JP4234504B2 - Tool turret - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a tool turret for a machine tool that includes a rotary tool mounting portion and a fixed tool mounting portion on a circumference centered on an indexing shaft, and selects a tool by automatic tool change and rotation around the indexing shaft. It is.
[0002]
[Prior art]
Many of the currently available lathes are turret lathes. By rotating around the indexing axis of the tool turret mounted on the tool post, you can select one of multiple tools mounted on the turret and process the workpiece. Is going. At present, tool turrets with a built-in rotary tool drive are also widely used, and drilling, grooving, plane machining, etc. are performed on workpieces gripped by the lathe spindle by attaching rotary tools such as drills and milling tools. Is going.
[0003]
A general turret lathe does not include an automatic tool changer, and processes a workpiece within the range of a tool attached to the turret. Although the turret has a fast tool change speed, the number of tools that can be used is limited to a relatively small number. This limitation on the number of tools can be solved by providing an automatic tool changer for the turret.
[0004]
When the rotary tool is mounted on the turret, the rotary tool is pivotally supported on each holder so as to freely rotate, and the holder is mounted on the tool mounting portion of the turret. Accordingly, when performing automatic tool change, the rotary tool is changed together with the holder. That is, the rotary tools are accommodated in the tool magazine in a state where they are respectively mounted on the holders, and the rotary tool is attached to and detached from the turret by attaching / detaching the holder to / from the tool turret.
[0005]
[Problems to be solved by the invention]
In a normal turret lathe, the direction of the index axis of the tool turret is fixed in the main axis direction (Z-axis direction) or the cutting feed direction (X-axis direction) of the tool orthogonal to the main axis. For this reason, when the direction of the tool spindle built in the turret is limited to the X-axis direction or the Z-axis direction, and machining of the peripheral surface and end surface of the workpiece is required, even if the same tool is used, it is mounted on the straight holder. It is necessary to use two tools, a tool mounted on the angle holder and a tool mounted on the angle holder. Furthermore, if a holder having an angle corresponding to each inclination angle is not separately prepared, it is not possible to perform oblique hole machining or plane machining on the workpiece.
[0006]
Furthermore, since the holder of the rotary tool holds the tool that is subject to a large machining reaction force via the bearing, it is necessary to use a bearing with a high rigidity in order to increase the support rigidity of the tool, compared to the tool diameter. As a result, there is a problem that the holder becomes large, and the turret also becomes large. When the turret is large, the accessibility between the tool and the workpiece is lowered due to the interference between the workpiece, the spindle and the turret, and there is a problem that an unworkable region is generated when machining a workpiece with large irregularities.
[0007]
The present invention provides a tool turret to which a rotating tool can be mounted, and can reduce the size of the turret housing and its tool mounting portion, improve the accessibility of the tool to the workpiece, and process the peripheral surface of the workpiece and the end surface. It is an object to provide a tool turret and a lathe equipped with such a tool turret that can be machined without exchanging a rotating tool and that can also be machined into an oblique hole or plane with respect to the workpiece. Yes.
[0008]
[Means for Solving the Problems]
In the present invention, on the assumption that automatic tool change is performed, the turret 3 is provided with a fixed tool mounting portion 57 and a single rotary tool mounting portion 48 separately, and the rotary tool mounting portion 48 is provided with a collet chuck 40. The above-mentioned problem is solved by providing the tool itself so that it can be exchanged. The rotational force of the rotary tool is transmitted from the transmission shaft 30 disposed on the axis of the indexing shaft 6 to the tool spindle 37 via the bevel gear pairs 34 and 47. The collet chuck claw 40 a is connected to the tip of a pull rod 41 inserted through the hollow hole of the tool spindle 37, and an open / close cylinder 43 of the collet claw 40 a is disposed at the opposite end of the tool spindle 37. . As a general structure, the collet claw 40a is urged in the closing direction by a spring and is released by the hydraulic pressure of the chuck opening / closing cylinder 43 against the spring force.
[0009]
The tool turret according to the invention of claim 1 of the present application is a tool turret for a machine tool that rotates around the index shaft 6 and selects one of a plurality of tools 4 and 5 mounted on the outer periphery thereof. and one fixed tool mounting portion 57 to the differing positions the indexing axis of the phase and a single rotary tool mounting portion 48, the rotary tool mounting portion is a collet chuck which is opened and closed by the opening and closing piston 42 40.
[0010]
Turret housing 35, the bar portion in a diameter direction that pivotally supports the tool spindle 37 and 61 (lateral bar portion of the T-shape), which a stem portion extending in cross direction orthogonal (vertical bar portion of the T-shape) 49 And the end portion of the stem portion 49 is a fixed tool attachment portion 57. The T shape of the turret housing 35 may be an italic T shape in which the stem portion 49 is inclined with respect to the bar portion 61.
[0011]
Tool turret according to the present invention of claim 1, the front comprises a turret housing 35 of the T-shaped in KiTadashi plane view, and a rotary tool mounting portion 48 and the collet chuck opening and closing cylinder 43 at both ends of the bar portion, the A fixed tool mounting portion 57 is provided at the end of the stem portion.
[0012]
The tool turret 3 having the above structure is attached to and detached from the rotary tool mounting portion 48 using an automatic tool changer without using a holder that pivotally supports the rotary tool. Since the holder of the rotary tool used in the conventional structure has a built-in bearing, it is larger than the tool itself. On the other hand, since the fixed tool 5 can be integrated with the holder 58, even if the holder is provided, the dimension does not become so large.
[0013]
From the above, the tool turret according to the invention of this application can be greatly reduced in size as compared with the conventional tool turret in which the rotary tool is mounted via the holder. Furthermore, since the turret housing 35 is T-shaped when viewed from the front, a clearance space 60 in which no housing exists is formed on both sides of the rotary tool mounting portion 48 and the fixed tool mounting portion 57, so that the tools 4, 5 approach the workpiece. The space required for indexing rotation and movement of the turret housing 35 can be reduced, and the machine tool can be reduced in size.
[0014]
In addition, since the tool turret according to the invention of the present application performs tool change by an automatic tool changer, it takes time compared to tool change by indexing rotation of the turret, but in a machine tool equipped with a plurality of tool rests, This problem can be avoided by adopting a machining procedure in which machining is performed with a tool of another tool post while the tool is being changed.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing an example of a lathe equipped with the tool turret of the present invention, FIG. 2 is a sectional side view showing a tool turret and an indexing device, FIG. 3 is a partially enlarged sectional view of the indexing device, and FIG. It is a front view of a turret.
[0016]
In FIG. 1, a lathe bed 50 is provided with a Z-axis guide rail 51 parallel to a main shaft 52, and a Z-axis slide 53 is slidably mounted on the Z-axis guide rail. The Z-axis slide 53 is provided with a Y-axis guide rail 54, and a Y-axis slide 55 is slidably mounted on the Y-axis guide rail. An X-axis guide rail 56 is provided on the top of the Y-axis slide 55, and the tool post 1 is slidably mounted on the X-axis guide rail. A turret indexing device 2 including a tool turret 3 is mounted on the tool post 1 so as to be rotatable around the Y axis. Therefore, the indexing shaft 6 of the tool turret 3 turns in a plane orthogonal to the Y axis. Here, the Z axis is the principal axis direction, the X axis is the feed direction of the tool orthogonal to the Z axis, and the Y axis is the direction orthogonal to the Z axis and the X axis.
[0017]
2 and 3, which show cross sections of the tool turret 3 and the turret indexing device 2, a ring-shaped cross roller bearing 12 is provided on one end surface of a housing (hereinafter referred to as “indexing housing”) 11 of the turret indexing device 2. The disc-shaped turret base 13 is supported so as to be freely rotatable. A ring-shaped wheel gear 14 is fixed to the turret base 13, and a pinion 7 fixed to an output shaft of an indexing motor 15 that rotationally drives the tool turret 3 is engaged with the wheel gear. The indexing motor 15 is installed on the outer periphery of the indexing housing 11. With this structure, the axial length of the indexing device 2 can be shortened while ensuring high support rigidity of the tool.
[0018]
A three-piece surface gear joint 16 that fixes the index position of the tool turret 3 is disposed on the inner diameter side of the cross roller bearing 12. The surface gear joint 16 includes a fixed gear 17 fixed to the indexing housing 11, a rotating gear 18 fixed to the lower portion of the turret housing 35, and an engagement / disengagement gear 19 facing these gears. The fitting / removing gear 19 is formed on the end face of the fitting / removing piston 20. The fitting / removing piston 20 is fitted to a ring-shaped cylinder 22 formed between the cylindrical member 21 fixed to the turret housing 35 and extending into the indexing housing 11 and the indexing housing 11.
[0019]
When the tool turret 3 is rotated, hydraulic pressure is supplied to the rod side chamber 23 of the cylinder 22 to move the piston 20 to the counter turret side, and the engagement / disengagement gear 19 is disengaged. When the tool turret 3 is fixed at the index position, hydraulic pressure is supplied to the cylinder side chamber 24 to move the piston 20 to the turret side, and the fitting / removing gear 19 is simultaneously meshed with the fixed gear 17 and the rotating gear 18. The pressure receiving surface of the cylinder side chamber 24 that urges the fitting / removing gear 19 in the meshing direction is formed by a tip flange portion 26 of the cylindrical member 21 extending from the turret housing and a step portion 27 formed on the indexing housing, and the pressure receiving area of both of them. Are equal. Therefore, when the hydraulic pressure is supplied to the cylinder side chamber 24, the fitting / removing gear 19 is engaged with the fixed gear 17 and the rotating gear 18 with equal pressure. The piston 20 is prevented from rotating around the indexing shaft by a rotation prevention pin 28.
[0020]
An inner housing 29 is integrally fitted and fixed at the center of the index housing 11, and a hollow transmission shaft 30 is pivotally supported on the inner housing 29. An output shaft 32 of a tool drive motor 31 provided on the base end side of the inner housing 29 is connected to the base end of the transmission shaft 30, and a gear shaft 33 supported by a turret housing 35 is connected to the tip. A driving side bevel gear 34 is formed at the tip of the gear shaft.
[0021]
A turret housing 35 that is T-shaped (see FIG. 4) in front view is fixed to the turret base 13 with an inlay 36 so that the axes coincide with each other. A tool main shaft 37 is supported on the turret housing 35 by bearings 38 and 39 in a direction orthogonal to the indexing shaft 6. The tool spindle 37 is a hollow shaft, and a collet claw 40a, a pull rod 41 connected to the collet claw, and a multi-layer disc spring 8 that urges the collet claw in the closing direction are accommodated in the hollow hole.
[0022]
The rear end of the pull rod 41 protrudes from the rear end of the tool main shaft 37, and the open / close piston 42 is loosely fitted to the protruding portion. The open / close piston 42 is fitted into an open / close cylinder 43 that is substantially integral with the turret housing 35. When hydraulic pressure is supplied to the hydraulic chamber 44 on the rear side of the opening / closing cylinder 43, the front end of the opening / closing piston 42 comes into contact with the stepped portion 62 formed on the pull rod 41, and this is further pushed to open the collet pawl 40a. On the other hand, when hydraulic pressure is supplied to the hydraulic chamber 45 in front of the open / close cylinder, the open / close piston 42 moves backward, the front end thereof is separated from the stepped portion 62, and the collet claw 40a is closed by the spring force of the disc spring 8 so that the tool is closed. 4, the pull rod 41 can rotate together with the tool spindle 37. The pull rod 41 is a hollow shaft, and a rotating union 46 for supplying a cutting fluid to the tool is connected to the rear end thereof.
[0023]
A driven bevel gear 47 is attached to an intermediate portion of the tool spindle 37 and meshes with the drive bevel gear 34. The tip end of the tool spindle 37 is a rotary tool mounting portion 48 on which the rotary tool 4 such as a milling cutter or a drill is mounted. On the other hand, the end portion of the stem portion 49 of the turret housing is a fixed tool mounting portion 57 on which the fixed tool 5 such as a tool integrated with the holder 58 is mounted (see FIG. 4).
[0024]
A tool necessary for processing a workpiece is mounted on the rotary tool mounting portion 48 and the fixed tool mounting portion 57 by an automatic tool changer disposed on the front side of the sheet of FIG. The fixed tool 5 is fixed by a taper shank 59, and the rotary tool 4 is fixed by being gripped by a collet claw 40a. When performing the tool change, the tool 1 is returned to the home position with the rotary tool 4 or the fixed tool 5 to be changed directed toward the automatic tool changer, and the tool is changed to a desired tool at the position.
[0025]
When machining the workpiece, it is necessary to bring the tool 4 or 5 close to the workpiece. At this time, the rotary tool mounting portion 48 and the fixed tool mounting are required because the turret housing 35 is T-shaped in front view. Since clearance spaces 60 that avoid interference with the workpiece are formed on both sides of the portion 57, the tools 4 and 5 can be brought close to the workpiece without causing interference with the workpiece, and the tool turret 3 itself can be reduced in size. Therefore, the movement space of the tool turret 3 can also be reduced, it is possible to process a workpiece with large irregularities, and the machine tool can be miniaturized. Further, when the tool turret of the present invention is used as a tool turret arranged in the middle between both spindles of a two-spindle opposed lathe, the interval between the two spindles during machining and the interval between the workpieces individually gripped by both spindles are set. Since processing is possible even in a narrow state, there are effects such as shortening the processing cycle and processing of workpieces with larger dimensions.
[Brief description of the drawings]
FIG. 1 is a schematic side view showing an example of a lathe equipped with the tool turret of the present invention. FIG. 2 is a sectional side view showing an example of a tool turret and its indexing device. [Fig. 4] Front view of tool turret [Explanation of symbols]
4 Rotating tool 5 Fixed tool 6 Indexing shaft
35 Turret housing
40 Collet chuck
42 Opening and closing piston
43 Open / close cylinder
48 Rotary tool mounting
49 Stem
57 Fixed tool mounting
61 Bar

Claims (1)

In a tool turret of a machine tool that rotates around an indexing shaft (6) and selects one of a plurality of tools (4, 5) mounted on the outer periphery thereof, a diametrical direction orthogonal to the indexing shaft is provided. A bar- shaped part (61) and a radial stem part (49) are integrally provided with a T-shaped turret housing (35) in front view, and a fixed tool mounting part (57) is provided at the end of the stem part. the a rotating tool mounted at both ends of the bar portion (48) opening and closing the cylinder (43), the rotary tool mounting portion, a collet chuck which is opened and closed by the piston before Symbol closing cylinder (42) (40) It has a tool turret.

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