JPH0337844Y2 - - Google Patents

Description

[Detailed description of the invention] "Industrial application field" This invention is a spindle positioning device that stops the spindle in a fixed position for automatic tool exchange in machine tools such as tapping centers using computer numerical control (CNC). Regarding.

``Prior art'' In conventional machine tools of this type, the main spindle was stopped in a fixed position by numerically controlling a fixed position stopping member such as a notch fitted into the main spindle.
There was a problem in that the mechanism and system for stopping the spindle in a fixed position were complicated.

For this reason, in the conventional machine tool disclosed in Japanese Patent Application Laid-Open No. 60-155338, a key is provided on the main shaft 26 protruding from the lower end surface of the main shaft to prevent rotation between the main shaft 26 and the tool 20. At the same time, tool 2
0 is formed with a keyway into which the key fits. The tool gripper 96 is provided with a key that fits into the key groove for positioning when holding the tool 20.

When replacing the tool, after stopping the spindle 26 at a fixed position, when the tool gripper 96 grips the tool 20, the key on the tool gripper 96 side fits tightly into the keyway on the tool 20 side. At the same time, drawbar 7
6 is pushed down by the second crank 30, the tool 20 is released from the tool holding member 66, and then the tool 20 is replaced.

Here, if the stopping precision of the main shaft 26 is poor,
When the tool 20 is gripped by the tool gripper 96,
There was a problem in that the key on the gripping tool 96 side did not fit into the key groove on the tool 20 side, resulting in damage to the key or the key groove.

``Problems that the invention attempts to solve'' This invention was made to solve the above problems, and uses a simple mechanism to accurately stop the spindle in a fixed position. It is an object of the present invention to provide a spindle positioning device for a machine tool that does not damage a tool gripper side key.

"Means for Solving the Problems" According to the present invention, a main shaft having a tool mounting portion at one end is movable in the axial direction and non-rotatable in the circumferential direction. A drawbar having a tool release pin perpendicular to the axis of the main spindle and operatively connected to a clamping member provided in the tool mounting portion and a spindle head rotatably supporting the main spindle are rotatable. A substantially V-shaped groove is provided at the free end that can be engaged with the tool release pin, and when the free end is rotated toward the tool release pin, the tool holding member is supported by the tool holding member. A tool release lever is used to release the tool, and the tool is fixed to the frame.
There is provided a spindle positioning device for a machine tool, comprising: an actuating member for rotating the tool release lever so as to release the clamping of the tool when the spindle is moved back. .

"Operation" According to the above configuration, when the tool release lever 36 is operated when the main spindle 14 is moved back through the automatic exchange area beyond the machining operation area, the release end 78 of the tool release lever 36 is activated. When the tool presses the tool release pin 72, at the same time, the approximately V-shaped groove 9 at the tip thereof presses the tool release pin 72.
The tool release pin 72 is fitted into the tool 6, and the main shaft 14 is accurately positioned and stopped at a fixed position.

"Example" Next, an example of the present invention will be described with reference to the drawings.

As shown in FIGS. 1 and 2, this machine tool 10 includes a spindle head 18 that rotatably supports a spindle 14 having a tool mounting portion 12 at one end.
The frame 16 is supported so as to be movable up and down in a reciprocating manner as will be described later, so that required processing can be performed on the workpiece. The tool mounting portion 12 is provided with a tool holding member 22 that holds the tool 20 in a detachable manner. A tool magazine 28 in which a plurality of tool grippers 26 are arranged radially is rotatably supported on a tool support 24, and the tool support 24 is attached to a frame independently of the spindle head 18, as will be described later. 1
6, it is supported so that it can be raised and lowered freely. Additionally, a tool support 24 is provided between the spindle head 18 and the frame 16.
A cam that engages with a part of the main shaft 14 to move the tool support stand 24 up and down with respect to the frame 16, and urges the tool gripper 26 to grip and release the tool 20 provided at the tip of the main shaft 14. A crank lever 36 and a cam 34 are provided, which act as a tool release lever for operating the tool holding member 22 and releasing the tool 20 from the main shaft 14.

An AC servo motor 40 with a built-in rotary encoder 38 is disposed in fixed relation to the frame 16 , and a ball screw 44 is connected to the tip of a vertical rotating shaft 41 of the servo motor 40 via a coupling 43 . It is fixed. Further, a nut 46 is horizontally fixed to the rear protrusion of the spindle head 18 via a bolt 48.
A ball screw 44 is screwed into this nut 46.

A hollow cylindrical main shaft 14 is rotatably supported at the lower part of the main shaft head 18 via a bearing 50.
It is connected via a coupling 58 to an output shaft 56 of a motor 52 and a speed reducer 54, which are arranged upright on the top of the motor 8.

The tool mounting section 12 is for detachably mounting a tool 20 having an arbor 62 made of a tapered shank. In addition, the arbor 62 of the tool 20
A pull stud 64 is provided at the rear end, and the tool 20 is fixed to the main shaft 14 by holding the pull stud 64 with a tool holding member 22 slidably inserted into the hollow main shaft 14. It's summery. The tool clamping member 22 is composed of a known collet configured such that a pull stud 64 is surrounded by a plurality of balls 60, and as the tool clamping member 22 slides in the axial direction within the main shaft 14, the pull stud 64 is It has a structure that allows it to be clamped and released.

A plug 66 is inserted into the hollow portion of the main shaft 14 at a predetermined height position so as to be slidable up and down.
The drawbar 6 is inserted into the vertical hole drilled in the plug 66.
The upper end of 8 is screwed and fixed. The drawbar 68 hangs down along the central axis of the main shaft 14, and the lower end of the drawbar 68 is connected to the top of the tool holding member 22. As shown in FIG. 1, the location of the plug 66 on the main shaft 14 is
Oval slot 7 extending in the axial direction of the main shaft 14
0 and 70 are opposed to each other, and both ends of a tool release pin 72 inserted perpendicularly into the plug 66 pass through a pair of oval slots 70 and 70 to the main shaft 14.
It extends outward. Note that when the tool 20 is attached to the tool attachment portion 12, there is a gap between the step formed at the upper part of the tool holding member 22 below the hollow part of the main shaft 14 and the washer 74 provided at the lower end of the plug 66. A group of disc springs 76 are elastically compressed and inserted into the disc springs 76, and a draw bar 68 extends through the center of the disc springs 76. The elasticity of the disk spring 76 always presses the plug 66 upward and holds it in place, and the tool holding member 22
is pulled up elastically to ensure that the pull stud 64 is clamped.

Above the tool release pin 72 extending outward from the main shaft 14, a fork portion 78 formed in a bifurcated shape at the tip of the crank lever 36, which forms the tool release lever, faces closely without contact. ,
The vertical rear end 80 of the crank lever 36 is a leaf spring 81
is biased clockwise.

A horizontal support plate 82 is attached to the upper side surface of the frame 16, and a round bar-shaped guide rail 84 is slidably inserted into the horizontal support plate 82. Further, a horizontal support plate 86 extends from below the frame 16, and the guide rail 84 is slidably inserted through the horizontal support plate 86. The upper and lower ends of the guide rail 84 are connected to the tool support base 2
They are fixed to a support plate 90 provided on a top plate 88 and a support plate 92 provided on the bottom of the 4, respectively. Therefore, the tool support stand 24 can be moved up and down with respect to the frame 16 by sliding the guide rail 84 with respect to the horizontal support plates 82 and 86.

Crank lever 36 serving as a tool release lever
is rotatably attached to the spindle head 18 via a pin 94, while a cam 34 serving as an actuating member is attached to the side surface of the rotary encoder 38 in a fixed relationship with the frame 16. The cam 34 has a slope 35 at its front end. As shown in Fig. 1, the crank lever 3
The fork portion 78 of No. 6 is provided with a substantially V-shaped V groove portion 96 that expands downward. Note that a rotating wheel 98 is attached to the vertical rear end 80 of the crank lever 36.

(Operation) In the above configuration, after the required machining is completed, the motor 52 is deenergized, the main shaft 14 is approximately positioned, and then stopped. Servo motor 40, ball screw 44
When the spindle head 18 is moved upward in the automatic exchange area by the nut 46, the slope 35 of the cam 34
The vertical rear end 80 of the crank lever 36 is connected to the rotating wheel 9.
8, the crank lever 36 is rotated counterclockwise about the pin 94 and presses the tool release pin 72 downward by the fork portion 78 at its release end. For this reason, the tool release pin 72 is guided by the oval slot 70 and moved downward in the axial direction of the main shaft 14, and the draw bar 68 descends in the axial direction to lower the tool holding member 22 and release the pull stud by the ball 60. 64 is released, and thus the tool 20 is released from the tool mounting portion 12 and is ready to be extracted.
At the same time, when the fork portion 78 presses the tool release pin 72 downward, as the fork portion 78 rotates downward, the tool release pin 72 moves into the V-groove portion 9.
The main shaft 14 is positioned in a fixed position through the oblong slot 70 in order to be guided by the V-shaped slope 6 and engage the top of the V-groove 96 thereof. Furthermore, due to the engagement between the tool release pin 72 and the V-groove portion 96, the main spindle 14 is restrained by the main spindle head 18 and is always stopped at its regular position with high accuracy.

Further, in this machine tool 10, the motor 52 is
When configured with an AC servo motor, when connecting the output shaft 56 of the motor 52 and reducer 54 to the main shaft 14 via the coupling ring 58 during assembly, the tool release pin 72 is inserted into the V-groove portion 96 of the fork portion 78. By connecting while engaged with
The predetermined index position where the main shaft 14 grips the tool 20 and the origin of the motor 52 can be easily positioned.

"Effects" As described above, since the main spindle positioning device of the present invention has the above configuration, the main spindle is always held at the same time as the tool is released by engaging the tool release pin 72 and the substantially V-shaped groove 96. It has excellent effects such as being able to be positioned at a fixed position and stopped with high precision, without damaging the tool side keyway and the tool gripper side key, and having a simple structure.

[Brief explanation of drawings]

1 and 2 show a spindle positioning device according to an embodiment of the present invention, and FIG. 1 is a perspective view of the main parts thereof;
FIG. 2 is a sectional view showing the overall configuration. 12...Tool mounting part, 14...Main shaft, 16...
Frame, 18... Spindle head, 20... Tool,
22... Tool holding member, 34... Cam forming an operating member, 36... Crank lever forming a tool release lever, 40, 44, 46... AC servo motor, ball screw and nut forming a reciprocating drive device,
68... Drawbar, 72... Tool release pin,
78...Fork portion forming an open end, 96...V groove portion.

Claims (1)

[Claims for Utility Model Registration] A reciprocating drive device for reciprocating a spindle head rotatably supporting a spindle having a tool mounting portion at one end in the axial direction of the spindle with respect to a frame; A machine tool that is provided with a tool holding member that always holds a tool mounted in the tool mounting part, which is movable in the axial direction within the main shaft and cannot rotate in the circumferential direction. established in
a drawbar having a tool release pin perpendicular to the axis of the spindle and connected to the tool holding member; and a drawbar rotatably supported by the spindle head and capable of engaging with the tool release pin at its release end. a tool release lever provided with a substantially V-shaped groove, the release end of which is rotated toward the tool release pin to release the tool from being held by the tool holding member; A main spindle positioning device for a machine tool, comprising: an actuating member for rotating the tool release lever so as to release the grip of the tool when the main spindle is fixed and the main spindle is moved back.