JP2017024125A - Machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce size and weight of a rotary tool driving device mounted on a tool post of a machine tool.SOLUTION: A machine tool comprises: a tool main spindle 11 which performs fixation and fixation release of a tool fitted to its tip by forward and backward movement of a rod 15 inserted into a shaft center in an axial direction; and a tool changer which performs a change of a tool fitted to the tool main spindle 11. A cylinder unit 2 that moves forward and backward the rod 15 is provided at a fixed position on the side of the tool changer, which becomes a positional relationship where a rear end of the tool main spindle 11 positioned to a tool change position is opposed to a tip of a piston rod 21 of the cylinder unit 2.SELECTED DRAWING: Figure 1

Description

  The present invention includes a tool mounting shaft (hereinafter referred to as “tool spindle”) on which a rotary tool such as a drill or a mill can be mounted, and a tool changer for exchanging the tool between the tool spindle and a tool magazine. It relates to machine tools.

  A lathe called a compound lathe equipped with a tool post equipped with a rotary tool driving device for processing a workpiece with a rotary tool is known. This type of lathe includes a tool magazine for holding a large number of tools for mounting on a tool spindle of a rotary tool driving device, and a tool changer for exchanging tools between the tool magazine and the tool spindle. In addition to workpiece turning, flat machining using a milling machine, grooving using an end mill, drilling using a drill, and the like are possible.

  The rotary tool driving device requires a tool spindle for attaching a tool, a tool motor for rotating the tool spindle, and a cylinder device for fixing and releasing the tool mounted on the tool spindle. The tool attached to the tool spindle is fixed by the axial movement of a rod, usually called a pull rod, inserted through the axis of the tool spindle. In other words, the tool is fixed by pulling the tip of the shank inserted into the fitting hole provided at the tip of the tool spindle into the tip of the pull rod, and the fixing is released by pushing the pull rod toward the tool with the cylinder device.

  FIG. 5 is a view showing an example of a rotary tool driving device having the above structure. The tool spindle 11 is supported by bearings 13 and 13 and is driven to rotate by a built-in motor 3. The tool spindle 11 is provided with a through hole in the shaft center, and a pull rod 15 having a locking tool 14 formed at the tip is inserted into the through hole. The pull rod 15 is urged by the clamp spring 16 in the retracting direction. The tool is fixed by pulling the shank of the tool inserted into the fitting hole 17 at the tip of the tool spindle 11 with the pull rod 15. A cylinder chamber 23 is provided on the rear end side of the pull rod 15, and the tool is released by pushing the pull rod 15 with its piston 24.

  When the rotary tool driving device having the above-described structure is mounted on the tool post, hydraulic pressure is supplied to the cylinder chamber 23 in addition to the power cable for driving the tool motor 3 between the tool post and the machine tool body. It is necessary to connect signal cables of two sensors for detecting the forward and backward movement ends of the pull rod 15 and confirming the fixation and release of the tool.

  For machine tools, we want to make it possible to process larger workpieces with machines of the same dimensions. In other words, there is a demand for reducing the size of a machine having the same capability and a demand for processing at a higher speed. In order to satisfy these requirements in the composite lathe, it is desired to reduce the size and weight of the rotary tool driving device mounted on the tool post.

  According to the present invention, in a machine tool provided with a tool spindle mounted on a tool post and a tool changer for exchanging a tool mounted on the tool spindle, the rotary tool driving device can be reduced in size and weight. The challenge is to obtain machine tools.

  In the present invention, the cylinder unit 2 provided integrally with the tool spindle unit 1 on the rear end side of the tool spindle is separated from the tool spindle unit 1 and fixedly provided on the tool changer 46 (46L, 46R) side. When the tool post 5 on which the tool spindle unit 1 is mounted moves to the tool change position P, the rear end of the tool spindle 11 and the tip of the piston rod 21 of the cylinder unit are opposed to each other on the same axis. The above-mentioned problem is solved by arranging the cylinder unit 2 (2L, 2R) in the cylinder.

  The machine tool according to the present invention is held by a tool spindle 11 that fixes and releases a tool attached to the tip by an axial advance / retreat operation of a rod 15 inserted through an axis, and a tool magazine 45 (45L, 45R). Cylinder unit 2 (2L, 2R) for moving the rod 15 forward and backward in a machine tool including a tool changer 46 (46L, 46R) for exchanging the tool 6m and the tool 6w mounted on the tip of the tool spindle 11 Is provided at a fixed position on the tool changer 46 side where the rear end of the tool spindle 11 positioned at the tool change position P and the front end of the piston rod 21 of the cylinder unit 2 face each other. And

  In the tool spindle unit 1 in which the rotor axis of the tool motor 3 for rotating the tool is the tool spindle 11, the length of the tool spindle 11 is increased due to the structure of the motor, and a spring for fixing the tool is incorporated in the tool spindle 11. It becomes possible to do. In this case, by pushing and releasing the rear end 15e of the rod 15 with the piston rod 21 of the cylinder unit 2, the tool is fixed and released, so that the cylinder unit 2 installed separately at a fixed position is used. Thus, the tool of the tool spindle 11 can be fixed and released with a simple structure.

  A tool spindle unit 1 provided with a spring 16 for urging the rod 15 on the side where the tool is fixed, and a cylinder unit 2 for pushing the rod 15 in the direction of releasing the tool against the urging force of the spring 16. In the machine tool according to the present invention in which the cylinder unit 2 is provided in the tool changer 46 separately, the reaction force of the piston rod 21 that pushes the tool spindle 11 against the biasing force of the spring 16 causes the frame 48 of the tool changer 46. The pressing force of the piston rod 21 acts on the tool post 5. Therefore, it is necessary to increase the support rigidity of the tool changer, which causes a problem that the force acting on the feed screw of the tool post 5 becomes large when changing the tool.

  This problem is caused by the uneven engagement pair 19 which is engaged and disengaged by the approach and retraction movement of the tool spindle 11 to and from the frame 48 of the tool changer 46 or the housing 22 of the cylinder unit 2 and the housing 12 of the tool spindle. This can be solved by the structure provided with 29.

  In the two-spindle opposed composite lathe mounted on the tool post 5 so that the tool spindle unit 1 can turn about an axis perpendicular to the axis of the workpiece spindle, the tool spindle unit 1 is held by one spindle 4L as shown in FIG. When the tool spindle unit 1 having the tool spindle 11 parallel to the workpiece spindle 4 is inserted between the tip of the workpiece wL and the tip of the other spindle or the workpiece wR gripped by the other spindle There is.

  In such a machine tool, the length of the work w (wL, wR) that can be processed is increased by the amount of separation of the cylinder unit 2 from the tool spindle unit 1. In other words, a workpiece having the same dimensions can be processed by a smaller machine.

  The machine tool according to the present invention separates the cylinder unit 2 for fixing and releasing the tool mounted on the tool spindle 11 from the tool spindle unit 1 and separately places it at a fixed position on the tool changer side. The unit mounted on can be made compact.

  By separating the cylinder unit 2 from the tool spindle unit 1, the tool spindle related device mounted on the tool post 5 becomes compact, the tool post can be reduced in weight, and the tool post feed motor can be downsized. In particular, since the dimension in the tool spindle direction of the apparatus mounted on the tool post 5 (dimension A in FIG. 3) is reduced, in a machine tool in which the workpiece spindle is arranged in an opposed form, the machined workpiece size is reduced while reducing the machine size. The width of the processing layout can be widened.

  Furthermore, the hydraulic piping to the cylinder unit 2 and the two confirmation sensors 31 and 32 for confirming the fixing and releasing of the tool are changed from the connection to the movable part to the connection to the fixed part. Will improve.

Cross section of tool spindle unit and cylinder unit Front view showing an example of a two-spindle facing lathe Explanatory drawing showing the processable dimensions The figure seen from the main-axis axis direction of Drawing 2 showing the example of the fitting structure of a tool main-axis unit and a cylinder unit Sectional view of the main part of a conventional device

  FIG. 1 is a cross-sectional view showing a tool spindle unit 1 and a cylinder unit 2 that is separated from the tool spindle unit 1 and mounted on the tool changer side. The tool spindle unit 1 includes a built-in (built-in) tool motor 3. The rotor shaft 11 of the tool motor 3 is a tool spindle. The tool spindle 11 is supported by bearings 13 and 13 on a housing 12 of the tool spindle unit. The tool spindle 11 is provided with a through hole in the shaft center, and a pull rod 15 having a locking tool 14 formed at the tip is inserted into the through hole. The pull rod 15 is urged in a retracting direction (direction in which the tool shank is drawn) by a clamp spring 16 made up of a number of disc springs and the like stacked in an elongated cylindrical space formed between the tool spindle 11 and the pull rod 15. ing. A fitting hole 17 for fitting with a tool shank is provided at the tip of the tool spindle 11, and a locking tool 14 at the tip of the pull rod 15 faces the bottom of the fitting hole. The rear end 15 e of the pull rod 15 faces an opening 18 provided at the rear end (on the opposite tool side) of the housing 12.

  The cylinder housing 22 of the cylinder unit 2 includes an annular cylinder chamber 23, and an annular piston 24 is fitted in the cylinder chamber. The piston rod 21 provided at the axial center of the piston 24 is integral with the piston 24, and the tip thereof faces an opening 28 provided in the cylinder housing. When hydraulic pressure is supplied to the fluid chamber 25 on the cylinder head end side, the piston rod 21 moves in a direction protruding from the opening 28 of the cylinder housing. The cylinder unit 2 includes a sensor 31 that detects a moving end of the piston rod 21 in the protruding direction, a sensor 32 that detects a backward moving end of the rear end 15e of the pull rod 15 that has moved toward the cylinder unit 2, and a fluid. A return spring 26 is provided for returning the piston rod 21 to the retracted end when the hydraulic pressure in the chamber 25 is released.

  FIG. 2 is a front view showing a two-spindle opposed lathe according to the present invention. The two-spindle opposed lathe shown in the figure includes two opposed spindles 4L and 4R, and tool rests 5 and 7 arranged above and below the spindle axis. A tool spindle unit 1 is mounted on a tool post 5 arranged above the spindle axis so as to be able to turn around a direction perpendicular to the plane of the drawing (Y-axis direction) orthogonal to the tool spindle 11. The lower tool post 7 is a turret tool post including a turret 8 that rotates around an axis parallel to the spindle axis.

  The opposing main shafts 4L and 4R are pivotally supported by the main shaft bases 41L and 41R, and are rotationally driven by the main shaft motors 43L and 43R via the synchronous belts 42L and 42R. One of the headstocks 41L is fixed to the bed, and the other 41R can be moved in the main shaft axis direction (Z-axis direction) by the main shaft feed motor 44.

  Tool magazines 45 (45L, 45R) for storing tools to be mounted on the tool spindle 11 are arranged at positions above the left and right spindle bases 41 (41L, 41R), and a tool changer is provided inside each tool magazine 45. 46 (46L, 46R) is arranged. Each tool changer includes a tool change arm 47 (47L, 47R) that moves up and down and rotates about a vertical axis by 180 degrees. The cylinder unit 2 (2R, 2L) is fixedly mounted above the frame 48 (48L, 48R) of each tool changer 46.

  The tool changer arm 47 has tool gripping tools at both ends, and is located symmetrically with the tool 6m with the tool 6m directed downward at the lower end of the tool magazine 45 and the turning center of the tool changer arm 47 interposed therebetween. The tool 6w of the tool spindle 11 that has moved is exchanged by the raising / lowering operation of the tool changing arm 47 and the 180-degree turning operation. The cylinder unit 2 is installed at a position where the end of the tool spindle 11 positioned at the tool change position faces the tip 21f of the piston rod 21 on the same axis.

  The tool spindle housing 12 and the cylinder housing 22 are formed with a concave engagement portion 19 and a convex engagement portion 29 that are fitted and removed by movement of the tool rest 5 in the Z-axis direction. FIG. 4 is a diagram showing the shapes of the tool spindle housing 12 and the cylinder housing 22 as seen from the direction of arrow B in FIG.

  When the tool post 5 is first moved in the X-axis direction and then moved in the Z-axis direction when the tool is changed, the tool rest 5 is positioned in the tool change position. The portion 29 is fitted to prevent relative movement between the cylinder unit 2 and the tool spindle unit 1 in the X-axis direction (axis direction of the tool spindle).

  That is, in this state, if fluid pressure is supplied to the fluid chamber 25 of the cylinder unit and the rear end 15e of the pull rod 15 is pushed by the tip of the piston rod 21, then it acts on the cylinder unit 2 and the tool spindle unit 1 at that time. Since the reaction force to be received is received by the engagement of the concave and convex engaging portions 19 and 29, a large reaction force when the tool is released by pushing the pull rod 15 is fed to the frame 48 or the tool post 5 of the tool changer. It can prevent acting on a screw.

  As understood from the above description, in this invention, the cylinder unit 2 for releasing the fixation of the tool mounted on the tool spindle at the time of tool replacement is mounted at a fixed position on the tool changer 46 side, and the tool post Since only the tool spindle unit 1 is mounted on 5, the weight of the tool post on which the tool spindle unit is mounted can be reduced, and there is no need to connect a hydraulic hose or signal cable to the moving tool post.

  In particular, in a two-spindle opposed lathe equipped with a tool spindle unit that can be swung around an axis orthogonal to the spindle axis and mounted on the tool post, the machine Z-axis dimension is reduced, and the machine rigidity is improved as the dimension is reduced. There is an effect that can be achieved.

DESCRIPTION OF SYMBOLS 1 Tool spindle unit 2 (2L, 2R) Cylinder unit 3 Tool motor 4 (4L, 4R) Work spindle 5 Tool post 6m, 6w Tool 11 Tool spindle 12 Housing 15 Rod 16 Spring 19 Concave engaging part 21 Piston rod 22 Housing 29 Convex engagement part 45 (45L, 45R) Tool magazine 46 (46L, 46R) Tool changer 48 Frame P Tool change position w (wL, wR) Workpiece

Claims (4)

A tool spindle that fixes and releases a tool attached to the tip by the axial movement of a rod inserted through the shaft center, a tool held in a tool magazine, and a tool attached to the tip of the tool spindle. In a machine tool equipped with a tool changer that performs exchange,
A cylinder unit for advancing and retracting the rod is provided at a fixed position on the tool changer side where the rear end of the tool spindle positioned at the tool change position and the front end of the piston rod of the cylinder device face each other. A machine tool.   The rod is a pull rod that moves in a direction retreating from the tip of the tool spindle to fix the tool, the tool spindle is a rotor shaft of a built-in motor that rotationally drives the spindle, and the tool spindle is connected to the pull rod. The machine tool according to claim 1, further comprising a spring biasing in a backward direction, wherein a tip end of the piston rod pushes a rear end of the pull rod to release the tool.   A frame or cylinder unit housing of the tool changer and a tool spindle housing are provided with a concavo-convex engagement pair that is engaged and disengaged by an approach and retraction movement of the tool spindle in a direction perpendicular to the axis of the tool spindle. The machine tool according to claim 1 or 2.   The machine tool according to claim 1, 2, or 3, wherein the machine tool is a two-spindle opposed composite lathe provided with the tool spindle that rotates about an axis orthogonal to the workpiece spindle.

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