The invention relates to a rotating tool magazine for a machining apparatus having at least one tool that can be driven by a motor and relates to a machining apparatus equipped with such a rotating tool magazine.
A rotating tool magazine with cutting tools for turning and tools that can be driven for boring or grinding is known from DE 298 07 842 U1. A rotating tool magazine having a direct drive for pivoting is known from DE 199 19 553 A1 [U.S. Pat. No. 6,276,035]. For both rotating tool magazines, the tools are mounted in a revolver disk. The driven tools are driven via an angular transmission extending through the revolver disk. Due to the limited space, the maximum drive power for the tools, and thus also the size of grinding tools that can be used, are clearly limited.
The object is therefore to fashion a machining apparatus with a rotating tool magazine such that the drive for the tools can be created, with a reduced space requirement, in a cost-effective and simple manner.
This object is attained with a rotating tool magazine with the characterizing features of claim 1 and using a machining apparatus in accordance with claim 6 that is equipped with such a rotating tool magazine. Advantageous embodiments can be taken from each of the dependent claims.
The basic idea behind the invention is comprised in mounting the driven tool on the end of the tool holder. Thus the drive can extend through the tool holder without deflection or intermediate mechanical members such as e.g. an angle transmission, and the limited amount of space on the tool holder is no longer a factor in the design of the drive. In addition, the driven tool is not carried along during the pivot movement of the tool holder. This permits greater acceleration when the tool is replaced and decreases the amount of time necessary for machining a workpiece. In one advantageous embodiment, the tool holder is angularly fixed to a tube shaft. The spindle for the tool drive is mounted inside the tube shaft. At its outer side, the tube shaft is surrounded by a ring motor to the drive for the pivot movements of the tool holder. In another embodiment, the interior diameter of the tube shaft is selected such that the drive motor for the tool can be mounted inside the tube shaft.
The invention is explained in greater detail in the following with reference to the illustrated embodiments.
FIG. 1 shows a machining apparatus with two rotating tool magazines;
FIG. 2 shows a rotating tool magazine, partially in section;
FIG. 3 shows a rotating tool magazine having a drive motor mounted in the tube shaft, partially in section.
FIG. 1 shows a machining apparatus 1 and does not show details of the workpiece feed, drive, control, or housing that are not essential to the invention. The described machining apparatus 1 is suitable in particular for machining elongated workpieces 7. The latter are clamped in and rotated by the workpiece holding device 29 comprising a headstock 8 and a tailstock 9. The two rotating tool magazines 10 and 11 are movably guided on the machine frame 2 in two mutually orthogonal directions (X- and Z-axes). To this end, vertical guides 3 are provided on a machine frame 2 for a vertical slide 4 and each in turn carrying guides 12 for a respective horizontal slide 5. Respective tool holders 6 are each rotatable about a respective pivot axis 13 on the horizontal slides 5. The tool holders 6 hold stationary tools 14, in particular for turning. Driven tools 15 and 16 are mounted on the ends of the tool holders 6. The tool 16 is a conical grinding wheel. The rotating tool magazine can pivot about an axis 17 so that the spindle of the tool 16 can be appropriately inclined at the cone apex angle with respect to the workpiece 7. Even conical surfaces 18 on the workpiece 8 can be machined with this arrangement.
FIG. 2 shows the rotating tool magazine 10, in partial section. Its housing 19 can be mounted fixed on the machine, or, as shown in FIG. 1, on a slide. Its tube shaft 21 is supported in the housing 19 by bearings 20 and 20′. A rotor 22 made up of an array of magnets is mounted outside. A stator 23 formed of electrical windings is juxtaposed therewith in the housing 19. The tool holder 6 is screwed securely to the tube shaft 21. Rotor 22 and stator 23 together form a ring motor that acts as the drive for rotating the tool holder 6. The tool holder 6 is a disk that carries the tools 14 on its outer edge, in particular for turning. Bearings 24 and 24′ for a spindle 25 of the driven tool 15 are in the center of the tool holder 6. The tool 15 is mounted on the end of the tool holder 6. The spindle 25 is connected directly to the motor 28 by a shaft extending through the tube shaft 21. In this arrangement, the limited space in the tool holder 6 no longer has any effect on the design of the drive. In addition, the driven tool 15 is not moved the rotation of the tool holder 6. This permits higher accelerations during tool changes and makes possible shorter cycles for machining workpieces 7.
In the embodiment in accordance with FIG. 3, the inside diameter of the tube shaft 21 is dimensioned such that the motor 28 for driving the tool 16 is located inside the tube shaft 21. In this space-saving arrangement, the spindle 25 for the tool 15 is connected directly to the motor 28. The housing 19, tool holder 6, and pivot drive with ring motor are mounted as described with reference to the embodiment in accordance with FIG. 2.
REFERENCE LIST
1 Machining apparatus
2 Machine frame
3 Guide
4 Vertical slide
5 Horizontal slide
6 Tool holder
7 Workpiece
8 Motor spindle
9 Tailstock
10 Rotating tool magazine
11 Rotating tool magazine
12 Guide
13 Pivot axis
14 Tool
15 Tool
16 Tool
17 Pivot axis
18 Conical surface
19 Housing
20, 20′ Bearing
21 Tube shaft
22 Rotor
23 Stator
24, 24′ Bearing
25 Spindle
26 End
27 Shaft
28 Motor
28 Workpiece holding device
Patent Application
20080141837
