JPH10138094A - Tool breakage detection method and device in machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve work efficiency by performing tool breakage detection during processing work. SOLUTION: As a tool T installed on a pot 6 in a tool magazine 2 gets to a stand-by position P, a tool length measuring device 31 provided outside a processing range Z moves a contact sensor 32 forward by a cylinder 33 to get in contact with a tip of the tool T at the stand-by position P to measure length of the tool T. After processing with the length-measured tool T is completed, and as the tool T is installed on the tool pot 6 at the stand-by position P by a tool changer 3, the tool length measuring device 31 is actuated again to measure the length of the tool T at the stand-by position. Determination of breakage of a used tool is performed by comparison with a normal tool length before use. Since the tool length measuring device 31 is provided outside the work range Z for a work W, measuring of tool length can be perfored without disconnecting processing to the work W, thereby processing work efficiency can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for detecting a broken tool in a machine tool.

[0002]

2. Description of the Related Art In a machine tool, such as a machining center, in which a plurality of tools are automatically changed by a tool changer and the operation is continued, it is indispensable to automatically detect whether or not a used tool is broken.

For this reason, conventionally, for example, FIG.
0, the table 5 on which the workpiece W is mounted
1, the tool T mounted on the main shaft 1 is moved in the axial direction by the main shaft 1, and the length of the tool T is determined from the moving distance until the tip of the tool T touches the contact sensor 52. The presence or absence of breakage is detected by measuring and comparing the length with the length of a normal tool that has not been broken.

[0004]

However, in the above-described conventional method for detecting a tool breakage, machining is interrupted during a machining cycle to detect a breakage, and machining operations such as cutting cannot be performed during that time. There is dissatisfaction that efficiency falls.

An object of the present invention is to provide a method and an apparatus for detecting a tool breakage in a machine tool capable of detecting a breakage in parallel with a machining operation and improving the working efficiency.

[0006]

In order to achieve the above object, a tool breakage detecting method for a machine tool according to the present invention comprises a spindle on which a tool is mounted, a tool magazine for accommodating the tool, and a tool magazine. A tool accommodated in the tool spindle, and a tool changer for accommodating the tool attached to the spindle in the tool magazine, the length of the tool accommodated in the tool magazine is attached to the spindle. The broken length of the tool is detected by measuring with a tool length measuring device provided outside the work area of the workpiece by the tool.

It is preferable that the tool length is measured by the tool length measuring device at a standby position of a tool magazine where the tool is taken out by the tool changer or at a standby position of the tool magazine where the tool is accommodated by the tool changer.

A tool breakage detecting device for a machine tool according to the present invention includes a spindle on which a tool is mounted, a tool magazine for accommodating the tool, a tool for accommodating the tool accommodated in the tool magazine, and a spindle. A tool changer that measures the length of the tool stored in the tool magazine in a machine tool provided with a tool changer that stores the tool mounted in the tool magazine in the tool magazine. The structure was provided outside the processing area.

It is preferable that the tool length measuring device is provided at a standby position of a tool magazine where the tool is taken out by the tool changer, or at a standby position of the tool magazine where the tool is stored by the tool changer.

[0010] The tool length measuring device may be configured to include a contact sensor that outputs a contact signal when the tool comes into contact with the tool, and moving means for moving the contact sensor forward and backward in the longitudinal direction of the tool. Further, it is desirable that the tool changer has a configuration including a pair of arms for gripping the tool with the gripper.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on embodiments with reference to the drawings. FIGS. 1 to 9 show an embodiment of a tool breakage detecting device in a machine tool according to the present invention. A machine tool A includes a spindle 1 on which a tool T is mounted.
A tool magazine 2 for accommodating a tool T, and a tool T accommodated in the tool magazine 2 mounted on the spindle 1;
And a tool changer 3 for accommodating the tool T mounted on the tool magazine 2 in the tool magazine 2.

The main shaft 1 has an X-axis direction (vertical direction in FIG. 1, and a horizontal direction in FIG. 5) and a Y-axis direction (a direction perpendicular to the plane of FIG.
The table 51 can move in the Z-axis direction (the horizontal direction in FIG. 1 and the direction perpendicular to the plane of FIG. 5).

The tool magazine 2 includes, for example, an endless chain 7 (FIG. 6) having a plurality of links provided with a tool pot 6 (FIGS. 1 and 2) for a tool T, and pulleys 8, 9, and 1.
The tool T mounted on the tool pot 6 is wound together with the tool pot 6 along the X-axis direction (the direction perpendicular to the plane of FIG. 6) as shown by the solid line in FIG. The pulley 8 can be turned 90 degrees horizontally so that its axial direction can be turned to the Z-axis direction as shown by the two-dot chain line in FIG.

As shown in FIGS. 7 to 9, the tool changer 3 includes a support frame 13 to which a drive motor 12 is fixed.
The rotating shafts 16 and 17 and their driven bevel gears 18 and 19 are mounted on the bearings 14 and 15 of the output shaft 12a of the drive motor 12, respectively.
The rotating arms 24 and 25 are provided with grippers 22 and 23 which grip and hold the tool T at their free ends, and are attached to the rotating shafts 16 and 17.

The swing arms 24, 25 are provided with grippers 22,
23, and each rotation axis 1
6 and 17 are attached to each other with a phase shift of 90 degrees, and the driving motor 12 does not interfere with each other including the grippers 22, 23 and the tools T, T gripped by the grippers 22, 23, respectively. And at the same time, turns 90 degrees in a plane along the main axis 1 of the machine tool A to
The grippers 22 and 23 are arcuately moved in the first plane along the main shaft 1 from the mounting position (the state of the turning arm 24 in FIG. 7) to the retracted (preparation) position (the state of the turning arm 25 in FIG. 7). The other swing arms 25 and 24 are configured to swing the grippers 23 and 22 from the preparation (retreat) position to the mounting position in an arc shape in the second plane along the main shaft 1.

The mounting positions of the tool T with respect to the main shaft 1 of both grippers 22 and 23 are common (coincident) and exist on the center axis of the main shaft 1.

The turning arm 2 of the tool changer 3
The grippers 22 and 23 grip the tool T whose axial direction is oriented in the Z-axis direction by the rotation of the tool magazine 2 to the standby position P (FIGS. 1, 5 and the like) of the tool magazine 2. The used tool T can be removed from the tool pot 6 and the used tool T can be mounted on the tool pot 6 at the standby position P and stored in the tool magazine 2.

The tool changer 3 is provided between the main shaft 1 of the machine tool A and the tool magazine 2, as shown in FIGS. The support frame 13 of the tool changer 3
It is attached to the guide rod 27 (FIG. 6) and is movable in the X-axis direction and the Y-axis direction. The configuration of the machine tool A is well known (Japanese Patent Laid-Open No. 6-315841).

Reference numeral 31 denotes a tool length measuring device. The tool length measuring device 31 outputs a contact signal when it comes into contact with the tool T, and moves the contact sensor 32 forward and backward.
A cylinder (moving means) 33 having a built-in position detector such as a pulse encoder and the like. The tool T is used to measure the length of the tool T. The tool T is pulled out of the machining area Z of the workpiece W by the tool T mounted on the main spindle 1 and the tool pot 6 in which the tool T is stored. It is arranged at the standby position P.

The contact sensor 32 includes a mounting member 35 fixed to a guide rod 34 moved by the cylinder 31.
It is attached to the lower end.

The determination of the breakage of the tool T is performed by comparing the length of the tool T measured by the tool length measuring device 31 with the length of the normal tool T as in the conventional case.

Next, the operation of the tool breakage detecting device in the machine tool having the above configuration will be described. Swivel arm 24,
In order to grip the tool T by the 25 grippers 22 and 23, the tool changer 3 is moved from the position shown in FIG. 5 in the X-axis direction relative to the main spindle 1 or the tool magazine 2, and is lowered. The grippers 22 and 23 of the revolving arms 24 and 25 are mounted on the main shaft 1 at the position indicated by the two-dot chain line in FIG. 5 or directly above the target tool T of the tool pot 6 rotated to the standby position P. The operation is performed by lowering the tool T at the main spindle 1 or the tool T at the standby position P as it is.

When the tool T gripped by the grippers 22, 23 is detached from the grippers 22, 23, the tool T gripped by the grippers 22, 23 is mounted on the spindle 1 or the tool pot 6 at the standby position P. In the state where
This is performed by raising the tool changer 3 relatively to the main shaft 1 and the like.

When the tool T is exchanged between the spindle 1 and the tool magazine 2, for example, as described above, one tool T of the tool magazine 2 is gripped by the gripper 23 of the swiveling arm 25 which has been lowered. Then, the drive motor 12 is operated. Swivel arm 25 holding tool T by gripper 23
Is turned upward by the operation of the drive motor 12 to pull out the tool from the tool magazine 2 to be in a horizontal state, and the other turning arm 24 with the vacant gripper 22 turns downward simultaneously with the turning.

Next, after the tool changer 3 is once moved to the upper position, the tool changer 3 is moved relatively in the X-axis direction with respect to the main shaft 1 so that the gripper 22 of the revolving arm 24 is positioned directly above the main shaft 1.
Then, the tool changer 3 is relatively lowered to grip the tool T of the spindle 1 with the gripper 22 (see FIG. 7).

In the above prepared state, the drive motor 12
Are operated in the opposite direction. Thereby, the revolving arm 24 is revolved upward to take out the tool T used up to that time from the main spindle 1 to be in a horizontal state, and the other revolving arm 25 is revolved downward at the same time as the revolving arm 24 is revolved. Another tool T is mounted on the spindle 1 from which T has been extracted. The tool changer 3 is raised relatively to the main spindle 1 to remove the gripper 22 from the tool T of the main spindle 1, and the
The machining operation is started by the tool T mounted on the. on the other hand,
By the same operation as above, the used tool T of the turning arm 24 is returned to the tool pot 6 at the standby position P of the tool magazine 2, and
The exchange ends.

When the tool T to be used for the next processing is placed at the standby position P, the tool length measuring device 31 advances the contact sensor 32 by the cylinder 33 to contact the tip of the tool T at the standby position P. Measure the length of the tool T. The tool T
If it is necessary to know if is broken, compare the length of the measuring tool with the length of the normal tool.

Further, when the machining with the tool T whose tool length has been measured is completed and the tool is mounted on the tool pot 6 at the standby position P, the tool length measuring device 31 is operated again to activate the tool T at the standby position P. Measure the length. Needless to say, the determination of the breakage of the used tool is compared with the normal tool length before use.

Since the tool length measuring device 31 is provided outside the machining area Z of the workpiece W by the tool T mounted on the main shaft 1, the tool length measurement is continued without interrupting the machining of the workpiece. The efficiency of the machining operation can be improved by performing the operation.

The tool changer is a two-piece type as in the embodiment shown in FIG.
Although it is preferable to have one arm 24 or 25, one having only one arm or one having a standby position of a tool pot for taking out a tool before use and a standby position of a tool pot for storing a used tool, etc. , And other structures. In some cases, it is possible to measure the tool length while holding the tool T with a tool changer.

[0031]

As described above, the tool breakage detecting method for a machine tool according to the present invention comprises a spindle on which a tool is mounted, a tool magazine for accommodating the tool, and a spindle for accommodating the tool contained in the tool magazine. And a tool changer for accommodating a tool attached to the spindle in a tool magazine, the length of the tool accommodated in the tool magazine is reduced by machining the workpiece with the tool attached to the spindle. It is configured to detect breakage of the tool by measuring with a tool length measuring device provided outside the area, and the tool breakage detection device in the machine tool includes a spindle on which the tool is mounted, a tool magazine for housing the tool, A tool changer for mounting a tool accommodated in the tool magazine on a main spindle and accommodating a tool mounted on the main spindle in a tool magazine. The tool length measuring device that measures the length of the accommodated tool is provided outside the machining area of the workpiece by the tool mounted on the main spindle, so that the tool breakage can be performed in parallel with the machining operation. It can be detected, and thus the machining operation can be performed efficiently.

The tool length measuring device is provided at a standby position of a tool magazine where a tool is taken out by a tool changer or at a standby position of a tool magazine where a tool is accommodated by a tool changer, and the tool length is measured in the standby mode. When the configuration is performed at the position, the measurement and exchange of the tool length can be performed quickly.

Further, when the tool changer is provided with a pair of arms for gripping the tool with the gripper, the measurement and replacement of the tool length can be performed more quickly without any delay, thereby increasing the work efficiency.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing an embodiment of a tool breakage detecting device in a machine tool according to the present invention.

FIG. 2 is a plan view of a tool length measuring device.

FIG. 3 is a side view of the tool length measuring device with a part broken.

FIG. 4 is a front view of a tool length measuring device.

FIG. 5 is a front view showing an example of a machine tool to which the present invention is applied.

FIG. 6 is a side view of the machine tool of FIG.

FIG. 7 is a partially cutaway front view of a tool changer provided in the machine tool of FIG.

FIG. 8 is a left side view of the tool changer of FIG. 7;

FIG. 9 is a right side view of the tool changer of FIG. 7;

FIG. 10 is a diagram of a tool breakage detection device in a conventional machine tool.

[Explanation of symbols]

 Reference Signs List 1 spindle 2 tool magazine 3 tool changer 22, 23 gripper 24, 25 swivel arm 31 tool length measuring device 32 contact sensor 33 cylinder (moving means) A machine tool P standby position T tool W workpiece Z machining area

Claims (8)

[Claims] 1. A spindle on which a tool is mounted, a tool magazine for accommodating the tool, a tool changer for accommodating the tool accommodated in the tool magazine on the spindle, and accommodating the tool mounted on the spindle in the tool magazine. In a machine tool equipped with a tool magazine, the length of the tool housed in the tool magazine is measured by a tool length measuring device provided outside the machining area of the workpiece by the tool mounted on the spindle, and breakage of the tool is measured. A method for detecting a tool breakage in a machine tool, comprising: detecting a broken tool in a machine tool. 2. The method according to claim 1, wherein the measurement of the tool length by the tool length measuring device is performed at a standby position of a tool magazine from which the tool is taken out by the tool changer. 3. The method according to claim 1, wherein the measurement of the tool length by the tool length measuring device is performed at a standby position of a tool magazine in which the tool is accommodated by the tool changer. 4. A main spindle on which a tool is mounted, a tool magazine for storing the tool, a tool changer for mounting the tool stored in the tool magazine on the main spindle, and storing the tool mounted on the main spindle in the tool magazine. Wherein the tool length measuring device for measuring the length of the tool housed in the tool magazine is provided outside the machining area of the workpiece by the tool mounted on the spindle. Tool breakage detection device for machines. 5. The tool breakage detecting device for a machine tool according to claim 4, wherein the tool length measuring device is provided at a standby position of a tool magazine from which a tool is taken out by a tool changer. 6. The tool breakage detecting device for a machine tool according to claim 4, wherein the tool length measuring device is provided at a standby position of a tool magazine in which the tool is accommodated by the tool changer. 7. A tool length measuring device comprising: a contact sensor for outputting a contact signal when the tool comes into contact with a tool; and a moving means for moving the contact sensor forward and backward in the longitudinal direction of the tool. 7. A tool breakage detecting device for a machine tool according to 4, 5, or 6. 8. The tool breakage detecting device for a machine tool according to claim 4, wherein the tool changer includes a pair of arms for gripping the tool with a gripper.