JPH07276113A - Unclamp device of main spindle - Google Patents

Abstract

PURPOSE:To provide a new unclamp device to respond at high speed by a motor and a screw mechanism. CONSTITUTION:A screw bar or a female screw cylinder is connected to a motor M, they are made related with each other to separate from and to make pressure contact with a tail end of a draw bar 4 by advancing and retreating drive of a pressure body 11 screwed on the, screw bar or a pressure bar screwed in the female screw cylinder, and an advancing and retreating position of the pressure body 11 or the pressure bar by the motor M is controlled by a detection means. Additionally, this is an unclamp device 20 of a main spindleto reciprocally drive and control the motor M synchronously with a tool exchange motion actuated by a tool exchange command and to control the pressure body 11 or the pressure bar to press on or to separate from the tail end of the draw bar 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an unclamping device for a tool mounted on a spindle, and relates to a novel control operation technique in which the unclamping device is composed of a motor and a screw mechanism.

[0002]

2. Description of the Related Art Conventionally, the type of an unclamping device for a tool mounted on a spindle of a machine tool is a pressing mechanism using a hydraulic or pneumatic cylinder. In addition, JP-A-6-63806
The type of the unclamping device described in No. 1 provides a motor which is used as a drive source and which pushes down the draw bar via a cam mechanism.

[0003]

However, in the above-mentioned conventional unclamping device, the pressing mechanism by the hydraulic or pneumatic cylinder cannot be operated at high speed because of poor response, and the operation with the tool changing device is not possible. It was difficult to adjust the timing, and it took more time than necessary to change tools. In addition, the drive unit of the hydraulic or pneumatic cylinder must be placed in a large-scale, constantly operating state, which entails energy loss, requires a large installation space, requires time and effort for maintenance, and contributes to high-speed space-saving and energy-saving. I can't handle it.

Therefore, as in the unclamping device of Japanese Patent Application Laid-Open No. 6-63806, a motor which is used as a drive source and pushes the draw bar through the cam mechanism of this rotational force has good responsiveness and can operate at high speed. The advantage is that the tool can be changed quickly. However, since the cam attached to the rotary shaft of the motor presses the draw bar through the slide bush by the change in the height of the cam that occurs within one rotation of this rotary shaft, the tool is unclamped. Must generate motor torque. For this reason, since a motor with a reduction gear is adopted, the cam is rotated at a low speed, and the slide bush surface is frictionally pushed by the change in height to push the draw bar, resulting in poor energy transmission efficiency. Also, the drive system must be complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above conventional problems, and an object thereof is to solve the above problems. In order to simplify the mechanism and suppress energy loss, a new unclamping device using a motor and a screw mechanism is provided. The purpose is to provide.

[0006]

In order to achieve the above object, the present invention provides an unclamping device for unclamping a tool when a tail end of a drawbar projecting to the center of the tail end of a spindle is pushed into a rotary shaft of a motor. A screw rod or a female screw cylinder is connected, and there is no relation to separate and press contact with the tail end of the draw bar by the forward / backward drive of the pressing body screwed with the screw rod or the pressing rod screwed with the female screw cylinder, and the motor. The forward / backward position of the pressing body or the pressing rod is controlled by the sensing means, and the motor is controlled to rotate in the forward / reverse direction in synchronization with the tool changing operation operated by the tool changing command, and the pressing body or the pressing rod is attached to the tail end of the draw bar. This is an unclamping device for a main shaft, which is characterized by controlling pressing and separating.

Further, in order to achieve the above object, the present invention provides an unclamping device for unclamping a tool when the tail end of a draw bar protruding into the center of the spindle tail end is pushed in.
Connect a screw rod or female screw cylinder to the rotary shaft of the servo motor,
The pressing body screwed into the screw rod or the pressing rod screwed into the female screw cylinder is moved back and forth so that the tail end of the drawbar is separated from and pressed against the tail end of the drawbar. The advancing / retreating position is controlled, and the servomotor is controlled to drive in the forward / reverse direction in synchronization with the tool changing operation operated by the tool changing command, and the pressing body or the pressing rod is pressed and separated from the tail end of the drawbar. This is an unclamping device for a spindle.

[0008]

In the unclamping device of the present invention, when the screw rod or the female screw cylinder connected to the rotary shaft of the motor is driven in the normal direction, the pressing body screwed into the screw rod or the pressing rod screwed into the female screw cylinder is driven. Is brought into and out of contact with the tail end of the drawbar by the forward and reverse driving of the screw rod or the female screw cylinder. Here, when unclamping the tool mounted on the main shaft of the machine tool, the rotary shaft of the motor is drive-controlled in the direction so as to press the pressing body or the pressing rod against the tail end of the drawbar by the motor drive. with this,
The pressing body screwed into the rotating screw rod or the pressing rod screwed into the female screw cylinder smoothly generates a strong pressing force against the tail end of the drawbar in a decelerated state. Then, by the motor drive, the pressing body or the pressing rod presses the tail end of the draw bar to unclamp efficiently, smoothly and quickly.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Each embodiment shown in the drawings will be described below.
FIG. 1 is a sectional view of a main shaft unclamping device 20 according to the present invention as viewed from the front. FIG. 1 shows a spindle head 1 of a machine tool (machining center), and a spindle 2 is held in a cylindrical body 3 of the spindle head 1 by a plurality of bearings. In the main shaft 2, a drawing bolt 4 is pulled toward the main spindle tail end by the elastic force of a large number of disc springs 5 ..., and a tip end collet 6 of the draw bar 4 is attached to the main spindle taper hole 2A. The pull stat 7 of the tool T is pulled in strongly. In this state, the spindle 2 is rotated and the tool T
Processes the work.

When exchanging the tool T, the exchanging arm 8 of the automatic tool exchanging device and the tool unclamping device 20 work, and first, the disc unclamping device 20 compresses the disc spring 5 to loosen the attachment of the tool T. Following this, the exchange arm 8 grips the tool T and pulls it out from the spindle tapered hole 2A,
After replacing with a new tool, the tool unclamping device 20 is released again and the elastic force of the disc spring 5 causes the spindle taper hole 2A.
Install a new tool on.

An unclamping device 20 for a spindle according to a first embodiment of the present invention will be described. The unclamping device 20 is attached to the rear bracket 1A of the spindle head 1 with the pressing body 11 facing the spindle tail end 2B. The pressing body (nut body) 11 is screwed with a screw rod (ball screw) 12 directly connected to the rotation shaft of the motor M attached to the support body 1C, and cannot rotate in the key hole 1B of the rear bracket 1A, and only moves up and down. Engageable. Then, the threaded rod 12 of the motor M
When is rotated in the direction of the solid arrow (a), the pressing body 11 is separated from the spindle tail end 2B, and when the screw rod 12 is rotated in the direction of the broken arrow (b), the pressing body 11 is approached to the spindle tail end 2B. Press to unclamp.

The spindle unclamping device of the present invention may be one in which the relationship between the screw rod and the pressing body is reversed as shown in FIG. That is, this is screwed to the gear 21A of the female screw cylinder 21 with the gear G fitted to the rotating shaft M1 of the motor M interposed. The female screw cylinder 21 is the rear bracket 1
It is rotatably held with a bearing in the hole 1D of A,
It faces the spindle tail end 2B. A female screw is provided on the central axis of the female screw cylinder 21, and the pressing rod 22 is screwed into the female screw. On the tail end side of the pressing rod 22,
A spline (which may be a key groove) 22A is provided, which engages with the slot 1E of the support 1C. Then, when the female screw cylinder 21 of the motor M is rotated in the direction of the solid line arrow (a), the pressing rod 22 is brought close to the spindle tail end 2B to be pressed and clamped, and the female screw cylinder 21 is broken line arrow (b). When rotated in the direction, the pressing rod 22 is pushed away from the spindle tail end 2B and pressed to unclamp.

Unclamping device 20, 20 'of the present invention
Are operated by the control circuits of the two embodiments shown in FIGS. First, FIG. 3 shows a control method by the general-purpose motor M. The sensor S1 detects the retracted position (clamping position) of the pressing body 11 and the sensor S2 detects the forward moving position (unclamping position) of the pressing body 11. Sensing means S1, S2
Are arranged. With respect to the signals from the sensors S1 and S2, the controller C is activated by the "ATC command signal" to rotate the motor in the forward direction, and the "arm return signal" and the OFF command of the timer To which is timed with the signal to activate the reverse rotation. On the other hand, it is exclusively used as a command source for sudden stop of the motor M. When the motor M is started in the normal direction, the pressing body 11 or the pressing rod 22 is pressed toward the spindle tail end 2B so as to be clamped by 11 ', and when the motor M is started in the reverse direction, the pressing body 11 or the pressing rod 22 is rotated against the main spindle. Unclamp away from the tail end 2B. In the above-mentioned FIG. 2, the exchange arm 8 stops the grippers AH1 and AH2 at both ends thereof at the standby position ST on the spindle 2 side or the standby position MT on the magazine side.

Next, the control circuit of the embodiment shown in FIG. 4 shows a control method by the servomotor SM, and the retracting position (clamping position) of the pressing body 11 and the advancing position (unclamping position) of the pressing body 11 are detected by the sensing means. S1 and S2 are not required.
That is, the controller C that receives the "ATC command signal" from the NC control device (not shown) commands the servo motor SM to move a predetermined amount from the backward position 11 to the forward position 11 '. Further, the controller C also commands the servomotor SM with respect to the backward movement amount from the forward movement position 11 'to the backward movement position 11 by the "arm return signal" or the OFF instruction of the timer To which is timed with this. Since other configurations are the same as those in FIG. 3, the same reference numerals are given and the description is omitted.

As described above, in the unclamping device 20 or 20 'of the present invention configured as described above, the motors M and SM are driven in the forward and reverse directions according to the time chart shown in FIG. First, in the control method using the general-purpose motor M shown in FIG. 3, when the "ATC command signal" is issued at time t1, the controller C that receives the "ATC command signal" starts the motor M in the normal direction, and the pressing body 11 is activated after the time t2. The motor is stop-controlled so as to make an abrupt stop at the forward position 11 'detected by the sensor S2. In synchronization with this, the exchange arm 8
Moves the grippers AH1 and AH2 at both ends thereof to the spindle 2 side and the magazine side MG to grip the tool, and subsequently, at time t2 ′.
It is pulled out later, turned 180 degrees after time t3 ', the new and old tools are exchanged, and the spindle 2 and the MG on the magazine side are replaced after time t3. Here, the controller C receives an “arm return signal” or an OFF command of the timer To which is timed with this signal, and the like.
Reverse rotation is commanded to the motor M, and after time t4,
The sensor S1 senses the pressing body 11 and suddenly stops the motor M to bring it into a clamped state. Exchange arm 8 in synchronization with this
Returns the grippers AH1 and AH2 at both ends thereof to the standby positions ST and MT on the spindle 2 side and the magazine side MG, respectively, and stands by.
The unclamping operation is completed as described above, and this state is maintained until the next tool change.

Subsequently, in the control method by the servomotor SM shown in FIG. 4, when the "ATC command signal" is issued at time t1, the controller C which receives the "ATC command signal" receives the servomotor S.
The servomotor is controlled to stop so that the pressing body 11 suddenly stops at the forward movement position 11 'after the time t2 after the normal rotation start of M by a predetermined movement amount. In synchronization with this, the exchange arm 8
The grippers AH1 and AH2 at both ends thereof are moved to the spindle 2 side and the magazine side MG to grip the tool, then withdrawn after the time t2 ′, and swiveled 180 degrees after the time t3 ′ to replace the old and new tools and the spindle 2 and The magazine MG is replaced after time t3. Here, the controller C commands the servomotor SM to perform the reverse rotation drive by an "arm return signal" or an OFF command of the timer To which is timed with this, and after the time t4, the pressing body 11 is in the standby position. Then, the servo motor SM is suddenly stopped and brought into a clamped state. In synchronization with this, the exchange arm 8 returns the grippers AH1 and AH2 at both ends thereof to the standby positions ST and MT on the spindle 2 side and the magazine side MG, respectively, and stands by. The unclamping operation is completed as described above, and this state is maintained until the next tool change.

[0017]

As described above, in the unclamping device of the present invention, the screw rod or the female screw cylinder is connected to the rotating shaft of the motor, and the push body which is screwed to the screw rod or the push rod which is screwed to the female screw cylinder is moved back and forth. There is no relation to separate and press contact with the tail end of the draw bar by driving, and the motor is controlled to drive forward and reverse in synchronization with the tool change operation operated by the tool change command, and the pressing body or the pressing rod is pressed against the tail end of the draw bar. Since the separation control is performed, the pressing body screwed with the rotating screw rod or the pressing rod screwed with the female screw cylinder generates a strong pressing force against the tail end of the drawbar in a decelerated state, There is an effect that the pressing body or the pressing rod presses the tail end of the draw bar by driving to unclamp smoothly and quickly.

[Brief description of drawings]

FIG. 1 is a sectional view of an unclamping device according to a first embodiment of the present invention.

FIG. 2 is a sectional view of an unclamping device according to a second embodiment of the present invention.

FIG. 3 is a block diagram of a control circuit device according to a first embodiment of the present invention.

FIG. 4 is a block diagram of a control circuit device according to a second embodiment of the present invention.

FIG. 5 is a flowchart showing an operation according to the present invention.

[Explanation of symbols]

 1 spindle head 2 spindle 2B spindle tail end 8 exchange arm 11 pressing body 12 screw rod 20 unclamping device 20 'unclamping device 21 female screw cylinder 22 pushing rod C controller M, SM motor T tool

Claims (2)

[Claims] 1. An unclamping device for unclamping a tool by pushing in the tail end of a drawbar protruding to the center of the spindle tail end, wherein a screw rod or female screw cylinder is connected to the rotary shaft of the motor, and the screw rod is connected to the screw rod. There is no relationship of separating and pressing against the tail end of the drawbar by the forward / backward drive of the pressing body to be screwed or the pressing rod screwed to the female screw cylinder, and the forward / backward position of the pressing body or the pressing rod by the motor is controlled by the sensing means. The unclamping of the main shaft is characterized in that the motor is controlled to rotate in the forward and reverse directions in synchronization with the tool changing operation that is operated by the tool changing command, and the pressing body or the pressing rod is pressed and separated from the tail end of the drawbar. apparatus. 2. An unclamping device for unclamping a tool when a tail end of a drawbar protruding to the center of a spindle tail end is pushed in, wherein a screw rod or a female screw cylinder is connected to a rotary shaft of a servomotor, and the screw rod is attached. There is no relationship of separating and pressing against the tail end of the draw bar by the forward / backward drive of the pressing body screwed with the pressing body or the pressing rod screwed with the female screw cylinder, and the advancing / retracting position of the pressing body or the pressing rod by the servo motor. It is controlled, the servo motor is controlled to drive in the forward and reverse directions in synchronization with the tool changing operation that is operated by the tool changing command, and the pressing body or the pressing rod is pressed against the tail end of the draw bar and separated from the main shaft. Unclamping device.