JPH0422910Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an automatic tool changer for a machine tool.

[Prior Art] Generally, in a machine tool that processes a workpiece by reciprocating a spindle head that rotatably supports a spindle having a tool holder at one end in the axial direction of the spindle with respect to a frame, a tool holder is used. A tool magazine having a plurality of tool holders on the outer periphery for removably gripping the tool holder is rotatably supported on the frame, and the axis of the tool holder gripped by one rotationally indexed tool holder. A known tool is equipped with an automatic tool changer that is set so that the tool is located on the axis of the spindle.

In machine tools equipped with this type of automatic tool changer, the tool holder, which is rotatably indexed on the axis of the spindle based on the forward movement of the spindle head during machining of the workpiece, is attached to the tool holding section of the spindle. installed,
Furthermore, since the spindle head is moved forward toward the workpiece to perform machining, there are problems such as chips, etc. generated during machining scattering into the tool gripper and tool magazine, which may interfere with subsequent tool exchange operations. The point was hot.

In order to solve these problems, conventionally, a tool magazine cover for surrounding the tool holder is integrally formed with the tool magazine by casting or the like, and the spindle head can pass through the tool magazine cover. By forming a notch in each tool gripper, the spindle head and the tool magazine cover do not interfere with each other during machining of a workpiece, and chips and the like are prevented from entering the tool magazine.

[Problems to be solved by the invention] In the case where the tool magazine and the tool magazine cover are integrally formed by casting etc. as described above, and the spindle head passes between the notches formed in the tool magazine, Since the notch cannot be made smaller than the spindle head and requires a very large space, there are problems such as chips entering the tool magazine from the notch corresponding to the adjacent tool gripper.

[Purpose of the invention] The present invention solves the above-mentioned problems, and aims to reliably prevent chips from entering the tool gripper and the tool magazine by making the notch in the tool magazine cover as small as possible. The purpose of this invention is to provide an automatic tool changer for machine tools that can perform the following functions.

[Means for Solving the Problems] In order to achieve the above object, in the present invention, a tool magazine cover provided on the outer periphery of the tool holder for each tool holder surrounds the inside of the tool magazine. It is supported on the tool magazine so as to be able to swing freely between a first position and a second position retracted toward the rotation axis of the tool magazine.

[Function] With the above-described configuration, when processing a workpiece, only the tool magazine cover corresponding to the tool gripper that grips the tool rotationally indexed on the axis of the spindle moves from the first position to the second position. is swung to the position of
The other tool magazine cover is held in the first position.

[Embodiments] Next, an automatic tool changer for a machine tool according to the present invention will be described below with reference to the accompanying drawings, citing preferred embodiments.

A machine tool equipped with an automatic tool changer shown in FIG.
A spindle head 24 that can reciprocate vertically within
and a tool magazine 66 which is disposed on the frame 12 via a magazine support stand 58 and is capable of rotatably indexing the built-in tool holder 48. That is, the guide rail 14 is attached to the column 10.
are arranged vertically, and the spindle head 24 is moved through a pair of sliding pieces 16, 16 arranged vertically.
It is attached so as to be vertically movable along the guide rail 14. A nut (not shown) is fixed to the spindle head 24 at an appropriate position, and a rotatable ball screw (not shown) supported parallel to the guide rail 14 is screwed into the nut. There is. By rotating the ball screw in both forward and reverse directions by an AC servo motor 22 disposed above the frame 12, a guide rail 14 is attached to the spindle head 24 under the screwing action of the nut and ball screw. A smooth vertical movement is provided along the vertical direction.

Inside the main spindle head 24, a main spindle 40 with a tool holder (not shown) at its lower end is rotatably arranged vertically. It is connected to a motor 36 via a coupling (not shown) and is rotationally driven by the motor 36. The tool holder of the spindle 40 can be fitted with an arbor (not shown) of a tool holder 48 with a tool 50 inserted at its tip, and when the tool holder 48 is inserted into the tool holder, the holder A pull stud (not shown) provided at 48 is clamped by a known holder clamping mechanism provided in the main shaft 40. In addition, this holder clamping mechanism is connected to the main shaft 40.
When pressed by a drawbar (not shown) coaxially inserted into the center hole of the tool holder 48, the pull stud is unclamped by the holder clamping mechanism, and the tool holder 48 can be removed.

A magazine support stand 58 fixed to the frame 12 is provided with a support shaft (not shown) adjacent to the vertical movement area of the spindle head 24 and oriented diagonally downward to the left.
A magazine base 64 of the shape shown in the figure is attached to this support shaft.
It is rotatably supported. On the magazine base 64, a plurality of grip arms 82 (10 in the illustrated example) are swingably disposed radially at a required central angle, which function as tool grippers to be described later. The magazine base 64 is provided with a plurality of roller-shaped cam followers (not shown) centered around the support shaft (ten in the embodiment) corresponding to the positions of the grip arms 82, which will be described later.

An indexing motor 68 is arranged upside down on the upper part of the casing 67 arranged perpendicularly to the magazine support stand 58, and a barrel cam is connected to this motor 68 via a rotating shaft and a bevel gear (not shown).
Each of the cam followers can be sequentially fitted into this cam groove. The rotation of the barrel cam applies intermittent indexing rotation to the magazine base 64.

Next, a required tool gripper indexed by the above-mentioned rotary indexing mechanism and a mechanism for swinging the tool gripper for delivery of the tool holder 48 will be explained. In the magazine base 64, which constitutes a part of the tool magazine 66, clevises 81 are sequentially arranged at a required center angle in the circumferential direction around the support shaft (10 in the illustrated example). A grip arm 82 having the shape shown in the drawing is swingably supported on each clevis 81 via a pivot shaft 84, with the free end of the arm facing outward in the radial direction. The free end of the grip arm 82 is formed with a bifurcated portion (not shown) having a size that allows the maximum diameter portion of the tool holder 48 to be gripped. Further, a composite cam body 86 is vertically bolted to the vertical surface of the spindle head 24 and on the side facing the tool magazine 66, and its first cam surface 86a and second cam surface 86b are connected to the tool magazine 66. The tool holder 48 is positioned at a desired indexing position of the tool holder 48 (a position close to the grip arm 82 correspondingly indexed to the tool holding portion of the main spindle 40).

Then, within the required lifting area of the spindle head 24,
Two cam followers (not shown) are provided on the grip arm 82 and are positioned to slidably abut the first cam surface 86a and the second cam surface 86b of the composite cam body 86, respectively. .
Then, when the spindle head 24 is moved up and down,
One cam follower abuts the first cam surface 86a, and the other cam follower abuts the second cam surface 86b, so that the grip arm 8 is under the action of the respective cams.
2 performs a predetermined rocking motion about a pivot shaft 84.

A magazine cover 30 having an area larger than that of the grip arm 82 and having a generally doglegged side surface is fixed to the outer circumferential surface of each grip arm 82 with screws. (10 pieces in the illustrated example). The magazine cover 30 is configured to have a complete truncated cone shape as a whole when the spindle head 24 is moved back to the tool exchange area and the magazine base 64 can be rotated and indexed. Also, magazine cover 3
0 are each made of synthetic resin, and each has a notch 3 on the spindle head 24 side so as not to interfere with the tool holder 48 gripped by the grip arm 82.
0a is formed.

The present embodiment is constructed as described above, and its operation will be explained next.

The spindle head 24 and the composite cam body 86 fixed thereto are moved up and down under the screwing action of the ball screw and nut caused by the rotation of the servo motor 22, but the tool magazine 66 itself remains at a fixed position on the frame 12. The magazine base 64 is rotated by the rotation of the indexing motor 68, and the tool holder 48 held by each grip arm 82 is indexed.

FIG. 1 shows a state in which a workpiece is being cut by a machine tool according to the present invention. Spindle head 24
The lower open end of the main shaft 40 is located below the origin, and in this state the grip arm 82
The cam follower provided in the corresponding composite cam body 8
It is located at a position where it engages with each of the cam surfaces 86a and 86b of No.6. That is, the bifurcated portion of the grip arm 82 is located at a large distance from the specific tool holder 48 attached to the tool holding portion of the main shaft 40, and the magazine cover 30 is retracted to the second position toward the support shaft. Therefore, the spindle head 24 can independently descend toward the workpiece and perform the required cutting process.

Next, in order to replace the tool holder 48, when the spindle head 24 rises by a predetermined distance from the origin, just before reaching this state, the holder clamping mechanism releases the pull stud due to the action of a cam mechanism and crank lever (not shown), and the tool Unclamping of the holder 48 has been completed. Grizpoom 82 is
Under the action of both cam surfaces 86a, 86b and their respective cam followers, the tool holder 48 is chucked by the grip arm 82 by swinging counterclockwise, and the magazine cover 30 is moved to the first position.

Also, from this point on, removal of the tool holder 48 from the main spindle 40 is started. That is, the spindle head 24 further rises, and the tool holder 48 used for machining the workpiece remains gripped by the grip arm 82.
8 (transfer from the spindle head 24 to the tool magazine 66) has been completed. In this state,
The indexing motor 68 is rotationally driven, and the magazine base 64 is rotationally indexed under the action of the barrel cam and the cam follower. As a result, another grip arm 82 holding the tool holder 48 to be used next is positioned directly below the tool holding portion 42 of the spindle head 24 with its center lines aligned.

This newly indexed tool holder 48 is then
Now, the process of inserting the tool holding portion of the spindle head 24 will be explained. When the servo motor 22 is rotated,
The spindle head 24 is lowered under the action of the ball screw and the nut, and as the spindle head 24 is lowered, the newly indexed arbor of the tool holder 48 is inserted into the tool holder. On the other hand, the two cam followers of the grip arm 82 again come into engagement with the corresponding two cam surfaces 86a, 86b, and the releasing motion of the grip arm 82 is started. That is, the grip arm 82 begins to swing clockwise about the pivot shaft 84. At the same time, when the spindle head 24 descends, the holder clamping mechanism starts clamping the pull stud of the tool holder 48 by the action of the cam mechanism and crank lever.

When the spindle head 24 further descends, the holder clamping mechanism clamps the pull stud and completes the clamping operation, and the grip arm 82 completely separates from the tool holder 48 that is fitted and held in the tool holder. This allows rotation of the main shaft 40, making it possible to process the workpiece. When the spindle head 24 further descends from the origin, the grip arm 82 moves further away, and only the magazine cover 30 corresponding to the grip arm 82 is retracted to the second position. Descending is possible.

In this way, in this embodiment, since the magazine cover 30 is made of synthetic resin, it is not only possible to process it easily, but also to significantly reduce the weight of the tool magazine 66 itself.

In addition, in this embodiment, the magazine cover 30
are fixed to each grip arm 82 with screws, but the present invention is not limited to this, and in the case where the tool holder 48 is gripped in an openable/closable manner using a pair of claws, It may also be provided separately.

[Effects of the invention] As detailed above, in the present invention, a tool magazine cover is provided for each tool gripper supported by the tool magazine, and the tool is rotatably indexed on the axis of the spindle when machining a workpiece. Since only the tool magazine cover corresponding to the tool gripper that grips the tool is retracted toward the axis of rotation of the tool magazine, there is no need to provide a notch in the tool magazine cover for the spindle head to pass through, and the tool magazine can be easily inserted into the tool magazine. This has the effect of reliably preventing the intrusion of chips.

[Brief explanation of drawings]

FIG. 1 is an explanatory view showing the processing state of a workpiece in an embodiment embodying the present invention, and FIG. 2 is a view taken in the direction of arrow A in FIG. In the figure, 12 is a frame, 24 is a spindle head, and 3
0 is a tool magazine cover, 40 is a main shaft, 48 is a tool holder, 66 is a tool magazine, and 82 is a grip arm.

Claims (1)

[Claims for Utility Model Registration] 1. A spindle head 24 that rotatably supports a spindle 40 having a tool holding portion at one end is attached to a frame 12.
In contrast, in a machine tool that processes a workpiece by reciprocating the main spindle 40 in the axial direction, a plurality of tool grips are rotatably supported on the frame 12 and grip a tool holder 48 in a removable manner. a tool magazine 66 having a tool 82 on its outer periphery and set such that the axis of the tool holder 48 held by one rotatably indexed tool holding tool 82 is located on the axis of the main spindle 40; A first position provided for each tool gripper 82 on the outer periphery of the gripper 82 and surrounding the inside of the tool magazine 66;
6, and a second position retracted toward the rotation axis of the main shaft 40, and a tool magazine cover 30 swingably supported on the tool magazine 66. An automatic tool changer for a machine tool, characterized in that only the tool magazine cover 30 corresponding to the tool gripper 82 that grips the rotationally indexed tool holder 48 is swung to the second position. 2. Utility model registration claim 1, characterized in that the tool magazine covers 30 are each directly attached to the outer peripheral surface of the tool gripper 82.
An automatic tool changer for a machine tool as described in .