JP4372286B2 - Machine Tools - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a machine tool such as a lathe provided with a first spindle stock and a second spindle stock arranged opposite thereto.
[0002]
[Prior art]
There is a commercially available lathe equipped with a first spindle stock and a second spindle stock arranged opposite thereto. According to this type of lathe, the work is gripped by the chuck of the first headstock and the front part of the work is processed, and the processed part of the work is gripped by the chuck of the second headstock and the remaining part is processed. Thus, the turning process can be performed efficiently.
[0003]
[Problems to be solved by the invention]
By the way, the machine tool provided with the said 1st, 2nd headstock aims at the process of a short workpiece | work, and is not suitable for the process of a long workpiece | work. In the case of a long workpiece, the tip of the workpiece is supported and processed by a tailstock arranged to face the headstock.
[0004]
The present invention has been made in view of the above-described conventional situation, and includes first and second headstocks, and a short work piece by allowing the second headstock to function as a tailstock as necessary. It is an object to provide a machine tool that can process not only long workpieces but also long workpieces.
[0005]
[Means for Solving the Problems]
The present invention provides a machine tool comprising: a first spindle stock having a chuck for holding a workpiece; and a second spindle stock having a chuck arranged to face the first spindle stock and holding a workpiece. The chuck is composed of a chuck body fixed to the main shaft and a claw plate that is detachably attached to the chuck body by a lock mechanism, and the workpiece gripping claw of the claw plate is driven to advance and retract in the direction perpendicular to the axis. A claw drive mechanism is provided, and the tailstock unit can be detachably attached to the chuck body by the lock mechanism with the claw plate removed, and the quill of the tailstock unit is axially moved by the work gripping claw drive mechanism. It is characterized by providing a quill drive mechanism for advancing and retreating.
[0006]
[Effects of the invention]
According to the present invention, when a short workpiece is machined, the workpiece is machined by cutting the tool while turning and gripping a part of the workpiece with the chuck of the first headstock, and then the machined portion of the workpiece. Is gripped by the chuck of the second headstock and the remaining part is processed. When processing a long workpiece, remove the claw plate of the second headstock, attach the tailstock unit to the chuck body with the lock mechanism, and operate the workpiece gripping claw drive mechanism to remove the quill with the quill drive mechanism. Advancing and retreating in the axial direction, the tip of a long workpiece is supported by the quill, and the workpiece is processed.
[0007]
As described above, in the present invention, the claw plate or the tailstock unit can be attached to the second head stock as necessary, and any of a short workpiece and a long workpiece can be processed. A quill drive mechanism that moves the quill back and forth using the operation of the workpiece gripping claw drive mechanism that drives the workpiece gripping claw of the claw plate to move back and forth in the direction perpendicular to the axis can be installed. However, the complexity of the structure can be suppressed.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
1 to 4 are views for explaining a machine tool according to an embodiment of the present invention. FIG. 1 is a front perspective view of the machine tool, and FIG. 2 is a partial sectional side view of a second headstock. 3 and 4 are a front view, a cross-sectional side view, and a cross-sectional side view of the state where the claw plate is attached to the chuck body, and FIG.
[0009]
In the figure, reference numeral 1 denotes a lathe as a machine tool according to the present embodiment, which has a headstock (first headstock) 3 mounted on the left end of the bed 2 and faces the headstock 3 on the right side. In addition, it has a general structure in which a sub spindle stock (second spindle stock) 4 is mounted so as to be movable to the left and right in the figure, and a tool rest 5 is mounted on the back side so as to be movable to the left and right. A tool spindle 6 is movably mounted on the inclined surface 5a with the front side of the tool post 5 lowered, and a plurality of tools T are provided on the right side surface of the tool post 5. A tool magazine 7 is provided.
[0010]
The spindle stock 3 has a main shaft rotatably inserted into a main body 3a mounted on the bed 2, and a chuck 3b is mounted on the tip of the main shaft, and the main shaft is rotated by a drive motor. It is configured as follows. Further, the sub spindle stock 4 has a sub spindle 9 rotatably inserted in a main body portion 8 slidably mounted on the guide rail 2 a on the bed 2, and the sub spindle 9 rotates and drives the sub spindle 9. A drive motor (not shown) is provided, and a substructure 10 is mounted on the front end surface.
[0011]
The sub chuck 10 includes a chuck main body 11 fixed to the front end portion of the sub main shaft 9 and a claw plate 12 detachably mounted on the front surface of the chuck main body 11. The chuck body 11 has a substantially cylindrical shape, and a tapered concave portion 11a provided at the rear end thereof is fitted into a tapered convex portion 9a provided at the front end surface of the auxiliary main shaft 9.
[0012]
The claw plate 12 has three guide grooves 12b formed in a disc-like base plate 12a so as to extend in the radial direction at intervals of 120 degrees, and a rectangular parallelepiped workpiece gripping claw 12c is provided in each of the guide grooves 12b. The structure is slidably arranged. The base plate 12a engages the locking heads 13a of the three lock rods 13 with the locking recesses 12h of the base plate 12a, and pulls the lock rod 13 toward the sub main shaft 9 by a cylinder mechanism 22 described later. The chuck body 11 is fixed by crimping.
[0013]
Here, the locking head 13a has a substantially oval shape, and when it is rotated to a position parallel to the rectangular insertion hole 12i formed in the locking recess 12h, the claw plate 12 is removed outward. In addition, the claw plate 12 can be fixed to the chuck body 11 by being rotated 90 degrees from the parallel position. Reference numeral 13b denotes a cover that covers the locking recess 12h.
[0014]
Three connecting members 12d constituting a part of a work gripping claw driving mechanism 14 described later are fastened and fixed to the back surface of the three work gripping claws 12c by bolts 12e. The connecting member 12d has a rectangular parallelepiped shape similar to the workpiece gripping claw 12c, and an engagement groove 12f is recessed on the back surface thereof.
[0015]
The workpiece gripping claw driving mechanism 14 for advancing and retracting the three workpiece gripping claws 12c in the direction perpendicular to the axis (radial direction) is disposed at the front end (right end in FIG. 4) of the chuck body 11. The workpiece gripping claw drive mechanism 14 includes three driven cam members 15 that are arranged on the back surface of the three connecting members 12d so as to be movable in the radial direction, and one drive for moving the driven cam members 15 forward and backward in the radial direction. A cam member 16 and one guide member 17 for guiding the drive cam member 16 in the axial direction are provided.
[0016]
On the front surface of each driven cam member 15, an engaging projection 15a is provided so as to engage with the engaging groove 12f of each connecting member 12d. A driven cam piece 15b having a T-shaped cross section is formed on the inner edge in the radial direction of each driven cam member 15 so as to be inclined away from the axial center on the rear side (left side in FIG. 4). The inner and outer surfaces of each driven cam piece 15b are an inner cam surface 15c and an outer cam surface 15d.
[0017]
The guide member 17 is a cylindrical member having a guide surface 17a having a circular cross section, is arranged coaxially with the sub main shaft 9, and is fixed to the front end surface of the chuck body 11 with bolts. A tapered surface 17b is formed at the front end of the guide member 17, and the tapered surface 12g of the base plate 12a of the claw plate 12 is fitted to the tapered surface 17b.
[0018]
The drive cam member 16 has a disk shape having a slide hole 16a having a circular cross section guided by the guide surface 17a of the guide member 17 at the center. A drive cam groove 16b having a T-shaped cross section is formed in a portion of the drive cam member 16 facing the driven cam piece 15b of the driven cam member 15 so as to be inclined closer to the axial center on the front side (right side in FIG. 4). ing. The inner and outer surfaces of the drive cam groove 16b are an inner cam surface 16c and an outer cam surface 16d. A driven cam piece 15b of the driven cam member 15 is slidably inserted into the drive cam groove 16b, and an inner cam surface 16c and an outer cam surface 16d of the drive cam groove 16b are formed on the inner side of the driven cam member 15. It is in sliding contact with the cam surface 15c and the outer cam surface 15d.
[0019]
A cylindrical coupling nut 18 is fixed to the rear surface of the drive cam member 16 by a clamping piece 19 and a bolt 20. A front end portion of an inner draw pipe 21 is screwed and connected to the coupling nut 18, and the inner draw pipe 21 extends rearward in the sub main shaft 9, and a cylinder mechanism 22 is connected to the rear end portion thereof. Yes.
[0020]
The cylinder mechanism 22 has a structure in which the inside of a cylinder body 23 is defined by front and rear chambers 23b and 23c by a partition wall 23a, and an outer and inner pistons 24a and 24b are arranged in the front and rear chambers 23b and 23c. . Outer and inner draw pipes 25 and 21 are coupled to the outer and inner pistons 24a and 24b. A clamping mechanism (not shown) is driven by the front end portion of the outer draw pipe 25 to pull the claw plate 12 toward the chuck body 11, thereby fixing the claw plate 12 to the chuck body 11. Reference numerals 26a and 26b denote hydraulic pressure supply chambers for supplying hydraulic pressure to the front and rear chambers 23b and 23c.
[0021]
And in this embodiment, it replaces with the nail | claw plate 12 in the said subchuck 10, and the tailstock unit 27 can be mounted | worn so that attachment or detachment is possible. The tailstock unit 27 includes a base board 28 corresponding to the base plate 12a of the claw plate 12 and a quill 29 held slidable in the axial direction by a slide hole 28c formed in the axis of the base board 28. I have.
[0022]
The base board 28 has a disk shape, and locking recesses 28a recessed in three places are fixed to the front end face of the chuck body 11 by the lock rod 13. Also, guide grooves 28h are formed at three locations corresponding to the driven cam member 15 of the base board 28 so as to extend in the radial direction, and slide pieces 28g are slidably disposed in the guide grooves 28h. The engagement protrusion 15a of the driven cam member 15 is engaged with an engagement groove 28b that is recessed on the back surface of the slide piece 28g. A drive cam groove 28d is formed in the radial inner edge of each slide piece 28g so as to have a T-shaped cross section and to be inclined closer to the axis toward the front side (right side in FIG. 5). The drive cam groove 28d has an upper cam surface 28e and a lower cam surface 28f that constitute the side of the T-shape.
[0023]
Three driven cam pieces 29a projecting from the quill 29 at intervals of 120 degrees are in sliding contact with the drive cam grooves 28d of the slide pieces 28g. The driven cam piece 29a has a T-shaped cross section, and is inclined so as to approach the axis toward the front side. The upper cam surface 29b and the lower cam are in sliding contact with the upper cam surface 28e and the lower cam surface 28f of the drive cam groove 28d. It has a surface 29c. The cam surfaces 28e and 28f of the drive cam groove 28d and the cam surfaces 29b and 29c of the driven cam piece 29a constitute a quill drive mechanism 30 for moving the quill 29 back and forth by the operation of the work gripping claw drive mechanism 14. .
[0024]
Next, operations and effects of the apparatus according to the present embodiment will be described.
When processing a short workpiece, as shown in FIGS. 3 and 4, a claw plate 12 is attached to the chuck body 11 on the side of the auxiliary headstock 4. In this case, the base plate 12 a is fixed to the front end surface of the chuck body 11 by the lock rod 13. In order to mount the workpiece, hydraulic pressure is supplied to the rear surface side of the inner piston 24b of the rear chamber 23c of the cylinder mechanism 22, and the inner piston 24b advances the inner draw pipe 21. Then, the drive cam member 16 moves forward, and the inner cam surface 16c pushes the inner cam surface 15c of the driven cam member 15 radially outward, whereby the driven cam member 15 moves radially outward. Along with this, the workpiece gripping claws 12c also move outward, the gripping diameter formed by the three workpiece gripping claws 12c is enlarged, and the workpiece is inserted into the gripping diameters.
[0025]
Subsequently, hydraulic pressure is supplied to the front side from the inner piston 24 b of the rear chamber 23 c of the cylinder mechanism 22, and the inner piston 24 b moves the inner draw pipe 21 backward. Then, the drive cam member 16 moves backward, and its outer cam surface 16d pushes the outer cam surface 15d of the driven cam member 15 radially inward, whereby the driven cam member 15 moves radially inward. Along with this, the workpiece gripping claws 12c also move inward, the gripping diameter formed by the three workpiece gripping claws 12c is reduced, and thereby the workpiece is clamped. The sub-spindle 9 is rotationally driven to turn the workpiece, and turning is performed by cutting the tool.
[0026]
On the other hand, when processing a long workpiece, hydraulic pressure is supplied to the rear side of the outer piston 24a of the front chamber 23b of the cylinder mechanism 22, the outer draw pipe 25 moves forward, and the lock rod is moved by a clamp mechanism (not shown). The head 13 rotates 90 degrees while moving forward, and the locking head 13a of the lock rod 13 becomes parallel to the insertion hole 12i, whereby the claw plate 12 is removed. Instead, the tailstock unit 27 is disposed on the front end surface of the chuck body 11 and is pressed and fixed by the lock rod 13 (see FIG. 5).
[0027]
When the inner draw pipe 21 is advanced by the cylinder mechanism 22, the drive cam member 16 moves forward to move the driven cam member 15 radially outward together with the slide piece 28g, and the inner cam surface 28f of the slide piece 28g An upward force is applied to the inner cam surface 29c of the quill 29, whereby the quill 29 moves forward, and the tip end portion of the workpiece is supported by the center 29a of the quill 29. In this state, a long workpiece is processed.
[0028]
Further, when the support of the tip of the workpiece is removed, the inner draw pipe 21 is moved backward by the cylinder mechanism 22. Then, the drive cam member 16 moves backward to move the driven cam member 15 together with the slide piece 28g radially inward, and the outer cam surface 28e of the slide piece 28g exerts a downward force on the outer cam surface 29b of the quill 29. As a result, the quill 29 is retracted, and the support of the tip of the workpiece is removed.
[0029]
The claw plate 12 and the tailstock unit 27 may be supplied to and discharged from the sub spindle stock 4 manually or manually by a loader mechanism.
[0030]
As described above, in this embodiment, the claw plate 12 or the tailstock unit 27 can be attached to the auxiliary head stock 4 as necessary, and either a short workpiece or a long workpiece can be processed. Since the quill driving mechanism 30 for advancing and retracting the quill 29 using the operation of the work gripping claw driving mechanism 14 for driving the workpiece gripping claw 12c of the claw plate 12 to move back and forth in the direction perpendicular to the axis is provided, 27 can be mounted while suppressing the complexity of the structure.
[Brief description of the drawings]
FIG. 1 is a front perspective view of a lathe according to an embodiment of the present invention.
FIG. 2 is a partial cross-sectional side view around the sub spindle stock of the embodiment.
FIG. 3 is a front view of a claw plate portion of the embodiment.
FIG. 4 is a cross-sectional side view of a sub chuck portion provided with the claw plate.
FIG. 5 is a cross-sectional side view of a sub chuck portion including the tailstock unit of the embodiment.
[Explanation of symbols]
1 Lathe (machine tool)
3 headstock (first headstock)
4 Sub headstock (second headstock)
9 Sub-chuck 11 Chuck body 12 Claw plate 12c Work gripping claw 14 Work gripping claw drive mechanism 27 Tailstock unit 29 Quill 30 Quill drive mechanism

Claims (1)

In a machine tool comprising a first spindle stock having a chuck for holding a workpiece and a second spindle stock having a chuck arranged to face the first spindle stock and holding a workpiece, the chuck of the second spindle stock is A workpiece gripping claw drive mechanism that includes a chuck body fixed to the main shaft and a claw plate that is detachably attached to the chuck body by a lock mechanism and that drives the workpiece gripping claw of the claw plate in a direction perpendicular to the axis. A quill drive that allows the tailstock unit to be detachably attached to the chuck body by the lock mechanism with the claw plate removed, and the quill of the tailstock unit is advanced and retracted in the axial direction by the work gripping claw drive mechanism. A machine tool characterized by a mechanism.

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