JP4460351B2 - Feed drive device with clamp function and machine tool - Google Patents

Description

  The present invention relates to a feed drive device that feeds and drives a movable body with respect to a fixed body by a ball screw mechanism, and a machine tool including the feed drive device.

  In the field of NC machine tools and the like, for example, a device that linearly drives a turret head that holds a tool for processing a workpiece held on a spindle is mounted, and such a feed driving device is generally attached to a fixed body. A slide mechanism that linearly guides the moving body and a ball screw mechanism that linearly feeds the moving body to the fixed body are provided.

  However, in the field of NC machine tools and the like, further improvement in machining accuracy is required, but the conventional configuration cannot completely prevent the backlash between the screw shaft of the ball screw mechanism and the screw nut. For this reason, the tool is displaced during processing. For this reason, it is difficult for a machine tool using a conventional feed driving device to dramatically improve machining accuracy.

  In view of the above problems, an object of the present invention is to provide a feed driving device capable of improving the positional accuracy of a moving body fed and driven by a ball screw, and a machine tool including the feed driving device. .

In order to solve the above-mentioned problems, in the present invention, in a feed driving device including a ball screw mechanism that linearly feeds a moving body in a vertical direction with respect to a fixed body, the moving body is moved in a vertical direction with respect to the fixed body. A sliding mechanism that linearly guides the clamp shaft, a clamp shaft configured to extend in the vertical direction on one side member of the fixed body and the movable body, and the clamp shaft held by the other side member in a clamped state And a clamp mechanism in which the collet is driven in the clamping direction and the unclamping direction by air pressure or hydraulic pressure, thereby forming a feed driving device with a clamping function. And

  In the present invention, since the feed driving device including the ball screw mechanism is provided with the clamp mechanism for the moving body, the positional accuracy of the moving body can be improved. Further, in configuring the clamp mechanism, a clamp shaft configured to extend in the feed direction of the moving body and a collet that can be switched between a clamped state and an unclamped state are used. Do not occupy. Moreover, since the clamp mechanism restrains the moving body via a clamp shaft extending in the feed direction of the moving body, the position of the moving body can be reliably defined regardless of the position.

In the present invention, preferably, the two clamp shafts are provided, and the collet is provided on each of the two clamp shafts .

The feed drive device with a clamp function according to the present invention is used for a machine tool or the like. For example, in a machine tool having a spindle for holding a workpiece and a turret head for holding a tool for processing the workpiece held by the spindle, the X-axis direction perpendicular to the spindle axis with respect to the spindle An X-direction feed driving device that linearly drives the turret head; and a Y-direction that linearly drives the turret head in a Y-axis direction extending in the vertical direction perpendicular to both the X-axis direction and the spindle axis. A feed driving device, and a Z-direction feed driving device that linearly drives the turret head in a Z-axis direction parallel to the spindle axis, the X-direction feed driving device, the Y-direction feed driving device, and the Z-direction feed The feed driving device with the clamp function is used for at least the Y-direction feed driving device among the driving devices .

  In the present invention, since the feed driving device is provided with the clamp mechanism for the moving body, the positional accuracy of the moving body can be improved. Therefore, when the feed drive device with a clamping function according to the present invention is used for feed drive of the turret head in a machine tool, the position accuracy of the tool can be increased, so that highly accurate machining can be performed. Further, in configuring the clamp mechanism, a clamp shaft configured to extend in the feed direction of the moving body and a collet that can be switched between a clamped state and an unclamped state are used. Do not occupy. Moreover, since the clamp mechanism restrains the moving body via a clamp shaft extending in the feed direction of the moving body, the position of the moving body can be reliably defined regardless of the position.

  With reference to the drawings, an example of a feed drive device with a clamping function to which the present invention is applied and an NC machine tool including the same will be described.

(overall structure)
FIG. 1 is a schematic configuration diagram showing a main configuration of an NC machine tool to which the present invention is applied. FIG. 2 is a cross-sectional view showing a configuration of a feed driving device with a clamping function to which the present invention is applied.

  In FIG. 1, an NC machine tool 1 according to the present embodiment holds a spindle 2 that holds a workpiece (not shown) at its tip, and a plurality of tools (not shown) that process the workpiece held on the spindle 2. And a turret head 3. With respect to the turret head 3, the turret head 3 has an X-axis direction orthogonal to the spindle axis L2, a Y-axis direction orthogonal to both the X-axis direction and the spindle axis L2, and a Z-axis direction parallel to the spindle axis L2. A turret feed driving device 4 is configured to be moved.

  The turret feed driving device 4 includes a base 5, a Z-direction slide 6, an X-direction slide 7, and a Y-direction slide 8, and the turret head 3 and the like are mounted on the Y-direction slide 8.

  Between the base 5 and the Z-direction slide 6, a Z-direction feed drive device 30 having a slide mechanism having a guide rail 31 formed on the upper surface of the base 5 and a ball screw mechanism driven by a drive motor 32. The Z-direction feed drive device 30 performs linear feed drive in the Z direction of the turret head 3 by driving the Z-direction slide 6 in the Z direction.

  Between the Z-direction slide 6 and the X-direction slide 7, an X-direction having a slide mechanism including a guide rail 41 formed on the upper surface of the Z-direction slide 6 and a ball screw mechanism driven by a drive motor 42. A feed driving device 40 is configured, and the X-direction feed driving device 40 performs linear feed driving in the X direction of the turret head 3 by linearly feeding the X-direction slide 7 in the X direction.

  As shown in FIGS. 1 and 2, a slide mechanism using a guide rail 51 of a plate portion 70 extending upward from the X-direction slide 7 and a drive motor between the X-direction slide 7 and the Y-direction slide 8 A Y-direction feed drive device 50 including a ball screw mechanism 53 driven by 52 is configured. The Y-direction feed drive device 50 performs linear feed driving in which the Y-direction slide 8 is directed in the Y direction. The turret head 3 is linearly driven in the Y direction.

  That is, in the Y-direction feed driving device 50, a substantially rectangular opening 80 is formed in the Y-direction slide 8, and the plate portion 70 and the screw shaft 54 of the ball screw mechanism 53 are passed through the opening 80. Has been placed. A screw nut 55 that engages with the screw shaft 54 is fixed to a protruding portion 81 from the Y-direction slide 8 into the opening 80. For this reason, when the screw shaft 54 rotates around the axis by the drive motor 52, the screw nut 55 moves along the screw shaft 54, and linear feed driving in the Y direction of the Y direction slide 8 is performed.

(Configuration of feed drive with clamp function)
As shown in FIGS. 1 and 2, in the NC machine tool 1 of the present embodiment, the Y-direction feed driving device 50 is a feed with a clamping function including a clamp mechanism 60 that clamps the Y-direction slide 8 at a predetermined position in the Y-direction. It is configured as a driving device. That is, the Y-direction slide 8 (moving body) holds the upper ends of the two clamp shafts 61 by the pair of upper flange portions 85 protruding toward the opening 50, and the Y-direction slide 8. Lower end portions of the two clamp shafts 61 are held by the lower flange 86. Further, in the plate portion 70 of the X-direction slide 7 (fixed body), a support portion 75 through which the two clamp shafts 61 penetrate in the vertical direction is provided on the surface opposite to the side on which the guide rail 51 is formed. A cylindrical cap 62 (cylinder) is fixed to the support portion 75 with bolts 63 so as to surround the two clamp shafts 61.

  In an annular space defined by the clamp shaft 61 and the cap 62, a collet 64 is held by the support portion 75 of the X-direction slide 7 so as to be movable in the axial direction of the clamp shaft 61 so as to surround the clamp shaft 61. In the annular space, a cylindrical piston 65 is arranged at a position adjacent to the collet 64. Here, air or oil that drives the collet 63 in the pushing direction (upward) is supplied between the lower surface side of the flange portion of the piston 65 and the lower end side of the cap 62 and the upper surface side of the support portion 75. While the first fluid chamber 66 is configured, air or oil that drives the collet 63 in the pulling direction (downward) is between the upper surface side of the flange portion of the piston 65 and the stepped portion of the cap 62. A second fluid chamber 67 to be supplied is configured. Accordingly, when a fluid is supplied to the first fluid chamber 66, the piston 65 moves upward, and the collet 64 pushed upward by the piston 65 clamps the clamp shaft 61. On the other hand, when the fluid is supplied to the second fluid chamber 67, the piston 65 descends, and the collet 64 pushed downward by the piston 65 returns to the state where the clamp shaft 61 is unclamped.

(Main effects of this form)
In the NC machine tool 1 configured as described above, the turret feed driving device 4 moves the turret head 3 to a predetermined position on the basis of data inputted in advance, and the workpiece held on the spindle 2 by a predetermined tool is moved. Process. At that time, when the turret head 3 is fed and driven in the Y-direction feed driving device 50, fluid is supplied to the second fluid chamber 67 to bring the collet 62 into an unclamped state so that the turret head 3 can be moved. When 3 reaches a predetermined position, the feed drive is stopped and at the same time, a fluid is supplied to the first fluid chamber 66 to clamp the collet 62 and fix the turret head 3. Therefore, even if there is a backlash between the screw shaft 54 and the screw nut 55 of the ball screw mechanism, the tool is not displaced during processing. Therefore, the processing accuracy can be dramatically improved.

  Further, in configuring the clamp mechanism 60, a clamp shaft 61 configured to extend in the feed direction of the Y-direction slide 8 and a collet 62 that is switched between a clamped state and an unclamped state are used. The clamping mechanism 60 does not occupy a large space. In addition, the clamp mechanism 60 restrains the Y-direction slide 8 via the clamp shaft 61 configured to extend in the feeding direction of the Y-direction slide 8, so that the Y-direction slide 8 is reliably located at any position. Its position can be defined.

It is a schematic block diagram which shows the principal part structure of the NC machine tool to which this invention is applied. It is sectional drawing which shows the structure of the feed drive device with a clamp function to which this invention is applied.

Explanation of symbols

1 NC machine tool 2 Spindle 3 Turret head 4 Turret feed drive 5 Base 6 Z-direction slide 7 X-direction slide (fixed body)
8 Y-direction slide (moving body)
31, 41, 51 Guide rails 32, 42, 52 Drive motor 30 Z direction feed drive device 40 X direction feed drive device 50 Y direction feed drive device 53 Ball screw mechanism 54 Screw shaft 55 Screw nut 60 Clamp mechanism 61 Clamp shaft 62 Cap (Cylinder)
64 Collet 65 Piston 66 First fluid chamber 67 Second fluid chamber L2 Spindle axis

Claims (4)

A ball screw mechanism that linearly feeds and drives the movable body with respect to the fixed body;
A slide mechanism for linearly guiding the movable body in the vertical direction with respect to the fixed body;
A clamp shaft configured to extend in the vertical direction on one side member of the fixed body and the movable body, and a collet held by the other side member to switch the clamp shaft between a clamped state and an unclamped state. And a clamping mechanism in which driving of the collet in the clamping direction and unclamping direction is performed by air pressure or hydraulic pressure . In claim 1,
Two clamp shafts are provided,
A feed driving device with a clamp function , wherein the collet is provided on each of the two clamp shafts .   A machine tool using a feed driving device with a clamping function as defined in claim 1. In claim 3,
A spindle for holding the workpiece;
A turret head holding a tool for processing the workpiece;
An X-direction feed drive device that linearly feeds the turret head in the X-axis direction perpendicular to the spindle axis with respect to the spindle;
A Y-direction feed driving device that linearly feeds the turret head in a Y-axis direction extending in the vertical direction perpendicular to both the X-axis direction and the spindle axis;
A Z-direction feed driving device that linearly feeds the turret head in the Z-axis direction parallel to the spindle axis,
A machine tool, wherein the feed driving device with a clamp function is used in at least the Y-direction feed driving device among the X-direction feeding drive device, the Y-direction feeding drive device, and the Z-direction feeding drive device.

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