JP6501583B2 - Machine tool and control method for machine tool - Google Patents

Description

  The present invention relates to a machine tool and a control method of the machine tool.

  Heretofore, supporting means for supporting two work main spindles holding a work at a tip end portion as holding shafts and supporting each of the holding shafts in an axial direction movably against the movement resistance of the support means There is generally known a machine tool having a drive means for moving and driving a holding shaft via each support means (see, for example, Patent Document 1).

  In this machine tool, the end of the work held by one holding shaft is held by the other holding shaft by moving at least one holding shaft by the drive means so that both holding shafts approach each other. be able to.

  Thus, for example, a chuck capable of holding one end of the work on one end of the holding shaft and holding the other end of the work on the other holding shaft, and inserting the other end of the work into the chuck By holding the other end by the chuck, the work can be held by both holding shafts and the next process of processing can be performed.

  On the other hand, a bolt which is a work having an external thread is held in a rotationally driven socket, and this bolt is tightened in a screw hole (female thread) provided in a body or the like corresponding to a work having an internal thread. An apparatus is known (see, for example, Patent Document 2). By allowing such screwing to be performed by the machine tool, it is possible to assemble on a machine by screwing two works having an external thread portion and an internal thread portion which are engaged with each other. Become.

Japanese Patent Application Publication No. 08-118200 Patent No. 4359774 gazette

  In the machine tool described in Patent Document 1, when the work is delivered from one of the opposing main spindles to the other, both main spindles hold the both ends of the work in a fixed state, so that the work is pushed against each other It may be held in a state, and an adverse effect may occur in processing or the like in the next step.

  Further, in the screw tightening device described in Patent Document 2, the bolt is pressed against the screw hole and once rotated reversely, and when the male screw and female screw are engaged, the bolt is rotated forward to be screwed into the screw hole. If the same control is performed by the machine tool, there is a disadvantage that complicated rotation control needs to be performed on the bolt (socket).

  The present invention has as its technical object the solution of the problems of the prior art, and in a machine tool provided with two opposing holding shafts such as opposing main spindles, the work held by one holding shaft is held by the other When holding with the shaft, hold stably with high accuracy, or screw a work with an external thread attached to one spindle and a work with an internal thread attached to the other spindle It is an object of the present invention to provide a machine tool capable of assembling both works and a control method thereof.

In order to achieve the above object, the present invention according to claim 1 comprises two holding shafts facing each other holding a work at a tip end, and supporting means for axially movably supporting each of the holding shafts. And driving means for moving and driving each holding shaft via the supporting means against movement resistance of the supporting means, and at least one of the holding means is moved by the driving means so that the holding shafts approach each other. In a machine tool in which the end of a work held by one holding shaft can be held by the other holding shaft by moving the holding shaft of
When the work held by one of the holding shafts is held by the other holding shaft, the one driving shaft can be moved in the axial direction while receiving the movement resistance of the supporting means. Equipped with stop control means for stopping the means ;
The two holding shafts hold a work having screw portions screwed together,
The two holding shafts are rotationally driven relative to each other in a direction in which the screw portion of the work is screwed,
The stop control means controls to stop at least one of the drive means when holding the work held by one of the holding shafts by the other holding shaft by engaging the screw portions of the work with each other. It is characterized by

  The two holding shafts can hold a work having screw portions screwed to each other. In this embodiment, the two holding shafts are relatively driven to rotate in a direction in which the screw portions of the work are screwed together, and the screw portions of the work are engaged with each other, thereby holding the one holding shaft When the work is held by the other holding shaft, the stop control means can control to stop at least one of the drive means.

  Further, a chuck capable of holding one end of the work on the tip end of the one holding shaft, and holding the other end of the work on the other holding shaft, and inserting the other end of the work into the chuck The stop control means may perform stop control of at least one of the drive means when the chuck grips the other end.

  Further, the supporting means may include a slide rail extending in the axial direction of each main shaft, a spindle stock slidably supported by the slide rail, and a ball screw provided on the spindle stock and the slide rail side. You can

According to another feature of the present invention, two opposing holding shafts for holding the work at the tip end, supporting means for axially movably supporting the holding axes, and movement resistance of the supporting means are provided. Against each other by driving at least one of the holding shafts by the driving means so that the holding shafts move closer to each other, In a control method of a machine tool in which an end portion of a work held by a holding shaft of can be held by the other holding shaft,
A work having screw portions screwed to each other is held by the two holding shafts, and the two holding shafts are relatively driven to rotate in a direction in which the screw portions of the work are screwed to engage the screw portions of the work when holding a work held on one of the holding shaft by engaged by the other holding shaft, one holding axis, so that it can move in the axial direction while receiving transfer resistance of the supporting means, at least one of There is provided a control method of a machine tool characterized in that the driving means is stopped.

  A work having screw portions screwed to each other is held by the two holding shafts, and the two holding shafts are relatively driven to rotate in a direction in which the screw portions of the work are screwed to engage the screw portions of the work When the work held by one holding shaft is held by the other holding shaft by combining, at least one of the drive means can be controlled to stop.

  A chuck capable of holding one end of the work is disposed at the end of the one holding shaft, the other end of the work is held at the end of the other holding shaft, and one end of the work is inserted into the chuck. When the chuck grips the one end, at least one of the drive means may be controlled to stop.

  The support means may include a slide rail extending in the axial direction of each main shaft, a spindle stock slidably supported by the slide rail, and a ball screw provided on the spindle stock and the slide rail side. .

  According to the present invention, when the two holding shafts opposed to each other are moved close to each other, and one end of the work held by the one holding shaft is held by the other holding shaft, the one holding is performed. One of the drive means is stopped so that the shaft can move in the axial direction while receiving the movement resistance of the support means, so that both ends of the work can be held easily and with high accuracy by the two holding shafts. Can. As a result, the work is delivered from one main spindle to the other main spindle, or a work having an external thread mounted on one main spindle and a work having an internal thread mounted on the other main spindle are engaged. Then, it becomes possible to assemble both works.

FIG. 1 is a schematic perspective view showing an automatic lathe having three spindles as an example of a machine tool to which the present invention is applied. FIG. 2 is a schematic plan view of the automatic lathe of FIG. 1; It is a flowchart explaining the operation | work which assembles by screwing together the workpiece | work which had an external thread part, and the workpiece | work which has an internal thread part on the automatic lathe of FIG. FIG. 5 is a schematic operation explanatory view for explaining the operation of FIG. 3; As another embodiment of the present invention, it is a schematic operation explanatory view for explaining an operation of holding the work held by the collet chuck on one of the main spindles opposed to each other by the collet of the other main spindle.

  In FIGS. 1 and 2, in the automatic lathe 100, three lathe modules M1 to M3 are mounted on a bed 60. Two lathe modules M1 and M2 are juxtaposed parallel to each other, and one lathe module M3 is disposed opposite to the two lathe modules M1 and M2 juxtaposed.

  Each lathe module M1 to M3 has substantially the same structure, and includes a base 62, a spindle head 63 provided on the base 62, and a spindle 64 rotatably supported by the spindle head 63. . The lathe modules M1 to M3 are provided such that the central axes of the respective spindles 64 are in the same direction. The base 62 of the lathe module M1, M2 is fixed to the bed 60, and the base 62 of the lathe module M3 is fixed on the slide mechanism SL attached to the bed 60, and the spindle relative to the bed 60 via the slide mechanism SL. It is slidably mounted in a horizontal direction (Y-axis direction) orthogonal to the direction of the central axis of 64 (Z-axis direction). A built-in motor conventionally known as a spindle motor is provided inside the spindle stock 63 between the spindle stock 63 and the spindle 64, and the spindle 64 is rotationally driven by the spindle motor (built-in motor).

  Slide rails 67 are provided on the bases 62 in the Z-axis direction. Two slide rails 67 are provided in parallel, and the headstock 63 is mounted on both slide rails 67 via a slide block 61 sliding on the slide rails 67. A ball screw 65 extends in parallel to the slide rail 67 in the Z-axis direction between the slide rails 67. A headstock motor 66 is connected to one end of the ball screw 65, and the ball screw 65 is rotationally driven by driving the headstock motor 66. The headstock 63 has a nut (not shown) screwed to the ball screw 65, and moves in the Z-axis direction along the slide rail 67 by rotational driving of the ball screw 65. The slide mechanism SL includes a pair of slide rails 50 extending in the Y-axis direction, a ball screw 52 extending in the Y-axis direction between the slide rails 50, and a drive motor 54 that rotationally drives the ball screw 52. The base 62 of the lathe module M3 is mounted on both slide rails 50 via a slide block (not shown) that slides on the slide rail 50, and is screwed into the ball screw 52 via a nut (not shown). There is. The lathe module M3 can be moved in the Y-axis direction by the rotational drive of the ball screw 52 by the drive motor 54.

  The headstock motor 66 generates friction and lubricant viscosity between the ball screw 65 and the nut and between the slide rail 67 and the sliding block 61, which are generated based on the force required to rotate the ball screw 65. The ball screw 65 is rotated against the movement resistance to drive the movement of the main shaft 64. Each headstock motor 66 is composed of a servomotor controlled by the control device of the automatic lathe 100. In the present embodiment, the slide rail 67, the headstock 63, the ball screw 65, and the nut attached to the headstock 63 constitute supporting means for slidably supporting the spindle 64 in the axial direction (Z-axis direction). .

  As shown in FIG. 2, a support stand 72 is provided in front of the spindle stock 63. The support 72 is fixed to the base 62. At the front of the support stand 72, a tool rest 73 is provided movably in two directions (Y-axis direction and X-axis direction orthogonal to the Y-axis direction) orthogonal to the Z-axis direction. A tool (not shown) is attached to the tool rest 73. In addition, in FIG. 1, in order to clarify the mounting state to the bed of the headstock 63, the support stand 72, the blade stand 73, etc. are abbreviate | omitted.

  At the front end face of the spindle 64, a spindle chuck 68 is provided so as to be able to open and close. The spindle chuck 68 is provided with a plurality of chuck claws 69. Each chuck jaw 69 is closed by moving toward the chuck center axis. By inserting a work between the chuck jaws 69 in the open state and closing the chuck jaws 9, the work is held by the spindle chuck 68 and held by the spindle 64. The main shaft 64 can detachably hold the end portion of the work by the chuck 68, and the tip end portion constitutes a holding axis for holding the work. The automatic lathe 100 can perform processing such as cutting with a tool mounted on the tool rest 73 by moving the tool rest 73 with respect to the work held by the main shaft 64 with each lathe module M1 to M3.

  The lathe module M3 is mounted on the lathe module M1 or M2 such that the central axis of the main shaft 64 of the lathe module M1 or M2 coincides with the central axis of the main shaft 64 of the lathe module M3 by movement in the Y-axis direction by the slide mechanism SL. It can be positioned relative to it.

  Both spindle blocks 63 of lathe module M1 or M2 and lathe module M3 arranged opposite to each other so that the axes of the main spindles coincide with each other are moved by the spindle motor 66 through the support means in the Z-axis direction and relative to each other Approach and depart from each other. As a result, the end portion of the work machined by one lathe module M1 or M2 is held by the spindle 64 of the other lathe module M3, and the work by the spindle 64 of the machined side (lathe module M1 or M2) Is released, and both spindle heads 63 are relatively moved in the Z-axis direction so that both spindles 64 move away from one lathe module M1 or M2 (spindle 64) to the other lathe module M3 (main shaft 64). The workpiece can be delivered to the main spindle 64).

  In the lathe module M3 on the side of receiving the workpiece, the workpiece after being machined (primary machining) by the lathe module M1 or M2 can be further subjected to another machining (secondary machining). In the lathe module M1 or M2 on the side to which the workpiece is delivered, after the workpiece is delivered to the lathe module M3, primary processing can be performed on another workpiece supplied by a not-shown workpiece loader or the like.

  Thus, in the automatic lathe 100, the primary processing and the secondary processing can be simultaneously performed by performing the primary processing and the secondary processing with the lathe module M1 or M2 and the lathe module M3. Furthermore, since the lathe module M3 mounted on the slide mechanism SL can similarly exchange work with both lathe modules M1 and M2, the exchange of work between the three lathing modules M1 to M3 is performed. Processing can be performed sequentially while performing.

  Also, it is held on the main shaft 64 of the lathe module M1 or M2 by moving the lathe module M3 so that the axis lines of the main shaft 64 of the opposing lathe modules M1 or M2 and the main shaft 64 of the lathe module M3 coincide. The work and the work held by the lathe module M3 can be assembled.

  The control device of the automatic lathe 100 includes an external thread formed on a work held by the spindle 64 of one of the lathe modules M1 to M3 in two lathe modules M1 to M3 in which the axes of the spindles coincide and face each other. Screwing and assembling to control the operation of both lathe modules M1 to M3 so as to screw together the internal thread formed on the work held by the spindle 64 of the other lathe module M1 to M3 and assemble the two works Means are provided.

  FIG. 3 is a schematic view for explaining an operation of screwing and assembling a work having an external thread and a work having an internal thread on the automatic lathe of FIGS. 1 and 2; FIG. FIG. 6 is a schematic operation explanatory view for explaining the operation of FIG. The screwing assembly operation is performed based on a processing program input to a control device (NC device) of the automatic lathe 100 as a machine tool, whereby the control device functions as a screwing assembly means.

  As shown in FIG. 4A, first, in step S101, in the two lathe modules M1 or M2 and M3 arranged so that the axes of the main axes 64 coincide with each other, the main axis 64 of one lathe module M3 The work (male screw work) 51 having the screw portion 51a is held, and the work (female screw work) 52 having the female screw portion 52a formed thereon is similarly held in the main shaft 64 of the other lathe module M1 or M2.

  In the one lathe module M3, the main spindle 64 holds a predetermined work, and the male screw portion 51a is processed to form the male screw work 51, thereby realizing the holding state of the male screw work 51 shown in FIG. May be Further, in the other lathe module M1 or M2, a predetermined work is held by the main shaft 64, and the female screw portion 52a is processed to form the female screw work 52, thereby holding the female screw work 52 shown in FIG. A state may be realized.

  Next, in step S102, the spindle motor of the spindle 64 of one lathe module M1 or M2 is excited and fixed in the C-axis mode, and the spindle motor 66 is servo-off by the controller (NC device) of the automatic lathe 100, that is, the spindle The power supply to the table motor 66 is stopped, and in the present embodiment, the control device of the automatic lathe 100 constitutes stop control means for the headstock motor 66 serving as the driving means. Furthermore, the spindle 64 of the other lathe module M3 is driven to rotate by the drive of the spindle motor, and drives the spindle motor 66 toward the spindle 64 of the lathe module M1 or M2 having the spindle motor 66 servo-off. Driven to approach.

  Then, as shown in FIG. 3B, when the two main spindles 64 approach in the Z-axis direction and the male screw portion 51a of the male screw work 51 contacts the female screw portion 52a of the female screw work 52 Before the peak and valley of each screw portion 51a, 52a are engaged, the spindle 64 of the lathe module M1 or M2 with the headstock motor 66 servo-off is a lathe through the male screw work 51 and the female screw work 52. It is pressed by the main shaft 64 moving in the Z-axis direction of the module M3.

  At this time, since the headstock motor 66 is servo-off, the main spindle 64 of one lathe module M1 or M2 is retracted in the direction away from the main spindle 64 of the lathe module M3 by the external force by the pressing force. Meanwhile, the ball screw 65 of the lathe module M1 or M2 is forced to rotate in response to the retraction by the pressing force. Since the movement resistance exists in the ball screw 65 and the slide rail 67, the main shaft 64 of the lathe module M1 with the headstock motor 66 servo-off is retracted by being pressed by a force exceeding the movement resistance. That is, the spindle 64 of the lathe module M1 or M2 can freely move with the movement resistance by the servo-off of the headstock motor 66.

  However, when the peaks and valleys of the screw parts 51a and 52a are engaged by the rotation of the main shaft 64 of the other lathe module M3, the male screw part 51a and the female screw part 52a are screwed together, and the main shaft 64 of the lathe module M3. The pressing force on the main shaft 64 of the lathe module M1 or M2 is reduced, and the retraction of the main shaft 64 of the lathe module M1 or M2 is stopped in step S103 as shown in FIG. The screw work 52 and the screw work are smoothly screwed, and the male screw work 51 and the female screw work 52 are screwed by the movement of the lathe module M3 in the Z-axis direction and the screw engagement between the male screw 51a and the female screw 52a. It is assembled.

  Control is performed so that the rotational drive of the main shaft 64 does not become equal to or higher than a predetermined torque, and detection that this torque reaches the limit value stops rotation of the main shaft 64, and drives the headstock motor 66 of the lathe module M3. The tightening of the male screw work 51 and the female screw work 52 is completed. After tightening (assembling) of the male screw work 51 and the female screw work 52, the assembled work having the male screw work 51 and the female screw work 52 assembled is temporarily held by the main spindle 64 of either the lathe module M1 or M2 and the lathe module M3. Can be unloaded. Alternatively, the machining can be carried out by further transferring to another lathe module M2 or M1.

  Thus, according to the present invention, the male screw work 51 and the female screw work 52 are held by the two main spindles 64 opposed to each other, and one main spindle 64 is rotationally driven relative to the other main spindle 64 The headstock motor 66, which moves the headstock 63 in the direction of the Z axis, is servo-off to easily make the male screw work 51 and the female screw work 52 without complex control of the spindle motor and the headstock motor 66. It can be screwed and assembled. Under the present circumstances, in addition to the process process of cutting etc., the assembly process including a screwing process can be implement | achieved collectively, efficiency improvement of a manufacturing process and space saving of an installation can be achieved.

  Thus, in the present embodiment, the spindle 64 of the lathe module M3 is directed to the spindle 64 of the lathe module M1 or M2 such that both the spindle 64 of the opposing lathe module M1 or M2 and the spindle 64 of the lathe M3 approach each other. The headstock motor 66 is driven to move closer. Then, the male screw work 51 and the female screw work 52 are screwed together and engaged, whereby the other end of the male screw work 51 or the female screw work 52 held by one main shaft 64 is connected to the other main shaft 64. It will be held through the internal thread work 52 or the external thread work 51.

  In the above example, the spindle motor of the spindle 64 in the lathe module M3 driven by the spindle motor 66 is rotationally driven, and the spindle motor of the spindle 64 in the lathe module M1 or M2 with the spindle motor 66 servo-off The male screw 51a and the female screw 52a are screwed together by exciting and fixing. However, the spindle motor of the spindle 64 in the lathe module M3 in which the spindle motor 66 is driven is excited and fixed, and the spindle motor 66 The spindle motor of the spindle 64 in the lathe module M1 or M2 which is servo-off may be rotationally driven. Alternatively, both spindle motors of both spindles 64 may be rotationally driven.

  In the embodiment described above, the spindle chuck 68 is provided with a plurality of chuck claws 69, and the chuck claws 69 are closed by moving toward the chuck center, but in the present invention, such chuck claws are used. The collet chuck conventionally known can also be used without being limited to having a chuck.

  In FIG. 5, the collet chuck 71 is accommodated at a distal end portion of the main shaft 64 in a chuck sleeve 72 slidably mounted in the axial direction, and urged in the distal direction of the main shaft 64 by a compression spring 73. A cap 74 is screwed on the tip of the main shaft 64. The collet chuck 71 is biased by the compression spring 73, pressed against the cap 74, and positioned. The inner peripheral surface of the tip end portion of the chuck sleeve 72 is a tapered surface 72a which spreads in the tip direction. The tapered surface 72 a is formed to be engageable with the tapered surface of the collet chuck 71.

  As shown on the left side of FIG. 5A, when the chuck sleeve 72 is in the open position in which the chuck sleeve 72 is axially retracted with respect to the main shaft 64 and the collet chuck 71, the tapered surface 72a and the collet chuck 71 (taper surface) are not In the engaged state, the collet chuck 71 is expanded in the radial direction by the spring back and is in the opened state. When the chuck sleeve 72 advances axially to reach the closed position as shown in FIG. 5C, the tapered surface 72a and the collet chuck 71 (taper surface) are engaged, and the collet chuck 71 is The sleeve 72 is pressed in the radial direction by the tapered surface 72a of the sleeve 72, the inner diameter is reduced, and the closed state is achieved.

  In the embodiment of FIG. 5, from the state in which the work 70 is held by the main shaft 64 of one of the two lathe modules M1 or M2 arranged so that the axes of the main shafts 64 coincide, the tip of the work 70 is moved to the other lathe module. It is held by the main shaft 64 of M3.

  In this embodiment, as shown in FIG. 5A, in the two lathe modules M1 and M3 or the lathe modules M2 and M3 in which the axes of the spindles 64 coincide, the spindle 64 of one of the lathe modules M1 or M2 is provided. The workpiece 70 is held on the main shaft 64 of the lathe module M1 or M2 by holding the collet chuck 71 in the closed state and gripping one end of the workpiece 70 made of a bar material, and the workpiece 70 is primarily machined.

  When the primary machining of the work 70 is completed, the headstock motor 66 of the lathe module M3 not holding the work 70 is moved by the headstock motor 66 so as to approach the lathe module M1 or M2 holding the work 70. It is driven in the Z-axis direction. During this time, the lathe module M1 or M2 can control the headstock motor 66 so that the headstock 63 is fixed in the Z-axis direction.

  As shown in FIG. 6B, the two main spindles 64 approach in the Z-axis direction, and the other end of the work 70 is inserted into the collet chuck 71 in the open state of the main spindle 64 of the lathe module M3.

  Next, as shown in FIG. 5C, in the lathe module M3, the end of the workpiece 70 is gripped by the collet chuck 71 by the movement of the chuck sleeve 72 to the closed position, and the workpiece 70 is the main shaft of the lathe module M3. Retained by 64.

  When the collet chuck 71 of the main shaft 64 of the lathe module M3 is closed, the control device (NC device) constitutes stop control means when the lathe module M3 or the headstock motor 66 of the opposing lathe module M1 or M2 is closed. The controller turns off the servo and the power supply to the headstock motor 66 is stopped. Since the movement resistance is present in the support means of the main spindle 62, particularly the ball screw 65, the main spindle 64 of the lathe modules M1 to M3 with the headstock motor 66 servo-off is retracted by a force exceeding this movement resistance. Do. That is, the spindle 64 of the lathe modules M1 to M3 can freely move with the movement resistance by the servo-off of the headstock motor 66, and slightly advances in the chuck sleeve 72 when the collet chuck 71 grips the work 70 In response to the movement of the collet chuck 71, the opposing lathe module M1 or M2 and the lathe module M3 move away from each other, and the opposing lathe module M1 or M2 and the lathe module M3 push the workpiece 70 against each other. Such holding state can be prevented.

  Thus, the work 70 is held at its both ends by the collet chuck 71 of the main shaft 64 of the lathe module M1 or M2 and the collet chuck 71 of the main shaft 64 of the lathe module M3. The workpiece 70 is cut off from the side of the lathe M1 or M2 by cutting, and the workpiece 70 delivered to the lathe module M3 can be secondarily machined on the side of the lathe module M3. It is also possible to carry out processing while holding at In this case, the holding state in which the workpieces 70 are pressed against each other is prevented, and a predetermined predetermined position of the workpieces 70 can be held with high accuracy, and processing can be performed with high accuracy. The occurrence of damage to the work 70 due to the slip of the work 70 is also prevented.

  The collet chuck 71 is provided as a so-called push chuck that is opened and closed by moving the chuck sleeve 72 back and forth. However, the collet chuck 71 is fixed to the chuck sleeve 72 (taper surface 72a) fixed to the main shaft 64 side. It can also be a so-called pull chuck which is opened and closed by moving the In this case, when gripping the work 70, the collet chuck 71 moves backward relatively largely, and in response to the movement of the collet chuck 71, the facing lathe module M1 or M2 and the lathe module M3 approach each other. It is possible to prevent the holding state where the lathe module M1 or M2 and the lathe module M3 which move in the opposite direction and the opposing lathe module M3 pull the work 70 each other, and the effects such as the prevention of the occurrence of flaws and high precision processing are more high.

  In the embodiment described above, after the work 70 is held at both ends by the collet chuck 71 of the main shaft 64 of the lathe module M1 or M2 and the collet chuck 71 of the main shaft 64 of the lathe module M3, the work 70 is cut by parting processing As described above, when the workpiece 70 is not a bar but a blank, the workpiece 70 is held by the lathe module M1 or M2 and primarily machined, and then the workpiece 70 is held by the spindle 64 of the lathe module M1 or M2. The collet chuck 71 may be delivered to the collet chuck 71 of the main shaft 64 of the lathe module M3. In this case, no cutting process is performed.

  In the case where the workpiece 70 is used as a formed material, there is considered a case in which the workpiece 70 and the collet chuck 71 side are abutted against each other for positioning. When gripping by the collet chuck 71, the collet chuck 71 is Although pressing of the work 70 can occur relatively easily, the above movement of the opposing lathe module M1 or M2 and the lathe module M3 prevents the holding state where the work 70 is pushed against each other, and the same effect can be achieved efficiently. You can get well.

  The present invention is a machine tool capable of coaxially arranging opposed main spindles such as a common counter-spindle-type lathe in which opposed main spindles are arranged on one bed, and making these main spindles relatively close to each other It can be applied to any machine tool.

51 Male screw work 51a Male screw 52 Female screw work 52a Female screw 60 Bed 61 Slide block 62 Base 63 Spindle 64 Spindle 65 Ball screw 66 Spindle motor 67 Slide rail 68 Spindle chuck 69 Chuck claw 72 Support base 73 Tool base 100 Automatic Lathe (machine tool)
M1 to M3 Lathe module SL slide mechanism

Claims (4)

Two opposing holding shafts that hold the work at the tip,
Supporting means for movably supporting each of the holding shafts in the axial direction;
Drive means for moving and driving the holding shafts via the support means against movement resistance of the support means;
A machine tool in which an end portion of a work held by one holding shaft is held by the other holding shaft by moving at least one holding shaft by the driving means so that both holding shafts approach each other. In
When the work held by one of the holding shafts is held by the other holding shaft, the one driving shaft can be moved in the axial direction while receiving the movement resistance of the supporting means. Equipped with stop control means for stopping the means ;
The two holding shafts hold a work having screw portions screwed together,
The two holding shafts are rotationally driven relative to each other in a direction in which the screw portion of the work is screwed,
The stop control means controls to stop at least one of the drive means when holding the work held by one of the holding shafts by the other holding shaft by engaging the screw portions of the work with each other. machine tool characterized in that so as to. The main shaft for holding the work is the holding shaft, and the support means includes a slide rail extending in the axial direction of each main shaft, and a main shaft which rotatably supports the main shaft and is slidably supported on the slide rail. The machine tool according to claim 1 , further comprising: a base, and the headstock and a ball screw provided on the slide rail side. Two opposing holding shafts that hold the work at the tip,
Supporting means for movably supporting each of the holding shafts in the axial direction;
And driving means for moving and driving each holding shaft through each of the supporting means against movement resistance of the supporting means.
A control method of a machine tool, in which an end portion of a work held by one holding shaft is held by the other holding shaft by moving at least one holding shaft by the driving means so that both holding shafts approach each other In
Holding the workpieces having screw portions screwed to each other by the holding shafts;
Relatively driving the both holding shafts in a direction in which the screw portion of the work is screwed,
When holding the work held by one holding shaft by the other holding shaft by engaging the screw parts of the work with each other , one holding shaft is axially moved while receiving the movement resistance of the support means A control method of a machine tool, wherein at least one of the drive means is stopped so as to be movable. The main shaft for holding the work is the holding shaft, and the support means includes a slide rail extending in the axial direction of each main shaft, and a main shaft which rotatably supports the main shaft and is slidably supported on the slide rail. 4. The method of controlling a machine tool according to claim 3 , further comprising: a base, and said headstock and a ball screw provided on the slide rail side.

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