JP4503737B2 - Lathe milling holder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tool (milling) holder used when milling (milling) with a turret lathe provided with a rotary tool drive shaft, and is a milling cutter fixed to a turret case and connected to the tool drive shaft of the turret. It is related with the apparatus which pivotally supports.
[0002]
[Prior art]
With the practical use of a lathe equipped with a turret tool post to which rotary tools such as drills and end mills can be attached and capable of controlling the C axis (rotation angle of the main spindle), grooving and plane machining are conventionally performed on milling machines. Machining has been performed on a lathe. In order to perform this type of milling as a series of steps on a lathe together with turning or drilling, a milling holder for holding the milling cutter on the turret tool post is necessary.
[0003]
FIG. 3 is a view showing an example (first conventional structure) of a lathe milling holder that is most commonly used in the past, and is a structure for holding a tool in a cantilever manner. The milling holder includes a base 3 fixed to the turret case 2 with bolts 1 and a tool shaft 6 pivotally supported on the cylindrical portion 3 a of the base 3 by bearings 4 and 5. Is equipped with a collet chuck 7 for gripping a shank of a milling cutter, and provided with one element 8 of a joint connected to the tip of a tool drive shaft built in the turret at the inner end. The joint element 8 shown in the figure is a flat projection, and the rotation of the tool drive shaft is transmitted to the tool shaft 6 by being fitted into a groove at the tip of the tool drive shaft (not shown).
[0004]
When the shank 10 integrated with the milling cutter 9 is inserted into the collet chuck 7 and fixed, and the turret is indexed so that the milling cutter comes to the machining position, the joint element 8 at the inner end of the tool shaft is connected to the tool drive shaft. Then, milling is performed by rotationally driving the tool drive shaft. Since the tool axis 6 mounted on the turret faces the center axis of the workpiece, there is no problem when machining key grooves and spiral grooves with an end mill. When performing the above, it is necessary to move the tool post in the Y-axis direction (direction perpendicular to the cutting direction of the main shaft and the cutting tool) to perform processing.
[0005]
FIG. 4 is a view showing a second conventional structure of the milling holder. The holder of the second conventional structure is pivotally supported on both sides with the shaft 11 of the milling cutter 9 being tangential to the turret case 2 and is mounted using two tool mounting stations of the turret.
[0006]
In FIG. 4, a first base 12 is fixed to a tool mounting station A that is directed to the axis of a workpiece during milling, and a joint element that is connected to a tool drive shaft built in a turret at the inner end of the first base. A first intermediate shaft 13 provided with a shaft 8 is supported so as to be freely rotatable. Further, a bearing 14 that pivotally supports the driven end of the shaft 11 of the milling cutter 9 is attached to the first base 12.
[0007]
On the other hand, the second base 15 is fixed to the adjacent tool mounting station B, and the second intermediate shaft 16 and the tool shaft 6 having the collet chuck 7 are supported on the second base so as to be freely rotatable. . The first intermediate shaft 13 and the second intermediate shaft 16 are drivingly connected by a first bevel gear pair 17, and the second intermediate shaft 16 and the tool shaft 6 are drivingly connected by a second bevel gear pair 18.
[0008]
The milling cutter 9 has one end of a shaft 11 held by the collet chuck 7 and supported at the other end by the bearing 14 mounted on the first base. The shaft 11 is placed on the turret case 2 on the extension of the first intermediate shaft 13. It is mounted in the tangential direction.
[0009]
[Problems to be solved by the invention]
The first conventional structure for holding a milling cutter in a cantilever manner is simple and easy to mount the holder on the turret and to mount the tool on the holder, but using a milling cutter having a cutting edge on the outer peripheral surface, When plane machining is performed, a large bending moment acts on the tool shaft and the shank of the milling cutter due to the machining reaction force, so that distortion and vibration are likely to occur, and the machining speed and machining accuracy cannot be increased.
[0010]
On the other hand, the second conventional structure in which the milling shaft is supported at both ends can increase the support rigidity of the tool, so that the processing speed and processing accuracy can be increased. However, the structure is complicated and the holder is attached to the turret or the tool is attached to the holder. Wearing is very troublesome. Further, since two turret tool mounting stations are used, there is a disadvantage that the number of tools that can be mounted on the turret is reduced.
[0011]
In view of the widespread use of a lathe capable of moving and positioning the turret tool post in the Y-axis direction, the present invention is for holding a milling machine that performs grooving and planar processing using the Y-axis movement of the tool post. A milling holder that is simple in structure, easy to mount the holder on the turret and to mount the milling cutter on the holder, and can hold the milling cutter by supporting both ends, thus enabling high-speed and high-precision machining with high rigidity. The challenge is to obtain.
[0012]
[Means for Solving the Problems]
The milling holder according to the present invention includes a base 3 fixed to the turret case 2, a tool shaft 6 having a tool chuck 7 at an outer end thereof rotatably supported by a cylindrical portion of the base, and a tool shaft attached to the base 3. A bearing block 22 that is detachable in the axial direction and forms a U-shaped tool support frame together with the base 3, and a bearing sleeve 26 that is pivotally supported by the bearing block so as to freely rotate and is positioned on the extension of the tool shaft 6. It has.
[0013]
The base 3 is fixed to the turret case 2 by the mounting bolt 1 in a state where the cylindrical portion is fitted into the tool mounting hole of the turret. The milling cutter 9 is fixed by inserting one end of the shaft 30 into the tool chuck 7 with the bearing block 22 removed. By providing a stopper bolt 28 for adjusting the mounting position of the milling cutter 9 in the axial direction at the far end of the tool mounting hole of the tool chuck 7, the position of the milling tool 9 in the tool axial direction can be easily adjusted.
[0014]
After attaching the milling cutter to the tool chuck 7, the outer end of the milling shaft 30 is inserted into the bearing sleeve 26 and supported by fixing the bearing block 22 to the L-shaped frame portion 3b of the base. The bearing sleeve 26 is preferably provided with a fixture such as a set screw 27 for fixing the milling shaft 30 inserted into the bearing sleeve 26.
[0015]
When the tool mounting station equipped with the milling holder is indexed toward the workpiece, the inner end of the tool shaft 6 is connected to the tool drive shaft built in the turret. Therefore, by moving the turret in the X, Y, and Z axes, the milling machine is moved to the desired machining position to face the workpiece, and while the tool drive shaft is rotated, the workpiece is generally moved in the Z axis direction. Groove processing and planar processing are performed on the peripheral surface of The Z axis is the main axis direction, the X axis is the cutting direction of the cutting tool, and the Y axis is the direction orthogonal to the X and Z axes.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described with reference to the embodiment shown in FIGS. The base 3 fixed to the turret case 2 with the bolt 1 includes an L-shaped frame portion 3b protruding from the outer periphery of the turret, and a cylindrical portion 3a inserted into the tool mounting hole of the turret. A tool shaft 6 provided with a collet chuck 7 at the outer end is axially attached to the cylindrical portion 3a by bearings 4 and 5 so as to be freely rotatable. At the inner end of the tool shaft 6, a flat joint element 8 that fits with the tip of a tool drive shaft (not shown) built in the turret case 2 is formed.
[0017]
Two of the four bolts 1 for fixing the base 3 to the turret case 2 are attached through an insertion hole 21 provided in an L-shaped frame portion, and the opening end of the insertion hole 21 has a large diameter. A positioning hole 21a is formed. Two positioning pins 23 project from the bearing block 22 that forms a U-shaped frame for supporting both ends of the milling cutter 9 together with the L-shaped frame portion 3b of the base. The bearing block 22 is fixed to the base 3 with a bolt 24 in a state of being fitted into the positioning hole 21a on the side. The axial centers of the positioning hole 21 a and the positioning pin 23 are parallel to the central axis of the tool mounting shaft 6.
[0018]
On the extension of the tool shaft 6 when the bearing block 22 is fixed to the base 3, a bearing sleeve 26 is rotatably mounted by a bearing 25 so as to be freely rotatable. The bearing sleeve 26 includes a thick flange on the side facing the tool shaft 6, and a set screw 27 is provided in a direction perpendicular to the shaft at the flange portion.
[0019]
A stopper bolt 28 is screwed into the inner end of the shank insertion hole of the collet chuck 7, and a shaft of the milling machine 9 to be mounted is inserted by inserting a hexagon wrench into the shank mounting hole and rotating the stopper bolt 28. The direction position can be adjusted. The base 3 is provided with a cutting oil passage 29 for guiding the cutting oil supplied from the cutting fluid supply port opened in the peripheral surface of the turret case 2 to the upper side of the milling cutter 9.
[0020]
The milling machine 9 having the shafts 30 on both sides is inserted into the collet chuck 7 with the bearing block 22 removed from the base 3 until the shaft end on the driving side comes into contact with the stopper bolt 28. It is fixed by tightening. Next, while inserting the other shaft end of the milling shaft 30 into the bearing sleeve 26, the positioning pin 23 is positioned by the positioning hole 21 a, and the bearing block 22 is fastened to the base 3 by the bolt 24. Then, the set screw 27 is tightened, and the milling shaft inserted into the bearing sleeve 26 is fastened and fixed in the direction perpendicular to the axis.
[0021]
When the turret is indexed in the direction in which the milling holder 31 faces the workpiece, the joint element 8 at the inner end of the tool shaft 6 is fitted into the groove at the tip of the tool drive shaft built in the turret, so that the tool shaft 6 becomes the tool drive shaft. Connected to In this state, by moving the tool post in the X, Y, and Z axes, the milling tool 9 is opposed to the work 32 indicated by an imaginary line in FIG. ) To mill the workpiece.
[0022]
FIG. 1 shows a small-diameter groove milling tool as a tool, but it goes without saying that various types of milling cutters having different diameters, widths, and cutting edge shapes can be used in accordance with the machining shape. The milling cutter 9 can be easily replaced by attaching / detaching the bearing block 22 and opening / closing the collet chuck 7.
[Brief description of the drawings]
FIG. 1 is a cross-sectional side view of an embodiment. FIG. 2 is a cross-sectional side view of a first conventional structure. FIG. 4 is a cross-sectional side view of a second conventional structure.
2 Turret 3 Base 6 Tool axis 7 Collet chuck
22 Bearing block
26 Bearing sleeve
30 Milling shaft

Claims (2)

A base that is fixed to the turret case (2), and includes a cylindrical portion (3a) that is inserted into a tool mounting hole of the turret case and an L-shaped frame portion (3b) that projects to the outer periphery of the turret case. It was the base (3),
A tool shaft is rotatably supported on the cylindrical portion of the base, the tool in the turret casing the tool chuck (7) on the outer end protruding to the outer periphery of the turret casing in a closed-vital inner end tool axis to have a coupling element (8) fitted to the tip of the drive shaft (6),
A bearing block (22) forming a tool support frame U-shaped with a frame portion of the L-shaped provided freely attaching and detaching in the axial direction of the tool axis to the base,
This bearing block is rotatably supported and a bearing sleeve (26) the outer end you support shaft (30) milling by located on the extension of the tool shaft, lathe milling holder.   The milling holder according to claim 1, wherein the bearing sleeve (26) comprises a fixture for fixing the milling shaft (30).

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