JPH034324B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a tool attachment/detachment device that is effective for use in a machining center having an automatic tool changer.

[Prior Art] Conventionally, the pull stud method that has been commonly used as this type of tool attachment/detachment device requires a mechanism to pull in the tool, resulting in a complicated structure, and the tool is held only at the tapered part. Since the tool is held in place, it has the disadvantage of low tool gripping rigidity. Furthermore, in this type of system, the main spindle of the machine tool has a relatively long structure in the axial direction, which causes core runout during machining at high speed rotation, resulting in a decrease in performance. Moreover, since the tool holding part is long and large, it takes a long time for the tool holding member to be completely exposed from the end of the spindle when changing tools, so the arm size of the automatic tool changer must be sufficiently long. There is a need. Therefore, the time required for automatic tool exchange is long and has become one of the causes of inefficiency.

In addition, in the past, for example,
As seen in the publication, for face plate type machine tools such as front boring machines, a so-called face plate type tool attaching/detaching device in which a tool or a tool holder is attached to the face plate has also been proposed. However, although this type of machine can demonstrate excellent functionality in relatively low-speed rotating machine tools such as front boring machines, it is equipped with a general automatic tool changer, the so-called ATC device,
When used in a machining center or the like having a spindle end structure, the following problems occur.

(1) Since the operating member for attaching and detaching the tool is integrally attached to the side of the tool mounting section, it receives a large unbalanced load during rotation, making machining at high speed rotation impossible.

(2) At the same time, the structure becomes more complex, making the device more expensive.

(3) The control device for changing tools also needs to be dedicated to the ATC device, separate from the control system of the machine itself, so the overall process becomes complicated and expensive.

[Object of the Invention] The object of the present invention is to improve the problems of the conventional device as described above, shorten the automatic tool change time, and increase the tool gripping rigidity to enable processing at high speed rotation. Increase efficiency and productivity,
Furthermore, it is an object of the present invention to provide a low-cost tool attachment/detachment device that can simplify the structure of the tool attachment part and the tool exchange control system.

[Summary of the invention] The gist of the present invention for achieving the above object is as follows:
A shank insertion hole, a key for transmitting rotational force protruding from the end face, a main shaft with a male tightening screw provided on the outer circumferential surface, and a shank part to be inserted into the shank insertion hole.
a tool holding member having a concave portion that engages with the rotational force transmission key and a pressure contact portion that presses against the end face of the main spindle; and a female screw thread that engages with a tightening male thread of the main spindle on the inner surface thereof; A tightening nut for clamping in the axial direction to press the pressure contact part against the end face of the main shaft, and a lock for fixing the tightening nut in the rotational direction with respect to the main shaft when attached to the fixing part and removing the tool. and rotating the main shaft at a low speed by a predetermined angle while the tightening nut is locked by the locking means,
The tool attachment/detachment device is characterized in that the tool holding member is configured to be attached to and detached from the main shaft.

[Embodiments of the Invention] The present invention will be described in detail based on illustrated embodiments.

FIG. 1 illustrates a state in which, for example, a boring bar is attached as a tool to the main shaft of a machining center. The end of the main shaft 1 is provided with a tapered shank insertion hole 2 for fitting a shank portion of a tool holding member, and a tightening male thread 3 for screwing a tightening nut described later. As shown in FIG. 2, two or an appropriate number of key grooves 4 are provided on the end surface of the main shaft 1 at equal intervals around the shank insertion hole 2. A screw hole 5 is provided at the bottom of each keyway 4, into which a mounting screw 6 is screwed through a rotational force transmission key 7, with the key 7 protruding downward from the tip end surface of the main shaft 1. It is attached within the keyway 4. The tool holding member 8 attached to the end of the main spindle 1 has a cylindrical portion with a tool T attached to its tip, followed by a V-shaped grip portion 9 that is gripped by the arm of the exchange manpilulator during automatic tool exchange.
It has a flange 10 with an even larger diameter, and a tapered shank portion 11 that is inserted into the shank insertion hole 2 is formed at the end of the flange 10, and a notch corresponding to the keyway 4 of the main shaft 1 is formed around the flange 10. A section 12 is provided. However, in the case of this embodiment, the load is mainly received by the flange 10, so the shank part 11 of the tool holding member is mainly used as a guide when engaging with the shank insertion hole 2; The length is approximately two-thirds that of conventional devices.

Further, as shown in FIGS. 3 and 4, a recess 13 is formed on the upper surface side of each notch 12 of the flange 10, that is, on the main shaft 1 side, so that when the tool holding member 8 is inserted into the shank insertion hole 2, The rotational force transmitting key 7 engages with these recesses 13 to fix the tool holding member 8 in the rotational direction. The tool holding member 8 is attached to and removed from the main shaft 1 by operating a tightening nut 14 provided around the main shaft 1. As shown in FIG. It has an annular shape, and has a female screw 15 on the upper side of the inner surface that engages with the male tightening screw 3 of the main shaft 1, and an inner peripheral surface 16 on the lower side having an inner diameter slightly larger than the outer diameter of the flange 10. The flange 1 of the tool holding member 8 extends from the inner circumferential surface 16 toward the center.
A convex portion 17 for pressing the tool 0 against the end of the main shaft 1 is provided to protrude in correspondence with the notch 12 of the tool holding member 8.

By screwing and mounting such a tightening nut 14 onto the main shaft 1, and inserting it with the notch 12 of the tool holding member 8 aligned with the position of the protrusion 17,
The shank portion 11 of the tool holding member 8 can be fitted into the shank insertion hole 2. Tightening nut 14
A tapered lock hole 18 is provided on the outer periphery of the lock hole 18, and a detection protrusion 19 is provided at a position slightly away from the lock hole 18 in the axial direction. The lock hole 18 is normally located on the main shaft 1 as shown in FIG.
It is arranged at a position separated from one keyway 4 by a predetermined angle α.

Further, as shown in FIG. 1, a locking means 21 is attached to a fixed part or frame 20 of the machine tool, and the tip of the locking pin 22 can be engaged with the locking hole 18. In the case of this embodiment, a fluid cylinder mechanism is used as the locking means 21, and the piston rod is connected to the locking pin 22.
The lock pin 22 is retracted by a built-in spring 23 when there is no fluid pressure. The solenoid valve 24 in FIG. 1 is a three-way valve for supplying or discharging fluid to the locking means 21. Locking means 21
There is a detection protrusion 19 of the tightening nut 14 near the
A detection switch 25 consisting of, for example, a proximity switch is provided to detect this when the bolt approaches the solenoid valve. 24
It is designed to be inputted to a drive device (not shown).

Next, a description will be given of the tool attachment/detachment operation during tool exchange in the above-described embodiment. First, the position of the rotational force transmitting key 7 of the spindle 1 and the lock hole 18 of the tightening nut 14 is in a state where the position is separated by an angle α from the axis when the tool is attached. remains unchanged.

(1) In this state, the main spindle 1 rotates and machining is applied,
When machining is completed, the main spindle 1 stops.

(2) Next, a tool change signal is sent from the NC device to the ATC device.

(3) The exchange arm (not shown) of the ATC device moves and grips the V-shaped grip portion 9 of the tool holding member 8 shown in FIG.

(4) Next, the main shaft 1 starts rotating at a low speed, and the detection protrusion 19 of the tightening nut 14 detects the detection switch 25.
When it approaches the main shaft 1, the rotation of the main shaft 1 is stopped by a signal from the detection switch 25, and the solenoid valve 24 is switched to close the lock pin 2 of the locking means 21.
2 is moved forward, the tip of the lock pin 22 is engaged with the lock hole 18, and the tightening nut 14 is fixed in the direction of rotation of the main shaft 1.

(5) Subsequently, the main shaft 1 is rotated by an angle α in the opposite direction, in the direction of arrow D in FIG. As a result, the positions of the notch 12 of the tool holding member 8 and the protrusion 17 of the tightening nut 14 are aligned as shown in FIG.

(6) Now, when the exchange arm of the ATC device is lowered, the tool holding member 8 is lowered by its own weight and taken out from the main shaft 1.

After removing the used tool holding member 8 by the above procedure, remove another new tool holding member 8.
Attach it to spindle 1. In this case, Figures 7 and 8
The main shaft 1 is inserted through the tightening nut 14 in the state shown in the figure.
After the main shaft 1 is inserted into the interior, if the main shaft 1 is rotated by an angle α in the direction opposite to the arrow D in FIG. 7, the convex portion 17 of the tightening nut 14 presses against the flange 10, and the installation is completed. At this time, the low speed rotational position of the spindle 1 and the rotation amount of the angle α of the spindle 1 until the detection switch 25 is turned on are determined using the orientation function of the machine tool, and the completion of clamping is determined using a timer, etc. Therefore, it can be implemented.

In this way, in the embodiment, the rotation of the main shaft 1 is used to perform the attachment/detachment of the tool, which makes the control easier than in the conventional one. It is preferable that the lock hole 18 provided in the tightening nut 14 be an elongated hole or a long groove elongated in the axial direction. The reason for this is that the tightening nut 14 moves in the axial direction as the tool holding member 8 is attached and detached, so a margin for this movement is required.

9 and 10 show another embodiment, in which the tightening nut 14 is provided with an inwardly directed convex portion 17, and the flange 17 of the tool holding member 8 is
The notch 12 is provided in the tool holding member 8, but these are reversed, and the flange 2 having the notch 26 is provided on the tightening nut 14, and the flange 10 of the tool holding member 8 is removed to fit into the notch 26. A convex portion 28 is provided. A recess 29 into which the rotational force transmitting key 7 is fitted is provided on the projection 28.

Furthermore, in the above embodiment, the male tightening screw 3 was provided integrally with the main shaft 1;
A separate structure as illustrated in FIGS. 1 and 12 may also be used. That is, a sleeve member 30 having a male thread 3a on the outer periphery is fitted to the end of the main shaft 1a, and the keyway 4a of the main shaft 1a and the keyway 4 provided in the sleeve member 30 are connected to each other.
The sleeve member 30 and the rotational force transmission key 7a can be attached to the main shaft 1a at the same time by fitting the rotational force transmission key 7a into the key groove formed by matching the rotational force transmission key 7a and tightening with the mounting screw 6a. Can be done. In this case as well, since the rotational force transmission key 7a is attached to protrude from the end of the main shaft 1a, it can perform the torque transmission function as in the case of FIG. 1, but the sleeve member 30 is replaceable. Therefore, there is an advantage that the life of the main shaft 1 can be extended regardless of the life of the male thread 3a, and there is no need to machine a male thread on the main shaft 1.

In the embodiment shown in FIG. 1, the locking means 21 of the pneumatic cylinder mechanism is used as the positioning and fixing means, but other means may be used instead. Furthermore, in the above embodiment, the orientation function of the machine tool is used to detect the position of the spindle 1 when it is rotated in a predetermined direction using the detection switch 25 and drive the locking means 21. Although the detection switch 25 is not used, it is also possible to use only the orientation function of the machine tool.
In other words, the orientation function on the machine tool side can stop the spindle 1 at a predetermined angular position, so when the spindle 1 has rotated a predetermined angle, the drive signal of the locking means can be used to control the NC, etc. of the machine tool. The same thing can be done by outputting from the device.

Furthermore, it is preferable that the tool holding system be the so-called quick change system as in the embodiment, and the screws for the tool tightening part may be triangular screws, trapezoidal screws, ball screws, roller screws, etc. In consideration of wear during tightening, a trapezoidal screw shape is preferable.

[Effects of the Invention] As explained above, the tool attachment/detachment device according to the present invention has the following advantages.

(1) Compared to the conventional pull stud method,
Since the tool holding member can be held close to the tool tip, tool gripping rigidity is increased.

(2) Since the rotation function of the spindle is used for attaching and detaching tools, the structure of the tool mounting part is simplified.

(3) As a result, the weight of the tool holder can be made lighter than before, making it possible to perform machining at high speed rotation and greatly improve productivity.

(4) Also, since the tool holding part can be shortened in the axial direction, the travel distance of the automatic tool change arm, that is, the distance in the extraction direction when attaching and detaching tools, is shortened.
Tool exchange time can be shortened.

(5) In terms of control, since the orientation function of the main spindle of the machine tool is utilized for tool exchange, the control device for tool exchange can be simplified, making the entire system cheaper and easier to operate.

[Brief explanation of the drawing]

The drawings show an embodiment of the tool attaching/detaching device according to the present invention, and FIG. 1 is a sectional view showing the first embodiment, FIG. 2 is a perspective view of each member disassembled, and FIG. A sectional view of the main parts along the line C-C in FIG.
FIG. 4 is a perspective view of a part of the flange of the tool holding member, FIG. 5 is a sectional view taken along line A-A in FIG. 1,
Similarly, Fig. 6 is a sectional view taken along the line B-B, and Fig. 7
8 are sectional views for explaining the operation of the main shaft and its positioning and fixing means, FIGS. 9 and 10 are perspective views of other embodiments, and FIG. 11 is a main shaft end of still another embodiment. FIG. 12 is a cross-sectional view of the parts shown in FIG. 11 assembled together. 1, 1a is the main shaft, 22 is the shank insertion hole, 3,
3a is a male screw for tightening, 4 is a keyway, 7, 7a are keys for transmitting rotational force, 8 is a tool holding member, 9 is a V-shaped grip part, 10, 27 are flanges, 11 is a shank part, 12, 26 are Notches, 13 and 29 are recesses,
14 is a tightening nut, 15 is a female thread, 16 is an inner circumferential surface, 17 and 28 are convex parts, 18 is a lock hole, 19 is a detection projection, 20 is a frame, 21 is a locking means, 22 is a lock pin, and 24 is a 25 is a detection switch, and 30 is a sleeve member.

Claims (1)

[Scope of Claims] 1. A main shaft having a shank insertion hole, a key for transmitting rotational force protruding from the end face, and a male screw for tightening provided on the outer circumferential surface, and a shank portion inserted into the shank insertion hole, for transmitting the rotational force. A tool holding member having a concave portion that engages with a key and a pressure contact portion that presses against the end face of the main spindle, and a female thread that engages with a tightening male thread of the main spindle on the inner surface, and clamps the tool holding member in the axial direction. a tightening nut for pressing the pressure contact portion against the end face of the main shaft; and a locking means attached to the fixing portion to fix the tightening nut in the rotational direction with respect to the main shaft when the tool is attached or removed; A tool attaching/detaching device characterized in that the tool holding member is attached to and detached from the spindle by rotating the spindle at a low speed by a predetermined angle while the tightening nut is locked by the locking means. . 2. The tool attachment/detachment device according to claim 1, wherein the tool holding member can pass through the tightening nut only when the main shaft tightening nut is at a predetermined rotational position. 3. The tool attachment/detachment device according to claim 1, wherein said locking means comprises a locking hole provided on the outer peripheral surface of said tightening nut, and a locking pin engaging with said locking hole. 4. The tool attachment/detachment device according to claim 3, wherein the lock pin is driven by a fluid cylinder mechanism. 5. The tool attachment/detachment device according to claim 1, wherein the position of the tightening nut in its rotational direction is detected by a detection means. 6. The tool attachment/detachment device according to claim 1, wherein the male thread for tightening the main shaft is provided on the outer peripheral surface of a sleeve member attached to the end of the main shaft.