JP2001062673A - Method for synchronous operation of turning machine, and control device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an adjustment of the phases of two main spindles, mechanically separated from each other, with a work placed on a chuck part, in a turning machine to perform synchronous control of rotation phases, based on incremental position data. SOLUTION: This synchronous operation method is such that when, with a work 20 held in two chucks 22 and 25, a rotation phase difference is corrected, the work 20 is first clamped only by one of the chucks 22 and 25, and with this state, the two chucks 22 and 25 are individually rotated and a rotation phase difference between the two chucks 22 and 25 is corrected, and after correction, the work 20 is clamped by the other of the chucks 25 and 22. In this case, the synchronous operation method and a synchronous operation method wherein the work is immediately clamped by the two chucks to effect synchronous operation may be selectively carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turning machine, and more particularly, to a method for synchronously operating a turning machine in which two main shafts which are opposed to each other on a straight line are driven by respective electric motors, and a control device therefor.

[0002]

2. Description of the Related Art Conventionally, in machining a shaft work, for example, a central shaft portion of a crankshaft, there is a method in which shaft ends on both sides of the work are clamped by chucks and the work is rotated to turn the outer diameter of the shaft portion. It's being used. As a first example of the prior art of this turning machine, there is one having a configuration as shown in FIG. A pair of left and right first and second headstocks 6 are placed on the bed 61.
The first and second headstocks 63 and 67 support first and second drive shafts 64 and 68, respectively, in a rotatable manner and with their axes aligned. 1st, 2nd
The drive shafts 64, 68 are connected by shaft couplings 70, 70 via a drive shaft 69, and a shaft end of the first drive shaft 64 opposite to the drive shaft 69 is a bed 61.
Is connected via pulleys 65 and 62 and a belt 66 to an output shaft of a motor 60 attached to the motor 60. In addition, first and second spindles 71 and 81 are rotatably supported on the upper portions of the first and second spindle heads 63 and 67, respectively, coaxially.
The first and second main shafts 71 and 81 are driven by first and second drive shafts 64 and 68 via drive gears 72 and 73 and drive gears 82 and 83, respectively.
Respectively. First and second spindles 71, 81
Chucks 75 and 85 are respectively provided at the front end portions so as to be freely opened and closed. However, in the turning machine having the above-described structure, the distance between the first main shaft 71 and the second main shaft 81 is limited because the turning shaft 69 is mechanically connected by the drive shaft 69. Therefore, both chucks 7
There is a problem that the length between both shaft ends of the work 20 that can be set between 5, 85 is limited, and the type of the work 20 to be processed is limited.

[0003] As a second example of the prior art of a turning machine that solves this problem, there has been proposed a turning machine in which a pair of main shafts that are opposed to each other on a straight line and are mechanically separated are driven by respective electric motors. FIG. 7 shows a side view of such a turning machine. In FIG. 1, a first headstock 2 and a second headstock 3 that are mechanically separated are individually and movably mounted on a guide member (not shown) on the upper surface of a bed 1 in a longitudinal direction. First,
The second headstocks 2, 3 are moved by ball screws 5, 5 and nuts 6, 6 by horizontal moving motors 4, 4 attached to the bed 1.
The horizontal movement is performed via a drive transmission means such as the above. The first and second headstocks 2 and 3 have first and second headstocks respectively.
The main shafts 7, 13 are supported rotatably and with their axes aligned. The shaft ends of the first and second spindles 7 and 13 are connected to pulleys 11a, 9a, 11b and 9 on output shafts of electric motors 8 and 14 attached to the first and second headstocks 2 and 3, respectively.
b and belts 12a, 12b.
Further, an incremental encoder is attached to each of the electric motors 8 and 14 as a rotation angle detector.

[0006] Chuck portions T 1 and T 2 are provided at the distal ends of the first and second spindles 7 and 13, respectively. Since the structures of the chuck portions T1 and T2 are the same for both the first and second spindles 7 and 13, the first spindle 7 will be described here. First
A chuck holder 16 (second spindle 1) is attached to the tip of the spindle 7.
On the third side, a chuck holder 26) is attached. FIG.
FIG. 8 is a P view of FIG. 7. As shown in FIG. 8, three chucks 22 (the chuck 25 on the second main spindle 13 side) are provided on the end face of the chuck holder 16 facing the second main spindle 13 at three equally-divided positions in the circumferential direction. The three chucks 22 are provided with pawls 22 a at the tips thereof so as to be movable in the direction perpendicular to the center (that is, in the radial direction). The three chucks 22 are simultaneously moved in the radial direction of the chuck holder 16 by driving a hydraulic cylinder (not shown) to move the work 20.
Is clamped or unclamped at a predetermined pressure.

At the tip of the chuck holder 16,
A concave groove 16a (a groove 26a on the second spindle 13 side) for carrying in a workpiece is formed between two predetermined chucks 22 toward the axis. The remaining 2 where the groove 16a is not formed
Stoppers 28, 2 are provided between the chucks 22,
8 is fixed.

When the work 20 is machined, the first and second grooves 16a and 26a for carrying in the work are located at positions just above the axis of the first and second spindles 7 and 13, respectively.
By rotating the main shafts 7 and 13, the work 20 is formed into the grooves 16a and 26a.
And is supported by stoppers 28 at substantially the centers of the main spindles 7 and 13. Thereafter, the workpiece 20 is clamped by the two chucks 22 and 25 in a state where there is no rotational phase difference between the first and second spindles 7 and 13.

As a method of eliminating the rotational phase difference between the main spindles 7 and 13, the electric motors 8 and 14 are used to electrically control the main spindles 7 and 13 before the work 20 is clamped by the chucks 22 and 25. A method of synchronizing rotation phases, a method of mechanically providing a knock pin for fixing a phase between each of the chucks 22 and 25 and the corresponding headstocks 2 and 3, and fixing the chucks 22 and 25 when machining is stopped. There is.

[0008]

However, the above-mentioned second prior art has the following problems. That is, in a control device for synchronous operation of a turning machine in which a pair of spindles 7 and 13 are mechanically separated from each other and the rotational phase between the spindles 7 and 13 is synchronized by electrical control. In order to eliminate the rotational phase difference between the first and second main shafts 7 and 13, the rotations are synchronized by NC control based on the rotation angles of both main shafts 7 and 13 detected by the incremental encoder. However, the angle data serving as a reference for the synchronous control is not stored in the memory in the NC control device after the control power is once turned off. Also, while the control power is off or immediately after the power is turned on, the chucks 22 and 25 are in a dazzling state in which the position servo control is not performed, so that the operator can rotate the chucks with a small force. Therefore, when the power is turned off or immediately after the power is turned on, the operator can operate the chuck 2.
Turning 2,25 will shift the phase.

At this time, a phase difference is generated between the chucks 22 and 25 for the above-mentioned reason while the work remains between the chucks 22 and 25, and the control power is turned on in a state where the phase difference is generated. There is. In this case, if the rotation control of the phase adjustment of the main spindles 7 and 13 based on the rotation angle data of the incremental encoder is performed while the work is clamped by the chucks 22 and 25, the work is twisted and rotated with an excessive force. Therefore, the phase matching control cannot be started. In addition, by this, an abnormal external force is applied to the work to generate a distortion, or the electric motor 8,
14 and the motor drive circuit (so-called servo amplifier) of the NC control device, an overload current may flow to shorten the life. In addition, if the rotation control of the phase adjustment of both spindles 7 and 13 is performed in a state where both chucks 22 and 25 are unclamped,
There is also a problem that the work 20 comes off the chucks 22 and 25 and falls when the grooves 16a and 26a for carrying in the work face downward.

The present invention has been made in view of the above problems,
In a turning machine that performs synchronous control of a rotational phase based on incremental position data of two spindles that are mechanically separated from each other, a synchronous operation method of a turning machine that enables phase adjustment while a work is mounted on a chuck portion and a method thereof It is intended to provide a control device.

[0011]

In order to achieve the above object, a first invention according to the present invention comprises a pair of chucks respectively attached to a pair of mechanically separated spindles. In a synchronous operation method of a turning machine that processes a work by rotating both spindles individually by incremental control while clamping both ends of a shaft work, the rotational phase difference is determined while holding the work in both chucks. When correcting, first clamp the work with only one chuck, then rotate both chucks individually while clamping with only one chuck, and correct the rotational phase difference between both chucks, After the rotation phase difference is corrected, the other chuck is used to clamp the work.

According to the first aspect of the invention, when the phases of the two spindles are adjusted in a state where the work is present in both the chucks, the work is performed by rotating the spindle while the work is clamped by only one of the chucks. Phase adjustment between both spindles can be performed without removal. In addition, even when the chuck has a groove for carrying in the work, it is possible to prevent the work from dropping from the groove during rotation of the phase adjustment between the two chucks. Therefore, the operator does not need to remove the work from the chuck and perform phase adjustment between the two spindles as in the related art, and after the phase adjustment is completed, re-loads the work into both chucks and restarts machining. Therefore, work can be performed efficiently even when resuming from machining interruption,
Workability can be improved. Further, since the phase adjustment can be performed even when there is a work in the chuck by controlling the electric motor by the low-cost incremental position detector, the manufacturing cost can be reduced as compared with the control method using the absolute position detector.

According to a second aspect of the present invention, both spindles are individually driven to rotate by incremental control while both ends of a shaft work are clamped by a pair of chucks attached to a pair of mechanically separated spindles. In a synchronous operation method of a turning machine that processes a workpiece, a rotation phase difference between both chucks is calculated in a state where the workpiece is held in both chucks, and the calculated rotation phase difference exceeds a predetermined maximum allowable value. First, clamp the work with only one chuck, then rotate both chucks individually while clamping with only one chuck, correct the rotational phase difference between both chucks, and rotate After the correction of the phase difference, the other chuck chucks the workpiece, and corrects the rotation phase difference. The synchronous operation method, and the calculated rotation phase difference is within a predetermined maximum allowable value. If the the synchronous operation method for synchronizing operation immediately clamped workpiece chucks, and a method of selectively performed.

According to the second aspect of the invention, when working a workpiece continuously, the rotational phase difference between the two chucks is calculated in a state where the workpiece is held in both chucks, and this rotational phase difference exceeds the maximum allowable value. In such a case, when the phase of the two spindles is adjusted, the spindle is rotated while the work is clamped by only one chuck, so that the phase adjustment between the two spindles can be performed without removing the work from the chuck. In addition, even when the chuck has a groove for carrying in the work, it is possible to prevent the work from dropping from the groove during rotation of the phase adjustment between the two chucks. This eliminates the need for the operator to remove the work from the chuck and perform phase adjustment between the two spindles as in the conventional case, and after the phase adjustment is completed, re-load the work into both chucks and restart machining. Therefore, work can be performed efficiently even when processing is resumed after interruption, and workability can be improved. If the rotational phase difference is within the maximum allowable value, both chucks are immediately clamped for turning without correcting the rotational phase difference. Therefore, when the work is interrupted during machining of the work and the work is resumed with the work in both chucks, when the phase difference between the two main spindles is within the maximum allowable value, uselessly for adjusting the rotational phase of the main spindle. The machining operation can be efficiently restarted in a short time without performing the starting position return operation. As a result, since the starting position return operation can be selected and executed according to the magnitude of the phase difference at the time of restarting the machining operation, the workability of the turning machine can be remarkably improved. Furthermore, phase control is possible even when there is a work in the chuck by controlling the motor using a low-cost incremental position detector.
The manufacturing cost can be reduced as compared with a control method using an absolute position detector.

According to a third aspect of the present invention, a pair of chucks which are mechanically separated from each other and are openably and closably provided at opposing portions of a pair of main shafts facing each other, and each of the pair of main shafts are individually driven to rotate. A synchronous operation control device for a turning machine, comprising: a motor and a controller that clamps both ends of a shaft workpiece with a chuck and individually drives each of the motors by incremental control to control the processing of the workpiece. When the controller corrects the rotational phase difference with the work held in both chucks, the controller first clamps the work with only one chuck, and then clamps both chucks with only one chuck. Rotate them individually to correct the rotational phase difference between the two chucks, and after correcting the rotational phase difference, issue commands to clamp the workpiece with the other chuck. It is configured to output.

According to the third aspect of the invention, when the phases of the two spindles are adjusted in a state where the work is present in both chucks, the work is performed by rotating the spindle while the work is clamped by only one of the chucks. Phase adjustment between both spindles can be performed without removal. In addition, even when the chuck has a groove for carrying in the work, it is possible to prevent the work from dropping from the groove when the groove comes directly below the chuck axis during rotation for phase matching between the two chucks. Therefore, the operator does not need to remove the work from the chuck and perform phase adjustment between the two spindles as in the related art, and after the phase adjustment is completed, re-loads the work into both chucks and restarts machining. Therefore, work can be performed efficiently even when processing is resumed after interruption, and workability can be improved. In addition, since no phase fixing knock pin is mechanically provided between each chuck and the headstock, the structure can be simplified.
Further, since the phase adjustment can be performed even when there is a work in the chuck by controlling the electric motor by the low-cost incremental position detector, the manufacturing cost can be reduced as compared with the control method using the absolute position detector.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments will be described below in detail with reference to the drawings. FIG. 1 is a side view of a turning machine according to the present invention. In the turning machine, a pair of main shafts that face each other on a straight line and are mechanically separated are driven by respective electric motors.

In FIG. 1, a first headstock 2 and a second headstock 3, which are movably mounted on guide members (not shown) such as rails provided on a top surface of a bed 1 in a longitudinal direction, include a bed. 1 a pair of ball screws 5, 5 disposed in the longitudinal direction
Are respectively attached to nuts 6 and 6 which engage with
The pair of ball screws 5, 5 are connected to horizontal movement motors 4, 4 attached to both side surfaces of the bed 1, respectively. The first and second headstocks 2 and 3 are horizontally moved on the guide member by horizontal movement motors 4 and 4. First and second spindles 7 and 13 are rotatably supported on the first and second headstocks 2 and 3, respectively, with their axes aligned. The shaft end of the first spindle 7 is connected to the output shaft of the electric motor 8 attached to the first headstock via pulleys 11a, 9a and a belt 12a, and the shaft end of the second spindle 13 is The output shaft of the electric motor 14 attached to the second headstock is connected via pulleys 11b and 9b and a belt 12b. Motors 8, 14
Is constituted by, for example, an AC spindle motor, and the motors 8 and 14 are provided with an incremental encoder as a rotation angle detector.

At the tips of the first and second spindles 7 and 13, chuck holders 16 and 26 are provided in the same manner as described with reference to FIG.
Are attached to the chuck holders 16 and 26, respectively.
The chucks 22 and 25 are arranged to be movable in the radial direction by driving a hydraulic cylinder (not shown). In addition, concave grooves 16a, 26a for carrying in the work are formed in the radial direction between two predetermined chucks at the distal ends of the two chuck holders 16, 26, respectively.
Stoppers 28, 28 are fixed between the remaining two chucks on which a and 26a are not formed.

FIG. 2 is a structural view of the chuck portion and the center. As shown in FIG. 2, the first main shaft 7 is provided with a main shaft hole 7a penetrating in the longitudinal direction.
Main shaft hole 7a at the shaft end of first main shaft 7 on the side where
A tailstock shaft holder 18 having the same axis as the first main shaft 7.
Is installed. The tailstock shaft 17 is inserted through holes provided concentrically with the shaft center at the center of the tailstock shaft holder 18 and the center of the chuck holder 16, respectively, and the main shaft hole 7 a of the first main shaft 7. A substantially conical center 19 is provided at one end of the tailstock shaft 17 on the chuck holder 16 side.
The base end of the second spindle side is a center 24 is fastened. As shown in FIG. 1, a cylinder 21 rotatably supported by a holder 21 a provided on a side surface of the headstock 2 is attached to a shaft end of the first spindle 7 opposite to the chuck holder 16. ing. The piston in the cylinder 21 and the other end of the tailstock shaft 17 are connected.

The shaft end of the first spindle 7 and the first encoder 33 attached to the first headstock 2 engage with each other via pulleys 31 and 34 and a timing belt 32 attached respectively. The rotation angle of the first main shaft 7 is detected by the first encoder 33. Similarly, a shaft end of the second spindle 13 opposite to the chuck holder 26 and the second headstock 3
The second encoder 37 is engaged with the second encoder 37 via pulleys 35 and 38 and a timing belt 36 respectively attached thereto, and detects the rotation angle of the second main shaft 13 by the second encoder 37. ing.

Disks (not shown) are attached to the input shafts of the first encoder 33 and the second encoder 37, and the disks rotate at the same angular velocity in synchronization with the rotation of the main shaft. An outwardly protruding projection is provided at one place on the outer periphery of the disk, and two proximity switches 39b and 39 serving as chuck fixed position detectors 39 for detecting the projection are provided.
b is a bracket 39 attached to the first and second headstocks 2 and 3.
a, 39a. The two proximity switches 39b, 39b detect that the positions of the work loading / unloading grooves 16a, 26a of the chuck holders 16, 26 have reached a fixed position, respectively, and the first and second spindles 7, 1 are respectively.
Proximity switches 39b, 39b output a fixed position detection signal when 3 rotates and the positions of grooves 16a, 26a are each directly above the axis. For example, when the work 20 is carried into the two chucks 22 and 25 by a loader (not shown), the positions of the grooves 16a and 26a are controlled to fixed positions so that the shaft end of the work 20 does not interfere with both chucks.

The three chucks 22 and 25 provided on the chuck holders 16 and 26 are operated by cylinders 23 and 23 provided in the chuck holders 16 and 26, respectively. Not controlled by a solenoid directional switching valve.

The cylinder 21 pushes the tailstock shaft 17 so that the center 19 at the tip of the tailstock shaft 17 is pressed against the center hole of the work 20. In the following description, the center 1
The operation of pressing the center 9 into the center hole is called forward, and the operation of opening the center 19 from the center hole is called backward. The control of the advance and retreat of the centers 19 and 24 at the tip of the tailstock shaft is controlled by a solenoid-type directional switching valve (not shown).
In controlling the solenoid type directional switching valve, the centers 19 and 24 of the first and second spindles 7 and 13 can be simultaneously moved forward or backward by a manual operation changeover switch.
The forward and backward ends of the centers 19 and 24 are detected by a detector (for example, a limit switch or the like) (not shown), and a detection signal is output to a controller described later as a center position detection signal. .

FIG. 3 shows a hardware configuration diagram of a synchronous operation control device for a turning machine according to the present invention. The chuck fixed position detector (for example, composed of a proximity switch) 39
When the grooves 16a and 26a of the chuck holders 16 and 26 are located directly above the axis (fixed position), a detection signal is output. The center advance detector 41 detects that the centers 19 and 24 are at the forward end, and detects, for example, that the cylinder 21 has moved to the forward end by a detector such as a proximity switch. The clamp detector 42 detects that the chucks 22 and 25 are in a clamp state. For example, the clamp detector 42 detects a hydraulic pressure for extending the cylinder 23 to clamp the work 20 by a pressure detector such as a pressure switch (not shown). Judge clamp or unclamp. The main shaft rotation angle detector 46 detects the respective rotation angles of the first main shaft 7 and the second main shaft 13, and is constituted by encoders 33 and 37 in the present embodiment. The detection signals of the detectors 39, 41, 42, and 46 are input to a controller 40 described later.

The start position return push button 43 starts an operation for returning each of the first and second spindles 7 and 13 to a position where there is no phase shift. Thus, the centers 19 and 24 are moved forward to adjust the position of the work 20, clamp one end of the work 20, and perform operations until turning can be started. When the start position return push button 43 is turned ON, a return start signal is output to a controller 40 described later. The start position return completion display 44 is displayed by a start position return completion signal from the controller 40, and informs the operator that the start has been returned to a startable position where there is no rotational phase difference between the first and second spindles 7 and 13. Inform.

The controller 40 is mainly composed of a computer device such as a microcomputer and an arithmetic processing device such as a numerical processor, and has a readable / writable memory (so-called RAM) 40a. Memory 40a
Stores parameters for performing control for synchronizing the phases of the first and second spindles 7 and 13 (phase synchronization error completion width and the like). The phase synchronization error completion width parameter 48 includes the maximum allowable value of the phase difference between the two spindles 7 and 13 allowed during the synchronous operation, for example, the encoder 3 of the spindle rotation angle detector 46.
The pulse values are set in advance as 3, 37 pulse values.
If the phase difference exceeds the maximum allowable value at the time of actual control, the controller 40 performs a start position return operation. That is, only one of the chucks 22 and 25 is clamped, and then, in this state, the first and second spindles 7 and 13 are individually rotated to the respective fixed positions so that the phase difference is at the maximum. The motors 8 and 14 of the first and second spindles 7 and 13 are controlled so as to fall within the allowable value.

The control panel (not shown) of the turning machine includes a control power ON / OFF push button, a center and chuck hydraulic pressure generator power ON / OFF push button, a spindle synchronous control mode switch, a chuck operation switch, A position return push button 43, a start position return completion display 44, a production quantity setting means for setting a target production quantity, and the like are mounted.

Next, a synchronous operation method according to the present invention will be described with reference to FIG. FIG. 4 shows an example of a flowchart of this synchronous operation method. Here, each processing step number is represented by adding S, and the same applies to the subsequent flowcharts. First, in S1, the control power supply is turned on. At this time, both chucks 22 of the first and second spindles 7 and 13,
The spindle synchronization control mode switch for performing the phase adjustment of 25 is in an OFF state. At this time, since the rotations of both chucks 22 and 25 are not restrained, both chucks 22 and 25 are in a state of rotating lightly. Next, in S2, the target production number W of the work is set by the production number setting means. In S3, the presence or absence of a workpiece to be processed between the chucks 22 and 25 is confirmed based on a signal from the clamp detector 42. If there is no work, the process proceeds to S4 and the groove 1 for carrying the work of both chuck holders 16 and 26 is used.
6a and 26a are fixed positions, that is, first and second positions.
The electric motors 8, 14 are positioned right above the axes of the spindles 7, 13.
Is controlled at a predetermined speed. When the chuck fixed position detector 39 detects that the grooves 16a and 26a have reached the fixed positions, the rotation of the motors 8 and 14 is stopped. Next, in S5,
The work is chucked by a loader (not shown) or the like.
The chuck holders 16 and 26 are carried into the chucks 22 and 25 through the grooves 16a and 26a, and are supported by end faces of two stoppers 28 and 28 of the chuck holders 16 and 26. Thereafter, the process proceeds to S6. Also, in S3, the work is
When it is between 2 and 25, the process proceeds to S6.

At S6, the operator turns on the start position return button. Then, in step S7, the cylinders 21 are driven to advance the centers 19 and 24, and are pressed against the center holes machined on the end faces of the shafts of the work, thereby the center of the work and the first and second main spindles 7 and 13 are moved. The workpiece is held by the centers 19 and 24 so that the center of the workpiece is on a straight line. Next, S8
The operator operates the chuck using a chuck operation switch (not shown) to operate the chuck so that one end side of the work (in the case of processing in which the outer diameters of both ends are different from each other, such as a crankshaft or the like, usually the larger diameter side is used). Clamp). At this time, the small diameter side of the work is left in an unclamped state.
Normally, the outer diameters of both shaft ends of the work are different from each other, but even in the case of the same, only the shaft portion at one end is clamped and the chuck at the other shaft is unclamped.

Then, in S9, the first and second spindles 7, 1
The process shifts to the control of the phase matching of No. 3. That is, the motors 8 and 14 of the first and second spindles 7 and 13 are individually
It is rotated by more than one rotation, and waits for the input of one rotation signal from each of the encoders 33 and 37 (that is, the reference position signal output at a predetermined angular position every one rotation of the incremental encoder). In position, the motor 8,
14 is stopped. In order to detect one rotation signal, the electric motors 8 and 14 need only be rotated at least once or more, but here, the motors are rotated two or three times to ensure detection. After S9, the phase synchronization control is completed.

When the phase synchronization control is completed, at S10,
The spindles 7 and 13 are each rotated at a predetermined speed, and the rotation is stopped at a position where the detection signal of the chuck fixed position detector 39 is turned on. Next, in S11, the operator operates the chuck using a chuck operation switch (not shown), and also clamps the other end of the unclamped work (here, the small diameter side). When the above processing is completed, S12
At this point, the return of the turning machine to the startable chuck position (hereinafter referred to as the start position return) is completed. After the start position return is completed, the processing can be started, and the process proceeds to S13 to start the processing. During this machining, the first and second spindles 7, 13 are rotated in phase synchronization.

FIG. 5 is an example of a flow chart for explaining a synchronous operation method at the time of resuming machining during the machining operation after the machining is once performed in S13. After the processing in S13, when the processing is completed in S20, in S21, both chuck holders 16,
The first and second spindles 7, 13 are rotated to the fixed position 26, and then the two chucks 22, 25 are unclamped in S22. Thereafter, in S23, the work-completed work is carried out from both chucks 22, 25 by a loader or the like. Next, S
At 24, 1 is added to the production number Wi. And S2
In 5, it is determined whether or not the production number Wi has reached the target production number W set in S2. Target production quantity W
If not reached in step S26, both chuck holders 1
6, 26 are in the home position, that is, the chuck home position detector 2
The work is carried into both chuck holders 16 and 26 after confirming that the detection signal 9 is ON.

Then, in S27, it is determined whether or not the phase difference between the first and second spindles 7, 13 is within a maximum allowable value (phase synchronization error completion width parameter). If the phase difference is within the maximum allowable value, it is determined that there is no phase shift, and S28
Then, the centers 19 and 24 are moved forward to hold the work. Next, in S29, both chucks 22, 25 are clamped. Thereafter, the process returns to S12, and the machining can be started in a state where the starting position return is completed. In S27, when the phase difference between the two spindles exceeds the maximum allowable value, it is determined that there is a phase shift, and the process returns to S6 to return to the starting position for performing the phase adjustment of the first and second spindles 7, 13. Move to Then, the above processing is repeated. If the production number Wi has reached the target production number W in S25 while the production is continued, this processing ends.

According to the present invention, for example, after the work is interrupted in the course of machining the work, the control power is cut off, the power is turned on again, and the machining is resumed with the work remaining in both chucks 22 and 25. When performing work, the chucks 22 and 25
Phase adjustment without removing from In addition, there is no problem that the work falls from the grooves 16a and 26a of the chuck holders 16 and 26 during the rotation of the phase matching. Therefore, the worker removes the work from the chuck and adjusts the phase between the main spindles 7 and 13 as in the related art.
Since there is no need to carry the wafer into the inside 2 and 25 and restart the machining, the work can be efficiently performed even when the machining is resumed after the interruption. Further, when the work is interrupted during the work of the work, or after the work for each work is completed, the control power is not shut off, and the work is restarted in a state where the work is present in both the chucks 22 and 25, or Next, when a new work is started, if the phase between the two spindles 7 and 13 is within the maximum allowable value, it is not necessary to perform the starting position return operation for the phase adjustment. Machining can be started with the phases in phase. Therefore, the worker can resume the operation without worrying about whether the two chucks are in phase.

[Brief description of the drawings]

FIG. 1 is a side view of a turning machine according to the present invention.

FIG. 2 is a structural diagram of a chuck portion and a center.

FIG. 3 is a hardware configuration diagram of the synchronous operation control device according to the present invention.

FIG. 4 is a flowchart example of a synchronous operation method according to the present invention.

FIG. 5 is a flowchart example of a synchronous operation method at the time of resuming machining during machining operation.

FIG. 6 is a side view of a first example of a turning machine according to the related art.

FIG. 7 is a side view of a turning machine of a second example according to the related art.

8 is a view as viewed in the direction P in FIG. 7;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Bed, 2 ... 1st headstock, 3 ... 2nd headstock, 4 ... Horizontal movement motor, 7 ... 1st spindle, 8, 14 ... Electric motor, 13
... Second spindle, 16, 26 ... Chuck holder, 16a, 2
6a groove, 17 tailstock, 18 tailstock holder, 1
9, 24 ... center, 20 ... work, 22, 25 ... chuck, 28 ... stopper, 33, 37 ... encoder, 39 ...
Chuck fixed position detector, 39b ... proximity switch, 40 ...
Controller, 40a: memory, 41: center advance detector, 4
2 ... clamp detector, 43 ... start position return push button, 44 ...
Start position return completion display, 46 ... spindle rotation angle detector, 4
8: Phase synchronization error completion width parameter.

Claims (3)

[Claims] In a state in which both ends of a shaft work are clamped by a pair of chucks respectively attached to a pair of mechanically separated main shafts, both main shafts are individually driven to rotate by incremental control to load the work. In the synchronous operation method of the turning machine to be processed, when correcting the rotational phase difference with the work (20) held in both chucks (22) and (25), first, one of the chucks (22) and ( 25), the workpiece (20) is clamped, and then both chucks (22) and (25) are individually rotated while clamping with only one of the chucks (22) and (25). A turning machine characterized in that the rotational phase difference between (22) and (25) is corrected, and after correcting the rotational phase difference, the other chuck (25) and (22) also clamp the work (20). Synchronous operation method. 2. In a state in which both ends of a shaft work are clamped by a pair of chucks respectively attached to a pair of mechanically separated main shafts, both main shafts are individually driven to rotate by incremental control to load the work. In the synchronous operation method of the turning machine to be processed, with the work (20) held in both chucks (22) and (25), the rotational phase difference between both chucks (22) and (25) is calculated, If the calculated rotational phase difference exceeds a predetermined maximum allowable value, first, the work (20) is clamped only by one of the chucks (22) and (25), and then the other chuck (22) and Rotate both chucks (22) and (25) individually while clamping only with (25) to correct the rotational phase difference between both chucks (22) and (25), and after correcting the rotational phase difference. And a synchronous operation method in which the other chucks (25) and (22) clamp the work (20) and correct the rotational phase difference. If the calculated rotational phase difference is within a predetermined maximum allowable value, the synchronous operation method of immediately clamping and synchronously operating the work (20) with both chucks (22) and (25) is selectively performed. Synchronous operation method of a turning machine characterized by performing. 3. The method according to claim 1, further comprising the steps of:
A pair of chucks, each of which is provided to be openable and closable at opposing portions of the pair of spindles, an electric motor for individually rotating the pair of spindles, and clamping both ends of the shaft work with the chucks;
A synchronous operating device at the start of chuck rotation of a turning machine, comprising: a controller for controlling the machining of the workpiece by individually rotating each of the electric motors by incremental control. ) And (25), when correcting the rotational phase difference while holding the work (20), first clamp the work (20) with only one of the chucks (22) and (25), and then With the chucks (22) and (25) clamped only by rotating both chucks (22) and (25) individually,
After correcting the rotational phase difference between the two chucks (22) and (25), and correcting the rotational phase difference, the other chucks (25) and (22) also use the workpiece (2).
A synchronous driving device at the time of starting the rotation of the chuck of the turning machine, which outputs a command for clamping 0).