JP2010052073A - Lathe and method of controlling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a processing time for determining a new holding position of a workpiece after cut-off by a spindle. <P>SOLUTION: A lathe 1 is provided with the spindle 21 movable in a Z<SB>1</SB>direction and holding a workpiece W1 inserted in the Z<SB>1</SB>direction so as to be releasable, a workpiece supply device 40 for supplying the workpiece W1 to the spindle 21 from behind, a tool rest 30 having a cut-off tool 33 for cutting off the workpiece W1 protruded forward from the spindle 21, a counter spindle 51 for holding the workpiece after cutting by the cut-off tool 33 so as to be releasable, and a control means for pushing the workpiece W2 after cut-off to the counter spindle 51 side by the workpiece supply device 40 and allowing it to abut on the workpiece after cutting held by the counter spindle 51 in order to position the workpiece W2 after cut-off released from the holding of the spindle 21 to a reference position. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lathe including a main spindle and an opposing main spindle, and a control method thereof.

A numerically controlled lathe provided with a front spindle and a rear spindle provided facing each other performs machining while appropriately gripping and rotating a bar (workpiece) between the front spindle and the rear spindle according to a machining program. As this type of lathe, there is known an automatic lathe provided with a feeder (work supply device) for supplying a bar material from the rear to the front spindle. The front spindle of this automatic lathe has a gripping tool such as a collet, and grips the bar supplied by the material feeder with the gripping tool. Front machining is performed on the bar gripped by the front spindle by a machining tool attached to the tool post. The back spindle also has a gripping tool such as a collet, and grips the tip of the bar after front processing with the gripping tool. The bar gripped by the front main shaft and the rear main shaft is cut off by a cutting tool between these two main shafts.
The bar after cutting held by the back spindle is subjected to back processing with a processing tool attached to the tool post to obtain a product.

  On the other hand, the bar material cut off by the front spindle is re-gripped by the front spindle at a new holding position for processing the next product, and the above-described front machining is performed. Here, a stopper is attached to the tool post in order to perform the process of positioning the bar material after the cut-off to the reference position. The bar after cutting-off is released from the gripping of the front spindle, and the bar after cutting-off inserted into the front spindle is pushed forward by the feeder and brought into contact with the stopper, and the bar is gripped by the front spindle. Thus, the front surface processing can be performed on the bar material of the portion to be the next product.

  Patent Document 1 discloses a bar processing machine in which a stopper is attached to a tool post. In this bar processing machine, a bar passing through the headstock and the guide bush is urged forward and brought into contact with the stopper. After the headstock is moved backward, the bar is gripped by a collet chuck.

Patent Document 2 discloses a method of short-cutting the tip of a bar by a predetermined amount. In this method, the bar material is supplied by the feeder to a position where the guide bush has passed a predetermined amount through the headstock, and then the rear headstock is moved in the direction B perpendicular to the axial direction of the rear spindle. The center of the spindle is shifted from the axis of the front spindle, and a bar is brought into contact with the end face of the rear spindle and pushed back to a predetermined position for positioning.
Japanese Patent No. 3401323 JP 2000-225503 A

When attaching a stopper for positioning the cut-off bar to the reference position on the tool post, the time to move the stopper to the bar contact position after the bar cut-off or the bar after the cut-off It takes time to retract the stopper from the contact position after positioning to the position.
Also, when a bar is brought into contact with the end surface of the back spindle, it takes time to move the back spindle head to shift the center of the back spindle from the axis of the front spindle, or after positioning the cut-off bar to the reference position. In order to align the center of the back spindle with the axis of the front spindle, it takes time to move the back spindle head.

  In view of the above, an object of the present invention is to shorten the processing time for positioning the workpiece after parting to a reference position.

  In order to achieve the above object, a lathe according to the present invention is capable of moving in its own axial direction and releasably gripping a workpiece inserted in the axial direction, and the workpiece from behind with respect to the main shaft. A workpiece supply device to be supplied; a tool post having a cutting tool for cutting through the workpiece protruding forward from the spindle; an opposing spindle for releasably holding a workpiece cut by the cutting tool; and gripping the spindle In order to position the cut-off workpiece released from the reference position to a reference position, the workpiece after the cut-off is pushed to the opposite spindle side by the workpiece supply device and brought into contact with the cut workpiece gripped by the opposite spindle Means.

  Further, the lathe control method of the present invention supplies a main shaft that can move in its own axial direction and releasably grips the workpiece inserted in the axial direction, and supplies the workpiece from the rear to the main shaft. A lathe control method comprising: a workpiece supply device; a tool post having a cutting tool for cutting through the workpiece protruding forward from the spindle; and a counter spindle that releasably holds the workpiece after cutting by the cutting tool. In order to position the cut-off workpiece released from the gripping of the main shaft to a reference position, the workpiece after the cut-off is pushed to the opposite main shaft side by the work supply device and is cut by the opposite main shaft. It is made to contact | abut to the workpiece | work of this.

That is, the cut-off workpiece released from the gripping of the spindle is pushed toward the opposing spindle by the workpiece supply device and comes into contact with the cut workpiece gripped by the opposing spindle. Since the workpiece after cutting functions as a stopper, the workpiece after cutting off on the main shaft side comes into contact with the workpiece after cutting on the opposite main shaft side, so that the workpiece after cutting off on the main shaft side is positioned at the reference position.
From the above, there is no need to move the tool post stopper to the workpiece contact position or to shift the center of the back spindle from the front spindle axis, and the processing time for positioning the cut-off workpiece to the reference position is short. Become.

By the way, the main spindle and the counter main spindle include a front main spindle provided on the front main spindle, a rear main spindle provided on the rear main spindle, and the like.
The control means is a position for pressing the cut-off work toward the opposing main spindle by the work supply device and bringing it into contact with the post-cutting work gripped by the opposing main spindle, and processing with the tool of the tool post. A series of controls may be performed in which the main shaft is gripped by the cut-off work.

  According to the present invention, it is possible to shorten the processing time for positioning the workpiece after the cut-off to the reference position.

(1) Explanation of lathe:
FIG. 1 is a plan view showing an outline of a configuration of a lathe 1 according to an embodiment of the present invention, FIG. 2 is a block diagram showing an outline of an electric circuit of the lathe 1, and FIGS. 6 and 7 are flowcharts showing an example of the machining process performed by the lathe 1.
A lathe 1 shown in FIG. 1 is an NC (Numerical Control) lathe, and includes an NC (Numerical Control) device 10, a front headstock 20 having a front spindle 21, a machining tool 32 and a parting tool (parting tool) 33. A tool post 30, a material feeder (work supply device) 40, a back spindle stock 50 having a back spindle 51, and the like are provided. In the present embodiment, the front main shaft 21 corresponds to the main shaft referred to in the present invention, and the back main shaft 51 corresponds to the opposed main shaft referred to in the present invention. The NC device 10, the various actuators 23 and 53, the various servo circuits 24, 34 and 54, and the various motors 26, 36 and 56 correspond to the control means referred to in the present invention.

Front headstock 20 is movable relative to the front headstock table 2 to the Z ₁ direction is an axial direction of the front spindle 21 (horizontal direction in FIG. 1). The front spindle 21 is attached with a collet (gripping tool) 22 that releasably holds a long cylindrical material (work) W1 supplied from behind, and is rotated by a front spindle rotating motor (not shown). The material W1 is rotated about the rotation axis AX1. Further, the front spindle 21 is driven by the front spindle feed motor 26 shown in FIG. 2 to the Z ₁ direction. Therefore, the front main shaft 21 is movable in its own axial direction, and grips the material W1 inserted in the axial direction so as to be releasable.

Tool rest 30 (vertical direction in FIG. 1) X ₃ direction relative turrets table 3 and Y ₃ in the direction (Figure 1 in a direction perpendicular to the paper surface) and Z ₃ direction (horizontal direction in FIG. 1) It can be moved. The tool post 30 is driven in the X ₃ , Y ₃ , and Z ₃ directions by a tool spindle feed motor 36 shown in FIG. Of course, the tool rest 30 may be driven in a direction different from the X ₃ direction and Y ₃ direction or Z ₃ directions may be driven in the X ₃ direction only. The tool post 30 has a machining tool 32 and a parting tool 33 attached thereto, and the tools 32 and 33 to be used can be switched during the machining process.

The processing tool 32 is a tool for processing a workpiece that has come forward from the front spindle 21. The parting tool 33 is a tool for parting through the workpiece after front face machining.
Here, a plurality of processing tools 32 may be attached to the tool post 30, and one or more processing tools for back surface processing may be attached.

The material feeder 40 supplies the rod-shaped material W1 to the front main shaft 21 from the rear. Materials W1 used in this embodiment is an elongate metal rod which is disposed toward the Z ₁ direction around the rotational axis AX1 of the front spindle 21, Z ₁ direction forward side (the left in FIG. 1 Direction) and penetrates the front main shaft 21, and the end portion on the back main shaft 51 side is front processed. As the material feeder 40, a finger type material supply device that grips the material and feeds it to the front main shaft 21, a push-pull type material supply device that feeds the material to the front main shaft 21 simply by pushing it from the rear, and the like can be used. .

The back spindle stock 50 is movable in the Z ₂ direction (left and right direction in FIG. 1) that is the axial direction of the back spindle 51 with respect to the back spindle table 4 and also in the X ₂ direction that is the up and down direction in FIG. It is also possible to move to. Of course, the back spindle stock 50 may be movable in a direction different from the Z ₂ direction or the X ₂ direction, or may be movable only in the Z ₂ direction. The back spindle 51 is attached with a collet (gripping tool) 52 that releasably holds a workpiece supplied from the front, and is rotated by a back spindle rotating motor (not shown) to rotate the workpiece about the rotation axis AX1. . The back spindle 51 is driven in the Z ₂ direction and the X ₂ direction by a back spindle feed motor 56 shown in FIG. Therefore, the back main shaft 51 is movable in its own axial direction, and releasably holds the workpiece after the front surface machining and the workpiece W3 after being cut by the parting tool 33.

A product discharge device 60 is provided on the back spindle stock 50. The product discharge device 60 includes a product discharge member 62 and an actuator 64. The product discharge member 62 is inserted into the back main shaft 51 and pushes out the product formed by the back surface processing in the Z ₂ direction forward side (left direction in FIG. 1), and the Z ₂ direction backward side on the opposite side (FIG. 1). To the right). The product discharge member 62 of the present embodiment has a front end in front of the front end surface of the back main shaft 51 at the forward movement position, and a front end behind the rear end of the cut workpiece in the backward movement position. Product discharge actuator 64 is fixed to the back attachment 50, to drive the product discharge member 62 in the forward direction and the backward direction in the Z ₂ direction. As the actuator 64, an electric cylinder, a hydraulic cylinder, a pneumatic cylinder, or the like can be used.

  As shown in FIG. 2, the NC device 10 includes an internal bus 10g, a CPU (Central Processing Unit) 10a, semiconductor memories 10b and 10c, a timer circuit 10d, an I / F (interface) circuit 10e, an I / O (input). An output) circuit 10f, a recording medium 10h, and the like are connected to the computer. As the recording medium 10h, a hard disk (magnetic recording medium), a nonvolatile semiconductor memory, an optical disk, or the like is used, and a machining program PG1 used for machining a workpiece is recorded in a computer-readable manner. The recording medium 10h may be provided outside the NC apparatus 10 via the I / F circuit 10e, or may be a computer-readable medium that is attached to and detached from a drive provided in the NC apparatus 10. A RAM (Random Access Memory) 10b temporarily stores the machining program PG2 read from the recording medium 10h, and temporarily stores various data D. An ROM (Read Only Memory) 10c is written with an application program APL that interprets and executes each command of the machining program. The CPU 10a numerically controls various servo amplifiers and various actuators according to the application program APL and the machining program PG2 while using the RAM 10b as a work area.

  The operation panel 12 connected to the I / F circuit 10 e includes an operation unit 12 a and a display unit 12 b and functions as a user interface of the NC device 10. The operation unit 12a includes, for example, a button or a touch panel for receiving an operation input from a user. The display unit 12b includes, for example, a display that displays various settings regarding the operation input received from the user and various information related to the lathe 1.

The I / O circuit 10f of the NC device includes a front spindle servo circuit 24, a front collet opening / closing actuator 23, a tool spindle servo circuit 34, a feeder 40, a rear spindle servo circuit 54, and a rear collet opening / closing. An actuator 53, a product discharge actuator 64, and the like are connected.
The front spindle servo circuit 24 includes a servo amplifier 24 a and the like, and mediates information transmission between the NC device 10 and the front spindle feed motor 26. An encoder 26 a that detects the rotational position of the front spindle feed motor 26 is attached to the front spindle feed motor 26. The servo circuit 24, based on a signal input from the encoder 26a, and drives the front spindle feed motor 26 so that the command value input from the NC device 10 moves the front spindle 21 to Z ₁ direction. The servo circuit 24 transmits data representing the rotational position of the front spindle feed motor 26 to the NC device 10. The NC device 10 calculates the current position of the front spindle 21 based on the data received from the servo circuit 24.
The front side collet opening / closing actuator 23 opens and closes the front side collet 22 in accordance with a command input from the NC device 10.

The tool spindle servo circuit 34 includes a servo amplifier 34 a and the like, and mediates information transmission between the NC device 10 and the tool spindle feed motor 36. An encoder 36 a that detects the rotational position of the tool spindle feed motor 36 is attached to the tool spindle feed motor 36. The servo circuit 34, based on a signal input from the encoder 36a, NC tools 32 and 33 to drive the tool spindle feed motor 36 so that the command value input from the apparatus 10 X ₃ direction and Y ₃ direction and Z ₃ is moved in the direction. Further, the servo circuit 34 transmits data representing the rotational position of the tool spindle feed motor 36 to the NC device 10. The NC device 10 calculates the current positions of the tools 32 and 33 based on the data received from the servo circuit 34.

The material feeder 40 includes an I / O circuit 41 connected to the NC device 10. Material supplying apparatus 40 according to the instruction inputted from the NC device 10, or to drive the material W1 to Z ₁ direction forward side, or to stop the drive of the Z ₁ direction forward side.

The back spindle servo circuit 54 includes a servo amplifier 54 a and the like, and mediates information transmission between the NC device 10 and the back spindle feed motor 56. An encoder 56 a that detects the rotational position of the back spindle feed motor 56 is attached to the back spindle feed motor 56. The servo circuit 54, based on a signal input from the encoder 56a, the rear drive shaft 51 drives the sub spindle feed motor 56 so that the command value input from the NC device 10 Z ₂ direction or X ₂ in the direction Move. The servo circuit 54 transmits data representing the rotational position of the back spindle feed motor 56 to the NC apparatus 10. The NC device 10 calculates the current position of the back spindle 51 based on the data received from the servo circuit 54.
The back side collet opening / closing actuator 53 opens and closes the back side collet 52 in accordance with a command input from the NC device 10.

Product discharge actuator 64 includes a piston and a servo mechanism, in accordance with instructions input from the NC device 10, drives the product discharge members 62 to Z ₂ direction.

By the way, when the stopper is attached to the tool post for the material positioning process, it takes time to move the stopper to the contact position of the material or retract the stopper from the contact position after the material is cut off. Also, when using the end surface of the back spindle for the material positioning process, it takes time to move the back spindle head in order to shift the center of the back spindle from the axis of the front spindle or to align it with the axis of the front spindle. .
Therefore, in the present embodiment, the cut workpiece gripped by the back spindle is used as a stopper.

Next, the operation of the lathe 1 will be described with reference to FIGS.
FIG. 3A shows a state in which front processing is performed on the material W1. Here, the closed front side collet 22, the material W1 is suitably rotated with the front main shaft 21 about the rotation axis AX1, material W1 is sent to the appropriate Z ₁ direction together with the front main spindle 21, the machining tool 32 is suitably X ₃ direction Sent to etc. Thereby, the front-end | tip part of the material W1 hold | gripped by the front main axis | shaft 21 is processed into a product shape.
When the front surface processing for the material W1 is finished, as shown in FIG. 3B, the front main shaft 21 and the rear main shaft 51 are close to each other with the back side collet 52 opened, and the back side collet 52 is the processed material W1. Close with the tip W11 inserted. Thereby, the front end W11 of the processed material is gripped by the back main shaft 51. At this time, the position is the position L21 in Z ₂ direction position L11 and the sub spindle 51 in the Z ₁ direction front spindle 21 the cutting-off. Further, the tool of the tool post 30 is switched from the processing tool 32 to the cut-off tool 33.

Thereafter, as shown in FIG. 4A, the processed material W <b> 1 is cut off by the cut-off tool 33 between the front main shaft 21 and the rear main shaft 51. Here, the material W1 is rotated together with the both spindles 21, 51, parting byte 33 is sent to the X ₃ direction. As a result, the cut workpiece W3 is held by the back spindle 51, and the workpiece W2 remaining after the cut-off is held by the front spindle 21.
Thereafter, as shown in FIG. 4 (b), slightly open position L12, L22 next to the both spindles 21, 51 is slightly open, parting byte 33 is retracted to the X ₃ direction.

Thereafter, as shown in FIG. 4C, the back spindle 51 is positioned so that the tip W31 of the workpiece W3 after cutting on the back spindle 51 side is at a position L23 where the workpiece W2 after cutting off on the front spindle 21 comes into contact. to advance to the Z ₂ direction. The position L23 at which the workpiece W2 after the cut-off is brought into contact can be, for example, a position where the material tip W21 was present at the time of the cut-off. Further, the front side collet 22 is opened, and the workpiece W2 after the cut-off is released from the gripping of the front main shaft 21.
Thereafter, as shown in FIG. 5 (a), the sheet material device 40 is brought into contact with the workpiece W2 to the work W3 after cutting by pressing the Z ₁ direction forward side of the post cutting-off. As a result, the cut-off workpiece W2 inserted into the front spindle 21 is pushed to the back spindle 51 side, the tip W21 comes into contact with the cut workpiece W3 gripped by the back spindle 51, and cut off on the front spindle 21 side. The subsequent workpiece W2 is positioned to a reference position for gripping by the front main spindle 21.

Thereafter, as shown in FIG. 5B, the front main shaft 21 moves back to the new gripping position L13 of the workpiece W2 after the cut-off, and the front collet 22 is closed at the gripping position L13. Thereby, the workpiece W2 after the cut-off is gripped by the front main shaft 21. The gripping position L13 is a position for machining with the machining tool 32, and the tip of the workpiece W2 determined by pressing the workpiece W2 cut off by the material feeder 40 toward the back spindle 51 and contacting the workpiece W3 after cutting. It is a position away from the required distance for the processing of the product. Further, the tool of the tool post 30 is switched from the cut-off tool 33 to the machining tool 32, and the front machining is performed on the workpiece W2 held by the front spindle 21. On the other hand, the workpiece W3 after cutting is held by the back spindle 51 retracts the Z ₂ direction, is the product is performed back machining, it is discharged from the back spindle 51 by product discharge device 60.
A product is continuously formed from the rod-shaped material W1 by repeating the above-described series of operations.

(2) Lathe control method, action and effect:
The NC apparatus 10 performs a series of control processes shown in FIGS. This machining process is executed by an application program in accordance with each command of the machining program. For example, when receiving an operation input for starting machining from the operation unit 12a, the NC device 10 starts the machining process. Here, the front spindle servo circuit 24, the front side collet opening / closing actuator 23, the tool spindle servo circuit 34, and the processing of the system 1 for driving the material feeder 40, the back spindle servo circuit 54, and the back side collet. There is a system 2 process for driving the opening / closing actuator 53 and the product discharge actuator 64. The processing of the systems 1 and 2 is performed in parallel by time division processing or the like. The flowchart shown in FIG. 6 shows the first machining process in which the workpiece W3 after cutting is not gripped by the back spindle 51, and the flowchart shown in FIG. 7 is the second and subsequent times when the workpiece W3 after cutting is gripped by the back spindle 51. The processing is shown.

When the machining process is started, the NC device 10 drives the front side collet opening / closing actuator 23 and closes the front side collet 22 in step S102 of system 1 (hereinafter, “step” is omitted). Further, in S104, outputs a command to retract the parting byte 33 to a predetermined retracted position to the servo circuit 34 is retracted parting bytes 33 to X ₃ direction. On the other hand, in S202 of the system 2, it is determined whether or not the parting tool 33 has moved backward, and S202 is repeated until the condition is satisfied. The determination processing of S202, for example, can be performed by X ₃ coordinates of the cutting-off byte 33 is calculated by the NC device 10 it is determined whether the coordinates are retracted position.

In S204 of system 2, the back side collet opening / closing actuator 53 is driven to open the back side collet 52. Further, in S206, move the back spindle to a predetermined advanced position, to drive the product discharge actuator 64 to advance the product discharge members 62 to Z ₂ direction to a predetermined advanced position. Then, the product discharge member 62 comes out before the front end surface of the back main shaft 51. On the other hand, in S106 of the system 1, it is determined whether or not the product discharge member 62 has advanced to the advance position, and S106 is repeated until the condition is satisfied. The determination process in S106 can be performed, for example, by determining whether or not a predetermined time has elapsed since the drive of the product discharge actuator 64 was started in S206.

In S108 of the system 1, press drives the material supplying device 40 to material W1 to Z ₁ direction forward side. For example, a signal for turning on the motor of the material feeder 40 is output to the material feeder 40. In S110, the front side collet opening / closing actuator 23 is driven to open the front side collet 22. In S <b> 112, the process waits until the material W <b> 1 that moves forward toward the back main shaft 51 contacts the product discharge member 62. The process of S112 can be, for example, a process of waiting for a period of time sufficient for the material W1 to hit the product discharge member 62 after the front collet 22 is opened in S110. Of course, in the process of S112, the process of waiting until the torque value of the motor of the material feeder 40 becomes a predetermined value or more, or the output of the dedicated sensor that detects that the material W1 has contacted the product discharge member 62 is on. It is good also as a process which waits until it becomes. When the material W1 comes into contact with the product discharge member 62, the position of the tip W11 of the material W1 is determined.

In S114 of the system 1 outputs a command to move the front spindle 21 to the machining start point to the servo circuit 24, is stopped at the machining start point by moving the front spindle 21 to Z ₁ direction. In S116, the front side collet opening / closing actuator 23 is driven to close the front side collet 22. As a result, the front spindle 21 grips the material W1 at a position for processing with the processing tool 32. Further, in S118, so that the pressing force in the Z ₁ direction forward side material W1 stops driving of the sheet material machine 40 is not applied. For example, a signal for turning off the motor of the material feeder 40 is output to the material feeder 40. On the other hand, in S208 of system 2, it is determined whether or not the front side collet 22 is closed, and S208 is repeated until the condition is satisfied. The determination process in S208 can be performed, for example, by determining whether the value of the counter representing the execution position of the machining program exceeds a value corresponding to the command in S116.

In S210 of the system 2, and outputs a command to retract the back spindle 51 to a predetermined back machining position to the servo circuit 54, it is stopped at the rear working position back spindle 51 is retracted to the Z ₂ direction. On the other hand, in S120 of the system 1, it is determined whether or not the back spindle 51 has moved back to the back machining position, and S120 is repeated until the condition is satisfied. The determination process of S120 can be performed, for example, by determining whether or not the Z ₂ coordinate of the back spindle 51 calculated by the NC device 10 has become the coordinates of the back surface processing position. In S <b> 122, as shown in FIG. 3A, front processing is performed with the processing tool 32 on the material W <b> 1 gripped by the front side collet 22. That is, the NC device 10 outputs a command for appropriately driving the front spindle feed motor 26, the tool spindle feed motor 36, and the front spindle rotation motor to the servo circuit. Thereby, the front-end | tip part of the material W1 hold | gripped by the front main axis | shaft 21 is processed into a product shape.

Thereafter, in S152 and S252 (see FIG. 7), a command to move both spindles 21 and 51 to predetermined cut-off positions L11 and L21 is output to the servo circuits 24 and 54, and both spindles 21 and 51 are moved to Z ₁ and Z _2. It moves to the direction and stops at cut-off positions L11 and L21 shown in FIG. In S254 of system 2, the back side collet opening / closing actuator 53 is driven to close the back side collet 52. Thereby, the front end W11 of the material W1 after the front processing is gripped by the back main shaft 51. Thereafter, in S154 of the system 1, the material W1 after the front processing is cut off by the cut-off tool 33 between the front main shaft 21 and the rear main shaft 51. That is, the NC device 10 outputs a command to switch the tool of the tool post 30 from the machining tool 32 to the cut-off tool 33 to the servo circuit, and outputs a command to rotate the front spindle rotating motor to the servo circuit. and outputs a command to drive toward the rotational axis AX1 to X ₃ direction to the servo circuit 34. As a result, as shown in FIG. 4A, the material W1 after the front processing is cut off between the main spindles 21 and 51, and the cut workpiece W3 is held by the back side collet 52, and the workpiece after the cutting is cut off. W2 is held by the front side collet 22.

Thereafter, in S156 and S256, a command for slightly retracting the main spindles 21 and 51 to the predetermined opening positions L12 and L22 (for example, 0.1 mm, respectively) is output to the servo circuits 24 and 54, and both the main spindles 21 and 51 are moved. Retreat in the Z ₁ and Z ₂ directions and stop at the open positions L12 and L22 shown in FIG. In S158 of the system 1, to retract the X ₃ direction until the retracted position the parting byte 33 in the same manner as in S104. On the other hand, in S258 of the system 2, in the same manner as in S202, the cut-off tool 33 stands by until it is retracted to the retracted position.

In S260 of the system 2, and outputs a command to move (forward) the back spindle 51 to a predetermined reference position L23 to the servo circuit 54, the reference position shown in FIG. 4 (c) the back spindle 51 is moved in the Z ₂ direction Stop at L23. The reference position L23 is a position where the tip W21 of the workpiece W2 after being cut off is brought into contact with the workpiece W3 after being cut on the back spindle side. On the other hand, in S160 of system 1, it is determined whether or not the back spindle 51 has moved to the reference position L23, and S160 is repeated until the condition is satisfied. The determination process of S160 can be performed, for example, by determining whether or not the Z ₂ coordinate of the back spindle 51 calculated by the NC apparatus 10 has become the coordinate of the reference position L23.

In S162 of the system 1, pushes S108 and drives the material supplying unit 40 in the same manner of material W1 to Z ₁ direction forward side. In S164, the front side collet 22 is opened as in S110. As a result, the workpiece W <b> 2 after the cut-off is released from the gripping of the front spindle 21 and is pushed toward the back spindle 51 by the material feeder 40. In S166, the process waits until the cut-off workpiece W2 moving forward toward the back spindle 51 comes into contact with the back surface W31 of the cut workpiece W3. The process of S166 can be, for example, a process of waiting for a sufficient period of time after the front collet 22 is opened in S164 and the workpiece W2 after the cut-off strikes the workpiece W3 after the cut. Of course, the process of S166 is a process for waiting until the torque value of the motor of the material feeder 40 becomes equal to or greater than a predetermined value, or a dedicated sensor for detecting that the cut-off work W2 is in contact with the cut work W3. It is also possible to perform processing that waits until the output is turned on. As shown in FIG. 5A, when the cut-off work W2 comes into contact with the cut work W3, the cut-off work W2 on the front main shaft 21 side becomes the reference position. Thereby, the front spindle 21 can grip the workpiece W2 after the cut-off at the machining start point (grip position L13).

In S168 of the system 1, an instruction to move the front spindle 21 to the machining start point (gripping position L13) (backward) and outputs to the servo circuit 24 to move the front spindle 21 to Z ₁ direction in FIG. 5 (b) Stop at the indicated gripping position L13. In S170, the front side collet 22 is closed as in S116. Thereby, the front main shaft 21 grips the material W1 at the position L13 for processing with the processing tool 32. Moreover, in S172, the drive of the material feeder 40 is stopped similarly to S118. On the other hand, in S262 of system 2, it waits until front side collet 22 closes like S208. In S264, to stop the back spindle 51 in the same manner as in S210 in the rear working position L24 is retracted to the Z ₂ direction.

  In S174 of the system 1, as in S120, the process waits until the back spindle 51 moves back to the back machining position L24. In S 176, front machining is performed with the machining tool 32 on the workpiece W <b> 2 that has been cut off and held by the front collet 22. That is, the NC device 10 outputs a command for appropriately driving the front spindle feed motor 26, the tool spindle feed motor 36, and the front spindle rotation motor to the servo circuit. Thereby, the front-end | tip part of the workpiece | work W2 after a cut-off is processed into a product shape. In S178, it is determined whether or not to finish machining the workpiece. When the set number of products is produced, or when the material W1 is lost and the front collet 22 cannot grip the material W1, the NC device 10 determines that the condition is satisfied and ends the processing of the system 1 . On the other hand, when determining that the condition is not satisfied, the NC device 10 returns to S152.

On the other hand, in S266 of the system 2, the back machining is performed on the cut workpiece W3 held by the back side collet 52 with a machining tool. That is, the NC device 10 outputs a command to appropriately drive the back spindle feed motor 56, the tool spindle feed motor, and the back spindle rotation motor to the servo circuit. Thereby, the back part of the workpiece W3 after cutting is processed into a product shape, and the workpiece W3 after cutting is used as a product. In S268, by driving the rear side collet opening and closing actuator 53 to open the rear side collet 52, a predetermined after driving the product discharge actuator 64 to advance the product discharge members 62 to Z ₂ direction to a predetermined advanced position to a retracted position to retract the Z ₂ direction. Then, the product released from the grip of the back main shaft 51 is pushed out by the product discharge member 62 and discharged from the back main shaft 51. In S270, it is determined whether or not the machining of the workpiece is to be terminated, similar to S178. When determining that the condition is satisfied, the NC device 10 ends the machining process of the system 2, and when determining that the condition is not satisfied, returns to S252.

By the processing described above, the NC device 10 continuously processes the material W1.
As described above, in the lathe 1 of the present embodiment, the workpiece W3 after cutting held by the back spindle 51 functions as a stopper. The workpiece W2 after being cut off on the front main shaft 21 side pressed by the material feeder 40 comes into contact with the workpiece W3 after cutting on the rear main shaft 51 side, whereby the tip position of the workpiece W2 after being cut off by the front main shaft 21 is determined. When the workpiece is positioned using the stopper attached to the tool post, it takes time to switch between the machining tool and the cutting tool and the stopper. However, the lathe 1 does not need to perform such switching processing. Further, if the workpiece positioning process is performed with the end surface of the back spindle as a stopper, it takes time to move the back spindle head such as shifting the center of the back spindle from the axis of the front spindle. There is no need to perform move processing. Therefore, the lathe 1 can reduce the time for processing to position the workpiece after parting to the reference position, and the time for processing to determine a new gripping position of the part after parting by the spindle. .

  Further, by performing the positioning process of the material W1 using the product discharge member 62 as a stopper during the first processing, it is not necessary to attach the stopper to the tool post.

(3) Modification:
By the way, the lathe to which the present invention can be applied may be a lathe having a guide bush between the front main shaft and the rear main shaft.
In order to determine the gripping position of the material by the main shaft in the first processing, in addition to bringing the front end of the material into contact with the product discharge member, the front end of the material may be brought into contact with the end surface of the back main shaft, or the blade You may make the front-end | tip of material contact | abut to the stopper attached to the base. Even in these cases, the processing time for positioning the cut-off workpiece to the reference position is shortened by using the cut workpiece gripped by the opposite spindle as a stopper in the second and subsequent machining processes. An effect is obtained.

Reference position L23 giving abutting workpieces after cutting-off the after cleavage of the rear spindle side workpiece, than slightly opening position L22 not only Z ₂ direction forward side, may be as such slightly open position L22, slightly opening position L22 It may be on the backward side. If the reference position L23 is the open position L22, the processing of S160 and S260 for advancing the back spindle can be omitted, and the workpiece machining efficiency can be improved. Further, the reference position of the back spindle as gripping position L13 of the front spindle is slightly open position L12 L23 is if the Z ₂ direction backward side of the slightly open position L22, omitting the processing of S168 to retract the front spindle In some cases, the machining efficiency of the workpiece can be improved.
On the other hand, the sub spindle is a fixed counter spindles without moving the Z ₂ direction by abutting the workpiece after cutting-off the after cleavage of the rear spindle side workpiece, the position of the reference work after the cutting-off Can be positioned.

  The processing described above may be executed only by the application program regardless of the processing program, in addition to the processing program and the application program being executed in cooperation. Further, S160 to S172 are provided as a system 1 alignment batch command for machining program, S260 to S262 are provided as a system 2 alignment batch command for machining program, and system 1 and 2 alignment batch commands are applied to the application. The program may interpret and execute it.

  Note that the present invention is not limited to the above-described embodiments and modifications, but the configurations disclosed in the above-described embodiments and modifications are mutually replaced, the combinations are changed, known techniques, and the above-described configurations. Configurations in which the respective configurations disclosed in the embodiments and modifications are mutually replaced or combinations thereof are also included.

The top view which illustrates the outline of a structure of a lathe. The block diagram which illustrates the outline of the electric circuit of a lathe. The figure which illustrates operation | movement of a lathe. The figure which illustrates operation | movement of a lathe. The figure which illustrates operation | movement of a lathe. The flowchart which shows an example of the process which NC apparatus performs. The flowchart which shows an example of the process which NC apparatus performs.

Explanation of symbols

1 ... Lathe, 10 ... Numerical control device (part of control means),
20 ... Front spindle head, 21 ... Front spindle, 22 ... Front side collet,
24 ... Servo circuit, 24a ... Servo amplifier, 26 ... Front spindle feed motor,
30 ... Turret, 32 ... Processing tool, 33 ... Cut-off tool (cut-off tool),
34 ... Servo circuit, 34a ... Servo amplifier, 36 ... Tool spindle feed motor,
40 ... Material feeder (work supply device), 41 ... I / O circuit,
50 ... back spindle head, 51 ... back spindle (opposite spindle), 52 ... back side collet,
54 ... Servo circuit, 54a ... Servo amplifier, 56 ... Rear spindle feed motor,
60 ... Product discharging device, 62 ... Product discharging member, 64 ... Actuator,
L11, L21 ... cut-off position, L12, L22 ... opening position,
L13: Gripping position, L23: Reference position, L24 ... Back processing position,
W1 ... material (work), W2 ... work after cut-off, W3 ... work after cutting,

Claims (4)

A spindle that is movable in its own axial direction and releasably holds a workpiece inserted in the axial direction;
A workpiece supply device for supplying the workpiece from behind to the spindle;
A tool post having a cut-off tool for cutting through the workpiece from the main shaft forward;
An opposing spindle for releasably gripping the workpiece after cutting by the parting tool;
In order to position the cut-off workpiece released from the gripping of the spindle to a reference position, the workpiece after the cut-off is pushed toward the opposing spindle by the workpiece supply device, and the workpiece after cutting held by the opposing spindle A lathe comprising control means for contact. A spindle that is movable in its own axial direction and releasably holds a workpiece inserted in the axial direction;
A workpiece supply device for supplying the workpiece from behind to the spindle;
A machining tool for machining the workpiece that has moved forward from the spindle and a tool post having a cut-off tool for cutting through the workpiece;
An opposing spindle for releasably gripping the workpiece after cutting by the parting tool;
The workpiece after the parting released from the gripping of the main shaft is pushed to the opposite main shaft side by the work supply device to be brought into contact with the workpiece after cutting held by the main shaft, and the workpiece after the parting off is processed. And a control means for gripping the workpiece after the cut-off by the main shaft at a position. A spindle that is movable in its own axial direction and releasably holds a workpiece inserted in the axial direction;
A workpiece supply device for supplying the workpiece from behind to the spindle;
A machining tool for machining the workpiece that has moved forward from the spindle and a tool post having a cut-off tool for cutting through the workpiece;
An opposing spindle for releasably gripping the workpiece after cutting by the parting tool;
The workpiece gripped by the main shaft is processed by the processing tool, the tip of the processed workpiece is gripped by the opposed main shaft, and the processed workpiece is cut off by the cut-off tool between the main shaft and the opposed main shaft. The workpiece after the cut-off is released from the gripping of the main shaft, and the workpiece after the cut-off inserted into the main shaft is pushed to the opposite main shaft side by the work supply device and comes into contact with the cut workpiece gripped by the opposite main shaft. And a control means for performing a series of controls that causes the spindle to grip the cut-off workpiece at a position for machining with the machining tool. A main shaft that can move in its own axial direction and releasably grips a workpiece inserted in the axial direction, a workpiece supply device that supplies the workpiece to the main shaft from the rear, and a forward movement from the main shaft. A lathe control method comprising a tool post having a cut-off tool for cutting through the workpiece, and an opposing spindle for releasably gripping the workpiece cut by the cut-off tool,
In order to position the cut-off workpiece released from the gripping of the spindle to a reference position, the workpiece after the cut-off is pushed toward the opposing spindle by the workpiece supply device, and the workpiece after cutting held by the opposing spindle A method of controlling a lathe characterized by contacting the lathe.

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