JP2000117576A - Attachment spindle device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To share a drive mechanism for fixing and releasing a tool to a spindle of a machine tool and an attachment spindle,
The structure of the attachment spindle device is simplified and downsized. When a tool is attached to and detached from a spindle 29 of an attachment spindle device, a driving force of a cylinder mechanism acting on a draw bar 11 for fixing and releasing the tool to and from a spindle 1 of a machine tool is applied to a shaft member 43 of the attachment spindle device. The dedicated power source required for fixing and opening the small tool to the main shaft 29 of the attachment main shaft device is omitted by transmitting the power to the draw bar 35 of the attachment main shaft via the main shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an attachment spindle device for a machine tool.

[0002]

2. Description of the Related Art Conventionally, an attachment spindle device is attached to a spindle head of a machine tool in case a fine machining needs to be performed by using a machine for performing machining by driving a large (normal) tool. The desired machining is performed by a small tool fixed to the attachment spindle device.
In this case, a dedicated cylinder mechanism for operating a clamp and an unclamping member for attaching and detaching a small tool is attached to the attachment spindle device, so that the attachment spindle device is enlarged and the structure is complicated.

[0003]

SUMMARY OF THE INVENTION In view of the above-mentioned problems inherent in the prior art, an object of the present invention is to provide an attachment spindle device using a drive mechanism for a tool clamping and unclamping means on a spindle of a machine tool. An object of the present invention is to provide an attachment spindle device for a machine tool, in which a dedicated cylinder mechanism for clamping and unclamping the tool from the attachment spindle device can be omitted by interlocking and driving the tool clamp / unclamp members of the above. .

[0004]

In order to achieve the above object, an attachment spindle device of a machine tool according to the present invention has the following components. (1) An attachment spindle device attached to a spindle head of a machine tool, an attachment housing fixed to the spindle head of the machine tool, an attachment spindle supported and supported by the attachment housing, and inserted into the attachment spindle bore. An attachment tool clamping member configured to elastically urge the attachment main shaft rearward to clamp a tool to the attachment main shaft, and a tool for a main shaft tool of the machine tool provided slidably with respect to the attachment housing. A shaft member for receiving the unclamping force of the clamping means, pressing the attachment tool clamping member against its elastic urging force, and unclamping the tool clamped on the attachment main shaft.

[0005]

The operation of the present invention will be briefly described below. (1) A housing of an attachment spindle device (hereinafter, referred to as "spindle device") is detachably fixed to a front surface of a spindle head of a machine tool. At this time, the rear part of the shaft member having the taper shank and the pull stud is mounted coaxially with the taper shank mounting hole (hereinafter, referred to as “tapered hole”) of the main shaft of the machine tool. That is, the mounting position of the spindle device with respect to the spindle head satisfies the condition that the axes of the main shaft of the machine tool and the shaft member of the spindle device coincide (coaxial). The operation of attaching the spindle device to the spindle head of the machine tool is generally performed manually.However, in order to satisfy the above conditions, an assembling type is used between the coupling surfaces of the two or an assembly such as providing two or more positioning pins. Means are usually required. The attachment of the spindle device to the spindle head of the machine tool is performed in substantially the same process as the tool change operation in the machine tool.

(2) At this time, the collet chuck of the attachment tool clamp member in the spindle device is pulled by the draw bar of the attachment tool clamp member having elastic biasing means and is in a tightened state. Then, after operating the tool clamping means incorporated in the main shaft of the machine tool, an elastic urging force acts on the draw bar to grip the pull stud of the shaft member of the main shaft device.

(3) Attachment of the spindle device When a small (small diameter) tool is exchanged or mounted on the spindle of the spindle device, an external force is applied to a draw bar of a tool clamping means built in the spindle of the machine tool, so that the spindle of the spindle device is attached. An external force is applied to the draw bar of the attachment tool clamping member of the spindle device through the shaft member by pressing the bottom surface of the tapered shank of the member, and the collet chuck is opened, and the tool exchange of the small tool is performed during that time.

(4) After the external force on the drawbar of the clamping means built into the main shaft of the machine tool is eliminated after the installation of the new tool, the drawbar is returned to the old position by the elastic urging force applied to the drawbar. Since it is isolated from the tapered shank bottom surface of the shaft member of the device, the elastic biasing force attached to the attachment tool clamp member of the spindle device is restored, and the tool clamp member works to fix the shank of the small tool to the attachment spindle of the spindle device. (5) The spindle is rotated at a high speed or an ultra-high speed by an inner motor, which is a power transmission mechanism for an attachment spindle installed inside the spindle device, to perform desired machining. (6) If the attachment spindle device is removed from the spindle head of the machine tool, the function as the original machine tool is exhibited.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the attachment spindle device of the present invention will be described below. Some of the constituent elements of the present invention include those within the technical level of the art at the time of filing the present invention. Since it includes members that can be changed as appropriate,
It is not allowed to reduce the scope of the gist of the invention based on only the present embodiment. FIG. 1 is a partial sectional side view of a spindle head of a machine tool including an embodiment of the attachment spindle device of the present invention, and FIG. 2 is a sectional side view of the spindle head of the machine tool. In FIG. 2, a first spindle 1 (spindle of a machine tool) is supported at its front and rear ends in a longitudinal axis direction by a front bearing 2 and a rear bearing 4, respectively, and is supported by a spindle head 3. FIG. 2 shows a state in which a normal (large) tool is mounted on the main shaft 1.

At the front end of the main shaft 1, a taper hole 5 for fitting a taper shank of a tool is opened concentrically with the main shaft 1. Following the taper hole 5, a first collet chuck 9 is provided. 7 are formed, and the collet chuck 9 is formed.
An inner cylinder hole is drilled to the rear end of the main shaft 1 in which a first draw bar 11 for operating the main shaft 1 and a draw bar guide cylinder 13 for sliding each member in the longitudinal axis direction are fitted. Between the rear end of the drawbar 11 and the rear end surface of the drawbar guide tube 13, a plurality of disc springs 15 for urging the rear end of the drawbar 11 toward the drawbar guide tube 13 rearward in the longitudinal direction are inserted. ,
It is provided concentrically to the rear end of the main shaft 1. Here, the push rod 7 is not at the tip of the drawbar 11 but at the drawbar 11.
The same effect can be obtained by forming between the chucks 9 of the collet chucks 9 provided radially.

A front bearing retainer 19 is fixed to the front surface of the spindle head 3, and a first bracket 21 is fixed to the rear surface. Further, the collar 23 and the spring retainer 24 attached to the peripheral surface of the rear end shaft of the draw bar 11 receive the elastic biasing force of the disc spring 15 and transmit the elastic force to the draw bar 11. A cylinder 25 and a piston 27 as driving means for the draw bar 11 are attached to the rear side surface of the bracket 21 along the axis in the axial direction of the draw bar 11, and a front port 26 of the cylinder 25 is provided.
(At that time, the pressure oil on the rear side is discharged to the outside of the cylinder 25 through the rear port 28), so that the piston 27 moves rearward and retreats from the position where the rear end of the drawbar 11 is pressed. (See Fig. 2)
As a result of the elastic biasing force of 15 acting to move the draw bar 11 backward, the collet chuck 9 tightens the pull stud of a new (normal) tool mounted by tool change, and fixes the tool to the main shaft 1 to fix the work Prepare for processing.

The main shaft 1 is connected via a power transmission mechanism (not shown).
Is rotated, and the spindle head 3 is moved and controlled to perform predetermined machining. When pressurized oil is supplied to the rear port 28 of the cylinder 25, the piston 27 moves forward and presses the rear end of the draw bar 11, and the draw bar 11 moves forward against the elastic biasing force of the disc spring 15. The collet chuck 9 tightening the pull stud of the tool mounted on the spindle 1 opens to open the pull stud of the tool, and the push rod 7 of the draw bar 11 moves the bottom of the taper shank of the tool. When pressed, the mounting tool is pushed out of the main shaft 1 to enable tool exchange. A tool holding portion is provided on the front side of the taper shank of the tool, and when the tool is automatically changed, the tool holder is locked here to facilitate the changing operation.

FIG. 1 shows a state in which a tool is usually removed and an attachment spindle device is mounted on a spindle head 3 of a machine tool. The names and symbols of members constituting the spindle head 3 are shown in FIG.
The function, operation, or operation has been described in detail in the description of FIG. The attachment spindle device has been proposed for the purpose of performing fine machining using the same machine tool, for example, which is difficult to implement by machining with a tool. Here, the right side of the arrow in FIG. 1 is the attachment spindle device, and the left side of the arrow is the spindle device of the machine tool.

The detailed structure of the attachment spindle device will be described with reference to FIG. 1. A second spindle (attachment spindle) 29 has its front and rear ends in the longitudinal axis direction supported by a front bearing 30 and a rear bearing 32, respectively. It is supported by the housing 31. A rotor 34 is attached to the peripheral surface of the main shaft 29 between the front bearing 30 and the rear bearing 32, and a stator 38 is provided inside the housing 31 to face the rotor.
An inner motor (for example, a high-frequency motor) as a power transmission mechanism of the main shaft 29 is formed.

At the front end of the main shaft 29, a taper hole for fitting a second collet chuck 33 for fastening a shank of a small (small diameter) tool is opened concentrically with the main shaft 29. Second drawbar 35 for actuating 33
A guide hole for sliding the draw bar 35 in the longitudinal axis direction is coaxially formed up to the rear end of the main shaft 29, and a spring holder 36 and a collar 37 provided at the rear end of the draw bar 35 and a rear end surface of the main shaft 29. A plurality of disc springs 39 for urging the draw bar 35 rearward of the longitudinal axis of the main shaft 29 are inserted therebetween. In FIG. 1, the inner diameter of the plurality of disc springs 39 is fitted to the outer peripheral surface of the main shaft 29, and the disc spring 39 is inserted between the rear end surface of the main shaft 29 and the rear end of the draw bar 35. There is no change in what is being done.

Since the plurality of disc springs 39 constantly urge the drawbar 35 rearward with respect to the main shaft 29, the collet chuck 33 linked to the drawbar 35 is a small tool mounted on the chuck 33. The shank is tightened and the small tool is fixed to the main shaft 29. The attachment tool clamp member is configured as described above. A bracket (second bracket) 41 attached to the attachment spindle device is connected to the rear side surface of the housing 31. The device is mounted on the bearing presser 19 of the spindle head 3 of the machine tool via the bracket 41. ing. The bracket 41
On the extension of the rotation axis of the main shaft 29, a shaft member 43 slidable in the axial direction of the main shaft 29 and abutting against the tapered hole 5 of the main shaft 1 to perform centering and positioning of the attachment main shaft device with respect to the main shaft 1 is assembled. The rear end of the shaft member 43 has the same shape as the taper shank of a normal tool, and a pull stud is formed at the bottom.

The front surface of the shaft member 43 is connected to the draw bar.
The spring member 36 and the collar 37 provided at the rear end of the shaft 35 are spaced from each other with a gap therebetween.
Occupies a position where the drawbar has an influence on the drawbar 35. Here, a compression spring 44 is inserted between the rear surface of the inner wall of the housing 31 and the front end of the shaft member 43, and is independent of the disc spring 39. It is elastically biased to the rear side).

In the case of FIG. 1, the pull stud of the shaft member 43 is fastened by a collet chuck 9 provided on the spindle head 3, and the tapered shank portion is fitted in the tapered hole 5 of the spindle 1. Fine machining with a small tool is performed in this state by driving the inner motor at a high speed or a very high speed. Regarding the shape of the small tool, there are not a few tools having a small diameter at a portion where a cutting edge is attached than a portion having a shank diameter. Fine machining using such small tools,
It deviates from the processing area of a normal tool and is difficult to process with a machine tool that uses a normal tool. This is why it is necessary to attach an attachment spindle device.

If it is necessary to change a small tool at the fine machining stage, pressurized oil is supplied to the rear port 28 of the cylinder 25 attached to the spindle head 3 shown in FIG. The pressure oil on the front side is discharged to the outside of the cylinder through the front port 26). The piston 27 is moved forward, and the draw bar is pressed against the elastic biasing force of the plurality of disc springs 15.
When the rear end of the attachment 11 is pressed, the collet chuck 9 engaged with the back end is actuated, and the shaft member of the attachment spindle device is operated.
Open 43 pull studs and draw bar 11
Push rod 7 presses the tapered shank bottom of the shaft member 43, so that the shaft member 43 slides forward with respect to the bracket 41, and moves the draw bar 35 in the longitudinal axis forward direction.
In conjunction with this, the collet chuck 33 releases the shank of the small tool, and the tool is ready for tool change.

[0020] By automatic tool change or manual tool change,
After a new small tool is inserted into the collet chuck 33, pressure oil is supplied to the front port 26 of the cylinder 25 of the spindle head 3 (pressure oil on the rear side is discharged to the outside of the cylinder through the rear port 28). When the piston 27 is moved backward and the piston 27 is separated from the rear end of the draw bar 11, the elastic biasing force of the disc spring 15 is applied to the draw bar 11 again,
The collet chuck 9 engaged with the shaft member is actuated, the collet chuck 9 tightens the pull stud of the shaft member 43, and the push rod 7 moves away from the tapered shank bottom of the shaft member 43. Is released and slides rearward to release the pressing of the draw bar 35. As a result, the plurality of disc springs 39 moves the second draw bar 35 rearward in the axial direction, and accordingly, the collet chuck 33 releases the shank of the small tool. The tool is fastened and fixed to the main shaft 29. Thus, preparation for the next processing step is completed.

[0021]

As described above, in the attachment spindle device of the present invention, the driving mechanism for automatically tightening and releasing the tool on the spindle of the device is shared with the clamping means provided on the spindle head of the machine tool. Since the mechanism can be omitted from the attachment spindle device, the structure of the spindle device can be simplified and downsized, and the device can be easily attached to and detached from the spindle head of the machine tool. , A special operation and effect that cannot be expected from the conventional device can be achieved.

[Brief description of the drawings]

FIG. 1 is a partial side sectional view of a spindle head of a machine tool including an embodiment of an attachment spindle device of the present invention.

FIG. 2 is a side sectional view of a spindle head of the machine tool.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st spindle 3 Spindle head 5 Taper hole 7 Push rod 9 1st collet chuck 11 1st draw bar 15 1st disc spring 25 Cylinder 27 Piston 29 2nd spindle 31 Housing 33 2nd collet chuck 35 2nd drawbar 39 2nd disc spring 43 Shaft member 44 Compression spring

Claims (1)

[Claims] 1. An attachment spindle device attached to a spindle head of a machine tool, an attachment housing fixed to the spindle head of the machine tool, an attachment spindle supported and supported by the attachment housing, and an inner hole of the attachment spindle. And an attachment tool clamping member, which is elastically urged rearward of the attachment spindle to clamp a tool to the attachment spindle, and is provided slidably with respect to the attachment housing, and the spindle of the machine tool. A shaft member for receiving the unclamping force of the tool clamping means, pressing the attachment tool clamp member against its elastic biasing force, and unclamping the tool clamped on the attachment main shaft. Attachment Door spindle device.