JPH0586439U - Clamping structure of tool attachment in machine tool - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a clamp structure for a tool attachment in a machine tool that can minimize the indexable angle. [Configuration] Tool attachment 1 on motor shaft (spindle) 6
A clamp structure for removably mounting and mounting 1 is constructed. In this case, the tool attachment 11 has a circular locking step portion 1 centered on the turning axis a.
6d, and the plurality of collets 14a are connected to the locking step portion 1
A collet chuck 14 is provided so as to surround 6d, and the collet chuck 14 is further provided with the locking step portion 1
A drive mechanism 10 for engaging and disengaging the 6d is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a clamp structure, for example, when a tool attachment is pivotally indexable and detachably mounted on a spindle ram of a five-sided machine, and more specifically, there is no restriction due to the clamp structure in the indexable angle. Regarding the improvement of the clamp structure.

[0002]

[Prior Art]

 For example, in a five-sided machine, a tool attachment is attached to the spindle ram so that it can be swivel-indexed and detached. When such a tool attachment is provided, a clamp structure for clamping the tool attachment on the spindle ram side without hindering the turning index is required.

As a first conventional example of the clamp structure for this kind of tool attachment, for example, there is one described in Japanese Utility Model Laid-Open No. 1-121624. This is configured such that a clamping cylinder is formed at four corners of a main spindle ram, a piston rod of the cylinder is used as a clamp shaft, and an engaging surface formed on a tool attachment is pulled by a clamp claw of the clamp shaft.

A second conventional example is disclosed in, for example, JP-A-60-34251. This consists of a spindle ram on which a spindle-side disc with a recess formed in the inner circumference of an annular plate is arranged so that it can be drawn by a cylinder, etc. The attachment side disc having the above is provided, and the convex portion passes through the concave portion so that both can be attached and detached, and the remaining portions are engaged with each other to enable clamping after indexing.

[0005]

[Problems to be solved by the device]

 In the case of the above-mentioned first conventional example, since the clamp mechanisms are provided at the four corners, it is only possible to index every 90 °. The indexing angle can be reduced by arranging a large number of the crank mechanisms on a concentric circle, but in such a case, the structure becomes extremely complicated.

In the second conventional example, the indexing can be performed at a smaller angle, but since the concave portion and the convex portion are indispensable and the clamping at the portion is impossible, the indexable angle is made finer. Is limited.

The present invention has been made in view of the above conventional problems, and an object of the present invention is to provide a clamp structure for a tool attachment in a machine tool that can minimize the indexable angle to the utmost.

[0008]

[Means for Solving the Problems]

 The present invention provides a tool attachment clamping structure in which a tool attachment is attached to the main spindle in a manner that allows the tool attachment to be pivotally indexed and detachably attached. A collet chuck is formed by forming a circular locking step centering on the center of the collet chuck and arranging a plurality of collets so as to surround the locking step, and driving the collet chuck to engage with and disengage from the locking step. It is characterized by having a mechanism.

[0009]

[Action]

 When the tool attachment is clamped by the clamp structure according to the present invention, the collet chuck is moved to the spindle side by the drive mechanism. Then, each collet of the collet chuck is locked to the locking step on the attachment side, and the tool attachment is pulled toward the spindle side, whereby the tool attachment is clamped on the spindle side.

Further, when the tool attachment is pivotally indexed, the locking with the locking step portion of the collet chuck is released, and the tool attachment is rotated by utilizing the rotation of the spindle to perform the indexing. In this case, since the locking step portion has a circular shape concentric with the turning shaft, there is no restriction on the indexing angle. Therefore, the indexing angle of the present invention is determined by factors other than the clamp structure, such as the pitch of the meshing teeth of the coupling, and is about 1 °, for example, which is extremely miniaturized.

[0011]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. 1 to 4 are views for explaining a clamp structure of a tool attachment in a machine tool according to an embodiment of the present invention. FIG. 1 is a sectional front view, and FIG. 2 is a collet chuck and a locking step portion. FIG. 3 is a partial cross-sectional side view of the locked state, FIG. 3 is a cross-sectional view taken along the line III-III of FIG. 2, and FIG. 4 is a front view of a spindle ram having the structure of this embodiment.

In FIG. 1, reference numeral 1 denotes a main spindle ram on which a tool attachment 11 is removably and removably mounted around a revolving axis a. This main spindle ram 1 has a cylindrical ram body 2 in which a motor case 3 is inserted so as to be able to advance and retreat in the axial direction, and an axial feed motor for moving the motor case 3 in the axial direction at the upper end of the ram body 2. 4 is mounted, and a ball screw 5 connected to the output shaft 4a of the shaft feeding motor 4 is screwed into the upper end of the motor case 3.

A motor shaft 6 is inserted into the motor case 3, and is rotatably supported by the motor case 3 via bearings 3 a and 3 b. The motor shaft 6 and the ram body 2 are connected to each other. A motor 7 that rotationally drives the motor shaft 6 is interposed therebetween. A tool holding taper hole 6a is formed at the lower end of the motor shaft 6, and a draw bar 8 is inserted into the shaft center of the motor shaft 6 while being biased upward by a disc spring (not shown). ing. A lock mechanism 22 is formed at the lower end of the drawbar 8, and an output shaft 9a of a pressing cylinder 9 for pushing the drawbar 8 downward when unlocked is in contact with the upper end.

A clamp mechanism 10 is provided at the lower end of the ram body 2, and the tool attachment 11 of the present embodiment can be pivotally indexed to and detached from the lower end of the ram body 2 by the clamp mechanism 10. Is attached to.

As shown in FIG. 1, the clamp mechanism 10 includes a collet chuck 14 arranged so as to surround a locking step portion 16d of the tool attachment 11 described later, and the collet chuck 14 having the locking step portion 16d. And a driving mechanism 12 that disengages and moves in the clamping direction and the unclamping direction.

The drive mechanism 12 has a cylindrical piston 12b axially slidably inserted into a cylinder 12a arranged and fixed in the ram body 2, and a ring-shaped piston 12b at the upper end of the cylinder 12a. The end face plate 12c is fixed. Incidentally, 12d and 12e are hydraulic passages for supplying and discharging hydraulic pressure to and from a hydraulic chamber formed by the cylinder 12a, the piston 12b and the end plate 12c. Reference numeral 15 is a cylindrical dog fixed to the ram body 2 via the end face plate 12c.

The collet chuck 14 has a large number of collets 14a arranged around the rod portion 12f of the piston 12b, that is, on the circumference centered on the turning axis a (see FIG. 3). .. The upper end of each collet 14a is locked in the annular groove of the rod portion 12f, and the lower end is in sliding contact with the cam surface 12g of the cylinder 12a, so that the lower end of each collet 14a is the upper end. It is swingable about the center in a direction perpendicular to the swivel axis a.

The tool attachment 11 is arranged in an attachment case 16, a vertical main shaft 17 vertically arranged in the attachment case 16, and horizontally, and is connected to the vertical main shaft 17 by transmission gears 26 and 27. And a horizontal main shaft 18.

The attachment case 16 has a box-shaped case body 16a having an upward opening and a lateral opening, a vertical cylindrical portion 16b inserted and fixed to the upward opening, and an insertion and fixed to the lateral opening. And a substantially horizontal L-shaped portion 16c. The vertical main shaft 17 is rotatably supported by the vertical cylindrical portion 16b via a bearing 19a, and the horizontal main shaft 18 is rotatably supported by the horizontal cylindrical portion 16c via a bearing 19b. There is.

Further, a circular annular locking step portion 16d centered on the turning axis a is formed at the center upper end of the vertical cylindrical portion 16b of the attachment case 16. Each collet 14a of the collet chuck 14 is disengaged from the lower surface of the locking step portion 16d.

A cylindrical connecting ring 20 is arranged between the locking step portion 16d and the vertical main shaft 17. The connecting ring 20 is arranged so as to be vertically movable and urged upward by a spring 21, and the rising end position is regulated by the dog 15. The outer surface of the connecting ring 20 meshes with the inner surface of the locking step portion 16d so as to be movable up and down, and the rotation of the motor shaft 6 can be transmitted to the attachment case 16.

Further, a coupling 28 is arranged on the facing surface between the attachment case 16 and the cylinder 12a. The coupling 28 is composed of upper and lower meshing rings 28a and 28b having meshing teeth with a predetermined indexing pitch (for example, 1 °), which are bolted to the cylinder 12a and the attachment case 16, respectively. It is fixed.

A connecting cylinder portion 17c is formed at the upper end of the vertical main shaft 17, and transmission teeth 17b are formed on the inner peripheral surface of the connecting cylinder portion 17c. The transmission teeth 17b mesh with the transmission teeth 6b formed on the outer peripheral surface of the motor shaft 6 so as to be axially movable. A locking projection 17d is formed on the lower part of the outer peripheral surface of the connecting cylinder portion 17c so as to be engageable with and disengageable from the slit groove at the upper end of the connecting ring 20. Further, a taper portion 17a fitted into the taper hole 6a of the motor shaft 6 is arranged at the upper end shaft core portion of the vertical main shaft 17 so as to be biased upward.

A tool T formed by fixing a cutting tool 24 to a holder 23 is attached to a right end portion of the horizontal main shaft 18 by attaching a nut member 25 to a male screw 18a at a right end portion of the horizontal main shaft 18 so that the tool T can be attached and detached. It is installed.

Next, the function and effect of this embodiment will be described. First, a case where the tool attachment 11 of this embodiment is attached to and detached from the spindle ram 1 will be described. In the state shown by the solid line in FIG. 1, the piston 12b is lowered to the lower end by the hydraulic pressure from the hydraulic passage 12e, and each collet 14a is opened. Therefore, when the vertical main shaft 17 and the motor shaft 6 are disengaged from each other by the lock mechanism 22, the tool attachment 11 is detached downward from the main shaft ram 1.

To mount another tool attachment 11, the transmission tooth 17b of the tool attachment 11 is engaged with the transmission tooth 6b of the motor shaft 6 while the taper portion 17a of the vertical spindle 17 of the tool attachment 11 is fitted. Is inserted into the taper hole 6a of the motor shaft 6 and then locked by the lock mechanism 22. Then, hydraulic pressure is supplied from the hydraulic passage 12d of the clamp mechanism 10 to raise the piston 12b. Then, the lower end of the collet 14a is pushed inward by the cam surface 12g to clamp the locking step 16d of the attachment case 16 (see the chain double-dashed line in FIG. 1). As a result, another tool attachment 11 is attached to the spindle ram 1.

At this time, since the connecting ring 20 is prevented from rising by the dog 15, the connecting ring 20 and the locking projection 17d of the vertical shaft 17 are not locked. When the motor 7 is started in this state, the rotation of the motor shaft 6 is transmitted to the vertical main shaft 17 via the transmission teeth 6b and 17b, and further the rotation of the vertical main shaft 17 is transmitted horizontally via the transmission gears 27 and 26. It is transmitted to the main shaft 18, which causes the tool T to rotate.

Next, when performing swivel indexing for changing the processing direction of the tool T, the piston 12b of the clamp mechanism 10 is lowered to open the collet 14a, and the state shown by the solid line in FIG. 1 is obtained. Then, the feed motor 4 lowers the entire motor case 3. Then, the tool attachment 11 is lowered together with the motor shaft 6. On the other hand, since the connecting ring 20 is held by the biasing spring 21 at the position where it is in contact with the dog 15, the slit of the connecting ring 20 is locked by the locking projection 17d.

When the motor shaft 6 is rotated by a predetermined angle in this state, the rotation of the motor shaft 6 is transmitted to the attachment case 16 via the locking projection 17d and the coupling ring 20, whereby the entire tool attachment 11 is transferred. It turns around the turning axis a by a predetermined angle. Then, the feed motor 4 returns the tool attachment 11 together with the motor shaft 6 to the original position in the height direction, joins the coupling 28, and clamps the attachment case 16 by the clamp mechanism 10.

As described above, in this embodiment, a circular locking step portion 16d centering on the turning axis a is formed at the upper end of the vertical cylindrical portion 16b of the tool attachment 11, and the locking step portion 16d is surrounded by the locking step portion 16d. Since the collet chuck 14 including a large number of collets 14a is arranged, the collet chuck 14 can be clamped regardless of how many times the turning indexing angle is set. Therefore, the minimum indexing angle of this embodiment is determined by the indexing pitch of the cup link 28 and is, for example, about 1 °.

In the above embodiment, the case where the collet chuck 14 is composed of a large number of independent collets 14a has been described. However, in the collet chuck of the present invention, the upper ends of the collets are integrated. It may be one.

[0032]

[Effect of the device]

 As described above, according to the clamp structure of the tool attachment in the machine tool according to the present invention, a circular locking step portion centering on the turning axis is formed on the attachment side, and a large number of locking step portions are formed around the locking step portion. A collet chuck with a collet arranged is provided, and the tool attachment is clamped to the spindle side by pulling the collet chuck with a drive mechanism, so it can be clamped no matter how many times the turning angle is set. As a result, there is an effect that the indexable angle can be made as small as possible.

[Brief description of drawings]

FIG. 1 is a sectional front view showing a clamp structure of a tool attachment in a machine tool according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional side view of a collet chuck portion of the above embodiment.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a front view of a spindle ram having the above-described embodiment structure.

[Explanation of symbols]

 1 Spindle Ram (Spindle) 10 Clamping Mechanism 11 Tool Attachment 12 Drive Mechanism 14 Coretto Chuck 14a Collet 16d Locking Step a Rotating Axis

Claims (1)

[Scope of utility model registration request] 1. A machine tool in which a tool attachment is attached to a spindle so that the tool attachment can be rotationally indexed and detached, and a clamp structure of the tool attachment in which the tool attachment is brought into pressure contact with the spindle, and the tool attachment has a turning axis. Forming a circular locking step centering on the center, and providing a collet chuck in which a plurality of collets are arranged so as to surround the locking step, and a drive for engaging and disengaging the collet chuck with the locking step A clamp structure for a tool attachment in a machine tool, which is provided with a mechanism.