tool holder is cleaned to perform automatic tool replacement. Prevents dust such as chips and cutting fluid from entering the contact surface.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the dustproof device for the two-face restraint type tool shank mounting end face of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a spindle head tip portion of a machining center. A spindle 1 is rotatably supported by a plurality of bearings 4 fitted in a bearing housing 3 on a spindle head main body 2, and a through hole of the spindle 1 is formed. Has a tapered end formed in the tapered hole 1a.

The tool holder 5 mounted on the spindle 1 has a taper portion 5a in close contact with the spindle taper hole 1a and a flange portion 5b.
Has a two-face restraint type tool shank whose end face is in close contact with the spindle end face 1b, and is drawn in via a collet 7 by a draw bar 6 axially movably inserted into a central hole following the tapered hole 1a of the spindle 1. , It is designed to be detachably attached.

The bearing housing 3 is provided with oil-air lubrication channels 3a and 3b for lubricating the bearing 4, and a lid 8 is concentrically fixed to the tip thereof. An air passage 8a is bored in the lid 8 in the radial direction, the air passage 8a communicates with a screw joint 9 to which air is supplied from the spindle head main body 2 side, and is engraved in an annular shape on the outer periphery of the spindle 1. The front end is open to the air pocket 1c. Air jetted from the air pocket 1c forms an air seal between the outer peripheral surface of the tip of the main shaft 1 and the inner peripheral surface of the lid 8. Further, the collar 10 fitted on the front side of the air pocket 1c and the inner periphery of the lid 8 are drilled. The corresponding surface is formed on the labyrinth seal surface 11 to prevent dust such as fine chips and cutting water from entering the bearing 4 from the outside.

A radial shallow groove 1e is formed on the tip surface 1b of the main shaft 1.
Are engraved at equal intervals, a nozzle 1f at the tip is opened in this shallow groove 1e, and an L-shaped air passage 1d whose rear end communicates with the air pocket 1c is bored in the main shaft. A part of the air supplied into 1c is ejected from the nozzle 1f. Air is supplied from the air source to the threaded joint 9 via an air pressure control member having an unillustrated throttle valve and switching valve for switching the air pressure between high and low in order to increase the air pressure during automatic tool change and enhance the cleaning effect. Supplied.

On the other hand, the draw bar 6 has an air supply hole 6a for cleaning the axial spindle taper hole 1a and an air supply hole 6a.
An air supply hole 6b penetrating at a right angle to
The air supply hole 6b is the sleeve 1 fitted into the center hole of the spindle 1.
The air passage 12a in the radial direction, which is bored in 2, is communicated with the drawbar 6 when the drawbar 6 is advanced (the tool is removed).
An air passage 1h communicating with the air passage 12a and the inner peripheral groove 1g for engaging the collar portion of the collet 7 is formed in the main shaft 1 in a V shape, and a slit portion (not shown) of the collet 7 is formed when the tool is changed. The inside of the tapered hole 1a is cleaned by the air jetted through the inside of the tapered hole 1a.

Next, the operation of the dustproof device for the two-face restraint type tool shank mounting end face of this embodiment will be described. When the power of this machine is turned on, low-pressure air is supplied to the threaded joint 9 from the air source (not shown) through the throttle valve of the air pressure control member (not shown) regardless of whether the spindle 1 is rotated or stopped, and the periphery of the air pocket 1c is supplied. An air seal is formed on the rotating surface of the main shaft end surface 1 and a part of the air is ejected from the nozzle 1f of the air flow path 1d.
It is ejected from the shallow groove 1e of b to prevent dust such as cutting chips and cutting fluid from entering.

When the cutting process progresses and the cutting section of the tool mounted on the spindle 1 is finished and the automatic tool exchange is started, the switching valve of the pressure control member (not shown) is actuated and high pressure air is discharged from the nozzle 1f on the end face of the spindle. Gush out. Then, an exchange arm (not shown) grips the grip groove 5c of the tool holder 5, and the draw bar 6
Is pushed out to open the collet 7, and the tool holder 5 is slightly pushed out by the tip of the draw bar 6 to loosen the fitting between the spindle 1 and the tool holder 5. At this time, the air passage hole 6 of the draw bar 6
b and the air passage 12a of the sleeve 12 communicate with each other, and the air is jetted from the slit portion of the collet 7 into the spindle tapered hole 1a through the air passage 1h in the spindle.

Thus, the spindle end face 1b and the spindle taper hole 1a
While the air is ejected from both of them to perform cleaning, the tool holder 5 is exchanged by the action of the exchange arm (not shown). When the tool exchange is completed, the switching valve of the air pressure control member (not shown) is activated to switch to low pressure air, and the nozzle 1
Cutting is continued while ejecting air from f.

The air ejected from the nozzle 1f does not have to be always ejected regardless of whether the main shaft 1 is rotated or stopped, and may be ejected only during stop or during automatic tool change. In this case, it is not necessary to interpose the air pocket 1c if the supply passage on the spindle head 2 side and the air passage on the spindle 1 side communicate with each other when the spindle 1 stops at a fixed position.

[0016]

Since the dustproof device for the two-face restraint type tool shank mounting surface of the main shaft of the present invention is constructed as described above, it has the following effects. For a spindle that can be fitted with a two-face restraint type tool shank, in addition to the conventional cleaning in which air is jetted into the spindle tapered hole, air is jetted from a nozzle provided on the spindle end face to clean the crimping end face of the spindle and tool holder. Since this is done, the flange end surface of the tool holder and the tip end surface of the spindle can be kept clean at all times, and the tool mounting accuracy at the time of tool replacement can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a spindle head tip portion having a dustproof device for a two-face restraint type tool shank attachment end face of the present invention.

FIG. 2 is a view of the main shaft as seen from the front side.

FIG. 3 is a sectional view of a spindle head peripheral portion of a spindle head showing a conventional BT type tool holder dustproof device.

[Explanation of symbols]

 1 Spindle 1a Air flow path 1f Nozzle 2 Spindle head 3 Bearing housing 5 Tool holder 5a Tapered shank part 5b Flange part 6 Drawbar 7 Collet 8 Lid 9 Threaded joint

Claims (2)

[Claims] 1. A main shaft to which a two-face restraint type tool shank is attachable / detachable, is provided with an air flow path for supplying air supplied from the outer periphery of the main shaft tip end to a nozzle opened at a tool shank mounting end face, and from the main shaft head A two-face restraint type tool shank attachment end face dust preventive device for a spindle, which prevents dust such as chips from adhering to the tool shank attachment end face by ejecting air supplied to the nozzle from the nozzle. 2. A main shaft having a two-face constraining type tool shank detachable and having an air pocket for forming an air seal on the outer periphery of the tip, wherein a nozzle is provided at the end face of the tool shank which communicates with the air pocket in the main shaft. An air flow path that opens is provided, and a part of the air supplied to the pocket is ejected from the nozzle to prevent dust such as cutting chips from adhering to the tool shank attachment end surface. Surface restraint type tool shank dustproof device for mounting end face.