Tool Changing Method For Machine Tool and Tool Changing Apparatus Thereof

Abstract

The present invention reveals a tool changing method for machine tool and the apparatus thereof. The machine tool has a tool releasement detector disposed beside the spindle or the tool releasement apparatus. When the tool releasement apparatus hits the spindle to loose the clamp for tool releasement, the tool releasement detector generates a releasement signal. When the tool releasement apparatus resets and leaves the spindle, the tool releasement detector produces no signal. The tool changing apparatus is activated according the appearance of the releasement signal for changing the tool, activated according the disappearing of the releasement signal for declining from the spindle. Therefore, the tool changing apparatus can be operated timely and speedily, improving tool changing efficiency.

Claims

1. A tool changing method for machine tool, adapted for changing tools on a machine tool, the machine tool including a spindle, an unclamp apparatus, a tool releasement detector, and a tool changing apparatus, the unclamp apparatus having a releasement position and a clamped position; when the tool releasement apparatus is at the releasement position, the spindle releasing a tool, one of the tool releasement apparatus and the spindle is detected by the releasement detector so that the releasement detector sends a releasement signal; when the tool releasement apparatus is at the clamped position, the spindle clamping the tool, the releasement signal disappearing; the tool changing method for machine tool including moving the tool releasement apparatus to the releasement position, taking tools from the spindle and a magazine by the tool changing apparatus, exchanging positions of the tools, inserting one of the tool into the spindle, and moving the tool releasement apparatus to the clamped position, characterized by: activating the tool changing apparatus according to the disappearance of the releasement signal after inserting the tool into the spindle and moving the tool releasement apparatus to the clamped position.

2. The tool changing method for machine tool of claim 1, wherein the tool changing apparatus is activated according to the appearance of the releasement signal after the tool releasement apparatus moves to the releasement position.

3. The tool changing method for machine tool of claim 1, wherein the tool changing apparatus doesn't clamp the tool inserted in the spindle at a moment that the tool releasement apparatus is going to move toward the releasement position.

4. The tool changing method for machine tool of claim 2, wherein the tool changing apparatus doesn't clamp the tool inserted in the spindle at a moment that the tool releasement apparatus is going to move toward the releasement position.

5. A tool changing method for machine tool, adapted for changing tools on a machine tool, the machine tool including a spindle, an unclamp apparatus, a tool releasement detector, and a tool changing apparatus, the unclamp apparatus having a releasement position and a clamped position; when the tool releasement apparatus is at the releasement position, the spindle being able to release a tool; when the tool releasement apparatus is at the clamped position, the spindle being able to grasp the tool; the tool changing method for machine tool including moving the tool releasement apparatus to the releasement position, taking tools from the spindle and a magazine by the tool changing apparatus, exchanging positions of the tools, inserting one of the tool into the spindle, and moving the tool releasement apparatus to the clamped position, characterized by: the tool changing apparatus not clamping the tool inserted in the spindle at a moment that the tool releasement apparatus is going to move toward the releasement position.

6. The tool changing method for machine tool of claim 5, wherein the tool changing apparatus is activated according to the appearance of the releasement signal after the tool releasement apparatus moves to the releasement position.

7. A tool changing apparatus, used in the tool changing method for machine tool of claim 1, including: a power source; a transmission mechanism, having an output axle, the transmission mechanism being driven by the power source to make the output axle to rotate and to move following a specific operation order repeatedly; a tool changing arm, disposed on the output axle and being rotatable and movable following the output axle; an encoder, disposed on one of the power source and the transmission mechanism to detect a current position of the output axle in the specific operation order.

8. The tool changing apparatus of claim 7, wherein the power source is a lower inertia motor.

9. The tool changing apparatus of claim 7, wherein the transmission mechanism is a cam-worm assembly.

10. A tool changing apparatus, used in the tool changing method for machine tool of claim 5, including: a power source; a transmission mechanism, having an output axle, the transmission mechanism being driven by the power source to make the output axle to rotate and to move following a specific operation order repeatedly; a tool changing arm, disposed on the output axle and being rotatable and movable following the output axle; an encoder, disposed on one of the power source and the transmission mechanism to detect a current position of the output axle in the specific operation order.

11. The tool changing apparatus of claim 7, wherein the power source is a lower inertia motor.

12. The tool changing apparatus of claim 7, wherein the transmission mechanism is a cam-worm assembly.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present disclosure can be more fully understood by reading the following detailed description of the embodiment, with reference made to the accompanying drawings as follows:

[0018] FIG. 1 is an illustration of timing diagram of a prior art when

[0019] FIG. 2 is an illustration showing a machine tool suitable for a tool changing method for machine tool of the present invention;

[0020] FIG. 3 is a flow chart of a tool changing method for machine tool of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The present invention provides a tool changing method for machine tool, adapted for changing tools on a machine tool. Pleaser refer to FIG. 2, the machine tool includes a spindle 1, a tool releasement apparatus 2, a releasement detector 3, a clamped detector 4, a tool changing apparatus 5, and a magazine 6.

[0022] The spindle 1 is an output spindle of the machine tool, such as the spindle disclosed in patent TW 1418424. The spindle 1 has a pulling rod 11. The spindle 1 has a spring or other devices for restoration to push the pulling rod 11 upward. The spindle 1 is adapted for clamping a tool 7 for processing. When the pulling rod 11 is hit or pushed to move downward, the spindle 1 releases the tool 7.

[0023] The tool releasement apparatus 2 is arranged above the spindle 1. The tool releasement apparatus 2 has a pushing rod 21 which is movable up and down. The position of the pushing rod 21 corresponds to the pulling rod 11 of the spindle 1. When the pushing rod 21 moves downward a releasement position, the pushing rod 21 hits or pushes the pulling rod 11 to move downward to make the spindle 1 to release the tool 7. When the pushing rod 21 moves upward back to the clamped position, the pushing rod 21 releases and leaves the pulling rod 11 to make the spindle 1 to clamp the tool 7 again. Thereby, the pushing rod 21 can control the spindle 1 to clamp or to release the tool 7. Specifically, the too releasement apparatus 2 can be the structures disclosed in patents TW M458268, TW 465421, and TW 375213. The tool releasement apparatus 2 can have a sensing member 22 disposed on the pushing rod 21 to move up and down following the pushing rod 21. In other possible embodiments, the sensing member can be disposed on the pulling rod, the spindle, or other positions in the tool releasement apparatus to move up and down to achieve the same goal.

[0024] The releasement detector 3 and the clamped detector 4 are disposed on the spindle 1 or the tool releasement apparatus 2. The releasement detector 3 and the clamped detector 4 are located beside the sensing member 22 respectively and face the sensing member 22. When the pushing rod 21 moves downward to the releasement position, the sensing member 22 moves downward toward the releasement detector 3 to be located in front of the releasement detector 3. The releasement detector 3 detects the sensing member 22 to send a releasement signal. Thereby, the tool is completely released by the spindle. When the pushing rod 21 moves upward to the clamped position, the sensing member 22 moves upward to leave the releasement detector 3 and to be located in front of the clamped detector 4. The releasement detector 3 stops sending a releasement signal, and the clamped detector 4 detects the sensing member 22 to send a clamped signal. Thereby, the spindle is completely restored to clamp the tool.

[0025] The tool changing apparatus 5 is adapted for taking tools from the spindle 1 and the magazine 6, rotating to exchange the positions of the two tools, and inserting the tools into the spindle and the magazine. Specifically, the too changing apparatus 5 includes a power source 51, a transmission mechanism 52, a tool changing arm 53, and an encoder 54. The power source 51 can be a motor, preferably a low inertia motor to prevent the deviation caused by the motor inertia when the motor is activated or shut down. The transmission mechanism 52 can be a cam-worm assembly to connect to the power source directly or via the reducer. The transmission mechanism 52 has an output axle 521, and the tool changing arm 53 is disposed on the output axle 521. The transmission mechanism 52 is driven by the power source so that the output axle 521 triggers the tool changing arm 53 to rotate or move for exchanging tools 7 between the spindle 1 and the magazine 6. The transmission mechanism 52 can has a structure such as those disclosed in patents TW 1317312, TW 338014, and TW M458268. The encoder 54 is connected to the output axle 521 of the transmission mechanism 52 or other members in the transmission mechanism 52 so as to directly or indirectly detect the current position of the output axle 521 and to send position signal according to the position of the output axle 521. Because the power source 51 is connected to the transmission mechanism 52, the angular position of the power source 51 is related to the position of the output axle 521. Thus, in other possible embodiments, the encoder can be disposed on the power source to indirectly detect the current position of the output axle to send the position signal.

[0026] The magazine 6 can be a drum type magazine to provide tools to the tool changing apparatus 5 for changing tools. For example, the magazines disclosed in patents TW 445919, TW 1310715, and TW M565626 are suitable in the present invention. However, other types of magazine can be used if the magazine has appropriate size and position.

[0027] The tool changing method for machine tool of the present invention can be applied in the machine tool mentioned above. Please refer to FIG. 2 and FIG. 3, the tool changing method for machine tool includes standby step of tool changing arm, step of tool releasement, step of tool gripping, step of tool changing, step of tool insertion, and restoration step of tool changing arm. In the standby step of tool changing arm 81, activate the tool changing apparatus and rotate the tool changing arm 53 to make the two ends thereof located below the magazine 6 and the spindle 1 respectively. And then, shut down the tool changing apparatus and activate the braking apparatus. The tool changing arm 53 below the magazine 6 and the spindle 1 waits for other signals. In the step of tool releasement 82, activate the tool releasement apparatus 2 to move the pushing rod 21 downward to hit or push the pulling rod 11 of the spindle so that the spindle 1 releases the tool 7. After the pushing rod 21 has been moved, the releasement detector 3 detects the sensing member 22 to send the releasement signal. Specifically, the tool releasement apparatus 2 can be activated in advance before the tool changing arm 53 reaches the position below the spindle 1 and before the braking apparatus of the tool changing apparatus 5 is activated so that the tool is released quickly. In the step of tool gripping 83, shut down the braking apparatus and activate the tool changing apparatus 5 when the releasement signal appears, and drive the tool changing apparatus 5 to clamp the tool 7 released from the spindle 1 and the tool for replacement in the magazine 6 and to move the tools downward to leave the spindle 1 and the magazine 6. Specifically, the tool changing apparatus 5 is activated by activating the power source 51. In other words, activate the motor. In the step of tool changing 84, the tool changing apparatus drives the tools to rotate to exchange the positions of the tools from the magazine 6 and from the spindle 1. In the step of tool insertion 85, the tool changing apparatus 5 moves the tools 7 to insert them into the spindle 1 and the magazine 6. And then, shut the tool changing apparatus down and activate the braking apparatus. The tool releasement apparatus 2 drives the pushing rod 21 to move upward to leave the pulling rod 11 so that the pulling rod 11 is restored. Thus, the spindle 1 clamps the tool 7. After the pushing rod 21 is moved upward, the sensing member 22 leaves the releasement detector 3 to make the releasement signal disappear. Thereafter, the clamped detector 4 detects the sensing member 22 to send the clamped signal. In the restoration step of the too changing arm 86, shut down the braking apparatus and activate the tool changing apparatus 5 when the releasement signal disappears. The tool changing arm 53 is driven to move back to the standby position. The process is then ended.

[0028] In the process mentioned above, the appearance of the releasement signal means that the tool releasement apparatus has moved to the releasement position, that the pulling rod has moved downward, and that the spindle has released the tool. In the step of tool gripping, the braking apparatus is shut down and the tool changing apparatus is activated when the releasement signal appears. That is, the tool changing apparatus grips the tool to move at the moment that the tool is released to save time. In addition, the members connect correctly during the tool's transferring, so the efficiency of tool changing is improved. Also, the tool is prevented from hitting the machine or falling down.

[0029] In the process mentioned above, the disappearance of the releasement signal means that the tool releasement apparatus has leaved the releasement position, and the pulling rod is pushed by the restoration device in the spindle to move upward so as to clamp the tool. In the step of tool changing arm restoration, the braking apparatus is shut down and the tool changing device is activated at the moment that the releasement signal disappears, and the tool changing arm is moved to restore at the moment that the spindle clamps the tool. Thus, the time that moving the tool releasement apparatus to the releasement position and the time that confirming the spindle clamping the tool can be saved, so the efficiency is improved. The tool is held by the spindle due to the upward restoration at the moment that the tool enters the spindle, so the tool is prevented from falling down even if the speed of tool changing is raised.

[0030] Besides, the tool releasement apparatus can be activated in advance before the tool changing arm reaches the position below the spindle in 0.1-0.4 seconds. That is, at the moment that the tool releasement apparatus starts to move toward the releasement position, the tool is not clamped by the tool changing apparatus yet. The tool is released almost at the moment that the tool changing arm reaches the spindle. Thus, time is saved, and the time to brake and to shut the power source down is shortened. The inertia hysteresis caused by the shutting down and activating of the motor can be reduced so that the efficiency is improved.

[0031] It is noted that the direction “upward” and “downward” are used to define the relative positions of the members in the present embodiment. Thus, the structure having reversed or modified arrangement is also a possible embodiment of the present invention.

[0032] In conclusion, the tool changing apparatus can be activated early to shorten the time of tool changing to 1.26-1.34 seconds. Compared to that the time of tool changing in prior arts is about 2-2.5 seconds, it is advantageous that the time of tool changing of the present invention can save 33%-49% of time.

[0033] It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present disclosure without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the present disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims.