JPH0351523B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spindle head used in a boring machine such as a horizontal boring machine, and more particularly to a spindle head that allows numerical control of the position of the cutting edge.

Conventionally, for example, as shown in Fig. 1, the end of a large-diameter water pipe 60 with an inner diameter of 300 to 700 mm has been processed using a horizontal boring machine.
The contour (profile) of the machined part is complex, and the stepped part 6
1, 62 processing, tapered surface 63 processing, end surface 64
Since surface milling and other operations had to be carried out, the only option was to use skilled manual labor or a complicated tracing mechanism.

The present invention has been made in view of the above-mentioned points, and it is an object of the present invention to provide a spindle head that can reliably and easily form complex contours through numerical control.

An embodiment of the present invention will be described below with reference to FIGS. 2 to 5.

The bed 1 has a horizontal guide path 1a in the longitudinal direction (Z-axis direction).A movable table 2 is slidably supported on this guide path, and a gear box 4 is connected to a pulse motor 3.
It is designed to be reciprocated by a ball screw 5 connected via a. The spindle head 6 is mounted on the moving table 2.
is installed, and a box-shaped headstock 7, which forms the base of this spindle head, is fixed to the movable table 2. A cylindrical hollow main shaft 8 is rotatably supported on the headstock 7 by a bearing 9 with the axis 8a facing the Z-axis direction, and a facing head 1 in the form of a short hollow column is provided at the front end of the hollow main shaft.
0 is stuck. A pulse motor 12 is attached to the headstock 7 via a flanged cylindrical fitting 11 . A rotary shaft 15 is supported by the fixture 11 and the facing head 10 via bearings 13 and 14 and is rotatable around the axis 8a of the hollow main shaft.
The output shaft of the pulse motor 12 is connected via a coupling 17. The rotary shaft 15 is provided with a threaded portion 18 at one end, and this male threaded portion is inserted into the facing head 10. A movable tube 19 is screwed into the male threaded portion 18, and a round rack 20 is rotatably fitted into this movable tube. On the other hand, the other end of a cylindrical holding cylinder 22 whose one end is guided by a sleeve metal 21 fixed to the hollow main shaft 8 so as to be slidable in the longitudinal direction and relatively rotatable is connected to the movable cylinder 19.
The bases of the rods 23, 23, which are fixed to the holding tube 22 and slidably pass through the partition wall of the fixture 11, are attached to the holding tube 22.
This rod 23 and the holding cylinder 22 form a rotation preventing device 24 that slidably guides the movable cylinder 19 in the Z-axis direction. A cam 25 fixed to the tip of one rod 23 operates limit switches 26 and 27. A tool holder 30 is attached to the facing head 10 so as to be movable in the diametrical direction of the facing head, that is, in the X-axis direction perpendicular to the axis 8a of the hollow main shaft. This tool holder consists of a holder body 31 which is slidably attached to the facing head 10, and a clamp part 32 which is fixed to the holder body so that its attachment position can be changed. A bolt 34 for fixing the clamp portion 32 is screwed into a T-nut 35 fitted into a T-slot 33 extending in the X-axis direction formed in the holder body 31. A rack 36 is carved on the inside of the holder body 31 (inside the facing head). The facing head 10 also has an axis 8a of the hollow main shaft.
A pinion 38 is rotatably supported by shafts 37 perpendicular to the X-axis direction and the X-axis direction.
The pinion 38 is equipped with a backlash removing device that includes a built-in spring 39 that urges the two overlapping gears in opposite directions. Further, the driven gear 40 fixed to the hollow main shaft 8 meshes with a drive gear 42 fixed to a drive shaft 41 rotatably supported on the headstock 7, and the output shaft of a motor 43 for driving the hollow main shaft is connected to the drive shaft 41. The connection is via a belt transmission 44.

On the other hand, in front of the bed 1, a clamp table 52 is installed, which is equipped with electric clamp claws 50, 51 that grip the flange base and outer diameter of the water pipe 60, which is the workpiece, from both left and right sides. A workpiece pedestal 56 equipped with a saddle-shaped holder 55 for supporting the water pipe 60 is installed in front of this clamp pedestal. In addition, the clamp stand 52 and the workpiece stand 56
are centered so that the axis of the water pipe 60 gripped or supported by these substantially coincides with the axis 8a of the hollow main shaft.

The water pipe 6 is cut by a boring device consisting of each of the above devices.
In order to perform zero cutting, a cutting tool 66 is attached to the tool holder 30 using a set bottle 67, and a water pipe 60 is fixed using a clamp table 52 and a workpiece pedestal 56. Next, the motor 43 is started to continuously rotate the hollow main shaft 8, and the pulse motor 3 is rotationally controlled by a numerical control device (not shown) to move the entire spindle head 6 in the Z-axis direction, and the pulse motor 12 is also controlled numerically. The rotating shaft 15 is rotated by rotation control by the device. As the rotary shaft 15 rotates, a movable tube 19 screwed into the externally threaded portion 18 moves in the Z-axis direction, and the round rack 20 is pushed in the Z-axis direction by this movable tube. This movement of the round rack 20 is transmitted to the tool holder 30 via the pinion 38, and in this way the rotation of the rotary shaft 15 is converted into movement of the tool holder 30, that is, the cutting tool 66. Note that the tool holder 30, the pinion 38, and the round rack 20 that meshes with these rotate together with the facing head 10, so the round rack 20 moves in the Z-axis direction while rotating around the movable cylinder 19. It turns out. Since the pinion 38 is equipped with a deformation device, the movement of the cutting edge of the cutting tool 66 in the diametrical direction of the workpiece can be continuously and accurately controlled by the control of the pulse motor 12. In combination with continuous control of movement in the axial direction, it is possible to machine the water pipe 60 into a desired contour as shown in FIG. By selecting the number of teeth of the round rack 20 and the tool holder rack 36 and the diameter of the pinion 38, the amount of movement of the tool holder 30 can be set sufficiently large, and a desired machining diameter range can be obtained.

For workpieces with different diameters, loosen the bolt 34 on the tool holder 30 and change the mounting position of the clamp part 32 with respect to the holder body 31 to adjust the workpiece so that it is within the movement range of the cutting tool 66. Bye.

The present invention is not limited to the above-mentioned embodiment. For example, in the above-mentioned embodiment, a workpiece is fixed, and a spindle head 6 with a hollow spindle 8 arranged concentrically with the workpiece is moved only in the Z-axis direction. I tried to drive it, but
As shown in FIG. 6, a lifting platform 72 is vertically movably supported on a column 71 that is movable in the Y-axis direction on a bed 70 to center the center of the boring. The head 6 may be mounted so as to be movable in the Z-axis direction, and the movement in the Z-axis direction may be controlled by the pulse motor 3. In this case, a large workpiece can be machined at multiple locations.

Further, in the above embodiment, one pinion 38 was used as a gear with a backlash remover that meshed with the round rack 20 and the rack 36 of the tool holder.
Instead, a gear train consisting of a plurality of mutually meshing pinions may be used. In this case, the tool holder 30 can be easily positioned at a sufficient distance from the axis 8a of the hollow main shaft, so that the machining diameter can be reduced. Suitable for large sizes.

Further, the tool holder 30 may have a structure in which the holder main body 31 and the clamp portion 32 are fixed together.

The above has explained the equipment that processes the inner diameter, stepped portion, tapered surface, end surface, etc. of the workpiece.
According to the spindle head of the present invention, in addition to this, groove machining, thread cutting, spherical surface machining, and other arbitrary curved surface machining can be performed from the inner diameter side by numerical control.

As explained above, according to the present invention, the position of the cutting edge in the machining diameter direction of the cutter can be continuously controlled by a numerical control device, and by combining this with the position control of the entire spindle head in the machining center axis direction, various shapes can be formed. The inner diameter and end face contours can be reliably and easily formed by numerical control.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of a main part showing an example of a workpiece machined by the device of the present invention, FIG. 2 is a front view of a boring device showing an embodiment of the invention, and FIG. FIG. 4 is an enlarged sectional view taken along the line A-A in the figure, FIG. 4 is a sectional view taken along the line B-B in FIG. 3, FIG. 5 is a sectional view taken along the line C-C in FIG. FIG. 2 is a perspective view of an example boring device. 6... Spindle head, 7... Headstock, 8... Hollow spindle, 10
...Facing head, 12...Pulse motor, 1
5...Rotating shaft, 18...Male thread part, 19...Moving cylinder, 2
0... Round rack, 24... Stop device, 30... Tool holder, 31... Holder body, 32... Clamp section, 36... Rack, 38... Pinion, 43... Motor.

Claims (1)

[Claims] 1. A headstock, a hollow main shaft rotatably supported by the headstock, a facing head fixed to the front end of the hollow main shaft, and a facing head having a threaded portion at one end. A rotary shaft inserted into the hollow main shaft and the facing head with the male threaded portion facing the facing head and supported rotatably around the axis of the hollow main shaft is screwed into the male threaded portion. A movable cylinder, a rotation stopper connected to the movable cylinder and slidably guiding the movable cylinder in the longitudinal direction, a round rack rotatably mounted around the movable cylinder, and a front surface of the facing head. a tool holder mounted on the side so as to be movable in the diametrical direction of the facing head and having a rack on the inner surface;
A gear with a backlash remover that is pivotally supported by the facing head and meshes with the rack and the round rack, a servo motor connected to the rotating shaft, and a hollow main shaft driving motor connected to the hollow main shaft. Spindle head consisting of. 2. The spindle head according to claim 1, wherein the gear with a backlash removal device comprises one pinion. 3. The spindle head according to claim 1, wherein the gear with the backlash removal device comprises a gear train composed of a plurality of pinions that mesh with each other. 4. The spindle head according to claim 1, 2, or 3, wherein the tool holder comprises a holder body provided with a rack, and a clamp portion fixed to the holder body such that the attachment position can be changed.