JP2005125415A - Horizontal machining center - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a horizontal machining center for improving straightness in the Z axis direction of a spindle head by restraining an increase in mass, in a constitution for attaching upper and lower two rails to a case for advancing and retreating to/from a saddle for vertically moving the spindle head, fixing front and rear two sliders to the saddle, positioning a gravity center position of the spindle head between the front and rear sliders in an advance of the spindle head, and setting the gravity center position in the rear of the rear side slider in a retreat. <P>SOLUTION: Among one auxiliary rail 10 and an auxiliary slider 13, one is fixed to the case, and the other is fixed to the saddle, respectively. When the spindle head 4 is retreated, a place nearer to the gravity center position G than the rear side slider is supported by the auxiliary slider. When the spindle head is retreated, the rear of the gravity center position is supported by the auxiliary slider. An intermediate spindle is directly coupled to the rear of a spindle body via a rigid coupling, and the intermediate spindle is directly coupled to a motor via the coupling. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a rail moving device (slider unit) for a spindle head of a horizontal machining center, and a spindle in the spindle head.

  The horizontal machining center is provided with a column movably in the left-right direction, supports the saddle so as to move up and down along the column, and moves the spindle head forward and backward relative to the saddle. To move forward and backward, two upper and lower rails and two front and rear sliders are used for each rail. Here, the case where the rail is fixed to the spindle head is called a rail moving type, and this method is adopted in the present invention. On the other hand, the case where the slider is fixed is called a slider moving type.

  In the slider movement type, as shown in FIG. 6, a support block 92 is attached to the saddle surface of the spindle head 91, the support block is extended toward the spindle motor 93, and the slider 94 is fixed to the support block (patent) Reference 1).

  However, since the distance between the saddle 95 and the spindle head 91 is increased by the amount of the support block, the support rigidity of the spindle head is inferior to that of the rail movement type and can be used only as a drill tap machine.

On the other hand, in the case of the rail movement type employed in the present invention, there is no support block, and the rail 96 is directly attached to the saddle surface of the spindle head 91 as shown in FIG. On the other hand, there is a problem that the straightness of the spindle head in the front-rear direction is deteriorated (see Patent Document 2). This is because, as shown in FIG. 7 (b), the center of gravity is located between the front and rear sliders 94, 94 when the spindle head moves forward, so it is ideally supported when moving forward. However, when the spindle head is retracted, as shown in FIG. 7 (a), the portion supported by the front and rear sliders 94 becomes the tip of the spindle head and is far from the center of gravity G, and the motor side is bent slightly. Because. In order to prevent this, it is conceivable to increase the front and rear widths of each slider and lengthen the rail so that the center of gravity is always located between the front and rear sliders. However, if both the rails are lengthened, the mass increases accordingly, which is not suitable for high-speed machining. Further, the motor behind the spindle head and the front case are separate parts, and since the surfaces of the motor and the case do not normally coincide with each other, it is difficult to fix the extended portion to the motor even if the rail is lengthened. However, increasing the length of the case and its built-in parts by increasing the length of the rail is a significant increase in mass, making it unsuitable for moving the spindle head at high speed, and producing a long spindle with high accuracy. This is difficult and causes vibration when the spindle rotates.
Japanese Patent Laid-Open No. 2002-200534 JP 2002-137128 A

  The present invention has been developed in view of the above circumstances, and its solution is to suppress the increase in mass while adopting a rail moving type with high support rigidity, and in addition, the spindle head in the Z-axis direction (reciprocation) Direction) is to improve straightness.

  In the present invention, in order to provide a spindle head with a motor at the rear of the case so as to be able to move forward and backward with respect to a saddle that can move up and down, two rails are attached to the case of the spindle head with a vertical interval. When the two sliders that guide each rail are fixed to the saddle with a gap in the front and back, and the spindle head is advanced relative to the saddle, the center of gravity of the spindle head is located between the front and rear sliders. Is assumed to be a horizontal machining center in which the position of the center of gravity is rearward relative to the rear slider.

  According to the first aspect of the present invention, when one of the auxiliary rail and the auxiliary slider for guiding the auxiliary rail is fixed to the case and the other is fixed to the saddle, and the spindle head is retracted, the rear slider A portion closer to the center of gravity than the center of gravity is supported by an auxiliary slider.

  Further, when the spindle head is retracted, the auxiliary slider may support the portion closer to the center of gravity than the rear slider, but may be ahead of the center of gravity. As in the second aspect of the invention, when the spindle head is retracted, it is desirable to support the position of the center of gravity or the rear thereof with the auxiliary slider.

  The spindle main body may be formed long and directly connected to the motor. However, if the spindle main body is long, the coaxiality or runout accuracy of the spindle main body deteriorates, and vibration is likely to occur during rotation. To prevent this, the intermediate spindle is directly connected to the rear of the spindle body rotating in the case via a rigid coupling, and the intermediate spindle is directly connected to the motor via a rigid coupling. It is desirable that In other words, it is desirable that the spindle body, the intermediate spindle, and the motor be rigidly coupled with a rigid coupling.

  In the first aspect of the invention, when the spindle head is retracted using the auxiliary slider and the auxiliary rail, a portion closer to the center of gravity than the rear slider is supported by the auxiliary slider, so there is no auxiliary slider or the like. Compared to conventional products, the support rigidity is increased and the straightness of the spindle head in the Z-axis direction (reciprocating direction) is improved. In addition, since there is only one auxiliary rail, an increase in mass can be suppressed as compared with a method in which both rails are extended long, and this is suitable for high-speed movement of the spindle head.

  According to the second aspect of the present invention, when the spindle head is retracted, the center of gravity position or the rear thereof is supported by the auxiliary slider, so that the support rigidity is further increased.

  Since the spindle body, the intermediate spindle, and the motor are rigidly connected by the rigid coupling, the respective axes are naturally aligned and directly connected, and the coaxiality is improved and the rotation is improved. Occasionally shake is less likely to occur.

  The horizontal machining center used in the present invention has a rail moving spindle head. As shown in FIG. 1, the spindle head 4 is moved in the X, Y, and Z axis directions using slide units 1, 2, and 3. To do. More specifically, a column 6 is mounted on the bed 5 via a slide unit 1 for the X-axis direction (left-right direction). A saddle 7 is attached to the column 6 via a slide unit 2 for the Y-axis direction (vertical direction). A spindle head 4 is attached to the saddle 7 via a slide unit 3 for the Z-axis direction, and the spindle head 4 is supported so as to be movable back and forth.

  Each slide unit uses a mechanism for moving a slider along a rail by rotating a ball screw with a servo motor. The present invention is devised for matters closely related to the slider and rail of the slide unit for the Z-axis direction.

  As shown in FIGS. 1 and 2, the first example of the slide unit 3 for the Z-axis direction is configured such that the two rails 9 and 9 are separated from each other by a space above and below the flat saddle surface of the case 8 of the spindle head 4. Attached along the axial direction, an auxiliary rail 10 is attached between the upper and lower rails 9 at the rear of the saddle surface of the case 8, and the auxiliary rail 10 is extended to the slide surface side of the motor 11 of the spindle head 4. is there. Four saddles 7 for guiding the rails 9 are attached to the saddle 7 at intervals in the up / down and front / rear directions. Each of the sliders 12 and 12 supports the rails 9 and guides the auxiliary rail 10. The auxiliary slider 13 is rearward of the rear slider 12 and is attached between the upper and lower sliders with respect to the height. For example, bolting is used for attachment.

  When the spindle head 4 is moved backward as shown in FIG. 2A, the gravity center position G of the spindle head 4 is located between the auxiliary slider 13 and the rear slider 12. On the other hand, when the spindle head 4 is advanced relative to the saddle 7 as shown in FIG. 2B, the center of gravity G of the spindle head 4 is located between the front and rear sliders 12 and 12. In other words, since the two positions before and after the center of gravity G are always supported during forward and backward movement, the straightness in the Z-axis direction is improved. The center of gravity G of the spindle head 4 is at the rear part of the case 8.

  As shown in FIG. 3, the second example of the slide unit 3 for the Z-axis direction is obtained by reversing the attachment target of the auxiliary rail 10 and the auxiliary slider 13 from the first example, and the auxiliary rail 10 is fixed to the saddle 7. On the other hand, the auxiliary slider 13 is attached to the saddle surface of the case 8 and behind the center of gravity position G.

  As shown in FIG. 4, the spindle head 4 has a spindle 15 in the case 8 that rotates by clamping the tool 14. The spindle 15 rigidly couples the intermediate spindle 18 to the rotating shaft 16 of the motor 11 via the rigid coupling 17, and rigidly couples the spindle body 20 to the intermediate spindle 18 via another rigid coupling 19. The spindle body 20 is rotatably supported by a bearing 21. If the spindle body 20 and the intermediate spindle 18 are supported by the bearings 21 at equal intervals over the entire length, it is desirable because rotation is stabilized. Reference numeral 22 denotes an outer tube to be fixed in the case. By assembling other parts to the outer tube 22 or the spindle body 20, the spindle body 20 and the intermediate spindle 18 are positioned and supported. is there. It is clearly shown that the auxiliary slider 13 is bolted to the rear part of the case 8. The auxiliary slider 13 is extremely shorter than the auxiliary rail 10 in the front-rear width, and the auxiliary rail 10 is not attached across the two members of the motor 11 and the case 8 as in the first example shown in FIG. The straightness of is improved.

  The spindle body 20 has a cylindrical shape as shown in FIG. 5, and has a draw bar 23 slidably built in the Z-axis direction. The tool 14 is clamped by holding the pull stud 25 at the end of the tool with the collet 24 at the tip of the draw bar 23 and pulling the draw bar 23 backward with the disc spring 26 built in between the draw bar 23 and the spindle body 20. At the rear part of the draw bar 23, the passive pin 27 protrudes outward from the long hole 28 of the spindle body 20, and the passive pin 27 is caught at the end of the long hole 28, so that the draw-in state of the draw bar 23 to the rear is kept constant. When the draw bar 23 is pushed forward by the extrusion device 29, the draw bar 23 moves forward while the passive pin 27 moves to the tip side of the long hole 28, and the tool 14 is unclamped.

It is a perspective view which shows the horizontal type machining center of this invention. (A) The figure is a front view showing the retracted state of the first example of the slide unit, (B) the figure is a front view showing the advanced state, and (C) is an exploded view seen from the side. (A) The figure is a front view showing the retracted state of the second example of the slide unit, (b) the figure is a front view showing the advanced state, and (c) the figure is an exploded view seen from the side. It is sectional drawing which shows the connection state of a spindle main body and an intermediate | middle spindle. It is sectional drawing in the spindle main body which shows the clamp structure of a tool. It is principal part sectional drawing which looked at the conventional horizontal machining center from the plane direction. (A) is a front view showing a retracted state of a conventional horizontal machining center, (b) is a front view showing the advanced state, and (c) is a side view.

Explanation of symbols

4 Spindle head 7 Saddle 8 Case 9 Rail 10 Auxiliary rail 11 Motor 12 Slider 13 Auxiliary slider 17 Rigid coupling 18 Intermediate spindle 19 Rigid coupling 20 Spindle body G Center of gravity position

Claims (3)

In order to provide a spindle head (4) with a motor (11) behind the case (8) so that it can be moved forward and backward with respect to a saddle (7) that can move up and down, two rails (9, 9) Are attached to the case (8) of the spindle head with a vertical spacing, and the two sliders (12, 12) for guiding each rail are fixed to the saddle (7) with a longitudinal spacing,
When the spindle head (4) is moved forward with respect to the saddle, the center of gravity (G) of the spindle head is located between the front and rear sliders (12, 12), and when the spindle head (4) is moved backward, the center of gravity is located. In the horizontal machining center in which the position (G) is rearward from the rear slider (12),
One of the auxiliary rail (10) and the auxiliary slider (13) for guiding the auxiliary rail is fixed to the case (8) and the other is fixed to the saddle (7).
A horizontal machining center characterized in that, when the spindle head (4) is retracted, a position closer to the center of gravity (G) than the rear slider (12) is supported by an auxiliary slider (13).   The horizontal machining center according to claim 1, wherein when the spindle head (4) is retracted, the center of gravity (G) or the rear thereof is supported by the auxiliary slider (13).   The intermediate spindle (18) is directly connected to the rear of the spindle body (20) rotating in the case (8) via the rigid coupling (19), and the intermediate spindle (18) is connected to the motor via the rigid coupling (17). 3. The horizontal machining center according to claim 1, wherein the horizontal machining center is directly connected to (11).

Images