JPH08187602A - Drive device for pick-off spindle of multi-axis automatic machine tool - Google Patents

Abstract

(57) [Summary] [Purpose] To freely control the rotation speed and feed of the pickoff spindle drive. [Structure] The control device 201 rotates the pickoff spindle rotation drive motor 202 to drive the driven spindle 204.
To rotate. This allows the pickoff spindle 206
Can be rotated. Similarly, in the feed direction, the control device rotates the feed direction drive motor 208,
By converting this rotation into a horizontal movement, the pickoff spindle can be moved in the feed direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-axis automatic machine tool having a pickoff spindle, and more particularly to a drive device for the pickoff spindle.

[0002]

2. Description of the Related Art A pick-off spindle will be explained. For example, a back surface of a multi-axis automatic lathe, that is, a workpiece mounted on the headstock side via a chuck or the like is cut off by a chuck and then cut off. There are times when it is desired to chamfer the cut end surface of, and perform processing such as dowel removal. In such a case, the cut-off work piece is normally attached to the chuck again for machining, but there is a drawback that a lot of attachment time is required when the work piece is refastened to the chuck. However, by using the pick-off spindle, it is not necessary to reattach the work piece, and the back surface machining can be performed quickly and easily. For this reason, pick-off spindles are used in automatic machine tools to promote automation of machining.

When the pick-off spindle is mounted on a multi-axis automatic lathe, the back surface processing is performed according to the procedure shown in FIG. First, the material for the workpiece 102 is sent out to the spindle 101, and turning is performed by the cutting tool 301 (S1).
After the processing is completed (S2), the pickoff spindle 302 is moved to the workpiece side to fasten the workpiece and the pickoff spindle (S3). This causes the chuck, workpiece and pickoff spindle to rotate on the same axis at the same rotational speed. Next, the workpiece is cut off by the cutting tool 112 (S4), and the workpiece is separated into the chuck side and the pickoff spindle side. After that, the pickoff spindle is moved to the opposite side of the chuck so as not to disturb the turning (S5), and the back surface of the workpiece attached to the pickoff spindle is machined (S6). With such a processing method, since it is not necessary to remove the workpiece, continuous processing can be performed and rapid processing becomes possible.

A more specific structure of the pickoff spindle will be described. FIG. 4 is a diagram showing a conventional method of driving the pickoff spindle in a multi-axis automatic lathe. FIG. 4 shows a state in which the workpiece is fastened to the pickoff spindle after finishing the machining by the spindle. First, regarding the rotation of the pickoff spindle, the spindle drive motor 4
The main spindle drive shaft 402 is rotated by 01, and the driven spindle 404 is rotated via the gear 403 attached to the main spindle drive shaft. A pickoff spindle 406 is engaged with the driven spindle 404 via a spline shaft 405 so that the pickoff spindle 406 is free to slide in the axial direction and rotatable about the axis.
Workpiece 40 fastened to the collet chuck 416 of the
The structure is such that 7 can be rotated.

Regarding the movement of the pickoff spindle in the feed direction, a housing 408 enclosing the pickoff spindle and a cylinder 409 are fastened together, and slide on a slide guide 411 fixed to a tool slide 410 by a cylinder and a plate cam 412. It has a structure that Although it is difficult to finely adjust the feed rate of this cylinder, it can be moved forward and backward at high speed, so it is mainly used for moving the workpiece during fastening. Specifically, the pickoff spindle is moved toward the workpiece by the cylinder so that the end of the workpiece is held by the collet chuck of the pickoff spindle. The plate cam is used for the feeding operation for machining because the feeding speed can be finely adjusted. In the feeding operation by the plate cam, first, the plate cam is rotated to rotationally move the arm 413, and the rotational movement of the arm causes the transmission shaft 414 to horizontally move. This movement is transmitted from the piston rod 415 to the housing. In this way, the pickoff spindle is moved in the feed direction.

[0006]

However, the rotational speed of the pickoff spindle has a 1: 1 relationship with the rotational speed of the main shaft, and there is no particular problem when machining such as chamfering or doweling. It is not possible to perform machining, such as machining, that requires deceleration to about 1/10 or less of the spindle rotation speed used during rounding, and forward and reverse rotation. Also, in the actual machining with multi-axis automatic lathe,
Since the optimum cutting conditions differ depending on the machining process such as drilling, reamer, parting, and tapping, it is necessary to set the optimum cutting conditions for each process. However, in the processing using the conventional pick-off spindle, the processing conditions cannot be set appropriately because the rotation speed is the same as that of the spindle.

The reason why such a restriction occurs is that the rotation of the spindle is basically used as the drive source for the rotation of the pickoff spindle, and therefore the rotation speed cannot be changed during the rotation of the spindle. This is because the rotation is not stopped even when it is fastened to the pickoff spindle, and at that time, the rotation speed of the main shaft and the rotation speed of the pickoff spindle must match. Further, in the case of a multi-axis automatic lathe, since the rotation from the drive motor is transmitted to all the main spindles at the same rotational speed, it is not possible to selectively decelerate only a specific main spindle. Even if the rotation speed of the spindle rotation motor is decelerated to reduce the rotation speed of the spindle, all the spindles are decelerated and the machining time is eventually increased. As described above, in the conventional method, the rotation speed of the pick-off spindle has to match the rotation speed of the main shaft.

Therefore, the present invention has been made in view of such a conventional problem, and a pickoff spindle drive capable of controlling the rotational speed and the feed freely by driving the pickoff spindle independently of the spindle drive system. The purpose is to provide a device.

[0009]

For this reason, in the drive device for the pickoff spindle according to the invention of claim 1, a motor for driving the pickoff spindle which is installed separately from the motor for driving the main shaft, and the rotation speed of this motor. , The direction of rotation, etc. can be controlled freely, for example, input means,
It is characterized by including control means having a reading means, a computing means, a motor drive signal output means, and the like.

According to a second aspect of the present invention, there is provided a pick-off spindle driving device, wherein the pick-off spindle rotation driving device according to the first aspect of the present invention includes a pick-off spindle feed driving motor independently installed, and a rotation of the motor. It is characterized in that it is configured by adding a means for converting into a straight movement and a control means similar to the above for controlling the rotation of the motor.

According to a third aspect of the present invention, there is provided a pick-off spindle driving device characterized in that the means for converting the rotation of the pick-off spindle feed driving motor into a linear movement is a ball screw mechanism. There is.

[0012]

According to the first aspect of the present invention, the pickoff spindle rotation driving motor is installed independently of the spindle driving motor, so that the pickoff spindle can be rotated at an arbitrary speed regardless of the rotation speed of the spindle. The rotation direction can be reversed.

As a result, it becomes possible to perform back surface tapping, which has been impossible in the past, and it is possible to perform processing under different optimum processing conditions depending on the type of processing. According to the second aspect of the present invention, a motor for driving the pick-off spindle feed is installed at a place where movement in the feed direction has conventionally been performed by a cam and a cylinder, so that, for example, at the time of machining, through a linear motion converting means. The pick-off spindle can be controlled at a low speed and at a high speed when returned by a single drive mechanism.

According to the third aspect of the present invention, the rotation of the motor for driving the pickoff spindle feed is converted into the linear movement by using the ball screw mechanism, so that the feed operation can be controlled with high precision in a compact structure.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. When performing a plurality of different steps continuously in a multi-axis automatic machine tool, by using a spindle carrier in which a plurality of spindles are arranged on a concentric circle at regular intervals, by rotating this spindle carrier,
The positions of the respective spindles are revolved, and machining is performed on the respective spindles by a machining means including a plurality of cutting tools.

FIG. 1 shows a spindle carrier of a 6-axis automatic lathe. Here, the spindle carrier refers to a component for sequentially indexing the spindle with respect to the tool attached to the tool slide and maintaining an accurate positional relationship. As a processing procedure for this 6-axis automatic lathe, first, a workpiece 102 is attached to one of the six spindles equipped on a spindle carrier by a spindle driving motor, and the spindle is rotated. Next, although shown only for one spindle, a cutting tool 112 on the cross tool post 111, which is provided near the outer periphery of the spindle carrier and moves in a direction crossing the spindle, and the longitudinal direction (with the spindle). Turning is performed by the cutting tool 113 on the tool rest 104 attached to the tool slide 103 moving in the parallel direction).

For convenience of explanation, the workpieces attached to the respective spindles will be referred to as the first workpiece 102 to the sixth workpiece, respectively, and the machining positions of the 6 steps on the tool slide will be changed from the first position 105 to the first workpiece 105, respectively. 6th position 11
Defined as 0. Considering that the No. 1 workpiece 102 is continuously machined from the No. 1 position 105 to the No. 6 position 110, the workpiece that has been fed to the predetermined length at the No. 1 position (the workpiece is It is sent out to a predetermined length at position 6).
After finishing the machining with the tool on the cross tool post 111 or the tool post 104, set each spindle position to 60 ° in the counterclockwise direction.
By rotating, the first work piece 102 is sent to the second position 106. Predetermined processing is similarly performed at the second position, and the above-mentioned first workpiece 102 is sent to the third position 107. This operation is position 6 of 11
Repeat until 0.

At the final position 110 of No. 6, the pickoff spindle is moved to the workpiece side immediately before the parting process, and the workpiece is gripped by the collet chuck of the pickoff spindle. After that, the work piece is cut off into two pieces by cutting off the work piece with a cutting tool 112, which is a cut-off tool on the cross tool post 111. Then, the workpiece attached to the pickoff spindle side is subjected to back surface processing such as chamfering and doweling by rotating the pickoff spindle. Finally, the completed work piece attached to the pickoff spindle is removed, a new work piece is again fed to a predetermined length, and the work piece is chucked. Since all the processes at the positions 1 to 6 have been completed as described above, the spindle carrier is rotated to the first position. During actual continuous machining, workpieces are attached to all six axes of the spindle carrier, and machining is performed at positions 1 to 6, respectively, and one completed product is obtained each time the spindle carrier rotates one step. Will be available.

In particular, since the 6th position has three roles of cutting off, rear surface processing and material feeding, the load is usually larger than other positions. In a multi-axis automatic machine tool, of the multiple spindles, the spindle with the longest working time is matched with the machining time of the other spindle, so the machining time of position 6 often determines the overall machining time. is there. Therefore, if the back surface processing can withstand high speed rotation, accelerate the pickoff spindle after parting,
By shortening the time for processing the back surface, the overall processing time can be shortened.

Next, in such a multi-axis automatic lathe, a pick-off spindle drive device according to the present invention will be described with reference to FIG.
It will be described based on. The control device 201 rotates the pick-off spindle rotation driving motor 202, and this rotation is transmitted to the driven spindle 204 via the gear 203. This driven spindle has a spline shaft 2
The pickoff spindle 206 is slidable in the axial direction through the fitting with 05, and is engaged rotatably around the axis.
This enables the collet chuck 2 of the pickoff spindle.
The work piece 207 gripped by 15 can be rotated.

On the other hand, regarding the feed direction, the feed drive motor 208 is similarly rotated by the control device, and this rotation is converted into horizontal movement by the ball screw 209, and the ball screw nut 210 is moved horizontally. Since this ball screw nut is fixed to the drive shaft 211,
The horizontal movement of the ball screw nut causes the housing 21 on the slide guide 213 fixed to the tool slide 212.
4, that is, the operation of the pickoff spindle 206 in the feed direction.

Next, a processing method using an actual pickoff spindle will be described. Now, one of the workpieces attached to the spindle of the spindle carrier is numbered 1 to 5
Consider finishing the machining up to the No. 6 position and performing machining at the last No. 6 position. Assuming that the machining up to the cut-off at position 6 has been completed, the motor for independent pick-off spindle rotation drive is first rotated by the controller at the same speed as the spindle rotation speed. Further, the motor for driving the pickoff spindle feed is rotated by the control device and the pickoff spindle is moved to the workpiece side, whereby the workpiece is gripped by the collet chuck of the pickoff spindle. Next, the workpiece is cut off and cut in two. After that, for the workpiece on the pickoff spindle side, the rotation speed of the motor for driving the pickoff spindle rotation can be arbitrarily increased or decreased by the control device, and the rotation speed of the motor for pickoff spindle feed movement can also be changed arbitrarily. By changing the feed amount, feed rate, etc., the back surface processing such as tapping, chamfering, and doweling is performed under the optimum processing conditions. This not only improves the processing quality, but also contributes to the improvement of the cutting tool life. After this work is finished, the finished product can be obtained by removing the work piece attached to the pickoff spindle.

As described above, by separating the rotation driving method of the pick-off spindle from the spindle driving shaft and substituting the feeding operation with the motor, the cam and the cylinder are unnecessary, and the degree of freedom in which the type of processing and the processing conditions can be appropriately selected. Higher processing is possible. Therefore, it is possible to perform tapping by normal rotation and reverse rotation of the pickoff spindle, which was impossible in the past.

[0024]

According to the invention of claim 1, the pickoff spindle can be driven at an arbitrary rotation speed suitable for machining. As a result, for example, by performing the back surface machining at the final position in the multi-axis automatic machine tool by increasing the rotation speed of the pickoff spindle, the machining time can be reduced and the entire machining time can be shortened. Further, it becomes possible to perform tap processing on the back surface, which has been impossible in the past. Further, different processing conditions can be optimally set depending on the processing steps, which can contribute to improvement of processing quality and cutting tool life.

Further, according to the invention of claim 2, it is possible to accurately obtain an arbitrary feed speed with one system of drive mechanism, and it is possible to perform processing under optimum conditions together with the setting of the rotation speed of the pickoff spindle. The accuracy can be improved. Further, according to the invention of claim 3, since a ball screw is used for the linear movement converting mechanism, highly precise feed control can be performed with a compact structure.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between a spindle carrier, a work piece, and a cutting tool of a 6-axis automatic lathe.

FIG. 2 is a diagram illustrating a method of driving a pickoff spindle by two independent motors.

FIG. 3 is a view showing a procedure of back surface processing by an automatic lathe using a pickoff spindle.

FIG. 4 is a diagram illustrating a conventional drive method of a pickoff spindle in an automatic lathe.

[Explanation of reference numerals] 201 Control device 202 Pickoff spindle rotation drive motor 206 Pickoff spindle 208 Pickoff spindle feed drive motor

Claims (3)

[Claims] 1. A pick-off spindle driving device provided in a multi-axis automatic machine tool having a plurality of spindles for machining a workpiece separated from the spindles, the pick-off being installed separately from a motor for driving the spindles. A motor for driving the rotation of the spindle, and a control means for controlling the rotation of the motor.
Drive device for pick-off spindle of multi-axis automatic machine tools. 2. A motor for driving a pick-up spindle, which is installed separately from a motor for driving a spindle and a motor for driving a rotation of a pick-off spindle, a control means for controlling the rotation of the motor, and a rotation of the motor. 2. A drive device for a pickoff spindle of a multi-axis automatic machine tool according to claim 1, further comprising: a linear motion converting means for converting the pickoff spindle into a linear motion in a feed direction. 3. The drive device for a pick-off spindle of a multi-axis automatic machine tool according to claim 2, wherein the linear movement converting means is a ball screw mechanism.